Showing papers in "Molecular and Cellular Biochemistry in 2016"
TL;DR: The biology of the activation/deactivation of CDC25 by kinases/phosphatases to maintain the level of CDK-cyclin activities and thus the genomic stability, clinical implications due to dysregulation ofCDC25, and potential role of CDC 25 inhibitors in diseases are critically reviewed.
Abstract: Alterations in the cell-cycle regulatory genes result in uncontrolled cell proliferation leading to several disease conditions. Cyclin-dependent kinases (CDK) and their regulatory subunit, cyclins, are essential proteins in cell-cycle progression. The activity of CDK is regulated by a series of phosphorylation and dephosphorylation at different amino acid residues. Cell Division Cycle-25 (CDC25) plays an important role in transitions between cell-cycle phases by dephosphorylating and activating CDKs. CDC25B and CDC25C play a major role in G2/M progression, whereas CDC25A assists in G1/S transition. Different isomers of CDC25 expressions are upregulated in various clinicopathological situations. Overexpression of CDC25A deregulates G1/S and G2/M events, including the G2 checkpoint. CDC25B has oncogenic properties. Binding to the 14-3-3 proteins regulates the activity and localization of CDC25B. CDC25C is predominantly a nuclear protein in mammalian cells. At the G2/M transition, mitotic activation of CDC25C protein occurs by its dissociation from 14-3-3 proteins along with its phosphorylation at multiple sites within its N-terminal domain. In this article, we critically reviewed the biology of the activation/deactivation of CDC25 by kinases/phosphatases to maintain the level of CDK-cyclin activities and thus the genomic stability, clinical implications due to dysregulation of CDC25, and potential role of CDC25 inhibitors in diseases.
132 citations
TL;DR: RSV supplement decreases the inflammatory level and improves hepatic steatosis through activating AMPKα-SIRT1 pathway, and suggested an important clinical application of RSV in preventing NAFLD in humans.
Abstract: Nonalcoholic fatty liver disease (NAFLD) is characterized by high levels of nonesterified fatty acids (NEFA), inflammation, and hepatic steatosis. Inflammation plays a crucial role in the development of fatty liver. Resveratrol (RSV) supplement could improve inflammatory response and hepatic steatosis, whereas the underlying mechanism was not well understood. In this study, mice fed with high-fat diet (HFD) exhibited severe hepatic injury and high blood concentrations of the inflammatory cytokines TNF-α, IL-6, and IL-1β. Hepatic NF-κB inflammatory pathway was over-induced in HFD mice. In vitro, NEFA treatment further increased NF-κB pathway activation in mice hepatocytes, which then promoted the synthesis of inflammatory cytokines. Interestingly, RSV treatment significantly inhibited overactivation of NF-κB pathway and improved hepatic steatosis. Furthermore, RSV further increased the AMP-activated protein kinaseα (AMPKα) phosphorylation and sirtuin1 (SIRT1) protein levels to inhibit overactivation of NF-κB pathway induced by HFD or high levels of NEFA. AMPKα or SIRT1 inhibition significantly decreased the improvement effect of RSV on the NF-κB pathway induced by high levels of NEFA. Taken together, these findings indicate that RSV supplement decreases the inflammatory level and improves hepatic steatosis through activating AMPKα-SIRT1 pathway. Therefore, these data suggested an important clinical application of RSV in preventing NAFLD in humans.
115 citations
TL;DR: It is demonstrated that BCP provides neuroprotection against rotenone-induced PD and the neuroprotective effects can be ascribed to its potent antioxidant and anti-inflammatory activities.
Abstract: Parkinson disease (PD) is a neurodegenerative disease characterized by progressive dopaminergic neurodegeneration in the substantia nigra pars compacta (SNc) area. The present study was undertaken to evaluate the neuroprotective effect of β-caryophyllene (BCP) against rotenone-induced oxidative stress and neuroinflammation in a rat model of PD. In the present study, BCP was administered once daily for 4 weeks at a dose of 50 mg/kg body weight prior to a rotenone (2.5 mg/kg body weight) challenge to mimic the progressive neurodegenerative nature of PD. Rotenone administration results in oxidative stress as evidenced by decreased activities of superoxide dismutase, catalase, and depletion of glutathione with a concomitant rise in lipid peroxidation product, malondialdehyde. Rotenone also significantly increased pro-inflammatory cytokines in the midbrain region and elevated the inflammatory mediators such as cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in the striatum. Further, immunohistochemical analysis revealed loss of dopaminergic neurons in the SNc area and enhanced expression of ionized calcium-binding adaptor molecule-1 (Iba-1) and glial fibrillary acidic protein (GFAP), indicators of microglia activation, and astrocyte hypertrophy, respectively, as an index of inflammation. However, treatment with BCP rescued dopaminergic neurons and decreased microglia and astrocyte activation evidenced by reduced Iba-1 and GFAP expression. BCP in addition to attenuation of pro-inflammatory cytokines and inflammatory mediators such as COX-2 and iNOS, also restored antioxidant enzymes and inhibited lipid peroxidation as well as glutathione depletion. The findings demonstrate that BCP provides neuroprotection against rotenone-induced PD and the neuroprotective effects can be ascribed to its potent antioxidant and anti-inflammatory activities.
113 citations
TL;DR: This study exposes the experimental support in that high-fructose diet is equally detrimental in causing metabolic disorders and rats subjected to high-fat/fructose diets became glucose intolerant, insulin-resistant, and dyslipidemic.
Abstract: In the context of high human consumption of fructose diets, there is an imperative need to understand how dietary fructose intake influence cellular and molecular mechanisms and thereby affect β-cell dysfunction and insulin resistance. While evidence exists for a relationship between high-fat-induced insulin resistance and metabolic disorders, there is lack of studies in relation to high-fructose diet. Therefore, we attempted to study the effect of different diets viz., high-fat diet (HFD), high-fructose diet (HFS), and a combination (HFS + HFD) diet on glucose homeostasis and insulin sensitivity in male Wistar rats compared to control animals fed with normal pellet diet. Investigations include oral glucose tolerance test, insulin tolerance test, histopathology by H&E and Masson’s trichrome staining, mRNA expression by real-time PCR, protein expression by Western blot, and caspase-3 activity by colorimetry. Rats subjected to high-fat/fructose diets became glucose intolerant, insulin-resistant, and dyslipidemic. Compared to control animals, rats subjected to different combination of fat/fructose diets showed increased mRNA and protein expression of a battery of ER stress markers both in pancreas and liver. Transcription factors of β-cell function (INSIG1, SREBP1c and PDX1) as well as hepatic gluconeogenesis (FOXO1 and PEPCK) were adversely affected in diet-induced insulin-resistant rats. The convergence of chronic ER stress towards apoptosis in pancreas/liver was also indicated by increased levels of CHOP mRNA & increased activity of both JNK and Caspase-3 in rats subjected to high-fat/fructose diets. Our study exposes the experimental support in that high-fructose diet is equally detrimental in causing metabolic disorders.
73 citations
TL;DR: It is indicated that treatment with nobiletin mitigates cardiac dysfunction and interstitial fibrosis, and these beneficial ofnobiletin may belong to the suppression of JNK, P38, and NF-κB signaling pathways.
Abstract: Diabetic cardiomyopathy, characterized by the presence of diastolic and/or systolic myocardial dysfunction, is one of the major causes of heart failure. Nobiletin, which is extracted from the fruit peel of citrus, is reported to possess anti-inflammatory, anti-oxidative, and hypolipidemic properties. The purpose of this study was to investigate whether nobiletin exerts the therapeutic effect on streptozotocin-induced diabetic cardiomyopathy (DCM) in mice. 80 experimental male C57BL mice were randomly assigned into four groups: sham + vehicle (VEH/SH), sham + nobiletin (NOB/SH), DCM + vehicle (VEH/DM), and DCM + nobiletin (NOB/DM). Nobiletin treatment ameliorated cardiac dysfunction in the DCM group, as shown by the result of echocardiography and hemodynamic measurements. Nobiletin treatment also blunted the mRNA expression of NADPH oxidase isoforms p67phox, p22phox, and p91phox, and abated oxidative stress. Although administration of diabetic mice with nobiletin did not significantly effect the level of blood glucose, it decreased the TGF-β1, CTGF, fibronectin, and collagen Iα expressions and blunted cardiac fibrosis. In addition, nobiletin inhibited the activation of c-Jun NH2-terminal kinase (JNK), P38, and NF-κB in the cardiac tissue of diabetic mice. Collectively, our study indicates that treatment with nobiletin mitigates cardiac dysfunction and interstitial fibrosis, and these beneficial of nobiletin may belong to the suppression of JNK, P38, and NF-κB signaling pathways.
71 citations
TL;DR: The results suggest that dysregulation of miR-30c andMiR-181a may be involved in upregulation of p53–p21 pathway in DbCM and a synergistic effect of these microRNAs.
Abstract: p53-p21 pathway mediates cardiomyocyte hypertrophy and apoptosis and is upregulated in diabetic cardiomyopathy (DbCM). We investigated role of microRNAs in regulating p53-p21 pathway in high glucose (HG)-induced cardiomyocyte hypertrophy and apoptosis. miR-30c and miR-181a were identified to target p53. Cardiac expression of microRNAs was measured in diabetic patients, diabetic rats, and in HG-treated cardiomyocytes. Effect of microRNAs over-expression and inhibition on HG-induced cardiomyocyte hypertrophy and apoptosis was examined. Myocardial expression of p53 and p21 genes was increased and expression of miR-30c and miR-181a was significantly decreased in diabetic patients, DbCM rats, and in HG-treated cardiomyocytes. Luciferase assay confirmed p53 as target of miR-30c and miR-181a. Over-expression of miR-30c or miR-181a decreased expression of p53, p21, ANP, cardiomyocyte cell size, and apoptosis in HG-treated cardiomyocytes. Concurrent over-expression of these microRNAs resulted in greater decrease in cardiomyocyte hypertrophy and apoptosis, suggesting a synergistic effect of these microRNAs. Our results suggest that dysregulation of miR-30c and miR-181a may be involved in upregulation of p53-p21 pathway in DbCM.
66 citations
TL;DR: Kolaviron is a mixture of biflavonoids found in the West African edible seed Garcinia kola, and it has been reported to exhibit a wide range of pharmacological activities as mentioned in this paper.
Abstract: Kolaviron is a mixture of biflavonoids found in the nut of the West African edible seed Garcinia kola, and it has been reported to exhibit a wide range of pharmacological activities. In this study, we investigated the effects of kolaviron in neuroinflammation. The effects of kolaviron on the expression of nitric oxide/inducible nitric oxide synthase (iNOS), prostaglandin E2 (PGE2)/cyclooxygenase-2, cellular reactive oxygen species (ROS) and the pro-inflammatory cytokines were examined in lipopolysaccharide (LPS)-stimulated BV2 microglial cells. Molecular mechanisms of the effects of kolaviron on NF-κB and Nrf2/ARE signalling pathways were analysed by immunoblotting, binding assays and reporter assays. RNA interference was used to investigate the role of Nrf2 in the anti-inflammatory effect of kolaviron. Neuroprotective effect of kolaviron was assessed in a BV2 microglia/HT22 hippocampal neuron co-culture. Kolaviron inhibited the protein levels of NO/iNOS, PGE2/COX-2, cellular ROS and the pro-inflammatory cytokines (TNFα and IL-6) in LPS-stimulated microglia. Further mechanistic studies showed that kolaviron inhibited neuroinflammation by inhibiting IκB/NF-κB signalling pathway in LPS-activated BV2 microglia. Kolaviron produced antioxidant effect in BV2 microglia by increasing HO-1 via the Nrf2/antioxidant response element pathway. RNAi experiments revealed that Nrf2 is needed for the anti-inflammatory effects of kolaviron. Kolaviron protected HT22 neurons from neuroinflammation-induced toxicity. Kolaviron inhibits neuroinflammation through Nrf2-dependent mechanisms. This compound may therefore be beneficial in neuroinflammation-related neurodegenerative disorders.
65 citations
TL;DR: It is demonstrated for the first time that the PI3K/Akt/mTOR/S6K1 signal pathway plays an important role in regulating replicative senescence of human VSMCs.
Abstract: Replicative senescence of vascular smooth muscle cells (VSMCs) contributes to aging as well as age-related cardiovascular diseases. Rapamycin can delay the onset of aging-related diseases via inhibition of the mammalian target of rapamycin (mTOR), but its role in vascular aging remains elusive. This study investigated the involvement of mTOR signaling in replicative senescence of VSMCs. Replicative senescence was induced by the extended passages of human VSMCs. Aging-related cell morphology was observed. The aging-related proteins and enzyme activity, and oxidative stress were measured. Significant increase in SA-β-gal activity and protein expression, p53 and p16 protein expression, proliferation index (PI), malondialdehyde (MDA) concentration, superoxide dismutase (SOD) and glutathione peroxidase (GPX) activity, and significant decrease in telomerase activity was observed in aging VSMCs compared to young cells. Significant activation of PI3K/Akt/mTOR signaling was observed in aging cells but not young cells. Pretreatment of VSMCs with PI3K inhibitor blocked while PI3K activator increased the changes of the above replicative senescence-related parameters in VSMCs. Rapamycin and silencing of mTOR expression inhibited replicative senescence in VSMCs through decreasing the level of p-mTOR Ser2448, p-mTOR Thr2446, and S6K1 phosphorylation. This study for the first time demonstrated that the PI3K/Akt/mTOR/S6K1 signal pathway plays an important role in regulating replicative senescence of human VSMCs.
61 citations
TL;DR: Overall data suggest a potential promising therapeutic option for the management of chronic wounds but further studies are highly warranted to determine signaling pathways and target metabolisms in which boron is involved to elucidate the limitations and extend its use in clinics.
Abstract: Acute wounds do not generally require professional treatment modalities and heal in a predictable fashion, but chronic wounds are mainly accompanied with infection and prolonged inflammation, leading to healing impairments and continuous tissue degradation. Although a vast amount of products have been introduced in the market, claiming to provide a better optimization of local and systemic conditions of patients, they do not meet the expectations due to being expensive and not easily accessible, requiring wound care facilities, having patient-specific response, low efficiency, and severe side-effects. In this sense, developing new, safe, self-applicable, effective, and cheap wound care products with broad-range antimicrobial activity is still an attractive area of international research. In the present work, boron derivatives [boric acid and sodium pentaborate pentahydrate (NaB)] were evaluated for their antimicrobial activity, proliferation, migratory, angiogenesis, gene, and growth factor expression promoting effects on dermal cells in vitro. In addition, boron-containing hydrogel formulation was examined for its wound healing promoting potential using full-thickness wound model in streptozotocin-induced diabetic rats. The results revealed that while both boron compounds significantly increased proliferation, migration, vital growth factor, and gene expression levels of dermal cells along with displaying remarkable antimicrobial effects against bacteria, yeast, and fungi, NaB displayed greater antimicrobial properties as well as gene and growth factor expression inductive effects. Animal studies proved that NaB-containing gel formulation enhanced wound healing rate of diabetic animals and histopathological scores. Overall data suggest a potential promising therapeutic option for the management of chronic wounds but further studies are highly warranted to determine signaling pathways and target metabolisms in which boron is involved to elucidate the limitations and extend its use in clinics.
59 citations
TL;DR: It is found that miR-143-3p inhibits hypertrophic scarring by regulating the proliferation and apoptosis of human HSFs, inhibiting ECM production-associated protein expression by targeting CTGF, and restraining the Akt/mTOR pathway.
Abstract: Post-traumatic hypertrophic scar (HS) is a fibrotic disease with excessive extracellular matrix (ECM) production, which is a response to tissue injury by fibroblasts. Although emerging evidence has indicated that miRNA contributes to hypertrophic scarring, the role of miRNA in HS formation remains unclear. In this study, we found that miR-143-3p was markedly downregulated in HS tissues and fibroblasts (HSFs) using qRT-PCR. The expression of connective tissue growth factor (CTGF/CCN2) was upregulated both in HS tissues and HSFs, which is proposed to play a key role in ECM deposition in HS. The protein expression of collagen I (Col I), collagen III (Col III), and α-smooth muscle actin (α-SMA) was obviously inhibited after treatment with miR-143-3p in HSFs. The CCK-8 assay showed that miR-143-3p transfection reduced the proliferation ability of HSFs, and flow cytometry showed that either early or late apoptosis of HSFs was upregulated by miR-143-3p. In addition, the activity of caspase 3 and caspase 9 was increased after miR-143-3p transfection. On the contrary, the miR-143-3p inhibitor was demonstrated to increase cell proliferation and inhibit apoptosis of HSFs. Moreover, miR-143-3p targeted the 3′-UTR of CTGF and caused a significant decrease of CTGF. Western blot demonstrated that Akt/mTOR phosphorylation and the expression of CTGF, Col I, Col III, and α-SMA were inhibited by miR-143-3p, but increased by CTGF overexpression. In conclusion, we found that miR-143-3p inhibits hypertrophic scarring by regulating the proliferation and apoptosis of human HSFs, inhibiting ECM production-associated protein expression by targeting CTGF, and restraining the Akt/mTOR pathway.
55 citations
TL;DR: It is demonstrated that FBP1 (Fructose-1, 6-bisphosphatase) was frequently down-regulated in lung cancer tissues and cells, andFBP1 down-regulation was associated with poor prognosis in lung Cancer patients, and Zinc finger E-box-binding homeobox 1 (ZEB1) bond to FBP 1 promoter to enhance DNA methylation in lungcancer cells were identified.
Abstract: Lung cancer is the most common type of malignant tumor, but the molecular mechanisms for lung cancer progression remains to be elusive. Here, we demonstrated that FBP1 (Fructose-1, 6-bisphosphatase) was frequently down-regulated in lung cancer tissues and cells, and FBP1 down-regulation was associated with poor prognosis in lung cancer patients. Restored FBP1 expression inhibited glucose uptake and lactate production, but induced oxygen consumption. Restored FBP1 expression also inhibited lung cancer cells proliferation and invasion under hypoxia in vitro, and inhibited lung cancer growth in vivo. Moreover, we confirmed DNA methylation in the promoter contributed to the decrease of FBP1 expression in lung cancer cells. We identified Zinc finger E-box-binding homeobox 1 (ZEB1) bond to FBP1 promoter to enhance DNA methylation in lung cancer cells. Our findings indicate that the down-regulation of FBP1 is a critical oncogenic event in lung cancer progression.
TL;DR: It is demonstrated that miR-141-3p contributed to an acquired chemo-resistance through PTEN modulation both in vitro and in vivo.
Abstract: microRNAs (miRNAs) act as a major regulator of acquired chemo-resistance in various types of cancer therapeutics. This study investigated the contribution of miRNAs in influencing multiple drug resistance in esophageal squamous cell carcinoma (ESCC). The sensitivity of four ESCC cell lines (EC109, EC9706, TE-1 and KYSE-150) to 5-fluorouracil (5-FU) and oxaliplatin (OX) was determined by MTT assay. A 5-FU and OX-resistant subline, EC9706R, was established by continuous exposure to stepwise increasing concentration of 5-FU and OX. Microarray technology was used to compare the differential expression of miRNAs between resistant cells and parental cells. Chemo-sensitivity assay was performed to evaluate drug response in EC9706R cells transfected with miRNA mimic or inhibitor. The direct targets of miRNA were identified by employing pathway analysis and then confirmed with luciferase assay. Sixty ESCC tissue samples and their paired adjacent normal tissues were collected to validate the expression of identified miRNA. Mouse models were further utilized to investigate the function of miRNA on acquired chemo-resistance. MicroRNA panel results indicated that a total of 12 miRNAs were differentially expressed and miR-141-3p was highly over expressed in resistant cells. Inhibition of miR-141-3p reversed acquired chemo-resistance in EC9706R cells by stimulating apoptosis. The expression of miR-141-3p was significantly increased in ESCC tissue samples compared to their matched distant normal tissues. In addition, the elevated miR-141-3p expression was found to be associated with ESCC differentiation status and TNM stage. Moreover, Phosphatase and tensin homolog (PTEN) was identified as direct target of miR-141-3p. Western blot exhibited altered protein levels of PTEN, Akt, and PI3k with miR-141-3p inhibitor. An inverse correlation between PTEN expression and miR-141-3p expression was also observed in tissue samples. EC9706R xenograft mouse model became sensitized to 5-FU and OX treatment following miR-141-3p inhibitor transfection in vivo. Our study demonstrated that miR-141-3p contributed to an acquired chemo-resistance through PTEN modulation both in vitro and in vivo.
TL;DR: The data suggested that heat stress inhibited GCs proliferation, induced GCs apoptosis, decreased E2 and P4 secretion, reduced the steroids-related genes mRNA expression, and indicated that heat treatment-induced apoptosis of GCs through the mitochondrial pathway, which involved caspase-3 and Bax.
Abstract: Ovarian injury can be induced by heat stress. Mice granulosa cells (GCs) are critical for normal ovarian function and they synthesize a variety of growth factors and steroids for the follicle. Furthermore, the growth, differentiation, and maturate of theca cells and oocyte are dependent upon the synthesis of GCs. Due to the critical biological functions of GCs, we hypothesized that the apoptosis and dysfunction of GCs could also be induced by heat stress. We analyzed GCs apoptosis and evaluated the expression of apoptosis-related genes (caspase-3, Bax, Bcl-2) after heat treatment. Radio immunity assay was used to measure the secretion of 17β-estradiol (E2) and progesterone (P4). RT-PCR was used to evaluate the expression of steroids-related genes (Star, CYP11A1, CYP19A1). Our data suggested that heat stress inhibited GCs proliferation, induced GCs apoptosis, decreased E2 and P4 secretion, reduced the steroids-related genes mRNA expression. Besides, our results indicated that heat treatment-induced apoptosis of GCs through the mitochondrial pathway, which involved caspase-3 and Bax. The reduction in steroids secretion and mRNA expression of Star, CYP11A1, and CYP19A1 might also play a role in heat-induced GCs apoptosis and ovarian injury.
TL;DR: FGF21 corrects multiple metabolic parameters on NAFLD in vitro and in vivo by inducing autophagy and in vitro experimental results also showed that FGF21 remarkably increased autophagic flux.
Abstract: The aim of this study is to evaluate the role of fibroblast growth factor 21 (FGF21) in nonalcoholic fatty liver disease (NAFLD) and seek to determine if its therapeutic effect is through induction of autophagy. In this research, Monosodium L-glutamate (MSG)-induced obese mice or normal lean mice were treated with vehicle, Fenofibrate, and recombinant murine FGF21, respectively. After 5 weeks of treatment, metabolic parameters including body weight, blood glucose and lipid levels, hepatic and fat gene expression levels were monitored and analyzed. Also, fat-loaded HepG2 cells were treated with vehicle or recombinant murine FGF21. The expression levels of proteins associated with autophagy were detected by western blot, real-time PCR, and transmission electron microscopy (TEM). Autophagic flux was monitored by laser confocal microscopy and western blot. Results showed that FGF21 significantly reduced body weight (P < 0.01) and serum triglyceride, improved insulin sensitivity, and reversed hepatic steatosis in the MSG model mice. In addition, FGF21 significantly increased the expression of several proteins related to autophagy both in MSG mice and fat-loaded HepG2 cells, such as microtubule associated protein 1 light chain 3, Bcl-2-interacting myosin-like coiled-coil protein-1 (Beclin-1), and autophagy-related gene 5. Furthermore, the evidence of TEM revealed an increased number of autophagosomes and lysosomes in the model cells treated with FGF21. In vitro experimental results also showed that FGF21 remarkably increased autophagic flux. Taken together, FGF21 corrects multiple metabolic parameters on NAFLD in vitro and in vivo by inducing autophagy.
TL;DR: Data show that β-alanine mediates changes that reduce ATP generation and enhance oxidative stress, factors that contribute to heart failure.
Abstract: Hyper-beta-alaninemia is a rare metabolic condition that results in elevated plasma and urinary β-alanine levels and is characterized by neurotoxicity, hypotonia, and respiratory distress. It has been proposed that at least some of the symptoms are caused by oxidative stress; however, only limited information is available on the mechanism of reactive oxygen species generation. The present study examines the hypothesis that β-alanine reduces cellular levels of taurine, which are required for normal respiratory chain function; cellular taurine depletion is known to reduce respiratory function and elevate mitochondrial superoxide generation. To test the taurine hypothesis, isolated neonatal rat cardiomyocytes and mouse embryonic fibroblasts were incubated with medium lacking or containing β-alanine. β-alanine treatment led to mitochondrial superoxide accumulation in conjunction with a decrease in oxygen consumption. The defect in β-alanine-mediated respiratory function was detected in permeabilized cells exposed to glutamate/malate but not in cells utilizing succinate, suggesting that β-alanine leads to impaired complex I activity. Taurine treatment limited mitochondrial superoxide generation, supporting a role for taurine in maintaining complex I activity. Also affected by taurine is mitochondrial morphology, as β-alanine-treated fibroblasts undergo fragmentation, a sign of unhealthy mitochondria that is reversed by taurine treatment. If left unaltered, β-alanine-treated fibroblasts also undergo mitochondrial apoptosis, as evidenced by activation of caspases 3 and 9 and the initiation of the mitochondrial permeability transition. Together, these data show that β-alanine mediates changes that reduce ATP generation and enhance oxidative stress, factors that contribute to heart failure.
TL;DR: Investigation of the role ofHDAC9 in pathogenesis of oral squamous cell carcinoma revealed that overexpression of HDAC9 contributes to OSCC carcinogenesis via targeting a transcription factor, MEF2D, and NR4A1/Nur77, a pro-apoptotic MeF2 target.
Abstract: Histone deacetylases (HDACs) are a family of deacetylase enzymes that regulate the acetylation state of histones and a variety of other non-histone proteins including key oncogenic and tumor suppressor proteins, which modulates chromatin conformation, leading to regulation of gene expression. HDACs has been grouped into classes I-IV and histone deacetylase 9 (HDAC9) belongs to class IIa which exhibits tissue-specific expression. Recent reports have demonstrated both pro-oncogenic and tumor suppressive role for HDAC9 in different cancers; however, its role in OSCC remains elusive. Here, we investigated the role of HDAC9 in pathogenesis of oral squamous cell carcinoma (OSCC). Our data showed significantly increased mRNA and protein expression of HDAC9 in clinical OSCC samples and UPCI-SCC-116 cells as compared to normal counterpart. Kaplan-Meier analysis showed that the patients with high-level of HDAC9 expression had significantly reduced overall survival than those with low-level of HDAC9 expression (p = 0.034). Knockdown of HDAC9 using siRNA interference suppressed cell proliferation, increased apoptosis, and induced G0/G1 cell cycle arrest in UPCI-SCC-116 cells. Immunofluorescence analysis showed increased nuclear localization of HDAC9 in frozen OSCC sections, and indicative of active HDAC9 that may transcriptionally repress its downstream target genes. Subsequent investigation revealed that overexpression of HDAC9 contributes to OSCC carcinogenesis via targeting a transcription factor, MEF2D, and NR4A1/Nur77, a pro-apoptotic MEF2 target.
TL;DR: PA induces G2/M cell cycle arrest in A549 cells involving in the p38 MAPK/ROS pathway, and this study suggests that PA might be a promising therapeutic agent against NSCLC.
Abstract: Physalin A (PA) is an active withanolide isolated from Physalis alkekengi var. franchetii, a traditional Chinese herbal medicine named Jindenglong, which has long been used for the treatment of sore throat, hepatitis, and tumors in China. In the present study, we firstly investigated the effects of PA on proliferation and cell cycle distribution of the human non-small cell lung cancer (NSCLC) A549 cell line, and the potential mechanisms involved. Here, PA inhibited cell growth in dose- and time-dependent manners. Treatment of A549 cells with 28.4 μM PA for 24 h resulted in approximately 50 % cell death. PA increased the amount of intracellular ROS and the proportion of cells in G2/M. G2/M arrest was attenuated by the addition of ROS scavenger NAC. ERK and P38 were triggered by PA through phosphorylation in a time-dependent manner. The phosphorylation of ERK and P38 were not attenuated by the addition of NAC, but the use of the p38 inhibitor could reduce, at least in part, PA-induced ROS and the proportion of cells in G2/M. PA induces G2/M cell cycle arrest in A549 cells involving in the p38 MAPK/ROS pathway. This study suggests that PA might be a promising therapeutic agent against NSCLC.
TL;DR: It is implicates that oxidative stress and inflammation are the central players involved in the progression of DCM and rutin ameliorates DCM through its antioxidant and anti-inflammatory actions on heart.
Abstract: Diabetic cardiomyopathy (DCM) is a dreadful complication of diabetes responsible for 80 % mortality in diabetic patients, but unfortunately its pharmacotherapy is still incomplete. Rutin is a naturally occurring flavonoid having a long history of use in nutritional supplements for its action against oxidative stress, inflammation, and hyperglycemia, the key players involved in the progression of DCM, but remains unexplored for its role in DCM. This study was conducted to address this lacuna. It was performed in 4-week-old Streptozotocin-induced (45 mg/kg) diabetic rats for a period of 24 weeks to mimic the cardiotoxic effect of chronic hyperglycemia in diabetic patient's heart and to investigate the effect of rutin (50 mg/kg/day) in ameliorating these effects. Heart of the diabetic rats showed altered ECG parameters, reduced total antioxidant capacity, increased inflammatory assault, and degenerative changes. Interestingly, rutin treatment significantly ameliorated these changes with decrease in blood glucose level (p > 0.001), % HbA1c (p > 0.001) and reduced expression of TNF-α (p < 0.001), CRP (p < 0.001), and BNP (p < 0.01) compared to diabetic control rats. In addition, rutin provided significant protection against diabetes associated oxidative stress (p < 0.05), prevented degenerative changes in heart, and improved ECG parameters compared to diabetic control rats. The heart-to-body weight ratio was significantly reduced in rutin treatment group compared to diabetic control rats (p < 0.001). In conclusion, this study implicates that oxidative stress and inflammation are the central players involved in the progression of DCM and rutin ameliorates DCM through its antioxidant and anti-inflammatory actions on heart.
TL;DR: The data suggest that Pin1 contributes to cisplatin resistance, partly by up-regulating FoxM1 and Wnt/β-catenin signaling pathway involved in cervical cancer.
Abstract: The prolyl isomerase Pin1, which is frequently highly expressed in many different cancers, can directly regulate cell proliferation and the cell cycle. However, the role of Pin1 in chemo-resistance remains to be elucidated in cervical cancer. The purpose of the present study was to investigate the role of Pin1 in the chemo-resistance of cervical cancer. The cisplatin resistance was assessed using the MTT assay. Pin1, FoxM1, β-catenin, Cyclin D1, and c-myc expression levels were detected by RT-qPCR or Western blot. The results showed that Pin1 expression displayed a similar expression pattern with the resistance to cisplatin in five cervical cell lines. Knockdown of Pin1 significantly increased the sensitivity to cisplatin in HeLa cells, while Pin1 overexpression decreased the sensitivity to cisplatin in Me180 cells. Knockdown of Pin1 significantly down-regulated FoxM1 expression in HeLa cells, while Pin1 overexpression showed a contrary effect in Me180 cells. Besides, overexpression of Pin1 markedly increased the protein expression of β-catenin and its target genes cyclin D1 and c-myc. FoxM1 siRNA remarkably reversed the promotory effect of pcDNA-Pin1(+) on β-catenin and its target genes cyclin D1 and c-myc in Me180 cells. Furthermore, we also found that FoxM1 siRNA and IWP-2 markedly decreased cell viability, and IWP-2 decreased cell viability to the maximum extent in the Me180 cells co-transfected with pcDNA-Pin1(+) and FoxM1 siRNA. Taken together, these data suggest that Pin1 contributes to cisplatin resistance, partly by up-regulating FoxM1 and Wnt/β-catenin signaling pathway involved in cervical cancer.
TL;DR: An integrative analysis of genome-wide chromatin occupancy of BRD7 by chromatin immunoprecipitation coupled with high-throughput sequencing (ChIP-seq) and digital gene expression (DGE) profiling by RNA-sequencing upon the overexpression ofBRD7 is reported.
Abstract: BRD7 is a single bromodomain-containing protein that functions as a subunit of the SWI/SNF chromatin-remodeling complex to regulate transcription. It also interacts with the well-known tumor suppressor protein p53 to trans-activate genes involved in cell cycle arrest. In this paper, we report an integrative analysis of genome-wide chromatin occupancy of BRD7 by chromatin immunoprecipitation coupled with high-throughput sequencing (ChIP-seq) and digital gene expression (DGE) profiling by RNA-sequencing upon the overexpression of BRD7 in human cells. We localized 156 BRD7-binding peaks representing 184 genes by ChIP-sequencing, and most of these peaks were co-localized with histone modification sites. Four novel motifs were significantly represented in these BRD7-enriched regions. Ingenuity pathway analysis revealed that 22 of these BRD7 target genes were involved in a network regulating cell death and survival. DGE profiling identified 560 up-regulated genes and 1088 down-regulated genes regulated by BRD7. Using Gene Ontology and pathway analysis, we found significant enrichment of the cell cycle and apoptosis pathway genes. For the integrative analysis of the ChIP-seq and DEG data, we constructed a regulating network of BRD7 downstream genes, and this network suggests multiple feedback regulations of the pathways. Furthermore, we validated BIRC2, BIRC3, TXN2, and NOTCH1 genes as direct, functional BRD7 targets, which were involved in the cell cycle and apoptosis pathways. These results provide a genome-wide view of chromatin occupancy and the gene regulation network of the BRD7 signaling pathway.
TL;DR: It is reported that expression of KIM-1 facilitates renal tubular epithelial cell repair by promoting cell migration and proliferation and enhances ERK MAPK activation, and the modulatory effect of K IM-1 on cellular repair process is likely mediated via ERKMAPK signaling pathway.
Abstract: The expression of kidney injury molecule-1 (KIM-1), a very promising sensitive and specific urinary biomarker for acute renal injury, is markedly upregulated in injured and regenerating renal proximal tubular epithelial cells following ischemic or toxic insults, suggesting a possible role for this molecule in renal repair process. In the present study, we report that expression of KIM-1 facilitates renal tubular epithelial cell repair by promoting cell migration and proliferation. KIM-1 expression also enhances ERK MAPK activation, and the modulatory effect of KIM-1 on cellular repair process is likely mediated via ERK MAPK signaling pathway.
TL;DR: It is proven that IL-12-overexpressed monocytes could directionally differentiate to M1-like macrophages through downregulation of Stat-3 and result in the inhibition of HCC growth.
Abstract: Hepatocellular carcinoma is the third most common cause of cancer death worldwide. Novel early detection biomarkers and efficacious therapy strategies are needed. Macrophages recruited from circulation monocytes are the major component of solid cancer and play an important role in the carcinogenesis. Whether overexpression of L-12 in monocytes could induce the phenotype directional differentiation into tumoricidal M1 macrophages and inhibit HCC growth in tumor microenvironment was investigated in this study. For the establishment of the monocyte/IL-12 and polarization of M1-like macrophage, the IL-12 overexpressing recombinant monocyte/IL-12 cells were established by infecting with pAd5F35-CMV/IL-12 adenovirus and co-cultured with HCC SMMC-7721 and Hep3B cells. It was found that the phenotype of monocyte/IL-12 polarized to M1-like macrophages with CD197high IL-12high CD206low IL-10low, and decreased expression of TGF-β, VEGF-A, and MMP-9. In order to explore the mechanism underlying the macrophages polarization, we detected the Stat-3 pathway and its downstream transcription factor c-myc, and found that the p-Stat-3 and c-myc were down-regulated. To evaluate the effects of monocyte/IL-12 on inhibiting HCC growth, various assays including CCK8, flow cytometry, colony-forming and Transwell assays in vitro, and xenograft mouse models and immunohistochemical analyses in vivo were used to detect the HCC growth and relative markers. Treated with IL-12 overexpressing monocytes, the xenograft tumor growth was significantly inhibited in vivo. These results have proven that IL-12-overexpressed monocytes could directionally differentiate to M1-like macrophages through downregulation of Stat-3 and result in the inhibition of HCC growth.
TL;DR: It is demonstrated that globular CTRP9 (gCTRP9) significantly reduced oxidized low-density lipoprotein (oxLDL)-induced tumor necrosis factor alpha and monocyte chemoattractant protein 1 expression by suppressing nuclear factor-κB phosphorylation and nuclear translocation in RAW 264.7 macrophages.
Abstract: C1q-TNF-related protein-9 (CTRP9) is increasingly recognized as a promising cardioprotective adipocytokine, which regulates biological processes like vascular relaxation, proliferation, apoptosis, and inflammation. We recently showed that CTRP9 enhanced carotid plaque stability by reducing pro-inflammatory cytokines in macrophages. However, the underlying molecular mechanism of CTRP9 on anti-inflammatory response in macrophages still remains unclear. We demonstrated that globular CTRP9 (gCTRP9) significantly reduced oxidized low-density lipoprotein (oxLDL)-induced tumor necrosis factor alpha and monocyte chemoattractant protein 1 expression by suppressing nuclear factor-κB phosphorylation and nuclear translocation in RAW 264.7 macrophages. Treatment with gCTRP9 strikingly increased the level of phosphorylated adenosine monophosphate-activated protein kinase (AMPK). AMPK inhibitor abolished the anti-inflammatory effects of gCTRP9. Moreover, gCTRP9 increased the expression of adiponectin receptor 1 (AdipoR1). Downregulation of AdipoR1 by siRNA could abrogate the activation of AMPK and the anti-inflammatory effects of gCTRP9. These results suggested that gCTRP9 protected RAW 264.7 macrophages from oxLDL via AMPK activation in an AdipoR1 dependent fashion.
TL;DR: It is shown that TQ suppresses growth of MB cells in a dose- and time-dependent manner, causes G2M cell cycle arrest, and induces apoptosis, and its potential usefulness in the treatment of MB is suggested.
Abstract: Medulloblastoma (MB) is the most common malignant brain tumor of childhood. The transcription factor NF-κB is overexpressed in human MB and is a critical factor for MB tumor growth. NF-κB is known to regulate the expression of interleukin-8 (IL-8), the chemokine that enhances cancer cell growth and resistance to chemotherapy. We have recently shown that thymoquinone (TQ) suppresses growth of hepatocellular carcinoma cells in part by inhibiting NF-κB signaling. Here we sought to extend these studies in MB cells and show that TQ suppresses growth of MB cells in a dose- and time-dependent manner, causes G2M cell cycle arrest, and induces apoptosis. TQ significantly increased generation of reactive oxygen species (ROS), while pretreatment of MB cells with the ROS scavenger N-acetylcysteine (NAC) abrogated TQ-induced cell death and apoptosis, suggesting that TQ-induced cell death and apoptosis are oxidative stress-mediated. TQ inhibitory effects were associated with inhibition of NF-κB and altered expression of its downstream effectors IL-8 and its receptors, the anti-apoptotic Bcl-2, Bcl-xL, X-IAP, and FLIP, as well as the pro-apoptotic TRAIL-R1, caspase-8, caspase-9, Bcl-xS, and cytochrome c. TQ-triggered apoptosis was substantiated by up-regulation of the executioner caspase-3 and caspase-7, as well as cleavage of the death substrate poly(ADP-ribose)polymerase. Interestingly, pretreatment of MB cells with NAC or the pan-caspase inhibitor zVAD-fmk abrogated TQ-induced apoptosis, loss of cyclin B1 and NF-κB activity, suggesting that these TQ-mediated effects are oxidative stress- and caspase-dependent. These findings reveal that TQ induces both extrinsic and intrinsic pathways of apoptosis in MB cells, and suggest its potential usefulness in the treatment of MB.
TL;DR: Zingerone, through its antioxidant and anti-inflammatory effects, may represent a therapeutic option to protect against ethanol-induced hepatotoxicity.
Abstract: Alcoholic liver disease is a direct result of alcohol-induced hepatotoxicity coupled with impaired hepatic regenerative activity. Our aim of the study was to investigate the beneficial effect of zingerone on hepatic oxidative stress and inflammation induced by ethanol in experimental rats. Male albino Wistar rats were divided into four groups. Rats of groups 1 and 2 received isocaloric glucose and dimethyl sulfoxide (2 % DMSO). Hepatotoxicity was induced in groups 3 and 4 by supplementing 30 % ethanol post orally for 60 days. Rats of groups 2 and 4 received zingerone (20 mg/kg body weight in 2 % DMSO p.o) daily during the final 30 days of the experimental period. Ethanol alone administered rats showed significant increase in the plasma and tissue lipid peroxidation markers such as thiobarbituric acid reactive substances, lipid hydroperoxides, conjugated dienes, and a significant decrease in the activities of plasma and tissue enzymic and non-enzymic antioxidants such as superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, reduced glutathione, vitamin C, and vitamin E. Moreover, the presence of mast cells and increase in the expressions of inflammatory markers such as NF-κB, COX-2, TNF-α, and IL-6 and decrease in the expression of Nrf2 in the liver was observed in ethanol-fed rats. Supplementation with zingerone to ethanol-fed rats reversed the changes induced by ethanol in the experimental rats. Thus, zingerone, through its antioxidant and anti-inflammatory effects, may represent a therapeutic option to protect against ethanol-induced hepatotoxicity.
TL;DR: Results suggest that 18β-GA may be used as a chemopreventive agent in liver cancer through antiinflammation, antiproliferation, and induction of apoptosis in human hepatoma cell line HepG2.
Abstract: Hepatocellular carcinoma is one of the most common lethal diseases worldwide and there is no effective treatment till date. Natural products derived from the plants play an important role in chemoprevention and act as therapeutic antitumor agents. Licorice is a plant that has been used in food and medicine for the treatment of various diseases. 18β-Glycyrrhetinic acid (18β-GA), a pentacyclic triterpenoid obtained from the roots of licorice plant, is reported to possess various pharmacological properties such as antitumor and antiinflammatory activities. The present study was designed to elucidate the chemopreventive effect of 18β-GA through antiinflammation, antiproliferation, and induction of apoptosis in human hepatoma cell line HepG2. 18β-GA significantly inhibits the proliferation of HepG2 cell without affecting the normal liver cell line (Chang's). In the present study, 18β-GA increased the formation of reactive oxygen species, nitric oxide production, and loss of mitochondrial membrane potential, suggesting the involvement of 18β-GA in apoptosis which was also confirmed by assessing the markers involved in apoptosis like caspase-3, caspase-9, Bax:Bcl-2 ratio, and cleaved PARP. 18β-GA also downregulated the expression of inflammatory proteins such as NF-κB, iNOS, and COX-2. Keeping these data into consideration, our results suggest that 18β-GA may be used as a chemopreventive agent in liver cancer.
TL;DR: The current data suggest that CBD plays dual modulatory roles in the form of inducing the brown-like phenotype as well as promoting lipid metabolism and may be explored as a potentially promising therapeutic agent for the prevention of obesity.
Abstract: Recruitment of the brown-like phenotype in white adipocytes (browning) and activation of existing brown adipocytes are currently being investigated as a means to combat obesity. Thus, a wide variety of dietary agents that contribute to browning of white adipocytes have been identified. The present study was designed to investigate the effects of cannabidiol (CBD), a major nonpsychotropic phytocannabinoid of Cannabis sativa, on induction of browning in 3T3-L1 adipocytes. CBD enhanced expression of a core set of brown fat-specific marker genes (Ucp1, Cited1, Tmem26, Prdm16, Cidea, Tbx1, Fgf21, and Pgc-1α) and proteins (UCP1, PRDM16, and PGC-1α). Increased expression of UCP1 and other brown fat-specific markers contributed to the browning of 3T3-L1 adipocytes possibly via activation of PPARγ and PI3K. In addition, CBD increased protein expression levels of CPT1, ACSL, SIRT1, and PLIN while down-regulating JNK2, SREBP1, and LPL. These data suggest possible roles for CBD in browning of white adipocytes, augmentation of lipolysis, thermogenesis, and reduction of lipogenesis. In conclusion, the current data suggest that CBD plays dual modulatory roles in the form of inducing the brown-like phenotype as well as promoting lipid metabolism. Thus, CBD may be explored as a potentially promising therapeutic agent for the prevention of obesity.
TL;DR: Dihydromyricetin led to the downregulation of target genes involved in inflammation, proliferation, and potentiation of TNF-α-induced apoptosis through suppressing the activation of NF-κB.
Abstract: Nuclear factor-kappa B (NF-κB) has been reported to play a pivotal role in many physiological processes including inflammation, apoptosis, and angiogenesis. We discovered a potent natural NF-κB inhibitor, dihydromyricetin, from the traditional herb Ampelopsis grossedentata, which has a long history of use in food and medicine. In this study, we demonstrated the effect of dihydromyricetin on NF-κB activation in TNF-α-induced HeLa cells. Dihydromyricetin was found to markedly inhibit the phosphorylation and degradation of the inhibitor of NF-κB alpha (IκBα), and subsequent nuclear translocation of p65. Dihydromyricetin also has an impact on upstream signaling of IKK through the inhibition of expression of adaptor proteins, TNF receptor-associated factor 2 (TRAF2), and receptor-interacting protein 1 (RIP1). Furthermore, the current results reveal that dihydromyricetin led to the downregulation of target genes involved in inflammation, proliferation, as well as potentiation of TNF-α-induced apoptosis through suppressing the activation of NF-κB. In conclusion, our data indicate that dihydromyricetin may be a potentially useful therapeutic agent for inflammatory diseases.
TL;DR: Investigation of the neuroprotective effect of liraglutide, GLP-1 analogue in PTZ kindling epilepsy-induced comorbidities and neurochemical alteration in mice found it significantly prevented the seizure severity, restored behavioural activity, oxidative defence enzymes, and altered level of neurochemicals in mice brain.
Abstract: Epilepsy is a neurological disorder which occurs due to excessive firing of excitatory neurons in specific region of brain and associated with cognitive impairment and depression. GLP-1 has been reported to maintain hyperexcitability of neurons. Therefore, this study was designed to investigate the neuroprotective effect of liraglutide, GLP-1 analogue in PTZ kindling epilepsy-induced comorbidities and neurochemical alteration in mice. Male albino mice were administered PTZ (35 mg/kg) on every alternate day up to 29th days and challenge test was performed on 33rd day. From 1st day liraglutide (75 and 150 µg/kg) and diazepam (3 mg/kg) were administered up to 33rd day, 30 min prior to PTZ treatment. On 30th day animals were trained on elevated plus maze and passive shock avoidance paradigm and retention was recorded on 31st and 33rd day. On 32nd day tail suspension test was performed. Animals were sacrificed on 34th day for biochemical (LPO, GSH, and nitrite) and neurotransmitters (GABA, glutamate, DA, NE, 5-HT and their metabolites) estimation. Chronic treatment with PTZ developed generalized tonic-clonic seizures, reduced cognitive skills, increased oxidative stress and alteration in the level of neurotransmitters. Pre-treatment with liraglutide (75 and 150 μg/kg) significantly prevented the seizure severity, restored behavioural activity, oxidative defence enzymes, and altered level of neurochemicals in mice brain. The protective effect of liraglutide is attributed to restoration of altered level of GABA, glutamate, DA, NE, and 5-HT by the up-regulation of GLP-1Rs in mice brain.
TL;DR: It is demonstrated that both MC-A and TQ treatment negatively regulate the EMT process through modulation of signalling pathways in cancer cells, which emphasises the significance of combinational therapies in cancer treatment.
Abstract: Epithelial-mesenchymal transition (EMT) plays a prominent role in cancer progression and metastasis. Inhibition of EMT-associated regulators may hold a huge promise for cancer therapy. Although TGF-β signalling has a pivotal role in the induction of EMT, alterations during the EMT process are usually initiated and controlled by the cross-talk of multiple signalling pathways, and in most cases this is context-dependent. In the present study, we aimed at identifying the molecular mechanisms during the inhibition of EMT by novel anti-cancer agent myrtucommulone-A (MC-A) and thymoquinone (TQ). We used epithelial cancer cells to study the effects of MC-A and TQ on EMT. We first showed the functional inhibition of EMT by MC-A or TQ using migration assays and confirmed the EMT inhibition by analysing the expression of EMT markers with RT-PCR, immunocytochemistry and Western blotting. We evaluated the changes in intracellular dynamics by Western blotting and compared the effects of MC-A and TQ with the effects of selective inhibitors of PI3K (LY294002), ERK 1/2 (U0126) and TGF-βR (SB431542). We demonstrate that both MC-A and TQ treatment negatively regulate the EMT process through modulation of signalling pathways in cancer cells. MC-A and TQ treatment inhibited phosphorylation of multiple proteins in a context-dependent manner. Novel anti-cancer agent MC-A and TQ regulate distinct signalling pathways for the repression of EMT which emphasises the significance of combinational therapies in cancer treatment. MC-A and TQ could be considered as candidate molecules for combinational therapies with their ability to interfere signalling pathways regulating cancer cell behaviour.