Showing papers in "Cell & Bioscience in 2019"

Exosomes: biogenesis, biologic function and clinical potential

Abstract: Exosomes are nano-sized biovesicles released into surrounding body fluids upon fusion of multivesicular bodies and the plasma membrane. They were shown to carry cell-specific cargos of proteins, lipids, and genetic materials, and can be selectively taken up by neighboring or distant cells far from their release, reprogramming the recipient cells upon their bioactive compounds. Therefore, the regulated formation of exosomes, specific makeup of their cargo, cell-targeting specificity are of immense biological interest considering extremely high potential of exosomes as non-invasive diagnostic biomarkers, as well as therapeutic nanocarriers. In present review, we outline and discuss recent progress in the elucidation of the regulatory mechanisms of exosome biogenesis, the molecular composition of exosomes, and technologies used in exosome research. Furthermore, we focus on the potential use of exosomes as valuable diagnostic and prognostic biomarkers for their cell-lineage and state-specific contents, and possibilities as therapeutic vehicles for drug and gene delivery. Exosome research is now in its infancy, in-depth understanding of subcellular components and mechanisms involved in exosome formation and specific cell-targeting will bring light on their physiological activities.

Signaling pathways involved in colorectal cancer progression.

Abstract: Colorectal cancer (CRC) is the fourth leading cause of the worldwide cancer mortality. Different molecular mechanisms have been attributed to the development and progress of CRC. In this review, we will focus on the mitogen-activated protein kinase (MAPK) cascades downstream of the epidermal growth factor receptor (EGFR), Notch, PI3K/AKT pathway, transforming growth factor-β (TGF-β), and Wnt signaling pathways. Various mutations in the components of these signaling pathways have been linked to the development of CRC. Accordingly, numerous efforts have been carried out to target the signaling pathways to develop novel therapeutic approaches. Herein, we review the signaling pathways involved in the incidence and progression of CRC, and the strategies for the therapy targeting components of signaling pathways in CRC.

PKM2, function and expression and regulation

Abstract: Pyruvate kinase (PK), as one of the key enzymes for glycolysis, can encode four different subtypes from two groups of genes, although the M2 subtype PKM2 is expressed mainly during embryonic development in normal humans, and is closely related to tissue repair and regeneration, with the deepening of research, the role of PKM2 in tumor tissue has received increasing attention. PKM2 can be aggregated into tetrameric and dimeric forms, PKM2 in the dimer state can enter the nuclear to regulate gene expression, the transformation between them can play an important role in tumor cell energy supply, epithelial–mesenchymal transition (EMT), invasion and metastasis and cell proliferation. We will use the switching effect of PKM2 in glucose metabolism as the entry point to expand and enrich the Warburg effect. In addition, PKM2 can also regulate each other with various proteins by phosphorylation, acetylation and other modifications, mediate the different intracellular localization of PKM2 and then exert specific biological functions. In this paper, we will illustrate each of these points.

The single-cell sequencing: new developments and medical applications.

Abstract: Single-cell sequencing technologies can be used to detect the genome, transcriptome and other multi-omics of single cells. They can show the differences and evolutionary relationships of various cells. This review introduces the latest advances in single-cell sequencing technologies and their applications in oncology, microbiology, neurology, reproduction, immunology, digestive and urinary systems, highlighting the important role that single-cell sequencing techniques play in these areas.

Communication between mitochondria and other organelles: a brand-new perspective on mitochondria in cancer

Abstract: Mitochondria are energy factories of cells and are important pivots for intracellular interactions with other organelles. They interact with the endoplasmic reticulum, peroxisomes, and nucleus through signal transduction, vesicle transport, and membrane contact sites to regulate energy metabolism, biosynthesis, immune response, and cell turnover. However, when the communication between organelles fails and the mitochondria are dysfunctional, it may induce tumorigenesis. In this review, we elaborate on how mitochondria interact with the endoplasmic reticulum, peroxisomes, and cell nuclei, as well as the relation between organelle communication and tumor development .

CRISPR Cpf1 proteins: structure, function and implications for genome editing.

Abstract: CRISPR and CRISPR-associated (Cas) protein, as components of microbial adaptive immune system, allows biologists to edit genomic DNA in a precise and specific way. CRISPR-Cas systems are classified into two main classes and six types. Cpf1 is a putative type V (class II) CRISPR effector, which can be programmed with a CRISPR RNA to bind and cleave complementary DNA targets. Cpf1 has recently emerged as an alternative for Cas9, due to its distinct features such as the ability to target T-rich motifs, no need for trans-activating crRNA, inducing a staggered double-strand break and potential for both RNA processing and DNA nuclease activity. In this review, we attempt to discuss the evolutionary origins, basic architectures, and molecular mechanisms of Cpf1 family proteins, as well as crRNA designing and delivery strategies. We will also describe the novel Cpf1 variants, which have broadened the versatility and feasibility of this system in genome editing, transcription regulation, epigenetic modulation, and base editing. Finally, we will be reviewing the recent studies on utilization of Cpf1as a molecular tool for genome editing.

LncRNA MALAT1 promotes osteoarthritis by modulating miR-150-5p/AKT3 axis.

Abstract: Many studies have reported that long noncoding RNAs (lncRNAs) could act as sponges for microRNAs (miRNAs) and play important roles in the regulation of osteoarthritis (OA). Yet, the underlying mechanisms of lncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in OA are still unclear. Therefore, we aimed to explore the regulation mechanisms of MALAT1 in OA procession. IL-1β treatment in chondrocyte was used to mimic OA in vitro. MALAT1, miR-150-5p and AKT3 expression levels were detected via qRT-PCR. The protein levels of AKT3, MMP-13, ADAMTS-5, Bax, Bcl-2, cleaved-PARP, collagen II and aggracan were measured by western blot. MTT assay was performed to detect cell proliferation ability. The apoptosis of chondrocytes was determined using flow cytometry and western blot. Luciferase assay and RNA immunoprecipitation (RIP) assays were used to confirm the relationship among MALAT1, miR-150-5p and AKT3. In our study, MALAT1 and AKT3 were upregulated while miR-150-5p was downregulated in OA in vitro and vivo. The level of miR-150-5p was negatively correlated with that of MALAT1 or AKT3. More importantly, overexpression of MALAT1 promoted the expression of AKT3 by negatively regulating miR-150-5p. MALAT1 knockdown inhibited cell proliferation, promoted apoptosis, increased MMP-13, ADAMTS-5 expression and decreased collagen II, aggracan expression in IL-1β treated chondrocytes. MALAT1 upregulation or AKT3 overexpression enhanced proliferation, inhibited apoptosis and extracellular matrix (ECM) degradation, which was undermined by overexpression of miR-150-5p. By contrast, miR-150-5p depletion rescued the effect of MALAT1 downregulation or loss of AKT3 on IL-1β-stimulated chondrocytes. MALAT1 was responsible for cell proliferation, apoptosis, and ECM degradation via miR-150-5p/AKT3 axis.

Exosomes from hyperglycemia-stimulated vascular endothelial cells contain versican that regulate calcification/senescence in vascular smooth muscle cells

Abstract: To determine whether and how exosomes from human umbilical vein endothelial cells (HUVEC-Exos) regulates vascular smooth muscle cells (VSMCs) calcification/senescence in high glucose condition. HUVEC-Exos were isolated from normal glucose (NG) and high glucose (HG) stimulated HUVECs (NG/HG-HUVEC-Exos) by super speed centrifugation. HUVEC-Exos were identified by transmission electron microscopy and Western blot of CD63. Protein profile in HUVEC-Exos was examined to screen the candidate molecules that mediate HUVEC-Exos function. VSMCs were incubated with HUVEC-Exos. A series of functional assays in vitro were performed to assess the effects of HUVEC-Exos on the calcification/senescence of VSMCs. The role of the candidate protein in HUVEC-Exos-induced VSMCs dysfunction was assessed. Exosomes isolated from HG-HUVEC-Exos induced calcification/senescence in VSMCs as assessed by Alizarin Red Staining, senescence-associated β-galactosidase (SA-β-gal) staining, and the expression of ALP and p21. HG-HUVEC-Exos significantly increased LDH activity, as well as the product of lipid peroxidation (MDA content), and decreased oxidative stress marker activity, as compared with NG-HUVEC-Exos. Moreover, mechanism studies showed that mitochondrial membrane potential and the expression levels of mitochondrial function related protein HADHA and Cox-4 were significantly decreased in HG-HUVEC-Exos compared to controls. Proteomic analysis showed that HG-HUVEC-Exos consisted of higher level of versican (VCAN), as compared with NG-HUVEC-Exos. Observation under laser confocal microscopy revealed that most green fluorescence of VCAN could overlap with the red fluorescence came from mitochondria, indicating VCAN is mainly localized to the mitochondria of VSMCs. Knockdown of VCAN with siRNA in HUVECs, inhibited HG-HUVEC-Exos-induced mitochondrial dysfunction and calcification/senescence of VSMCs. Our data indicate an intracellular role for VCAN in VSMCs. VCAN participates in hyperglycemia-induced calcification/senescence via modulation of mitochondrial function in VSMCs.

Macrophages and hepatocellular carcinoma.

Abstract: Hepatocellular carcinoma (HCC) is among the most prevalent and lethal cancers in the human population. HCC is an inflammation-associated cancer caused by different etiological factors. The chronic inflammation leads to continuous cycles of hepatocytes destructive–regenerative process and contributes to HCC initiation and progression. Macrophages play a crucial role in chronic liver inflammation. The tumor microenvironment plays a key role in the progression of HCC. Tumor-associated macrophages are a well-known component of the tumor microenvironment and abundantly infiltrate HCC microenvironment. The roles of macrophages in the development and progression of HCC have been recognized. The deep understanding of macrophages in HCC will be critical for developing effective HCC therapy. Targeting of macrophages might provide novel therapeutic approaches for HCC patients and is an emerging field of interest. This review summarizes the knowledge on the contribution of macrophages in the development and progression of HCC, as well as potential immunotherapy being explored in targeting macrophages.

TGF-β in fibrosis by acting as a conductor for contractile properties of myofibroblasts.

Abstract: Myofibroblasts are non-muscle contractile cells that play a key physiologically role in organs such as the stem villi of the human placenta during physiological pregnancy. They are able to contract and relax in response to changes in the volume of the intervillous chamber. Myofibroblasts have also been observed in several diseases and are involved in wound healing and the fibrotic processes affecting several organs, such as the liver, lungs, kidneys and heart. During the fibrotic process, tissue retraction rather than contraction is correlated with collagen synthesis in the extracellular matrix, leading to irreversible fibrosis and, finally, apoptosis of myofibroblasts. The molecular motor of myofibroblasts is the non-muscle type IIA and B myosin (NMMIIA and NMMIIB). Fibroblast differentiation into myofibroblasts is largely governed by the transforming growth factor-β1 (TGF-β1). This system controls the canonical WNT/β-catenin pathway in a positive manner, and PPARγ in a negative manner. The WNT/β-catenin pathway promotes fibrosis, while PPARγ prevents it. This review focuses on the contractile properties of myofibroblasts and the conductor, TGF-β1, which together control the opposing interplay between PPARγ and the canonical WNT/β-catenin pathway.

Radiation: a poly-traumatic hit leading to multi-organ injury

Abstract: The range of radiation threats we face today includes everything from individual radiation exposures to mass casualties resulting from a terrorist incident, and many of these exposure scenarios include the likelihood of additional traumatic injury as well. Radiation injury is defined as an ionizing radiation exposure inducing a series of organ injury within a specified time. Severity of organ injury depends on the radiation dose and the duration of radiation exposure. Organs and cells with high sensitivity to radiation injury are the skin, the hematopoietic system, the gastrointestinal (GI) tract, spermatogenic cells, and the vascular system. In general, acute radiation syndrome (ARS) includes DNA double strand breaks (DSB), hematopoietic syndrome (bone marrow cells and circulatory cells depletion), cutaneous injury, GI death, brain hemorrhage, and splenomegaly within 30 days after radiation exposure. Radiation injury sensitizes target organs and cells resulting in ARS. Among its many effects on tissue integrity at various levels, radiation exposure results in activation of the iNOS/NF-kB/NF-IL6 and p53/Bax pathways; and increases DNA single and double strand breaks, TLR signaling, cytokine concentrations, bacterial infection, cytochrome c release from mitochondria to cytoplasm, and possible PARP-dependent NAD and ATP-pool depletion. These alterations lead to apoptosis and autophagy and, as a result, increased mortality. In this review, we summarize what is known about how radiation exposure leads to the radiation response with time. We also describe current and prospective countermeasures relevant to the treatment and prevention of radiation injury.

LncRNA SNHG7 promotes pancreatic cancer proliferation through ID4 by sponging miR-342-3p.

Abstract: Small nucleolar RNA host gene 7 (SNHG7) is a novel identified oncogenic gene in tumorigenesis. However, the role that SNHG7 plays in pancreatic cancer (PC) remains unclear. In this study, we aimed to investigate the functional effects of SNHG7 on PC and the possible mechanism. The expression levels of SNHG7 in tissues and cell lines were measured by RT-qPCR. Cell viability, apoptosis, migration and invasion were examined to explore the function of SNHG7 on PC. Bioinformatics methods were used to predict the target genes. The mechanism was further investigated by transfection with specific si-RNA, miRNA mimics or miRNA inhibitor. Tumor xenograft was carried out to verify the effects of SNHG7 in vivo. We found that SNHG7 was overexpressed in both PC tissues and cell lines. High expression level of SNHG7 was correlated with the poor prognosis. SNHG7 knockdown inhibited the proliferation, migration and invasion of PC cells. Moreover, SNHG7 was found to regulate the expression of ID4 via sponging miR-342-3p. Additionally, this finding was supported by in vivo experiments. LncRNA SNHG7 was overexpressed in PC tissues, and knockdown of SNHG7 suppressed PC cell proliferation, migration and invasion via miR-342-3p/ID4 axis. The results indicated that SNHG7 as a potential target for clinical treatment of PC.

Brusatol, an NRF2 inhibitor for future cancer therapeutic.

Abstract: Natural products from herbal medicines have long been investigated for their potentials as cancer therapeutics. Besides the development of several herbal medicine-derived anti-cancer agents, such as paclitaxel, vincristine and podophyllotoxin, many recent laboratory findings demonstrated that brusatol, a quassinoid from the seeds of Brucea sumatrana, exhibits potent tumor suppressing effect with improved disease outcome. Our recent finding further demonstrated that brusatol synergizes with the intrinsic metabolic burden in cancer cells. Here, we summarized the recent investigations of brusatol as an experimental therapeutic for human malignancies, such as leukemia, lung cancer, pancreatic cancer and brain tumor. We also discussed the molecular target brusatol, with a focus on the Nuclear factor erythroid 2-related factor 2 (NRF2)-guided gene transcription, as well as glutathione de novo synthesis. Further, we discussed the challenges and future applications of brusatol for cancer therapy. In conclusion, we believe increasing evidences have shown the value of brusatol as a novel strategy for cancer treatment, which may indicate future drug development and clinical translation.

The role of mRNA m 6 A methylation in the nervous system

Abstract: Epitranscriptomics, also known as “RNA epigenetics”, is a chemical modification for RNA regulation. Ribonucleic acid (RNA) methylation is considered to be a major discovery following the deoxyribonucleic acid (DNA) and histone methylation. Messenger RNA (mRNA) methylation modification accounts for more than 60% of all RNA modifications and N6-methyladenosine (m6A) is known as one of the most common type of eukaryotic mRNA methylation modifications in current. The m6A modification is a dynamic reversible modification, which can directly or indirectly affect biological processes, such as RNA degradation, translation and splicing, and can play important biological roles in vivo. This article introduces the mRNA m6A methylation modification enzymes and binding proteins, and reviews the research progress and related mechanisms of the role of mRNA m6A methylation in the nervous system from the aspects of neural stem cells, learning and memory, brain development, axon growth and glioblastoma.

Comparison of osteogenic differentiation capacity in mesenchymal stem cells derived from human amniotic membrane (AM), umbilical cord (UC), chorionic membrane (CM), and decidua (DC).

Abstract: Mesenchymal stem cells (MSCs) have been extensively explored as a promising therapeutic agent in the field of bone tissue engineering due to their osteogenic differentiation ability. In this study, the osteogenic differential ability and the effect of fibronectin and laminin on the osteogenic differentiation in four types of MSCs derived from placental tissue are compared to determine the ideal source for bone reconstruction tissue engineering. The present study examines the osteogenic differentiation levels of four types of MSCs using alizarin red staining and quantifies the calcium levels and alkaline phosphatase (ALP) activity. In addition, this study examines the osteoblast differentiation protein markers osterix, collagen I, osteopontin, and osteocalcin using a Western blot assay. qPCR and EdU labeling assays were employed to identify the kinetics of osteogenic differentiation. Calcium deposit levels, ALP activity, and osteopontin and osteocalcin concentrations were determined to confirm the role of Extracellular matrix (ECM) components role on the osteogenic differentiation of MSCs. The data demonstrated that MSCs isolated from different layers of placenta had different potentials to differentiate into osteogenic cells. Importantly, AM-MSCs and UC-MSCs differentiated into the osteoblast stage more efficiently and quickly than CM-MSCs and DC-MSCs, which was associated with a decrease in their proliferation ability. Among the different types of MSCs, AM-MSCs and UC-MSCs had a higher osteogenic differentiation potential induced by fibronectin due to enhanced phosphorylation during the Akt and ERK pathways. Taken together, these results indicate that AM-MSCs and UC-MSCs possess a higher osteogenic potential, and fibronectin can robustly enhance the osteogenic potential of the Akt and ERK pathways.

Metformin represses the pathophysiology of AAA by suppressing the activation of PI3K/AKT/mTOR/autophagy pathway in ApoE −/− mice

Abstract: The protective effect of metformin (MET) on abdominal aortic aneurysm (AAA) has been reported. However, the related mechanism is still poor understood. In this study, we deeply investigated the role of metformin in AAA pathophysiology. Angiotensin II (Ang-II) was used to construct the AAA model in ApoE−/− mice. The related mechanism was explored using Western blot and quantitative real time PCR (qRT-PCR). We also observed the morphological changes in the abdominal aorta and the influence of metformin on biological behaviors of rat abdominal aortic VSMCs. The PI3K/AKT/mTOR pathway was activated in aneurysmal wall tissues of AAA patients and rat model. Treatment with metformin inhibited the breakage and preserved the elastin structure of the aorta, the loss of collagen, and the apoptosis of aortic cells. In addition, metformin significantly suppressed the activation of the PI3K/AKT/mToR pathway and decreased the mRNA and protein levels of LC3B and Beclin1, which were induced by Ang-II. Moreover, PI3K inhibitors enhanced the effect of metformin while PI3K agonists largely reversed this effect. Interestingly, the cell proliferation, apoptosis, migration and autophagy of vascular smooth muscle cells (VSMCs) induced by Ang-II were also decreased following metformin treatment. PI3K inhibitors and agonists strengthened and weakened the effects of metformin in VSMCs, respectively. Metformin represses the pathophysiology of AAA by inhibiting the activation of PI3K/AKT/mTOR/autophagy pathway. This repression may be useful as a new therapeutic strategy for AAA.

Autophagy, cancer and angiogenesis: where is the link?

Abstract: Autophagy is a catabolic process for degradation of intracellular components. Damaged proteins and organelles are engulfed in double-membrane vesicles ultimately fused with lysosomes. These vesicles, known as phagophores, develop to form autophagosomes. Encapsulated components are degraded after autophagosomes and lysosomes are fused. Autophagy clears denatured proteins and damaged organelles to produce macromolecules further reused by cells. This process is vital to cell homeostasis under both physiologic and pathologic conditions. While the role of autophagy in cancer is quite controversial, the majority of studies introduce it as an anti-tumorigenesis mechanism. There are evidences confirming this role of autophagy in cancer. Mutations and monoallelic deletions have been demonstrated in autophagy-related genes correlating with cancer promotion. Another pathway through which autophagy suppresses tumorigenesis is cell cycle. On the other hand, under hypoxia and starvation condition, tumors use angiogenesis to provide nutrients. Also, autophagy flux is highlighted in vessel cell biology and vasoactive substances secretion from endothelial cells. The matrix proteoglycans such as Decorin and Perlecan could also interfere with angiogenesis and autophagy signaling pathway in endothelial cells (ECs). It seems that the connection between autophagy and angiogenesis in the tumor microenvironment is very important in determining the fate of cancer cells. Matrix glycoproteins can regulate autophagy and angiogenesis linkage in tumor microenvironment. Also, finding details of how autophagy and angiogenesis correlate in cancer will help adopt more effective therapeutic approaches.

Caspase-11, a specific sensor for intracellular lipopolysaccharide recognition, mediates the non-canonical inflammatory pathway of pyroptosis

Abstract: Pyroptosis, a type of programmed cell death that along with inflammation, is mainly regulated by two main pathways, cysteinyl aspartate specific proteinase (caspase)-1-induced canonical inflammatory pathway and caspase-11-induced non-canonical inflammatory pathway. The non-canonical inflammatory pathway-induced pyroptosis is a unique immune response in response to gram-negative (G−) bacteria. It is induced by lipopolysaccharide (LPS) on the surface of G− bacteria. This activates caspase-11 which, in turn, activates a series of downstream proteins eventually forming protein pores on the cell membrane and inducing cell sacrificial processes. Caspase-11 belongs to the caspase family and is an homologous protein of caspase-1. It has the ability to specifically hydrolyze proteins, but it is still unclear how it regulates cell death caused by non-canonical inflammatory pathways. The present study describes a pathway that enables LPS to directly enter the cell and activate caspase-11, and the key role caspase-11 plays in the activation of pyroptosis and inflammation.

Zika virus antagonizes interferon response in patients and disrupts RIG-I–MAVS interaction through its CARD-TM domains

Abstract: The emerging threat to global health associated with the Zika virus (ZIKV) epidemics and its link to severe complications highlights a growing need to better understand the pathogenic mechanisms of ZIKV. Accumulating evidence for a critical role of type I interferon (IFN-I) in protecting hosts from ZIKV infection lies in the findings that ZIKV has evolved various strategies to subvert the host defense line by counteracting the early IFN induction or subsequent IFN signaling. Yet, mechanisms underlying the counter-IFN capability of ZIKV and its proteins, which might contribute to the well-recognized broad cellular tropisms and persistence of ZIKV, remain incompletely understood. Using RNA sequencing-based transcriptional profiling of whole blood cells isolated from patients acutely infected by ZIKV, we found that transcriptional signature programs of antiviral interferon-stimulated genes and innate immune sensors in ZIKV-infected patients remained inactive as compared to those of healthy donors, suggesting that ZIKV was able to suppress the induction of IFN-I during the natural infection process in humans. Furthermore, by analyzing the molecular interaction in a ZIKV NS4A-overexpression system, or in the context of actual ZIKV infection, we identified that ZIKV NS4A directly bound MAVS and thereby interrupted the RIG-I/MAVS interaction through the CARD-TM domains, leading to attenuated production of IFN-I. Our findings collectively revealed that ZIKV NS4A targeted MAVS and contributed to ZIKV immune evasion through abrogating MAVS-mediated IFN production. These findings obtained from patient studies have added new knowledge and molecular details to our understanding regarding how ZIKV mediates suppression of the IFN-I system and may provide a new basis for the future development of anti-ZIKV strategies.

Transcriptome analysis reveals an important candidate gene involved in both nodal metastasis and prognosis in lung adenocarcinoma.

Abstract: Lymph node metastasis of lung cancer is a serious problem. Therefore, there is a need for a detailed transcriptome study of metastatic lung adenocarcinoma. The lung adenocarcinoma RNA-seq data and the corresponding clinical information available from TCGA were analyzed. Differential expression, gradient changes, and biological pathways were carried out. Potential gene(s) associated with tumor metastasis and survival were validated by Cox regression. A total of 406 and 439 differentially expressed genes were identified for lymph node metastasis and TNM stages, respectively. Of the 296 intersection genes, 112 were associated with nodal metastasis and/or staging. Only 25 of these 112 genes with gradient changes were involved in nodal metastasis, and 13 were involved in staging. Only one gene, RN7SL494P, might be involved in lung adenocarcinoma development and poor outcome. Finally, Cox regression results verified that age, pathology classification, radiotherapy and chemotherapy are all the independent prognostic factors. In particular, RN7SL494P was further verified to be an independent factor affecting lymph node metastasis and patient survival. Furthermore, we verified the RN7SL494P function using simulation data generated by mixing cell lines of the Cancer Cell Line Encyclopedia (CCLE) and obtained consistent results. Our findings suggest a potential clinical application of the RN7SL494P as a promising marker in the evaluation of patients with primary lung adenocarcinoma, not only for predicting nodal metastasis, but also for the prognosis of the outcome.

Autologous mitochondrial microinjection; a strategy to improve the oocyte quality and subsequent reproductive outcome during aging.

Abstract: Along with the decline in oocyte quality, numerous defects such as mitochondrial insufficiency and the increase of mutation and deletion have been reported in oocyte mitochondrial DNA (mtDNA) following aging. Any impairments in oocyte mitochondrial function have negative effects on the reproduction and pregnancy outcome. It has been stated that infertility problems caused by poor quality oocytes in women with in vitro fertilization (IVF) and repeated pregnancy failures are associated with aging and could be overcome by transferring large amounts of healthy mitochondria. Hence, researches on biology, disease, and the therapeutic use of mitochondria continue to introduce some clinical approaches such as autologous mitochondrial transfer techniques. Following mitochondrial transfer, the amount of ATP required for aged-oocyte during fertilization, blastocyst formation, and subsequent embryonic development could be an alternative modality. These modulations improve the pregnancy outcome in women of high reproductive aging as well. In addition to overview the clinical studies using mitochondrial microinjection, this study provides a framework for future approaches to develop effective treatments and preventions of congenital transmission of mitochondrial DNA mutations/diseases to offspring. Mitochondrial transfer from ovarian cells and healthy oocytes could lead to improved fertility outcome in low-quality oocytes. The modulation of mitochondrial bioactivity seems to regulate basal metabolism inside target oocytes and thereby potentiate physiological activity of these cells while overcoming age-related infertility in female germ cells.

BabaoDan attenuates high-fat diet-induced non-alcoholic fatty liver disease via activation of AMPK signaling

Abstract: Babaodan (BBD), a traditional Chinese medicine, has been shown to have protective effects during liver injury and ameliorate liver disease progression, but little is known about its effect on non-alcoholic fatty liver disease (NAFLD). The aim of this study was to investigate the effects of BBD on obesity-induced NAFLD. C57BL/6 J mice were fed with normal diet, high fat diet (HFD) or HFD + BBD for 8 weeks. Weights of all mice were recorded every 3 days. At the end of the experiments, the level of livers, kidneys and adipose tissues of each animal was weighed. Blood serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total cholesterol (TC), triglyceride (TG), high density lipoprotein cholesterol (HDL-C) cholesterol, low density lipoprotein cholesterol (LDL-C), glucose and leptin were detected with appropriate test kits. Haematoxylin–eosin (HE), Masson trichrome and Oil Red O staining of the liver were performed. We applied immunohistochemical analysis to investigate the expression of TNF-α, IL-6 and leptin in liver tissue. The expression of genes related lipid anabolism (SREBP1-c, ACC, SCD-1, LXRα and CD36) and s-oxidation (CPT-1 and PPARα) in liver and adipose tissues was determined by RT-PCR. The expression of AMPK and p-AMPK was determined by western blot analysis. We found the weight of bodies and tissues (retroperitoneal fat pads, kidneys and livers) of mice fed with HFD + BBD were significantly lower than that of HFD-fed mice. And liver injury induced by HFD was relieved in mice treated with BBD, accompanied with significant reduction were observed in serum ALT/AST activities and alleviated pathological damage. The levels of glucose, TG, TC, HDL-C and LDL-C in the liver or serum were significantly decreased on HFD + BBD group compared with HFD group. Furthermore, BBD treatment reduced the level of TNF-α and IL-6 induced by HFD. The level of leptin in the liver and serum were reduced in mice fed with HFD + BBD than that of HFD-fed mice. Several lipid synthesis genes (SREBP1-c, ACC, SCD-1, LXRα and CD36) were down-regulated and that of s-oxidation (CPT-1 and PPARα) up-regulated in HFD + BBD group compared with HFD group. In addition, BBD increased the expression of p-AMPK compared with untreated HFD group, which suggested BBD improved the activation of AMPK pathway. In summary, our results indicate that BBD has potential applications in the prevention and treatment of NAFLD, which may be closely related to its effect on lipid metabolism via activation of AMPK signaling.

Long non-coding RNA BLACAT1 promotes breast cancer cell proliferation and metastasis by miR-150-5p/CCR2

Abstract: Breast cancer was dangerous to women health. A growing number of evidences indicate that long non-coding RNAs (lncRNAs) have many functions in the development and progression of breast cancer and may serve as the markers of diagnosis or prognosis. BLACAT1 is one of lncRNA and the roles of it in breast cancer is not clear. In this study, it is aimed to explore the roles and molecular mechanisms of BLACAT1 in breast cancer. We found BLACAT1 took part in breast cancer cell aggressive phenotype. The real-time PCR result showed that BLACAT1 was up-regulated in tumor tissues compared to adjacent normal tissues. The molecular mechanism experiments demonstrated that BLACAT1 down-regulation suppressed the proliferation and metastasis of human breast cancer cells by regulating miR-150-5p targeting CCR2. The clinical studies indicated that lack of BLACAT1 was related to tumor size, metastasis. Conclusion: The present study verified the involvement of the BLACAT1 in the mediation of cell survival and metastasis through miR-150-5p targeting CCR2 in breast cancer cells.

Colon cancer cells secrete exosomes to promote self-proliferation by shortening mitosis duration and activation of STAT3 in a hypoxic environment.

Abstract: Colon-cancer-cell-derived exosomes (CDEs) are emerging mediators of tumorigenesis and serve as messengers of intercellular communication; however, whether the CDEs affect the proliferation of colon cancer cells themselves remains unknown. In the current study, the CDEs isolated from human colon cancer cell line SW480 and HCT116 showed a size range of 60–150 nm, typical bilayer-encapsulated vesicles, and expressed the exosomal markers CD81 and CD63. Incubation of SW480 cells with CDEs labelled with PKH67 fluorescent markers revealed that SW480 cells were able to absorb CDEs, which were mostly distributed around the nucleus. Hypoxic conditions promoted colon cancer cells to release a greater number of CDEs than normoxic conditions. MTT cell proliferation assay demonstrated CDEs promoted the proliferation of colon cancer cells in a time- and dose-dependent manner. Mechanistically, CDEs promoted colon cancer cell growth mainly through shortening mitosis duration. Meanwhile, the levels of phosphorylated STAT3 in colon cancer cells was up-regulated with the treatment of CDEs derived from hypoxic tumor cells. Our data suggests that colon cancer cells are able to promote self-growth through the secretion of exosomes, especially under hypoxic conditions, which shortens mitosis duration and activates STAT3.

Dose-dependent roles of aspirin and other non-steroidal anti-inflammatory drugs in abnormal bone remodeling and skeletal regeneration.

Abstract: The failure of remodeling process that constantly regenerates effete, aged bone is highly associated with bone nonunion and degenerative bone diseases. Numerous studies have demonstrated that aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) activate cytokines and mediators on osteoclasts, osteoblasts and their constituent progenitor cells located around the remodeling area. These cells contribute to a complex metabolic scenario, resulting in degradative or synthetic functions for bone mineral tissues. The spatiotemporal effects of aspirin and NSAIDs in the bone remodeling are controversial according the specific therapeutic doses used for different clinical conditions. Herein, we review in vitro, in vivo, and clinical studies on the dose-dependent roles of aspirin and NSAIDs in bone remodeling. Our results show that low-dose aspirin (< 100 μg/mL), which is widely recommended for prevention of thrombosis, is very likely to be benefit for maintaining bone mass and qualities by activation of osteoblastic bone formation and inhibition of osteoclast activities via cyclooxygenase-independent manner. While, the roles of high-dose aspirin (150–300 μg/mL) and other NSAIDs in bone self-regeneration and fracture-healing process are difficult to elucidate owing to their dual effects on osteoclast activity and bone formation of osteoblast. In conclusion, this study highlighted the potential clinical applications of low-dose aspirin in abnormal bone remodeling as well as the risks of high-dose aspirin and other NSAIDs for relieving pain and anti-inflammation in fractures and orthopedic operations.

CXCR4 knockdown prevents inflammatory cytokine expression in macrophages by suppressing activation of MAPK and NF-κB signaling pathways

Abstract: Recent evidence has shown that C-X-C chemokine receptor type 4 (CXCR4) plays a crucial role in acute lung injury (ALI). Macrophages are key factors in the pathogenesis of ALI. The aim of this study was to investigate the role of CXCR4 in macrophages after lipopolysaccharide (LPS) stimulation and confirm that CXCR4 knockdown can inhibit inflammatory cytokines by suppressing mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) signaling pathway activation. In this study, we found that CXCR4 expression in lung tissue of ALI was significantly increased using immunofluorescence. We also found that the expression of CXCR4 in macrophages sorted from bronchoalveolar lavage fluid (BALF) of ALI was obviously upregulated through RT-qPCR. After CXCR4 knockdown using siRNA, we found that the expression of interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) was obviously down regulated in macrophages. Additionally, the phosphorylation of p38, Erk, and p65 was significantly decreased after CXCR4 knockdown through western blotting. Taken together, the present study suggests that CXCR4 knockdown may inhibit inflammatory cytokine expression in macrophages by suppressing MAPK and NF-κB signaling pathway activation. Therefore, CXCR4 knockdown may have potential clinical value in treating ALI.

A prospect of cell immortalization combined with matrix microenvironmental optimization strategy for tissue engineering and regeneration

Abstract: Cellular senescence is a major hurdle for primary cell-based tissue engineering and regenerative medicine. Telomere erosion, oxidative stress, the expression of oncogenes and the loss of tumor suppressor genes all may account for the cellular senescence process with the involvement of various signaling pathways. To establish immortalized cell lines for research and clinical use, strategies have been applied including internal genomic or external matrix microenvironment modification. Considering the potential risks of malignant transformation and tumorigenesis of genetic manipulation, environmental modification methods, especially the decellularized cell-deposited extracellular matrix (dECM)-based preconditioning strategy, appear to be promising for tissue engineering-aimed cell immortalization. Due to few review articles focusing on this topic, this review provides a summary of cell senescence and immortalization and discusses advantages and limitations of tissue engineering and regeneration with the use of immortalized cells as well as a potential rejuvenation strategy through combination with the dECM approach.

LncRNA H19 over-expression inhibited Th17 cell differentiation to relieve endometriosis through miR-342-3p/IER3 pathway.

Abstract: To investigate the mechanism of LncRNA H19 in Th17 cell differentiation and endometrial stromal cells (ESCs) proliferation in endometriosis (EMS). LncRNA H19, miR-342-3p and IER3 expressions were detected by qRT-PCR and western blot. The percentage of Th17 cells/CD4+ T cells was detected by flow cytometry. IL-17 level was measured by ELISA. The interaction of miR-342-3p and IER3 was confirmed by Luciferase reporter assay. LncRNA H19 and IER3 expressions were down-regulated in mononuclear cells from peritoneal fluid (PFMCs) of patients with EMS or under Th17 differentiation conditions, whereas miR-342-3p expression was up-regulated and the percentage of Th17 cells was increased in PFMCs of patients with EMS or under Th17 differentiation conditions. Over-expression of LncRNA H19 decreased IL-17 level and the percentage of Th17 cells/CD4+ T cells. Besides, we confirmed that miR-342-3p could target to IER3 and negatively regulate IER3 expression. LncRNA H19 over-expression suppressed Th17 differentiation and ESC proliferation through regulating miR-342-3p/IER3. In vivo experiments showed LncRNA H19 over-expression suppressed the growth of Th17 cell differentiation-induced endometriosis-like lesions. LncRNA H19 was down-regulated in PFMC of patients with EMS or under Th17 polarizing conditions, and LncRNA H19 over-expression suppressed Th17 cell differentiation and ESCs proliferation through miR-342-3p/IER3 pathway.

Growth inhibition and apoptosis in colorectal cancer cells induced by Vitamin D-Nanoemulsion (NVD): involvement of Wnt/β-catenin and other signal transduction pathways

Abstract: More than the two decades, the question of whether vitamin D has a role in cancer frequency, development, and death has been premeditated in detail. Colorectal, breast, and prostate cancers have been a scrupulous spot of center, altogether, these three malignancies report for approximately 35% of cancer cases and 20% of cancer demises in the United States, and as such are a chief public health apprehension. The aim was to evaluate antitumor activity of Vitamin D-Nanoemulsion (NVD) in colorectal cancer cell lines and HCT116 xenograft model in a comprehensive approach. Two human colorectal cancer cell lines HCT116 and HT29 (gained from College of Pharmacy, King Saud University, KSA were grown. 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazoliumbromide protocol were performed to show the impact of NVD and β-catenin inhibitor (FH535) on the viability of HCT116 and HT29 cell lines. Apoptosis/cell cycle assay was performed. Analysis was done with a FACScan (Becton–Dickinson, NJ). About 10,000 cells per sample were harvested and Histograms of DNA were analyzed with ModiFitLT software (verity Software House, ME, USA). Western blotting and RT-PCR were performed for protein and gene expression respectively in in vitro and in vivo. We found that NVD induced cytotoxicity in colorectal cells in a dose-dependent manner and time dependent approach. Further, our data validated that NVD administration of human colorectal cancer HCT116 and HT29 cells resulted in cell growth arrest, alteration in molecules regulating cell cycle operative in the G2 phase of the cell cycle and apoptosis in a dose dependent approach. Further our results concluded that NVD administration decreases expression of β-catenin gene, AKT gene and Survivin gene and protein expression in in vitro and in vivo. Our findings suggest that targeting β-catenin gene may encourage the alterations of cell cycle and cell cycle regulators. Wnt/β-catenin signaling pathway possibly takes part in the genesis and progression of colorectal cancer cells through regulating cell cycle and the expression of cell cycle regulators.

Exercise-induced myokine FNDC5/irisin functions in cardiovascular protection and intracerebral retrieval of synaptic plasticity.

Abstract: Physical exercise is well known to benefit human health at every age. However, the exact mechanism through which physical exercise improves health remains unknown. Recent studies into exercise-induced myokine FNDC5/irisin, a newly discovered hormone, have begun to shed light on this mystery. Exercise-induced myokine FNDC5/irisin have been shown to be protective against cardiovascular damage post ischemic event, improve function in the neurons of Alzheimer’s disease patients, and have been implicated in macrophage and adipocyte regulation. Elegantly designed experiments have shown FNDC5/irisin to promote Nkx2.5+ cardiac progenitor cell dependent cardiac regeneration, neovascularization, and reduce cardiac fibrosis. It has also been shown to improve macrophage function, which may protect against injuries to the cardiac conduction system. Similarly, FNDC5/irisin knockout mice have been shown to have reduced memory performance, while peripheral overexpression of FNDC5/irisin has been shown to improve memory impairment in a murine Alzheimer’s disease model. Finally, FNDC5/irisin has been linked to regulation of osteocytes and adipocytes by signaling through the cytoplasmic membrane integrated protein aV/b5 integrin, the first known receptor for this newly discovered hormone. Although these recent discoveries have cemented the importance of FNDC5/irisin, many details regarding how FNDC5/irisin fits into the physiology of exercise benefits remain unknown and are deserving of future inquiry.