Manipal University

About: Manipal University is a education organization based out in Manipal, Karnataka, India. It is known for research contribution in the topics: Population & Health care. The organization has 9525 authors who have published 11207 publications receiving 110687 citations.

Embryonic fibroblasts represent a connecting link between mesenchymal and embryonic stem cells.

Abstract: It is well established that fibroblasts and mesenchymal stem cells (MSC) share several characteristics with subtle differences. However, no study highlighting the versatility of fibroblasts beyond their multipotentiality has been reported so far. Mouse embryonic fibroblasts (MEFs) are widely used as feeder layers to support the growth of embryonic stem cells (ESC). We hypothesized that MEF may retain ES-like features in concurrence to their developmental hierarchy in addition to their multipotent nature. Hence, we performed a comparative assessment of MEF and ESC to determine their ability to differentiate into cell types other than mesoderm as well as capacity to form teratoma using routine in vitro and in vivo techniques. MEF were derived by trypsin/ EDTA (ethylenediaminetetraacetic acid) digestion from E13.5 embryos after removing heads and viscera following plastic adherence. MEFs robustly proliferated in culture until passage 15 and formed aggregates by hanging drop method. Flow cytometry, reverse transcription-polymerase chain reaction (RT-PCR) and immunocytochemistry revealed the presence of key MSC markers such as CD90, CD73, Sca-1, CD44, CD29, Vimentin and absence of CD45. Additionally, they expressed SSEA-1, Oct-4, Nanog, Sox-2 and ABCG2 as pluripotency markers; Nestin, β-III tubulin, Otx-2 (ectoderm); MEF-2, Mesp2, GATA-2 (mesoderm) and GATA-4, α-amylase, PDX-1 (endoderm) as tri-lineage markers. Furthermore, MEFs formed representative tissues from all three germ layers upon transplantation into Balb/c mice. These unique abilities of MEF to exhibit pluripotency, in addition to fibroblast characteristics and their ready availability with less ethical concerns and low maintenance requirements make them an attractive model for further exploration as a possible tool for regenerative medicine.

In vitro and in vivo hepatoprotective effects of the total alkaloid fraction of Hygrophila auriculata leaves.

Abstract: Objective: To investigate the total alkaloid fraction of the methanol extract of leaves of Hygrophila auriculata for its hepatoprotective activity against CCl4-induced toxicity in freshly isolated rat hepatocytes, HepG2 cells, and animal models. Materials and Methods: Mature leaves of H. auriculata were collected, authenticated, and subjected to methanolic extraction followed by isolation of total alkaloid fraction. Freshly isolated rat hepatocytes were exposed to CCl4 (1%) along with/without various concentrations of the total alkaloid fraction (80–40 µg/ml). Protection of human liverderived HepG2 cells against CCl4-induced damage was determined by the MTT assay. Twenty-four healthy Wistar albino rats (150–200 g) of either sex were used for the in vivo investigations. Liver damage was induced by administration of 30% CCl4 suspended in olive oil (1 ml/kg body weight, i.p). Results: The antihepatotoxic effect of the total alkaloid fraction was observed in freshly isolated rat hepatocytes at very low concentrations (80–40 µg/ml). A dose-dependent increase in the percentage viability was observed when CCl4-exposed HepG2 cells were treated with different concentrations of the total alkaloid fraction. Its in vivo hepatoprotective effect at 80 mg/kg body weight was comparable with that of the standard Silymarin at 250 mg/kg body weight. Conclusion: The total alkaloid fraction was able to normalize the biochemical levels which were altered due to CCl4 intoxication. Mumbai. 3-(4,5-Dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), collagenase, insulin, dexamethasone, minimum essential medium (MEM), Ham’s F12 medium, Silymarin (Standard), and antibiotics were purchased from Sigma Chemical Co., St. Loius, MO, USA. Ecoline diagnostic kits were purchased from E – Merck, India. The human liver-derived HepG2 cell line was obtained from National Centre for Cell Science, Pune, India.

The PPE2 protein of Mycobacterium tuberculosis translocates to host nucleus and inhibits nitric oxide production

Abstract: Mycobacterium tuberculosis, the bacterium that causes tuberculosis, is one of the most successful pathogens of humans. It has evolved several adaptive skills and evasion mechanisms to hijack the immunologically educated host to suit its intracellular lifestyle. Here, we show that one of the unique PPE family member proteins of M. tuberculosis, PPE2, can limit nitric oxide (NO) production by inhibiting inos gene transcription. PPE2 protein has a leucine zipper DNA-binding motif and a functional nuclear localization signal. PPE2 was translocated into the macrophage nucleus via the classical importin α/β pathway where it interacted with a GATA-binding site overlapping with the TATA box of inos promoter and inhibited NO production. PPE2 prolonged intracellular survival of a surrogate bacterium M. smegmatis in vitro as well as in vivo. This information are likely to improve our knowledge of host-pathogen interactions during M. tuberculosis infection which is crucial for designing effective anti-TB therapeutics.