ALBERT

Description: Background: The overall goal of this study was to demonstrate potential chemopreventive effects of ferulic acid (FA), an antioxidant, combined with aspirin (ASP), a commonly used anti-inflammatory drug for pancreatic cancer chemoprevention, using a novel chitosan-coated solid lipid nanoparticles (c-SLN) drug delivery system encapsulating FA and ASP. Results: Our formulation optimization results showed that c-SLNs of FA and ASP exhibited appropriate initial particle sizes in range of 183 ± 46 and 229 ± 67 nm, encapsulation efficiency of 80 and 78 %, and zeta potential of 39.1 and 50.3 mV, respectively. In vitro studies were conducted to measure growth inhibition and degree of apoptotic cell death induced by either FA or ASP alone or in combination. Cell viability studies demonstrated combinations of low doses of free FA (200 µM) and ASP (1 mM) significantly reduced cell viability by 45 and 60 % in human pancreatic cancer cells MIA PaCa-2 and Panc-1, respectively. However, when encapsulated within c-SLNs, a 5- and 40-fold decreases in dose of FA (40 µM) and ASP (25 µM) was observed which was significant. Furthermore, increased apoptosis of 35 and 31 % was observed in MIA PaCa-2 and Panc-1 cells, respectively. In vivo studies using oral administration of combinations of 75 and 25 mg/kg of FA and ASP c-SLNs to MIA PaCa-2 pancreatic tumor xenograft mice model suppressed the growth of the tumor by 45 % compared to control, although this was not statistically significant. In addition, the immunohistochemical analysis of tumor tissue showed significant decrease in expression of proliferation proteins PCNA and MKI67, and also increased expression of apoptotic proteins p-RB, p21, and p-ERK1/2 indicating the pro-apoptotic role of the regimen. Conclusion: Combination of FA and ASP delivered via a novel nanotechnology-based c-SLN formulation demonstrates potential for pancreatic cancer chemoprevention and could be a promising area for future studies.

Description: Background: Acute kidney injury (AKI) is a severe disease with high morbidity and mortality. Methods that promote repair of the injured kidney have been extensively investigated. Cell-based therapy with mesenchymal stem cells or renal progenitor cells (RPCs) resident in the kidney has appeared to be an effective strategy for the treatment of AKI. Embryonic stem cells or induced pluripotent stem cells (iPSCs) are also utilized for AKI recovery. However, the therapeutic effect of iPSC-derived RPCs for AKI has yet to be determined. Methods: In this study, we induced iPSCs differentiation into RPCs using a nephrogenic cocktail of factors combined with the renal epithelial cell growth medium. We then established the rat ischemia–reperfusion injury (IR) model and transplanted the iPSC-derived RPCs into the injured rats in combination with the hydrogel. Next, we examined the renal function-related markers and renal histology to assess the therapeutic effect of the injected cells. Moreover, we investigated the mechanism by which iPSC-derived RPCs affect AKI caused by IR. Results: We showed that the differentiation efficiency of iPSCs to RPCs increased when cultured with renal epithelial cell growth medium after stimulation with a nephrogenic cocktail of factors. The transplantation of iPSC-derived RPCs decreased the levels of biomarkers indicative of renal injury and attenuated the necrosis and apoptosis of renal tissues, but resulted in the up-regulation of renal tubules formation, cell proliferation, and the expression of pro-renal factors. Conclusion: Our results revealed that iPSC-derived RPCs can protect AKI rat from renal function impairment and severe tubular injury by up-regulating the renal tubules formation, promoting cell proliferation, reducing apoptosis, and regulating the microenvironment in the injured kidney.

Description: Background: Preclinical evaluations of chemotherapies depend on clinically relevant animal models for pancreatic cancer. The injection of syngeneic murine adenocarcinoma cells is one efficient option to generate carcinomas in mice with an intact immune system. However, this option is constrained by the paucity of appropriate cell lines. Results: The murine pancreatic adenocarcinoma cell lines 6606PDA and 7265PDA were compared to the 6606l cell line isolated from a liver metastasis from mice suffering from pancreatic cancer. In tissue culture 6606PDA and 6606l proliferated faster than 7265PDA. 7265PDA cells were, however, significantly more sensitive to gemcitabine as assessed by BrdU-incorporation and trypan blue exclusion assays in vitro. Within 1 week after injection of either one of these three cell lines into the pancreas of C57BL/6J mice, carcinomas were observed by T2 weighted magnetic resonance imaging and histology. Three weeks after injecting 6606PDA or 6606l cells large carcinomas could be characterized, which were surrounded by extensive desmoplastic reaction. After injection of 7265PDA cells, however, remission of cancer was observed between the first and the third week. Compared to 6606PDA cell derived carcinomas a higher apparent diffusion coefficient was quantified by diffusion weighted magnetic resonance imaging in these tumors. This correlated with reduced cancer cell density observed on histological sections. Conclusion: All three cell lines can be used in vitro for testing combinatorial therapies with gemcitabine. The 6606PDA and 6606l cell lines but not the 7265PDA cell line can be used for evaluating distinct therapies in a syngeneic carcinoma model using C57BL/6J mice. Diffusion-weighted MRI proved to be an appropriate method to predict tumor remission.

Description: Background: Interleukin-22 (IL-22), a cytokine with important functions in anti-microbial defense and tissue repair, has been recently suggested to have beneficial effects in obesity and metabolic syndrome in some but not in other studies. Here, we re-examined the effects of IL-22 on obesity, insulin resistance, and hepatic glucose metabolism. Results: Genetic deletion of IL-22 did not affect high-fat-diet (HFD)-induced obesity and insulin resistance. IL-22 transgenic mice with relatively high levels of circulating IL-22 (~600 pg/ml) were completely resistant to Concanavalin A-induced liver injury but developed the same degree of high fat diet (HFD)-induced obesity, insulin resistance, and fatty liver as the wild-type littermate controls. Similarly, chronic treatment with recombinant mouse IL-22 (rmIL-22) protein did not affect HFD-induced obesity and the associated metabolic syndrome. In vivo treatment with a single dose of rmIL-22 downregulated the hepatic expression of gluconeogenic genes and subsequently inhibited hepatic gluconeogenesis and reduced blood glucose levels both in HFD-fed and streptozotocin (STZ)-treated mice without affecting insulin production. In vitro exposure of mouse primary hepatocytes to IL-22 suppressed glucose production and the expression of gluconeogenic genes. These inhibitory effects were partially reversed by blocking STAT3 or the AMPK signaling pathway. Conclusion: Biologically active, high levels of IL-22 do not affect obesity and the associated metabolic syndrome. Acute treatment with IL-22 inhibits hepatic gluconeogenesis, which is mediated via the activation of STAT3 and AMPK in hepatocytes.

Description: Background: Burkholderia pseudomallei is an emerging pathogen that causes melioidosis, a serious and potentially fatal disease which requires prolonged antibiotics to prevent relapse. However, diagnosis of melioidosis can be difficult, especially in culture-negative cases. While metabolomics represents an uprising tool for studying infectious diseases, there were no reports on its applications to B. pseudomallei. To search for potential specific biomarkers, we compared the metabolomics profiles of culture supernatants of B. pseudomallei (15 strains), B. thailandensis (3 strains), B. cepacia complex (14 strains), P. aeruginosa (4 strains) and E. coli (3 strains), using ultra-high performance liquid chromatography-electrospray ionization-quadruple time-of-flight mass spectrometry (UHPLC-ESI-Q-TOF-MS). Multi- and univariate analyses were used to identify specific metabolites in B. pseudomallei. Results: Principal component and partial-least squares discrimination analysis readily distinguished the metabolomes between B. pseudomallei and other bacterial species. Using multi-variate and univariate analysis, eight metabolites with significantly higher levels in B. pseudomallei were identified. Three of the eight metabolites were identified by MS/MS, while five metabolites were unidentified against database matching, suggesting that they may be potentially novel compounds. One metabolite, m/z 144.048, was identified as 4-methyl-5-thiazoleethanol, a degradation product of thiamine (vitamin B1), with molecular formula C6H9NOS by database searches and confirmed by MS/MS using commercially available authentic chemical standard. Two metabolites, m/z 512.282 and m/z 542.2921, were identified as tetrapeptides, Ile-His-Lys-Asp with molecular formula C22H37N7O7 and Pro-Arg-Arg-Asn with molecular formula C21H39N11O6, respectively. To investigate the high levels of 4-methyl-5-thiazoleethanol in B. pseudomallei, we compared the thiamine degradation pathways encoded in genomes of B. pseudomallei and B. thailandensis. While both B. pseudomallei and B. thailandensis possess thiaminase I which catalyzes degradation of thiamine to 4-methyl-5-thiazoleethanol, thiM, which encodes hydroxyethylthiazole kinase responsible for degradation of 4-methyl-5-thiazoleethanol, is present and expressed in B. thailandensis as detected by PCR/RT-PCR, but absent or not expressed in all B. pseudomallei strains. This suggests that the high 4-methyl-5-thiazoleethanol level in B. pseudomallei is likely due to the absence of hydroxyethylthiazole kinase and hence reduced downstream degradation. Conclusion: Eight novel biomarkers, including 4-methyl-5-thiazoleethanol and two tetrapeptides, were identified in the culture supernatant of B. pseudomallei.

Description: P53 is most well-known for its tumor suppressive function in differentiated cells. Its activities in embryonic stem cells (ESCs) are, however, less well understood. For many years it was thought that p53 is not active at all in ESCs and unable to elicit a DNA damage response in this cell type. In the last few years, it emerged that p53 may have some functions in ESCs. Nevertheless, it remained a mystery how its activity is controlled in ESCs. A recent report demonstrates that p53 activity is regulated by a novel RNA-containing negative feedback loop that promotes apoptosis specifically in ESCs. This study not only demonstrates unequivocally that p53 is active in ESCs, it further illustrates a novel mechanism of gene regulation–by protein coding RNAs.

Description: General control non-depressible 5 (GCN5) is a crucial catalytic component of a transcriptional regulatory complex that plays important roles in cellular functions from cell cycle regulation to DNA damage repai...

Description: The Eph family of receptor tyrosine kinases plays important roles in neural development. Previous studies have implicated Eph receptors and their ligands, the ephrins, in neuronal migration, axon bundling and ...

Description: Lymphopenia promotes naïve T-cell homeostatic proliferation and adoptive effector T-cell survival and memory formation. IL-7 plays a critical role in homeostatic proliferation, survival and memory formation of...

Description: Long non-coding RNAs (lncRNAs) are being discovered as a novel family of regulators of gene expression at the epigenetic level. Emerging lines of evidence demonstrate that interplays between lncRNAs and DNA me...