Bone marrow endothelial progenitor cells activate hepatic stellate cells and aggravate carbon tetrachloride induced liver fibrosis in mice via paracrine factors.

OBJECTIVES: Bone marrow derived endothelial progenitor cells (BM-EPCs) are increased in chronic liver disease (CLD). Their role in hepatic fibrosis and regeneration remains an area of intense studies. We investigated the migration and secretory functions of BM-EPCs in fibrotic mice liver. MATERIALS AND METHODS: Bone marrow cells from C57BL6-GFP mice were transplanted into the femur of irradiated C57BL6 mice, followed by CCl4 doses for 8 weeks, to develop hepatic fibrosis (n = 36). Transplanted C57BL6 mice without CCl4 treatment were used as controls. EPCs were analyzed in BM, blood and liver by flow cytometry and immunofluorescence. VEGF and TGF-ß were analysed in the hepatic stellate cells (HSCs) and BM-EPCs co-cultures using ELISAs. RESULTS: There was a significant migration of EPCs from BM to blood and to the liver (P ≤ 0.01). Percentage of GFP+ CD31+ EPCs and collagen proportionate area was substantially increased in the liver at 4th week of CCl4 dosage compared to the controls (19.8% vs 1.9%, P ≤ 0.05). Levels of VEGF (533.6 pg/ml) and TGF-ß (327.44 pg/ml) also increased significantly, when HSCs were treated with the EPC conditioned medium, as compared to controls (25.66 pg/ml and 5.87 pg/ml, respectively; P ≤ 0.001). CONCLUSIONS: Present findings suggest that BM-EPCs migrate to the liver during CCl4-induced liver injury and contribute to fibrosis.

Metabolic Syndrome Is Associated with Increased Oxo-Nitrative Stress and Asthma-Like Changes in Lungs.

Epidemiological studies have shown an increased obesity-related risk of asthma. In support, obese mice develop airway hyperresponsiveness (AHR). However, it remains unclear whether the increased risk is a consequence of obesity, adipogenic diet, or the metabolic syndrome (MetS). Altered L-arginine and nitric oxide (NO) metabolism is a common feature between asthma and metabolic syndrome that appears independent of body mass. Increased asthma risk resulting from such metabolic changes would have important consequences in global health. Since high-sugar diets can induce MetS, without necessarily causing obesity, studies of their effect on arginine/NO metabolism and airway function could clarify this aspect. We investigated whether normal-weight mice with MetS, due to high-fructose diet, had dysfunctional arginine/NO metabolism and features of asthma. Mice were fed chow-diet, high-fat-diet, or high-fructose-diet for 18 weeks. Only the high-fat-diet group developed obesity or adiposity. Hyperinsulinemia, hyperglycaemia, and hyperlipidaemia were common to both high-fat-diet and high-fructose-diet groups and the high-fructose-diet group additionally developed hypertension. At 18 weeks, airway hyperresponsiveness (AHR) could be seen in obese high-fat-diet mice as well as non-obese high-fructose-diet mice, when compared to standard chow-diet mice. No inflammatory cell infiltrate or goblet cell metaplasia was seen in either high-fat-diet or high-fructose-diet mice. Exhaled NO was reduced in both these groups. This reduction in exhaled NO correlated with reduced arginine bioavailability in lungs. In summary, mice with normal weight but metabolic obesity show reduced arginine bioavailability, reduced NO production, and asthma-like features. Reduced NO related bronchodilation and increased oxo-nitrosative stress may contribute to the pathogenesis.

Brain-specific knockdown of miR-29 results in neuronal cell death and ataxia in mice.

Several microRNAs have been implicated in neurogenesis, neuronal differentiation, neurodevelopment, and memory. Development of miRNA-based therapeutics, however, needs tools for effective miRNA modulation, tissue-specific delivery, and in vivo evidence of functional effects following the knockdown of miRNA. Expression of miR-29a is reduced in patients and animal models of several neurodegenerative disorders, including Alzheimer's disease, Huntington's disease, and spinocerebellar ataxias. The temporal expression pattern of miR-29b during development also correlates with its protective role in neuronal survival. Here, we report the cellular and behavioral effect of in vivo, brain-specific knockdown of miR-29. We delivered specific anti-miRNAs to the mouse brain using a neurotropic peptide, thus overcoming the blood-brain-barrier and restricting the effect of knockdown to the neuronal cells. Large regions of the hippocampus and cerebellum showed massive cell death, reiterating the role of miR-29 in neuronal survival. The mice showed characteristic features of ataxia, including reduced step length. However, the apoptotic targets of miR-29, such as Puma, Bim, Bak, or Bace1, failed to show expected levels of up-regulation in mice, following knockdown of miR-29. In contrast, another miR-29 target, voltage-dependent anion channel1 (VDAC1), was found to be induced several fold in the hippocampus, cerebellum, and cortex of mice following miRNA knockdown. Partial restoration of apoptosis was achieved by down-regulation of VDAC1 in miR-29 knockdown cells. Our study suggests that regulation of VDAC1 expression by miR-29 is an important determinant of neuronal cell survival in the brain. Loss of miR-29 results in dysregulation of VDAC1, neuronal cell death, and an ataxic phenotype.

Assessment of Potential In vitro Genotoxic and Cytotoxic Effects of Bupropion Hydrochloride (Wellbutrin) in Human Peripheral Lymphocytes and Human Cortical Neuron.

INTRODUCTION: Wellbutrin (bupropion hydrochloride; WB), an anti-depressant of the aminoketone class is new highly selective norepinephrine and dopamine reuptake inhibitor; it is effective in the treatment of patients with major depression. MATERIALS AND METHODS: To investigate the in vitro effects of WB in human cultured peripheral blood lymphocytes and human cortical neural (HCN2) cell lines, micronucleus, sister chromatid exchange analysis, cellular viability, and comet assays were employed. The present study is to our knowledge, the first report on WB genotoxicity in cultured human peripheral blood lymphocytes and its cytotoxicity in the HCN2 cell line. We have also investigated the genotoxic potential of WB to induce chromosomal aberrations. RESULTS: WB-induced cytotoxicity (measured as reduction of the nuclear division index) possibly prevented the division of damaged cells. CONCLUSION: We conclude that although, WB exerts potential genotoxic effects in cultured lymphocytes, its cytogenetic effects are very unlikely to occur in blood cultures of WB-administered subjects.