Reduced biliverdin reductase-a expression in visceral adipose tissue is associated with adipocyte dysfunction and nafld in human obesity

Biliverdin reductase A (BVR-A) is an enzyme involved in the regulation of insulin signalling. Knockout (KO) mice for hepatic BVR-A, on a high-fat diet, develop more severe glucose impairment and hepato-steatosis than the wild type, whereas loss of adipocyte BVR-A is associated with increased visceral adipose tissue (VAT) inflammation and adipocyte size. However, BVR-A expression in human VAT has not been investigated. We evaluated BVR-A mRNA expression levels by real-time PCR in the intra-operative omental biopsy of 38 obese subjects and investigated the association with metabolic impairment, VAT dysfunction, and biopsy-proven non-alcoholic fatty liver disease (NAFLD). Individuals with lower VAT BVR-A mRNA levels had significantly greater VAT IL-8 and Caspase 3 expression than those with higher BVR-A. Lower VAT BVR-A mRNA levels were associated with an increased adipocytes’ size. An association between lower VAT BVR-A expression and higher plasma gamma-glutamyl transpeptidase was also observed. Reduced VAT BVR-A was associated with NAFLD with an odds ratio of 1.38 (95% confidence interval: 1.02–1.9; χ2 test) and with AUROC = 0.89 (p = 0.002, 95% CI = 0.76–1.0). In conclusion, reduced BVR-A expression in omental adipose tissue is associated with VAT dysfunction and NAFLD, suggesting a possible involvement of BVR-A in the regulation of VAT homeostasis in presence of obesity

Heme oxygenase 1 in the nervous system: Does it favor neuronal cell survival or induce neurodegeneration?

Heme oxygenase 1 (HO-1) up-regulation is recognized as a pivotal mechanism of cell adaptation to stress. Under control of different transcription factors but with a prominent role played by Nrf2, HO-1 induction is crucial also in nervous system response to damage. However, several lines of evidence have highlighted that HO-1 expression is associated to neuronal damage and neurodegeneration especially in Alzheimer\u2019s and Parkinson\u2019s diseases. In this review, we summarize the current literature regarding the role of HO-1 in nervous system pointing out different molecular mechanisms possibly responsible for HO-1 up-regulation in nervous system homeostasis and neurodegeneration

The BACH1/Nrf2 axis in brain in down syndrome and transition to alzheimer disease-like neuropathology and dementia

Down syndrome (DS) is the most common genetic cause of intellectual disability that is associated with an increased risk to develop early-onset Alzheimer-like dementia (AD). The brain neuropathological features include alteration of redox homeostasis, mitochondrial deficits, inflammation, accumulation of both amyloid beta-peptide oligomers and senile plaques, as well as aggregated hyperphosphorylated tau protein-containing neurofibrillary tangles, among others. It is worth mentioning that some of the triplicated genes encoded are likely to cause increased oxidative stress (OS) conditions that are also associated with reduced cellular responses. Published studies from our laboratories propose that increased oxidative damage occurs early in life in DS population and contributes to age-dependent neurodegeneration. This is the result of damaged, oxidized proteins that belong to degradative systems, antioxidant defense system, neuronal trafficking. and energy metabolism. This review focuses on a key element that regulates redox homeostasis, the transcription factor Nrf2, which is negatively regulated by BACH1, encoded on chromosome 21. The role of the Nrf2/BACH1 axis in DS is under investigation, and the effects of triplicated BACH1 on the transcriptional regulation of Nrf2 are still unknown. In this review, we discuss the physiological relevance of BACH1/Nrf2 signaling in the brain and how the dysfunction of this system affects the redox homeostasis in DS neurons and how this axis may contribute to the transition of DS into DS with AD neuropathology and dementia. Further, some of the evidence collected in AD regarding the potential contribution of BACH1 to neurodegeneration in DS are also discussed

ГАЗОМЕДИАТОРЫ: ОТ ТОКСИЧЕСКИХ ЭФФЕКТОВ К РЕГУЛЯЦИИ КЛЕТОЧНЫХ ФУНКЦИЙ И ИСПОЛЬЗОВАНИЮ В КЛИНИКЕ

Nitric oxide II (NO), carbon monoxide (СО) and hydrogen sulfide (H2S) for many decades were described as the toxic gases inducing damaging action in man’s organisms. Recently it was found that NO, CO and H2S endogenously synthesized and served as signaling molecules of autocrine and paracrine regulation in many systems. The properties, mechanisms of synthesis and action in excitable systems are presented in this paper. Besides we also descried our results concerning the effects and mechanisms of action of gaseous messengers in peripheral nervous system – in neuromuscular junction. В течение многих десятилетий оксид азота (II) (NO), монооксид углерода (СО) и сероводород (H2S) описывались как токсичные газы, оказывающие повреждающие эффекты на организм человека. Недавно было обнаружено, что NO, CO и H2S эндогенно синтезируются и являются сигнальными молекулами, выполняющими как аутокринную, так и паракринную регуляцию во многих системах организма. В настоящей статье представлены данные о свойствах, ферментах синтеза и механизмах действия газообразных посредников в возбудимых системах. Кроме того, описываются результаты собственных исследований по выявлению эффектов и механизмов действия NO, СО и H2S в периферической нервной системе – в области нервно-мышечного синапса

HO-1 induction in cancer progression: A matter of cell adaptation

The upregulation of heme oxygenase-1 (HO-1) is one of the most important mechanisms of cell adaptation to stress. Indeed, the redox sensitive transcription factor Nrf2 is the pivotal regulator of HO-1 induction. Through the antioxidant, antiapoptotic, and antinflammatory properties of its metabolic products, HO-1 plays a key role in healthy cells in maintaining redox homeostasis and in preventing carcinogenesis. Nevertheless, several lines of evidence have highlighted the role of HO-1 in cancer progression and its expression correlates with tumor growth, aggressiveness, metastatic and angiogenetic potential, resistance to therapy, tumor escape, and poor prognosis, even though a tumor-and tissue-specific activity has been observed. In this review, we summarize the current literature regarding the pro-tumorigenic role of HO-1 dependent tumor progression as a promising target in anticancer strategy