Diabetes mellitus associated cardiovascular signalling alteration: A need for the revisit

Dysbiosis versus diabesity: pathological signaling and promising therapeutic strategies

A healthy life depends on the inseparable relationship between a host and the gut microbiota. A healthy gut microbiota regulates intestinal integrity, whereas an unbalanced gut microbiota contributes to junctional remodeling and leads to dysbiosis. Bacterial infiltration and dysbiosis are reported to activate a series of pathological cascades that trigger metabolic abnormalities, including diabesity. Conversely, recent studies revealed that the incidence of dysbiosis itself is fuelled by diabesity. In this review, we highlight the molecular aspects of multifaceted pathological signaling between dysbiosis and diabetes that could pave the way for new drug discovery. Moreover, to reinstate the gut microbiota and restrict the epidemic of dysbiosis and diabesity, we also scrutinize a promising therapeutic strategy that can challenge the pathological interlink. Teaser: Dysbiosis and diabesity are closely related and can influence each other. Dysbiosis can worsen diabesity, whereas diabesity can affect the gut microbiota. Thus, to prevent and treat diabesity, it is important to understand this complex interplay.

Preliminary investigation on impact of intergenerational treatment of resveratrol endorses the development of 'super-pups'

BACKGROUND

Redox biology balances free radical generation and scavenging systems, whereas an imbalanced cellular redox can hasten the onset of various diseases and be regarded as a Pandora's box of ailments. The current study aims to assess the pathophysiological impact of intergenerational resveratrol treatment on diabetes-related cognitive and cardio-renal disorders.

MATERIAL AND METHOD

Diabetic rats of the first, second, and third generations were subjected to an intergenerational treatment of resveratrol (20 mg/kg/p.o./day) for 5 months. During this period, the second generation of animals (pups of the first generation) was produced. After the adulthood of second-generation rats, they used to produce third-generation rats. The rats of each generation were evaluated for physiological parameters (BMI, litter size, and life expectancy) and the pathological impact of streptozotocin (55 mg/kg/i.p.), cognitive dysfunctions, and cardio-renal injury.

RESULTS

The intergenerational treatment of resveratrol significantly reduced litter size and improved anthropometric parameters, life expectancy, and blood glucose levels in diabetic animals. Resveratrol treatment ameliorates oxidative stress as measured by increased serum nitrite/nitrate concentrations, SOD activity, reduced glutathione concentrations, total serum antioxidant capacity, and diminished serum TBARS level in diabetic animals. Furthermore, diabetic rats receiving intergenerational resveratrol treatment showed improved cognitive behaviour and cardio-renal functionality when compared to the disease control group.

CONCLUSION

The intergenerational treatment of resveratrol improved the physiological traits and vital abilities of the heart, kidney, and brain, which endorse its antioxidant potential. Surprisingly, resveratrol treatment increases the second and third generations' resistance to neurobehavioral changes, diabetes, and -associated cardio-renal dysfunction, implying that these generations are "super-pups."

Mutations in EPAS1 in congenital heart disease in Tibetans

EPAS1 encodes HIF2 and is closely related to high altitude chronic hypoxia. Mutations in the EPAS1 coding sequence are associated with several kinds of human diseases, including syndromic congenital heart disease (CHD). However, whether there are rare EPAS1 coding variants related to Tibetan non-syndromic CHD have not been fully investigated. A group of 286 Tibetan patients with non-syndromic CHD and 250 unrelated Tibetan healthy controls were recruited from Qinghai, China. Sanger sequencing was performed to identify variations in the EPAS1 coding sequence. The novelty of identified variants was confirmed by the examination of 1000G and ExAC databases. Control samples were screened to establish that the rare candidate variants were specific to the Tibetan patients with non-syndromic CHD. Bioinformatics software was used to assess the conservation of the mutations and to predict their effects. The effect of EPAS1 mutations on the transcription of its target gene, VEGF, was assessed by dual-luciferase reporter assay. The mammalian two-hybrid assay was used to study the protein interactions between HIF2 and PHD2 or pVHL. We identified two novel EPAS1 mutations (NM_001430: c.607A>C, p.N203H; c.2170G>T, p.G724W) in two patients. The N203H mutation significantly affected the transcription activity of the VEGF promoter, especially in conditions of hypoxia. The N203H mutation also showed enhanced protein–protein interactions between HIF2 and PHD2, and HIF2 and pVHL, especially in conditions of hypoxia. However, the G724W mutation did not demonstrate the same effects. Our results indicate that EPAS1 mutations might have a potential causative effect on the development of Tibetan non-syndromic CHD.

Suppression of Excessive Histone Deacetylases Activity in Diabetic Hearts Attenuates Myocardial Ischemia/Reperfusion Injury via Mitochondria Apoptosis Pathway

Background. Histone deacetylases (HDACs) play a pivotal role in signaling modification and gene transcriptional regulation that are essential for cardiovascular pathophysiology. Diabetic hearts with higher HDACs activity were more vulnerable to myocardial ischemia/reperfusion (MI/R) injury compared with nondiabetic hearts. We are curious about whether suppression of excessive HDACs activity in diabetic heart protects against MI/R injury. Methods. Diabetic rats were subjected to 45 min of ischemia, followed by 3 h of reperfusion. H9C2 cardiomyocytes were exposed to high glucose for 24 h, followed by 4 h of hypoxia and 2 h of reoxygenation (H/R). Results. Both MI/R injury and diabetes mellitus elevated myocardium HDACs activity. MI/R induced apoptotic cell death was significantly decreased in diabetic rats treated with HDACs inhibitor trichostatin A (TSA). TSA administration markedly moderated dissipation of mitochondrial membrane potential, protected the integrity of mitochondrial permeability transition pore (mPTP), and decreased cell apoptosis. Notably, cotreatment with Akt inhibitor partly or absolutely inhibited the protective effect of TSA in vivo and in vitro. Furthermore, TSA administration activated Akt/Foxo3a pathway, leading to Foxo3a cytoplasm translocation and attenuation proapoptosis protein Bim expression. Conclusions. Both diabetes mellitus and MI/R injury increased cardiac HDACs activity. Suppression of HDACs activity triggered protective effects against MI/R and H/R injury under hyperglycemia conditions through Akt-modulated mitochondrial apoptotic pathways via Foxo3a/Bim.

Synthesis and preliminary therapeutic evaluation of copper nanoparticles against diabetes mellitus and -induced micro- (renal) and macro-vascular (vascular endothelial and cardiovascular) abnormalities in rats

Current study synthesized and investigated the effect of low-dose copper nanoparticles (CuNPs) against diabetes mellitus and -induced experimental micro- (nephropathy) and macro-vascular (cardio and endothelium) complications.

Albiglutide: Is a better hope against diabetes mellitus?

Type-2 diabetes mellitus (T2DM) is the chronic metabolic disorder which provokes several pitfall signalling. Though, a series of anti-diabetic drugs are available in the market but T2DM is still a huge burden on the developed and developing countries. Numerous studies and survey predict the associated baleful circumstances in near future due to incessant increase in this insidious disorder. The novelty of recent explored anti-diabetic drugs including glitazone, glitazaar and gliflozines seems to be vanished due to their associated toxic side effects. Brown and Dryburgh (1970) isolated an intestinal amino acid known as gastric inhibitory peptide (GIP) which had insulinotropic activity. Subsequently in 1985, another incretin glucagon likes peptide 1 (GLP-1) having potent insulinotropic properties was discovered by Schmidt and his co-workers. On the basis of results' obtained by Phase III Harmony program FDA approved (14 April, 2014) new GLP-1 agonist 'Albiglutide (ALB)', in addition to exiting components Exenatide (Eli Lilly, 2005) and Liraglutide (Novo Nordisk, 2010). ALB stimulates the release of protein kinase A (PKA) via different mechanisms which ultimately leads to increase in intracellular Ca(2+) levels. This increased intracellular Ca(2+) releases insulin vesicle from β-cells. In-addition, ALB being resistant to degradation by dipeptidyl peptidase-4 (DPP-4) and has longer half life. DPP-4 can significantly degrade the level of GLP-1 agonist by hydrolysis. In spite of potent anti-hypergycemic activity, ALB has pleiotropic action of improving cardiovascular physiology. In light of these viewpoints we reveal the individual pharmacological profile of ALB and the critical analyse about its future perspective in present review.

Evaluation of hepatic vascular endothelial injury during liver storage by molecular detection and targeted contrast-enhanced ultrasound imaging

We hypothesized that lack of the high-energy phosphates during liver storage may potentially cause persistent injury to the vascular endothelium. Biopsies were obtained from livers obtained from beating heart human donors, stored either in the standard storage solution, that is, University of Wisconsin solution (UWS) or Celsior, and examined for various markers related to progressive endothelial injury. The expression of P2Y1 receptor, the major signal transduction machinery for adenosine triphosphate/adenosine diphosphate, decreased in hepatic vascular endothelial cells over time. Despite unaltered endothelial nitric oxide synthase (eNOS) levels, serine1177-phosphorylated eNOS, the active form of eNOS, progressively decreased with time. The production of nitric oxide enzyme decreased with time when liver tissues were examined in vitro. This also coincided with decreased interaction of eNOS with actin nucleating proteins like myristoylated alanine-rich C kinase substrate and Rac1, which plays a role in modulating the cytoskeleton and helps position eNOS in a favorable cytosolic position for active enzymatic activity. Conversely, the interaction of eNOS with caveolin1 was significantly increased 6 H after ex vivo storage. Finally, we demonstrated by targeted contrast-enhanced ultrasound that membrane-bound vascular cell adhesion molecule-1 in the hepatic vascular endothelial cell increased after 6 H of ex vivo storage. Overall, the results of this study provide evidence of a progressive hepatic vascular endothelial injury during the ex vivo storage. This may be a causative factor for ischemic cholangiopathy and delayed graft function post liver transplantation. © 2015 IUBMB Life, 68(1):51-57, 2015.

Protection strategies during cardiopulmonary bypass: ventilation, anesthetics and oxygen

PURPOSE OF REVIEW

To provide an update of research findings regarding the protection strategies utilized for patients undergoing cardiopulmonary bypass (CPB), including perioperative ventilatory strategies, different anesthetic regimens, and inspiratory oxygen fraction. The article will review and comment on some of the most important findings in this field to provide a global view of strategies that may improve patient outcomes by reducing inflammation.

RECENT FINDINGS

Postoperative complications are directly related to ischemia and inflammation. The application of lung-protective ventilation with lower tidal volumes and higher positive end-expiratory pressure reduces inflammation, thereby reducing postoperative pulmonary complications. Although inhalation anesthesia has clear cardioprotective effects compared with intravenous anesthesia, several factors can interfere to reduce cardioprotection. Hyperoxia up to 0.8 FiO(2) may confer benefits without increasing oxidative stress or postoperative pulmonary complications. During the early postoperative period, inhalation anesthesia prior to extubation and the application of preventive noninvasive ventilation may reduce cardiac and pulmonary complications, improving patients' outcomes.

SUMMARY

Lung-protective mechanical ventilation, inhalation anesthesia, and high FiO(2) have the potential to reduce postoperative complications in patients undergoing CPB; however, larger, well powered, randomized control trials are still needed.

Nitric oxide, interorganelle communication, and energy flow: a novel route to slow aging

The mitochondrial lifecycle (mitochondrial biogenesis, dynamics, and removal by mitophagy) is carefully orchestrated to ensure the efficient generation of cellular energy and to maintain reactive oxygen species (ROS) production within an optimal range for cellular health. Based on latest research, these processes largely depend on mitochondrial interactions with other cell organelles, so that the ER- and peroxisome-mitochondrial connections might intervene in the control of cellular energy flow. Damaged organelles are cleared by autophagic mechanisms to assure the quality and proper function of the intracellular organelle pool. Nitric oxide (NO) generated through the endothelial nitric oxide synthase (eNOS) acts a gas signaling mediator to promote mitochondrial biogenesis and bioenergetics, with a favorable impact in diverse chronic diseases of the elderly. Obesity, diabetes and aging share common pathophysiological mechanisms, including mitochondrial impairment and dysfunctional eNOS. Here we review the evidences that eNOS-dependent mitochondrial biogenesis and quality control, and possibly the complex interplay among cellular organelles, may be affected by metabolic diseases and the aging processes, contributing to reduce healthspan and lifespan. Drugs or nutrients able to sustain the eNOS-NO generating system might contribute to maintain organelle homeostasis and represent novel preventive and/or therapeutic approaches to chronic age-related diseases.

Reactive oxygen species: friend or foe?

It is a need to define the line between pathological and physiological functions of reactive oxygen species (ROS) in order to understand their beneficial role over their injurious consequences.

Prediabetes: grounds of pitfall signalling alteration for cardiovascular disease

Prediabetes manifested by impaired glucose tolerance and impaired fasting glucose offers high risk of myocardial dysfunction by causing endothelial dysfunction, inflammation, oxidative stress, atherosclerosis and genetic alterations.