Hypoxia-Induced miR-101 Impairs Endothelial Barrier Integrity Through Altering VE-Cadherin and Claudin-5.

Stroke is a life-threatening medical condition across the world that adversely affects the integrity of the blood-brain barrier (BBB). The brain microvascular endothelial cells are the important constituent of the BBB. These cells line the blood vessels and form a semipermeable barrier. Disruptions in adherens junction and tight junction proteins of brain microvascular endothelial cells compromise the integrity of BBB. The Vascular Endothelial (VE)-cadherin is an integral adherens junction protein required for the establishment and maintenance of the endothelial barrier integrity. This study aims to investigate the role of miRNA in hypoxia-induced endothelial barrier disruption. In this study, brain endothelial cells were exposed to hypoxic conditions for different time points. Western blotting, overexpression and knockdown of miRNA, real-time PCR, TEER, and sodium fluorescein assay were used to examine the effect of hypoxic conditions on brain endothelial cells. Hypoxic exposure was validated using HIF-1α protein. Exposure to hypoxic conditions resulted to a significant decrease in endothelial barrier resistance and an increase in sodium fluorescein migration across the endothelial barrier. Reduction in endothelial barrier resistance demonstrated compromised barrier integrity, whereas the increase in migration of sodium fluorescein across the barrier indicated the increase in barrier permeability. The present study revealed microRNA-101 decreases the expression of VE-cadherin and claudin-5 in brain endothelial cells exposed to the hypoxic conditions.

Zika virus NS1 suppresses the innate immune responses via miR-146a in human microglial cells.

Zika virus (ZIKV) is a positive-single strand RNA virus that belongs to the Flaviviridae family. ZIKV infection causes congenital ZIKV syndrome (CZS) in children and Guillain Barre Syndrome (GBS) in adults. ZIKV infected cells secrete non-structural protein 1 (sNS1), which plays an important role in viral replication and immune evasion. The microglial cells are the brain resident macrophages that mediate the immune responses in CNS. The miRNAs are small non-coding RNAs that regulate the expression of their target genes by binding to the 3'UTR region. The present study highlights the bystander effect of ZIKV-NS1 via miR-146a. The Real-Time PCR, Immunoblotting, overexpression, knockdown studies, and reactive oxygen species measurement have been done to study the immunomodulatory effects of ZIKV-NS1 in human microglial cells. ZIKV-NS1 induced the expression of miR-146a and suppressed the ROS activity in human microglial cells. The up-regulated miR-146a led to the decreased expression of TRAF6 and STAT-1. The reduced expression of TRAF6 in turn led to the suppression of pNF-κBp65 and TNF-α downstream. The miR-146a suppressed the pro-inflammatory and cellular antiviral responses in microglial cells. Our findings demonstrate the bystander role of ZIKV-NS1 in suppressing the pro-inflammatory and cellular antiviral responses through miR-146a in human microglial cells.

SARS coronavirus 2: from genome to infectome.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) belongs to the group of Betacoronaviruses. The SARS-CoV-2 is closely related to SARS-CoV-1 and probably originated either from bats or pangolins. SARS-CoV-2 is an etiological agent of COVID-19, causing mild to severe respiratory disease which escalates to acute respiratory distress syndrome (ARDS) or multi-organ failure. The virus was first reported from the animal market in Hunan, Hubei province of China in the month of December, 2019, and was rapidly transmitted from animal to human and human-to-human. The human-to-human transmission can occur directly or via droplets generated during coughing and sneezing. Globally, around 53.9 million cases of COVID-19 have been registered with 1.31 million confirmed deaths. The people > 60 years, persons suffering from comorbid conditions and immunocompromised individuals are more susceptible to COVID-19 infection. The virus primarily targets the upper and the lower respiratory tract and quickly disseminates to other organs. SARS-CoV-2 dysregulates immune signaling pathways which generate cytokine storm and leads to the acute respiratory distress syndrome and other multisystemic disorders.

Differentially expressed miRNA-210 during follicular-luteal transition regulates pre-ovulatory granulosa cell function targeting HRas and EFNA3.

Ovarian folliculogenesis, ovulation, and luteinization are an important prerequisite for fertility performance in mammals. Spatial and temporal key factors and proteins for their regulation are well known. Recent advancement in the field of molecular biology led to the discovery of another class of gene regulators, microRNA (miRNA). Previous studies on profiling of miRNA in buffalo ovaries revealed that miRNA-210 (miR-210) is differently expressed in follicular-luteal transition. Therefore, the present study was planned to ascertain the role of miR-210 in buffalo granulosa cells. Cultured granulosa cells were transfected with miR-210 mimic. Effect of overexpression of miR-210 was analyzed on granulosa cell marker genes (CYP19A1 and PCNA) which were significantly downregulated (P < 0.05). Further, target genes of miR-210 were screened using Target Scan software v7.1 and a list of 37 genes with cumulative weight context score (CWCS) > 0.5 was sorted followed by their functional annotation and network analyses using PANTHER and STRING software. Bioinformatics analyses identified HRas gene as a potential hub gene of miR-210 targeted genes. HRas has been shown to be involved in diverse biological pathways regulating ovarian functions. An expression analysis of HRas was further validated both in vitro and in vivo. EFNA3 (EFHRIN-A3), another identified target of miR-210 known to be involved in angiogenesis, was also downregulated in miR-210 transfected granulosa cells. In conclusion, the present study demonstrated that miR-210 can regulate granulosa cell function at preovulatory stage through HRas and EFNA3. Further studies are needed to find the mechanism how miR-210 regulates the granulosa cells function through these targets.

Synthesis of new andrographolide derivatives and evaluation of their antidyslipidemic, LDL-oxidation and antioxidant activity.

Andrographis paniculata, native to Taiwan, Mainland China and India, is a medicinal herb, which possesses various biological activities including anti-atherosclerosis. Andrographolide (1) has been identified as one of the active constituents against atherosclerosis. In continuation of our drug discovery program we synthesized few novel derivatives of 1 to improve their antidyslipidemic, LDL-oxidation and antioxidant activity. The tosylated derivative 7 has been turned out to be more potent than the parent compound and comparable activity with marketed antidyslipidemic drugs.

Arbortristoside-A and 7-O-trans-cinnamoyl-6ß-hydroxyloganin isolated from Nyctanthes arbortristis possess anti-ulcerogenic and ulcer-healing properties.

Nyctanthes arbortristis Linn (Oleaceae) is widely distributed in sub-Himalayan regions and southwards to Godavari, India commonly known as Harsingar and Night Jasmine. In continuation of our drug discovery program on Indian medicinal plants, we isolated arbortristoside-A (AT) and 7-O-trans-cinnamoyl-6ß-hydroxyloganin (6-HL) from the seeds of N. arbortristis. AT and 6-HL exhibited anti ulcer activity in experimentally induced ulcer models including cold restraint stress (CRU), alcohol (AL), pylorus ligation-induced gastric ulcer (PL) models and they also showed ulcer healing effect in chronic acetic acid-induced ulcer model (AC).