HypoxamiR-210-3p regulates mesenchymal stem cells proliferation via P53 & Akt.

Transplanted stem cells (˃95%) into ischemic myocardium die because of unfavourable conditions. Moreover, hypoxia role in the cell cycle regulation has been studied in transformed/immortalized cell lines which may have altered cell cycle regulators and/or mutated and, can't be transplanted in patients. We quest to find out the mechanism of cell cycle regulation in mesenchymal stem cells (MSC) to regulate its survival and proliferation in repair processes. Additionally, critically analysed role of hypoxamiR-210-3p, and cell cycle regulators that can regulate cell proliferation under hypoxic conditions. Bone marrow-derived MSC (BM-MSC) isolated from young male Fischer-344 rats by flushing the cavity of femur and propagated in vitro under 1% hypoxia for 72 h showed an increased in cell proliferation ([Formula: see text] 30%, p < 0.05) compared to normoxia. miR-210-3p, role in cell proliferation under hypoxic condition was confirmed by knockdown. Loss of function studies with transfection of anti-mir-210-3p, we observed decrease in proliferation of BM-MSC under hypoxia. Furthermore, BM-MSC proliferation due to miR-210-3p was confirmed using CFSE assay and flow cytometry, in which more cells were observed in S-phase. Mechanistically, western blot analysis showed miR-210-3p inhibition upregulates p53 and p21 expression and subsequent decrease in pAkt under hypoxia. On contrary, CFSE and Western blot under normoxic conditions showed downregulation of p53 and p21 whilst upregulation of pAkt indicated the key role of miR-210-3p in BM-MSC proliferation. Our results demonstrate the role of miR-210-3p in BM-MSC proliferation under both hypoxic and normoxic conditions and illustrate the potential mechanism via the regulation of pAkt, p53 and p21.

Neonatal invasive candidiasis in low- and middle-income countries: Data from the NeoOBS study.

Neonatal invasive candidiasis (NIC) has significant morbidity and mortality. Reports have shown a different profile of those neonates affected with NIC and of fluconazole-resistant Candida spp. isolates in low- and middle-income countries (LMICs) compared to high-income countries (HICs). We describe the epidemiology, Candida spp. distribution, treatment, and outcomes of neonates with NIC from LMICs enrolled in a global, prospective, longitudinal, observational cohort study (NeoOBS) of hospitalized infants <60 days postnatal age with sepsis (August 2018-February 2021). A total of 127 neonates from 14 hospitals in 8 countries with Candida spp. isolated from blood culture were included. Median gestational age of affected neonates was 30 weeks (IQR: 28-34), and median birth weight was 1270 gr (interquartile range [IQR]: 990-1692). Only a minority had high-risk criteria, such as being born <28 weeks, 19% (24/127), or birth weight <1000 gr, 27% (34/127). The most common Candida species were C. albicans (n = 45, 35%), C. parapsilosis (n = 38, 30%), and Candida auris (n = 18, 14%). The majority of C. albicans isolates were fluconazole susceptible, whereas 59% of C. parapsilosis isolates were fluconazole-resistant. Amphotericin B was the most common antifungal used [74% (78/105)], followed by fluconazole [22% (23/105)]. Death by day 28 post-enrollment was 22% (28/127). To our knowledge, this is the largest multi-country cohort of NIC in LMICs. Most of the neonates would not have been considered at high risk for NIC in HICs. A substantial proportion of isolates was resistant to first choice fluconazole. Understanding the burden of NIC in LMIC is essential to guide future research and treatment guidelines.

Our study describes neonates from low- and middle-income countries with neonatal invasive candidiasis (NIC). Most of them were outside the groups considered at high risk for NIC described in high-income countries. Candida spp. epidemiology was also different. The mortality was high (22%). Further research in these settings is required.

Pharmacological preconditioning with phosphodiestrase inhibitor: an answer to stem cell survival against ischemic injury through JAK/STAT signaling.

Stem cell transplantation in regenerative medicine has been widely used in various disorders including cardiovascular diseases (CVD) and emerging next-generation therapy. However, transplanted stem cell encountered ischemia/reperfusion (IR) injury which is a major challenge for stem cell survival. During the acute phase after myocardial infarction (MI) cytokine-rich hostile microenvironment, extensive immune cell infiltration and lack of oxygen have been a bottleneck in cell-based therapy. During prolonged ischemia, intracellular pH and ATP level decrease results in anaerobic metabolism and lactate accumulation. Consequentially, ATPase-dependent ion transport becomes dysfunctional, contributing to calcium overload and cell death by apoptosis and necrosis. Although O2 level revitalizes upon reperfusion, a surge in the generation of reactive oxygen species (ROS) occurs with neutrophil infiltration in ischemic tissues further aggravating the injury. Ischemic preconditioning (IPC) of stem cells with a repeated short cycle of IR results in the release of chemical signals such as NO, ROS, and adenosine which triggers a cascade of signaling events that activates protein kinase C (PKC), Src protein tyrosine kinases, and nuclear factor κB (NF-κB) and subsequently increased synthesis of inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), Heme oxygenase-1 [HO-1], aldose reductase, Mn superoxide dismutase, and anti-apoptotic genes (Mcl-1, BCl-xL, c-FLIPL, c-FLIPS). Pharmacological preconditioning uses a phosphodiestrase inhibitor, another mode of protecting stem cell or heart per se from impending ischemic injury in two phases. During the early phase of cardioprotection (2 h), PC leads to increased expression of survival factors like BCl2/Bax ratio while late phase (24 h) showed activation of the JAK/STAT survival pathway. Phosphorylation of STAT3 at two crucial residues, Tyr-705 and Ser-727, allows its entry inside the nucleus and upregulates the expression of protein kinase G-1 (PKG1) which evokes cardioprotective signaling. To confirm, heart-specific conditional STAT3 knockout mice undergone IR surgery, abolishing late-phase cardioprotective effects.