Identification of an apical Cl-/HCO-3 exchanger in rat kidney proximal tubule

SLC26A6 (or putative anion transporter 1, PAT1) is located on the apical membrane of mouse kidney proximal tubule and mediates exchange in in vitro expression systems. We hypothesized that PAT1 along with a exchange is present in apical membranes of rat kidney proximal tubules. Northern hybridizations indicated the exclusive expression of SLC26A6 (PAT1 or CFEX) in rat kidney cortex, and immunocytochemical staining localized SLC26A6 on the apical membrane of proximal tubules, with complete prevention of the labeling with the preadsorbed serum. To examine the functional presence of apical exchanger, proximal tubules were isolated, microperfused, loaded with the pH-sensitive dye BCPCF-AM, and examined by digital ratiometric imaging. The pH of the perfusate and bath was kept at 7.4. Buffering capacity was measured, and transport rates were calculated as equivalent base flux. The results showed that in the presence of basolateral DIDS (to inhibit cotransporter 1) and apical EIPA (to inhibit Na⁺/H⁺ exchanger 3), the magnitude of cell acidification in response to addition of luminal Cl^– was 5.0-fold higher in the presence than in the absence of . The Cl^–-dependent base transport was inhibited by 61% in the presence of 0.5 mM luminal DIDS. The presence of physiological concentrations of oxalate in the lumen (200 µM) did not affect the exchange activity. These results are consistent with the presence of SLC26A6 (PAT1) and exchanger activity in the apical membrane of rat kidney proximal tubule. We propose that SLC26A6 is likely responsible for the apical (and Cl^–/OH^–) exchanger activities in kidney proximal tubule. putative anion transporter 1; chloride/formate exchanger; SLC26A6     

Postbiotics as potential promising tools for SARS-CoV-2 disease adjuvant therapy

The SARS-CoV-2 pandemic defines the global health tension of our time. There are several continuous efforts to find a definitive cure in this regard. According to some adverse effects and problems of customary SARS-CoV-2 disease therapies, bioactive compounds, for example probiotics-derived metabolites (postbiotics) have been accomplishing supreme importance by investigators for adjuvant cures in patients with SARS-CoV-2. Postbiotics inhibit angiotensin-converting enzyme 2 activity and stimulate the immune system. They also boost the SARS-CoV-2 disease treatment effectiveness and reduce its adverse effects in SARS-CoV-2 illness patients as a result of antiviral and anti-inflammatory effects. Furthermore, postbiotics having unique features such as high safety, high shelf life and stability to the gastrointestinal tract can be utilized as hopeful instruments for both adjuvant and inhibition strategies in SARS-CoV-2 patients with no earnest unfavourable adverse effects. The concept of postbiotics and their biocompatible characteristics are comprehensively discussed in the present review while highlighting the bilateral relationship between postbiotic biometabolites and respiratory tract infection with a special look at the potential biological role in the inactivation of SARS-CoV-2 and reduction of related inflammatory pathways.     

Improved infiltration of stem cells on electrospun nanofibers

Nanofibrous scaffolds have been recently used in the field of tissue engineering because of their nano-size structure which promotes cell attachment, function, proliferation and infiltration. In this study, nanofibrous polyethersulfone (PES) scaffolds was prepared via electrospinning. The scaffolds were surface modified by plasma treatment and collagen grafting. The surface changes then investigated by contact angle measurements and FTIR-ATR. The results proved grafting of the collagen on nanofibers surface and increased hydrophilicity after plasma treatment and collagen grafting. The cell interaction study was done using stem cells because of their ability to differentiate to different kinds of cell lines. The cells had normal morphology on nanofibers and showed very high infiltration through collagen grafted PES nanofibers. This infiltration capability is very useful and needed to make 3D scaffolds in tissue engineering.     

Novel oral transforming growth factor-β signaling inhibitor potently inhibits postsurgical adhesion band formation

Here, we have investigated the therapeutic potency of EW-7197, a transforming growth factor-β type I receptor kinase inhibitor, against postsurgical adhesion band formation. Our results showed that this pharmacological inhibitor prevented the frequency and the stability of adhesion bands in mice model. We have also shown that downregulation of proinflammatory cytokines, reduce submucosal edema, attenuation of proinflammatory cell infiltration, inhibition of oxidative stress, decrease in excessive collagen deposition, and suppression of profibrotic genes at the site of surgery are some of the mechanisms by which EW-7197 elicits its protective responses against adhesion band formation. These results clearly suggest that EW-7197 has novel therapeutic properties against postsurgical adhesion band formation with clinically translational potential of inhibiting key pathological responses of inflammation and fibrosis in postsurgery patients.     

Biotransformation of methyl tert-butyl ether by human cytochrome P450 2A6

Methyl tert-butyl ether (MTBE) is widely used as gasoline oxygenate and octane number enhancer for more complete combustion in order to reduce the air pollution caused by motor vehicle exhaust. The possible adverse effects of MTBE on human health are of major public concern. However, information on the metabolism of MTBE in human tissues is scarce. The present study demonstrates that human cytochrome P450 2A6 is able to metabolize MTBE to tert-butyl alcohol (TBA), a major circulating metabolite and marker for exposure to MTBE. As CYP2A6 is known to be constitutively expressed in human livers, we infer that it may play a significant role in metabolism of gasoline ethers in liver tissue.     

miRNA-375 promotes beta pancreatic differentiation in human induced pluripotent stem (hiPS) cells

Islet transplantation is considered as an ultimate option for the treatment of type I diabetes. Human induced pluripotent stem cells (hiPSCs) have raised the possibility that patient-specific insulin-secreting cells might be derived from somatic cells through cell fate reprogramming. However, current protocols mostly rely on the use of several cytokines and inhibitors for directing differentiation towards pancreatic fate. Given the high manufacturing cost of these recombinant proteins, this approach is prohibitive for clinical applications. Knowing that microRNAs (miRNAs) are key players in various stages of pancreatic development, we present a novel and cost-effective strategy in which over-expression of miR-375 promotes pancreatic differentiation in hiPSCs in the absence of any other stimulator. We used a polycistronic viral vector expressing Sox2, Klf4, c-Myc, and Oct4 to drive hiPSCs from human foreskin fibroblasts. The established hiPSCs are similar to human embryonic stem cells in many aspects including morphology, passaging, surface and pluripotency markers, and gene expression. For differentiation induction, miR-375 was lentivirally overexpressed in these hiPSCs. Morphological assessment, immunocytochemistry, and expression analysis of islet marker genes confirmed that islet like cells were obtained in miR-375 transduced cells compared to controls. Our differentiated clusters secreted insulin in a glucose-dependant manner, showing in vitro functionality. We demonstrated for the first time that miRNAs might be ideal substitutes to induce pancreatic differentiation in hiPSCs. This work provides a new approach to study the role of miRNAs in pancreatic specification and increase the feasibility of using patient-specific iPSCs for beta cell replacement therapy for type I diabetes.     

An efficient method for isolation of murine bone marrow mesenchymal stem cells

Mesenchymal stem cells (MSCs) have been isolated based on the ability of adherence to plastic surfaces. The potential of these cells to differentiate along multiple lineages is the key to identifying stem cell populations in the absence of molecular markers. Here we describe a homogenous population of MSCs from mouse bone marrow isolated using a relatively straightforward and novel approach. This method is based on the combination of frequent medium change (FMC) and treatment of the primary cultures with trypsin. Cells isolated using this method demonstrated the MSCs characteristics including their ability to differentiate into mesenchymal lineages. MSCs retained the differentiation potentials in expanded cultures up to 10 passages. Isolated MSCs were reactive to the CD44, Sca-1, and CD90 cell surface markers. MSCs were negative for the hematopoietic surface markers such as CD34, CD11b, CD45, CD31, CD106, CD117 and CD135. The data presented in this report indicated that this method can result in efficient isolation of homogenous populations of MSCs from mouse bone marrow.