Background: Neuronal tissue has a limited potential to self-renew or get repaired after damage. Cell therapies using stem cells are promising approaches for the treatment of central nervous system (CNS) injuries. However, the clinical use of embryonic stem cells is limited by ethical concerns and other scientific consequences. Bone marrow mesenchymal stromal cells (BM-MSC) could represent an alternative source of stem cells for replacement therapy. Indeed, many studies have demonstrated that MSCs can give rise to neuronal cells as well as many tissue-specific cell phenotypes. Purpose: Motor recovery by transplantation of bone marrow MSCs in rat models of spinal cord injury (SCI). Methods: Bone marrow was collected from the femur of albino Wistar rats. MSCs were separated using the Ficoll-Paque density gradient method and cultured in Dulbecco’s Modified Eagle Medium supplemented with 20% fetal bovine serum. Cultured MSC was characterized by immunohistochemistry and flow cytometry and neuronal-induced cells were further characterized for neural markers. Cultured MSCs were transplanted into the experimentally injured spinal cord of Wistar rats. Control (injured, but without cell transplantation) and transplanted rats were followed up to 8 weeks, analyzed using the Basso, Beattie, Bresnahan (BBB) scale and electromyography (EMG) for behavioral and physiological status of the injured spinal cord. Finally, the tissue was evaluated histologically. Results: Rat MSCs expressed positivity for a panel of MSC markers CD29, CD54, CD90, CD73, and CD105, and negativity for hematopoietic markers CD34, CD14, and CD45. In vitro neuronal transdifferentiated MSCs express positivity for β III tubulin, MAP2, NF, NeuN, Nav1.1, oligodendrocyte (O4), and negativity for glial fibrillary acid protein. All the treated groups show promising hind-limb motor recovery BBB score, except the control group. There was increased EMG amplitude in treated groups as compared to the control group. Green fluorescent protein (GFP)-labeled MSC survived and differentiated into neurons in the injured spinal cord, which is responsible for functional recovery. Conclusion: Our results demonstrate that BM-MSC has the potential to repair the injured cord in rat models of SCI. Thus, BM-MSC appears to be a promising candidate for cell-based therapy in CNS injury.

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Glomerular mesangial cell (GMC)‐derived pleiotropic cytokine, interleukin‐1 (IL‐1), contributes to hypercellularity in human and experimental proliferative glomerulonephritis. IL‐1 promotes mesangial proliferation and may stimulate extracellular matrix accumulation, mechanisms of which are unclear. The present study shows that the beta isoform of IL‐1 (IL‐1β) is a potent inducer of IL‐1 type I receptor‐dependent Ca2+ entry in mouse GMCs. We also demonstrate that the transient receptor potential ankyrin 1 (TRPA1) is an intracellular store‐independent diacylglycerol‐sensitive Ca2+ channel in the cells. IL‐1β‐induced Ca2+ and Ba2+ influxes in the cells were negated by pharmacological inhibition and siRNA‐mediated knockdown of TRPA1 channels. IL‐1β did not stimulate fibronectin production in cultured mouse GMCs and glomerular explants but promoted Ca2+‐dependent cell proliferation. IL‐1β also stimulated TRPA1‐dependent ERK mitogen‐activated protein kinase (MAPK) phosphorylation in the cells. Concomitantly, IL‐1β‐induced GMC proliferation was attenuated by TRPA1 and RAF1/ MEK/ERK inhibitors. These findings suggest that IL‐1β‐induced Ca2+ entry via TRPA1 channels engenders MAPK‐dependent mesangial cell proliferation. Hence, TRPA1‐mediated Ca2+ signaling could be of pathological significance in proliferative glomerulonephritis.

Background and Purpose:A water decoction of the poisonous shrub Cleistanthus collinus is used for suicidal purposes. The mortality rate is 28%. The clinical profile includes distal renal tubular acidosis (DRTA) and respiratory failure. The mechanism of toxicity is unclear.Objectives:To demonstrate features of C. collinus toxicity in a rat model and to identify its mechanism(s) of action.Materials and Methods:Rats were anesthetized and the carotid artery was cannulated. Electrocardiogram and respiratory movements were recorded. Either aqueous extract of C. collinus or control solution was administered intraperitoneally. Serial measurements of blood gases, electrolytes and urinary pH were made. Isolated brush border and basolateral membranes from rat kidney were incubated with C. collinus extract and reduction in ATPase activity was assessed. Venous blood samples from human volunteers and rats were incubated with an acetone extract of C. collinus and plasma potassium was estimated as an assay for sodium–potassium pump activity.Results:The mortality was 100% in tests and 17% in controls. Terminal event in test animals was respiratory arrest. Controls had metabolic acidosis, respiratory compensation acidic urine and hyperkalemia. Test animals showed respiratory acidosis, alkaline urine and low blood potassium as compared to controls. C. collinus extract inhibited ATPase activity in rat kidney. Plasma K+ did not increase in human blood incubated with C. collinus extract.Conclusions and Implications:Active principles of C. collinus inhibit proton pumps in the renal brush border, resulting in type I DRTA in rats. There is no inhibition of sodium–potassium pump activity. Test animals develop respiratory acidosis, and the immediate cause of death is respiratory arrest.

In patients with rhabdomyolysis, the overwhelming release of myoglobin into circulation is the primary cause of kidney injury. Myoglobin causes direct kidney injury as well as severe renal vasoconstriction. An increase in renal vascular resistance (RVR) results in renal blood flow (RBF) and glomerular filtration rate (GFR) reduction, tubular injury, and acute kidney injury (AKI). The mechanisms that underlie rhabdomyolysis-induced AKI are not fully understood but may involve the local production of vasoactive mediators in the kidney. Studies have shown that myoglobin stimulates endothelin-1 (ET-1) production in glomerular mesangial cells. Circulating ET-1 is also increased in rats subjected to glycerol-induced rhabdomyolysis. However, the upstream mechanisms of ET-1 production and downstream effectors of ET-1 actions in rhabdomyolysis-induced AKI remain unclear. Vasoactive ET-1 is generated by ET converting enzyme 1 (ECE-1)-induced proteolytic processing of inactive big ET to biologically active peptides. The downstream ion channel effectors of ET-1-induced vasoregulation include the transient receptor potential cation channel, subfamily C member 3 (TRPC3). This study demonstrates that glycerol-induced rhabdomyolysis in Wistar rats promotes ECE-1-dependent ET-1 production, RVR increase, GFR decrease, and AKI. Rhabdomyolysis-induced increases in RVR and AKI in the rats were attenuated by post-injury pharmacological inhibition of ECE-1, ET receptors, and TRPC3 channels. CRISPR/Cas9-mediated knockout of TRPC3 channels attenuated ET-1-induced renal vascular reactivity and rhabdomyolysis-induced AKI. These findings suggest that ECE-1-driven ET-1 production and downstream activation of TRPC3-dependent renal vasoconstriction contribute to rhabdomyolysis-induced AKI. Hence, postinjury inhibition of ET-1-mediated renal vasoregulation may provide therapeutic targets for rhabdomyolysis-induced AKI.