Mesenchymal Stem Cells Attenuates TGF-β1-Induced EMT by Increasing HGF Expression in HK-2 Cells

Stem cell-based therapy for fibrotic diseases: mechanisms and pathways

Fibrosis is a pathological process, that could result in permanent scarring and impairment of the physiological function of the affected organ; this condition which is categorized under the term organ failure could affect various organs in different situations. The involvement of the major organs, such as the lungs, liver, kidney, heart, and skin, is associated with a high rate of morbidity and mortality across the world. Fibrotic disorders encompass a broad range of complications and could be traced to various illnesses and impairments; these could range from simple skin scars with beauty issues to severe rheumatologic or inflammatory disorders such as systemic sclerosis as well as idiopathic pulmonary fibrosis. Besides, the overactivation of immune responses during any inflammatory condition causing tissue damage could contribute to the pathogenic fibrotic events accompanying the healing response; for instance, the inflammation resulting from tissue engraftment could cause the formation of fibrotic scars in the grafted tissue, even in cases where the immune system deals with hard to clear infections, fibrotic scars could follow and cause severe adverse effects. A good example of such a complication is post-Covid19 lung fibrosis which could impair the life of the affected individuals with extensive lung involvement. However, effective therapies that halt or slow down the progression of fibrosis are missing in the current clinical settings. Considering the immunomodulatory and regenerative potential of distinct stem cell types, their application as an anti-fibrotic agent, capable of attenuating tissue fibrosis has been investigated by many researchers. Although the majority of the studies addressing the anti-fibrotic effects of stem cells indicated their potent capabilities, the underlying mechanisms, and pathways by which these cells could impact fibrotic processes remain poorly understood. Here, we first, review the properties of various stem cell types utilized so far as anti-fibrotic treatments and discuss the challenges and limitations associated with their applications in clinical settings; then, we will summarize the general and organ-specific mechanisms and pathways contributing to tissue fibrosis; finally, we will describe the mechanisms and pathways considered to be employed by distinct stem cell types for exerting anti-fibrotic events.

Potential of Autologous Adipose-Derived Mesenchymal Stem Cells in Peritoneal Fibrosis: A Pilot Study

BACKGROUND

We aimed to determine the effects of systemic therapy with autologous adipose tissue derived mesenchymal stem cells (AD-MSCs) on different parameters of peritoneal function and inflammation in peritoneal dialysis (PD) patients.

METHODS

We enrolled nine PD patients with ultrafiltration failure (UFF). Patients received 1.2±0.1×106 cell/kg of AD-MSCs via cubital vein and were then followed for six months at time points of baseline, 3, 6, 12, 16 and 24 weeks after infusion. UNI-PET was performed for assessment of peritoneal characteristics at baseline and weeks 12 and 24. Systemic and peritoneal levels of tumor necrosis factor α (TNF-α), interleukin-6(IL-6), IL-2 and CA125 (by ELISA) and gene expression levels of transforming growth factor beta (TGF-β), smooth muscle actin (𝛼-SMA) and fibroblast-specific protein-1 (FSP-1) in PD effluent derived cells (by quantitative real-time PCR) were measured at baseline and weeks 3, 6, 12, 16 and 24.

RESULTS

Slight improvement was observed in the following UF capacity indices: free water transport (FWT, 32%), ultrafiltration - small pore (UFSP, 18%), ultrafiltration total (UFT, 25%), osmotic conductance to glucose (OCG, 25%), D/P creatinine (0.75 to 0.70), and Dt/D0 glucose (0.23 to 0.26). There was a slight increase in systemic and peritoneal levels of CA125 and a slight decrease in gene expression levels of TGF-β, α-SMA and FSP-1 that was more prominent at week 12 and vanished by the end of the study.

CONCLUSION

Our results for the first time showed the potential of MSCs for treatment of peritoneal damage in a clinical trial. Our results could be regarded as hypothesis suggestion and will need confirmation in future studies.

Umbilical Cord Mesenchymal Stem Cells Ameliorate Kidney Injury in MRL/Ipr Mice Through the TGF-β1 Pathway

The therapeutic effects and mechanism of umbilical cord mesenchymal stem cells (UC-MSC) on kidney injury in MRL/Ipr mice were studied. UC-MSC, methylprednisolone (MP), and their combination were used to treat MRL/Ipr mice. The therapeutic effects were evaluated by renal function assessment, and HE, PAS, and Masson staining were carried out on renal tissues and visualized by electron microscopy. Subsequently, podocyte injury was detected by the presence of podocin in renal tissues by immunofluorescence. To further explore the mechanism, serum TGF-β1 was measured, and TGF-β1, p-Smad3, and TRAF6 in the renal tissue were detected by Western blotting. In vitro, TGF-β1 was used to stimulate podocytes, and the podocyte activity and changes in synaptopodin were observed after UC-MSC treatment. Significant improvements in renal function and pathological injury were observed in the UC-MSC group compared to the lupus nephritis (LN) model group. UC-MSC and MP treatment improved podocyte injury in MRL/Ipr mice. Western blot examination showed a significant increase in TGF-β1, p-Smad3, and TRAF6 expression in renal tissues of the LN model group, while significant downregulation of those proteins was observed in the UC-MSC group. After TGF-β1 stimulation in vitro, podocyte activity decreased, and UC-MSC treatment improved podocyte activity and restored synaptopodin expression. UC-MSC therapy could improve the deterioration of renal function and the pathological changes of the renal tissues in MRL/Ipr mice. Our study suggested that UC-MSC may improve kidney injury and podocyte injury in LN mice by inhibiting the TGF-β1 pathway.

Understanding the Renal Fibrotic Process in Leptospirosis

Leptospirosis is a neglected infectious disease caused by pathogenic species of the genus Leptospira. The acute disease is well-described, and, although it resembles other tropical diseases, it can be diagnosed through the use of serological and molecular methods. While the chronic renal disease, carrier state, and kidney fibrosis due to Leptospira infection in humans have been the subject of discussion by researchers, the mechanisms involved in these processes are still overlooked, and relatively little is known about the establishment and maintenance of the chronic status underlying this infectious disease. In this review, we highlight recent findings regarding the cellular communication pathways involved in the renal fibrotic process, as well as the relationship between renal fibrosis due to leptospirosis and CKD/CKDu.