Effect of mesenchymal stem cells on anti-Thy1,1 induced kidney injury in albino rats

Intrarenal Transplantation of Hypoxic Preconditioned Mesenchymal Stem Cells Improves Glomerulonephritis through Anti-Oxidation, Anti-ER Stress, Anti-Inflammation, Anti-Apoptosis, and Anti-Autophagy

To confer further therapeutic potential and prevent some adverse effects by the mesenchymal stem cells (MSCs) transplantation, we explored the effects of locally intrarenal arterial administration of hypoxic preconditioned MSCs in the anti-Thy1.1 induced rat glomerulonephritis. Proteinuria, histochemical staining, and western blotting were used to explore the therapeutic effects and mechanisms. Locally intrarenal arterial MSCs transplantation successfully implanted the fluorescent or CD44 labeled MSCs in the nephritic glomeruli, ameliorated proteinuria, and glomerulosclerosis in nephritic rats. Hypoxic preconditioning significantly upregulated hypoxic inducible factor-1α/VEGF (HIF-1α/VEGF) in the MSCs and was more efficient than normoxic MSCs in reducing the degree of urinary protein, glomerulosclerosis, fibrosis, macrophage/monocyte infiltration, GRP78 mediated endoplasmic reticulum stress, Beclin-1/LC3-II mediated autophagy, and Bax/Bcl-2/caspase 3 mediated apoptosis. Hypoxic MSCs could further promote intranuclear nuclear factor (erythroid-derived 2, Nrf2) and reduce nuclear factor kappa B expression in nephritic kidneys. As compared to normoxic MSCs, hypoxic MSCs transplantation significantly upregulated the renal expression of anti-oxidative response elements/enzymes including glutamate-cysteine ligase catalytic subunit, glutamate-cysteine ligase modifier subunit, glutathione peroxidase, catalase, Mn, and Cu/Zn superoxide dismutase. In summary, intrarenal hypoxic preconditioning MSCs transplantation was more effective to activate hypoxic inducible factor-1α/VEGF/Nrf2 (HIF-1α/VEGF/Nrf2) signaling, preserve anti-oxidant proteins and anti-oxidative responsive element proteins, and subsequently reduce glomerular apoptosis, autophagy, and inflammation.

Sublytic C5b-9 Induces IL-23 and IL-36a Production by Glomerular Mesangial Cells via PCAF-Mediated KLF4 Acetylation in Rat Thy-1 Nephritis

Sublytic C5b-9 formation on glomerular mesangial cells in rat Thy-1 nephritis (Thy-1N), a model of human mesangioproliferative glomerulonephritis, is accompanied by the production of proinflammatory cytokines, but the relationship between sublytic C5b-9 and cytokine synthesis and the underlying mechanism remains unclear. To explore the problems mentioned above, in this study, we first examined the levels of proinflammatory ILs (e.g., IL-23 and IL-36a) as well as transcription factor (KLF4) and coactivator (PCAF) in the renal tissues of Thy-1N rats and in the glomerular mesangial cell line (HBZY-1) stimulated by sublytic C5b-9. Then, we further determined the role of KLF4 and PCAF in sublytic C5b-9-induced IL-23 and IL-36a production as well as the related mechanism. Our results showed that the levels of KLF4, PCAF, IL-23, and IL-36a were obviously elevated. Mechanistic investigation revealed that sublytic C5b-9 stimulation could increase IL-23 and IL-36a synthesis through KLF4 and PCAF upregulation, and KLF4 and PCAF could form a complex, binding to the IL-23 or IL-36a promoter in a KLF4-dependent manner, causing gene transcription. Importantly, KLF4 acetylation by PCAF contributed to sublytic C5b-9-induced IL-23 and IL-36a transcription. Besides, the KLF4 binding regions on IL-23 or IL-36a promoters and the KLF4 lysine site acetylated by PCAF were identified. Furthermore, silencing renal KLF4 or PCAF gene could significantly inhibit IL-23 or IL-36a secretion and tissue damage of Thy-1N rats. Collectively, these findings implicate that the KLF4/PCAF interaction and KLF4 acetylation by PCAF play a pivotal role in the sublytic C5b-9-mediated IL-23 and IL-36a production of Thy-1N rats.

Therapeutic potentials of mesenchymal stem cells on the renal cortex of experimentally induced hypertensive albino rats: Relevant role of Nrf2

Bone marrow derived-mesenchymal stem cells (BM-MSCs) have brought great attention in regenerative medicine field, various experimental & clinical trials were held to investigate their therapeutic effects in different disorders. We designed a histological & immunohistochemical study to evaluate effectiveness of MSCs therapy in withhold of end-stage renal disease (ESRD) secondary to hypertension which has become a growing & striking public health problem. 30 adult male albino rats were utilized, 20 of them were exposed to experimental induction of hypertension, then divided equally to MSCs treated group (injected with 1×10⁶ fluorescent labeled cell i.v./rat), while the second one was left without treatment. Renal specimens were subjected to histopathological, ultrastructural and immunohistochemical examination for Nrf2 in addition to biochemical estimation of serum urea & creatinine. Our results documented that BM-derived MSCs exerts considerable reversing effect of histopathologic and ultrastructural hypertensive nephropathy. Moreover, immunohistochemical results clearly pointed to relevant role of Nrf2 pathway in MSCs related renal therapeutic effects.

Stem cell therapy: An emerging modality in glomerular diseases

The kidney has been considered a highly terminally differentiated organ with low proliferative potential and thus unlikely to undergo regeneration. Glomerular disease progresses to end-stage renal disease (ESRD), which requires dialysis or renal transplantation for better quality of life for patients with ESRD. Because of the shortage of implantable kidneys and complications such as immune rejection, septicemia and toxicity of immunosuppression, kidney transplantation remains a challenge. Therapeutic options available for glomerular disease include symptomatic treatment and strategies to delay progression. In an attempt to develop innovative treatments by promoting the limited capability of regeneration and repair after kidney injury and overcome the progressive pathological process that is uncontrolled with conventional treatment modalities, stem cell-based therapy has emerged as novel intervention due to its ability to inhibit inflammation and promote regeneration. Recent developments in cell therapy have demonstrated promising therapeutic outcomes in terms of restoration of renal structure and function. This review focuses on stem cell therapy approaches for the treatment of glomerular disease, including the various cell sources used and recent advances in preclinical and clinical studies.

Therapeutic action of bone marrow-derived stem cells against acute kidney injury

Acute kidney injury (AKI) is a frequent clinical disease with a high morbidity rate and mortality rate, while the treatment options for this intractable disease are limited currently. In recent years, bone marrow-derived mesenchymal stem cells (BMSCs) have been demonstrated to hold an effect therapeutic action against AKI by scientists gradually, and the cells are capable to localize to renal compartments and contribute to kidney regeneration though differentiation or paracrine action. Especially, the advantages of BMSCs, such as low toxicity and side effect as well as autologous transplantation, endue the cell with a promising potential in clinical therapy against AKI. In this review, we mainly provide a concise overview of the application of BMSCs in the treatment of AKI, and summarize a series of published data regarding the mechanisms and optimizations of the BMSC-based therapy in renal repair after AKI. Even though some critical points about the BMSC-based therapy model still need clarification, we hope to develop more reliable pharmacological or biotechnical strategies utilizing the stem cell for the eventual treatment of humans with AKI, based on these studies and the understanding of mechanism of renal protection by BMSCs.

Stem cell-based cell therapy for glomerulonephritis

Glomerulonephritis (GN), characterized by immune-mediated inflammatory changes in the glomerular, is a common cause of end stage renal disease. Therapeutic options for glomerulonephritis applicable to all cases mainly include symptomatic treatment and strategies to delay progression. In the attempt to yield innovative interventions fostering the limited capability of regeneration of renal tissue after injury and the uncontrolled pathological process by current treatments, stem cell-based therapy has emerged as novel therapy for its ability to inhibit inflammation and promote regeneration. Many basic and clinical studies have been performed that support the ability of various stem cell populations to ameliorate glomerular injury and improve renal function. However, there is a long way before putting stem cell-based therapy into clinical practice. In the present article, we aim to review works performed with respect to the use of stem cell of different origins in GN, and to discuss the potential mechanism of therapeutic effect and the challenges for clinical application of stem cells.

Continued sustained release of VEGF by PLGA nanospheres modified BAMG stent for the anterior urethral reconstruction of rabbit

OBJECTIVE

To study the biocompatibility and neovascularization of the PLGA nanospheres wrapped with vascular endothelial growth factor (VEGF), which can improve bladder acellular matrix graft (BAMG) with local continuous release of VEGF.

METHODS

A total of 18 rabbit model (length of stenosis: 3 cm) with anterior urethral stricture were used as experimental animals and divided into three groups. Group A as the control group: Simple BAMG scaffold materials for urethral reconstruction. Group B as the blank group: PLGA microspheres modified BAMG for urethral reconstruction. Group C: PLGA conjugated with VEGF and modified BAMG for the urethral reconstruction. All rabbits underwent urethral angiography after 7 days, 15 days, 1 month and 3 months after the operation, and one rabbit in each group was sacrificed to be prepared for the organization histologic examination, HE staining, masson staining, CD31, 34 and a-SAM immunohistochemical detection in the repaired sites.

RESULTS

In group A, significant urethral restenosis occurred in two rabbits after 15 days of the operation, HE and masson staining showed a lot of collagen arranged in the repaired sites, and there were a large number of inflammatory cell infiltration, and there were also CD31, 34 in the repaired sites. a-SAM microvascular tag count showed a small amount of microvascular; Group B showed anastomotic restenosis, HE and masoon staining showed inflammatory cell infiltration and collagen deposition; Group C: urethrography showed lumen patency. There were a small amount of inflammatory cell infiltration after 7 and 15 days after the operation, and there were also CD31, 34 in the repaired sites. The a-SAM microvascular tag count showed many microvascular. And the difference was significant.

CONCLUSIONS

Anterior urethral reconstruction with sustained-release of VEGF by PLGA nanospheres modified BAMG stents can reduce postoperative restenosis. It can also reduce collagen deposition and scar formation, promote angiogenesis of the repair tissue; therefore it in valuable in the tissue-engineered urethral reconstruction.