Histologic and spectroscopic study of pluripotent stem cells after implant in ocular traumatic injuries in a murine model

Nephroprotective Effect of Embryonic Stem Cells Reducing Lipid Peroxidation in Kidney Injury Induced by Cisplatin

Introduction

The acute kidney injury (AKI) is characterized by a sudden glomerular filtration reduction. Renal or intrinsic causes of AKI include nephrotoxicity induced by exogenous agents like cisplatin, which causes oxidative stress altering the biochemical process and leading to apoptosis. Therefore, this research is aimed at analyzing the embryonic stem cells (ESC) nephroprotective effect in AKI induced by cisplatin, employing genetic, phenotypic, and microspectroscopic techniques.

Methods

Thirty mice were randomly divided into three groups (n = 10): the healthy, isotonic salt solution (ISS), and mouse embryonic stem cells (mESC) groups. The ISS and mESC groups were subjected to AKI using cisplatin; 24 h post-AKI received an intraperitoneal injection of ISS or 1 × 10⁶ mESC, respectively. At days 4 and 8 post-AKI, five mice of each group were sacrificed to analyze the histopathological, genetic (PDK4 and HO-1), protein (p53), and vibrational microspectroscopic changes.

Results

Histopathologically, interstitial nephritis and acute tubular necrosis were observed; however, the mESC group showed a more preserved microarchitecture with high cellularity. Additionally, the PDK4 and HO-1 gene expression only increased in the ISS group on day 4 post-AKI. Likewise, p53 was more immunoexpressed at day 8 post-AKI in the ISS group. About biomolecular analysis by microspectroscopy, bands associated with lipids, proteins, and nucleic acids were evidenced. Besides, ratios related to membrane function (protein/lipid), unsaturated lipid content (olefinic/total lipid, olefinic/total CH₂, and CH₂/CH₃), and lipid peroxidation demonstrated oxidative stress induction and lipid peroxidation increase mainly in the ISS group. Finally, the principal component analysis discriminated against each group; nonetheless, some data of the healthy and mESC groups at day 8 were correlated.

Conclusions

The mESC implant diminishes cisplatin nephrotoxicity, once the protective effect in the reduction of lipid peroxidation was demonstrated, reflecting a functional and histological restoration.

Functional and histologic effects after implanting pluripotent stem cells in a murine model with sphincterotomy

INTRODUCTION AND AIMS

Fecal incontinence is a disabling condition with devastating consequences for the patients. Medical and surgical options are not very satisfactory, reason by which regenerative medicine has been considered in this field. In the present research, we analyzed functional and histologic effects after implanting pluripotent stem cells (PSCs) in a murine model with sphincterotomy.

MATERIALS AND METHODS

Female Wistar rats were subjected to sphincterotomy and divided into three groups. Group 1 (control group) was treated with 300μL of balanced saline solution and group 2 (late treatment) and group 3 (early treatment) received 50,000 PSCs resuspended in 300μL of balanced saline solution. All animals were evaluated through high-resolution anorectal manometry 24hours before and after sphincterotomy and every month for three months. Finally, the rats were euthanized and histopathologic sections from the anal canal were obtained.

RESULTS

All groups showed a decrease in resting anal pressure and squeeze anal pressure 24hours after sphincterotomy. At the third month, higher anal pressures in the groups treated with PSCs were detected. Regarding the histologic effects, the microscopic architecture was restored and there was a significant decrease in the inflammatory response in the groups treated with PSCs.

CONCLUSION

PSCs implantation improves anal tone, as well as histologic structure, presenting better regenerative results when implanted as early treatment.

Effect of human umbilical cord blood mesenchymal stem cells administered by intravenous or intravitreal routes on cryo-induced retinal injury

Traumatic optic neuropathy is an important cause of severe vision loss. So, many attempts were performed to transplant stem cells systemically or locally to regenerate the injured retina. In this study, we investigated the effect of human umbilical cord blood mesenchymal stem cells (hUBMSCs) on histological structure, apoptotic, antiapoptotic, oxidant and antioxidant markers in an experimental model of cryo-induced retinal damage in mice. Forty-eight mice were included with 4 major groups; group I contained 18 mice as controls. The others included 30 mice exposed to cryo-induced retinal injury and were subdivided into three equal groups: group II received no treatment after injury. Group III was intravenously injected with hUCBMSCs after injury and group IV received an intravitreal injection with hUCBMSCs into both eyes. Retinal tissues were used for histopathological, immunological and gene expression studies. Real time-PCR was performed to assess B-cell lymphoma 2 (bcl2), Bcl2-associated X protein (bax), heme oxygenase-1 (hmox-1) and thioredoxin-2 (tnx-2) expression and to assess the differentiation of the stem cells into the retinal tissue. Immunohistochemical analysis was performed to assess caspase-3, 3-nitrotyrosine (3-NT) and basic fibroblast growth factor (bFGF). Disturbed retinal structure was seen in cryo-injured mice while hUCBMSCs treated groups showed nearly normal structure. By real time-PCR, significantly reduced mRNA expressions of Bax and notably enhanced mRNA expression of Bcl-2, hmox-1 and txn-2 were demonstrated in retinal injured mice with hUCBMSCs treatment compared to those without. In addition, immunohistochemical analysis confirmed downregulation of 3-NT and caspase-3 and upregulation of bFGF after hUCBMSCs injection in injured retina. Furthermore, there was no differentiation of transplanted stem cells into the retinal tissue. In conclusions, hUCBMSCs could improve the morphological retinal structure in cryo-induced retinal damage model by modulation of the oxidant-apoptotic status and by increased the expression of bFGF. © 2017 IUBMB Life, 69(3):188-201, 2017.

FTIR Spectroscopic and Molecular Analysis during Differentiation of Pluripotent Stem Cells to Pancreatic Cells

Some of the greatest challenges in stem cells (SCs) biology and regenerative medicine are differentiation control of SCs and ensuring the purity of differentiated cells. In this work, we differentiated mouse pluripotent stem cells (mPSCs) toward pancreatic cells characterizing this differentiation process by molecular and spectroscopic technics. Both mPSCs and Differentiated Pancreatic Cells (DPCs) were subjected to a genetic, phenotypic, and biochemical analysis by real-time quantitative PCR (RT-qPCR), immunocytochemistry, and Fourier Transform Infrared (FTIR) spectroscopy. Cultured mPCSs expressed pluripotent genes and proteins (Nanog and SOX2). DPCs expressed endodermal genes (SOX17 and Pdx1) at day 11, an inductor gene of embryonic pancreas development (Pdx1) at day 17 and pancreas genes and proteins (Insulin and Glucagon) at day 21 of differentiation. Likewise, FTIR spectra of mPSCs and DPCs at different maturation stages (11, 17, and 21 days) were obtained and showed absorption bands related with different types of biomolecules. These FTIR spectra exhibited significant spectral changes agreeing with the differentiation process, particularly in proteins and nucleic acids bands. In conclusion, the obtained DPCs passed through the chronological stages of embryonic pancreas development and FTIR spectra provide a new biophysical parameter based on molecular markers indicating the differentiation process of mPSCs to specialized cells.