Kidney tissue engineering using a well-preserved acellular rat kidney scaffold and mesenchymal stem cells.

The aim of this study was to acquire an effective method for preparation of rat decellularized kidney scaffolds capable of supporting proliferation and differentiation of human adipose tissue derived mesenchymal stem cells (AD-MSCs) into kidney cells. We compared two detergents, the sodium dodecyl sulfate (SDS) and triton X-100 for decellularization. The efficiency of these methods was assessed by Hematoxylin and Eosin (H&E), 4', 6 diamidino-2-phenylindole and immunohistochemistry (IHC) staining. In the next step, AD-MSCs were seeded into the SDS-treated scaffolds and assessed after three weeks of culture. Proliferation and differentiation of AD-MSCs into kidney-specific cell types were then analyzed by H&E and IHC staining. The histological examinations revealed that SDS was more efficient in removing kidney cells at all-time points compared to triton X-100. Also, in the SDS-treated sections the native extracellular matrix was more preserved than the triton-treated samples. Laminin was completely preserved during decellularization procedure using SDS. Cell attachment in the renal scaffold was observed after recellularization. Furthermore, differentiation of AD-MSCs into epithelial and endothelial cells was confirmed by expression of Na-K ATPase and vascular endothelial growth factor receptor 2 (VEGFR-2) in seeded rat renal scaffolds, respectively. Our findings illustrated that SDS was more effective for decellularization of rat kidney compared to triton X-100. We presented an optimized method for decellularization and recellularization of rat kidneys to create functional renal natural scaffolds. These natural scaffolds supported the growth of AD-MSCs and could also induce differentiation of these cells into epithelial and endothelial cells.

Novel function of Nanos2 in expression of innate immunity genes and its probable roles in maintenance of pluripotency state.

OBJECTIVES: Cell-based therapeutic approaches have witnessed significant developments during the last decade especially after approval of MSCs based treatment of graft versus host disease. Several cell-based approaches have shown immunomodulatory behavior during regeneration following the unknown cascade of events but the exact mechanisms are yet to be defined. Clinical applications of cell-based drugs are hampered all over the world because of incomplete understanding of molecular mechanisms requiring the application of mechanistic approaches to solving the mystery. Current work has given us the idea that Nanos2 enhances the cellular pluripotency characteristics while down-regulating the innate immunity genes, simultaneously. MATERIALS AND METHODS: The immunomodulatory behavior of cells was studied against cells carrying the ectopic expression of Nanos2 in comparison with Stella and Oct4 individually and simultaneously using SON vector (Stella, Nanos2 and Oct4). RESULTS: It was observed that overexpression of Nanos2 leads to down-regulation of Interferon-Stimulated Genes (ISGs)-mRNAs such as Ifitm1, lsg15, Oas2, and Oas12. Nanos2 overexpressing MEF cells have shown restrictive inflammatory effects when cells were treated with inflammatory stimuli such as LPS and Poly (I:C). CONCLUSION: From our recent findings in line with many others, it can be concluded that Nanos2 acts as a coin with two sides, regulating pluripotency and immunity together which enhances resistance against inflammatory stimuli. Nanos2 could be a potential candidate as a molecular drug for management of inflammation and immunomodulation but it requires a comprehensive comparative expression analysis of innate immunity genes in vitro and in vivo.

Comparison of chromosomal instability of human amniocytes in primary and long-term cultures in AmnioMAX II and DMEM media: A cross-sectional study.

BACKGROUND: The genomic stability of stem cells to be used in cell therapy and other clinical applications is absolutely critical. In this regard, the relationship between in vitro expansion and the chromosomal instability (CIN), especially in human amniotic fluid cells (hAFCs) has not yet been completely elucidated. OBJECTIVE: To investigate the CIN of hAFCs in primary and long-term cultures and two different culture mediums. MATERIALS AND METHODS: After completing prenatal genetic diagnoses (PND) using karyotype technique and chromosomal analysis, a total of 15 samples of hAFCs from 650 samples were randomly selected and cultured in two different mediums as AmnioMAX II and DMEM. Then, proliferative cells were fixed on the slide to be used in standard chromosome G-banding analysis. Also, the senescent cells were screened for aneuploidy considering 8 chromosomes by FISH technique using two probe sets including PID I (X-13-18-21) & PID II (Y-15-16-22). RESULTS: Karyotype and interphase fluorescence in situ hybridization (iFISH) results from 650 patients who were referred for prenatal genetic diagnosis showed that only 6 out of them had culture- derived CIN as polyploidy, including mosaic diploid-triploid and diploid-tetraploid. Moreover, the investigation of aneuploidies in senesced hAFCs demonstrated the rate of total chromosomal abnormalities as 4.3% and 9.9% in AmnioMAX- and DMEM-cultured hAFCs, respectively. CONCLUSION: hAFCs showed a low rate of CIN in two AmnioMAX II and DMEM mediums and also in the proliferative and senescent phases. Therefore, they could be considered as an attractive stem cell source with therapeutic potential in regenerative medicine.

In vitro histological investigation of interactions between rat decellularized large intestine scaffold and human adipose derived mesenchymal stem cells.

The aim of this study was to investigate the interactions between rat intestine decellularized scaffold and human adipose derived mesenchymal stem cells. Rat large intestine was dissected in fragments and decellularized by physicochemical methods. The scaffolds were loaded by human adipose derived mesenchymal stem cells expressing green fluorescent protein. Microscopic sections were prepared from the scaffolds after two weeks of culture with stem cells and studied by histological methods. The interactions of scaffolds with MSCs were also studied by electron microscopy. Histological and electron microscopy studies revealed human mesenchymal stem cell adhesion, migration, division and maintenance during the 14 days of culture in vitro. According to the results, scaffolds prepared from rat intestine matrix could be a suitable scaffold for studying in vitro cell behaviors such as division, migration and attachment. These various behaviors of cultured cells might be due to inductive effects of the extracellular matrix derived scaffold. However, more investigations are required to discover the exact effects of this scaffold and its interactions with mesenchymal stem cells.