miR-106b-5p Intensifies the Proliferative Potential of Spermatogonial Stem Cells as a Prerequisite for Male Infertility Treatment

Although numerous studies have investigated the molecular basis of male infertility, various aspects of this area have remained uncovered. Over the past years, researchers have reported the significant potential of miRNAs in posttranscriptional regulatory roles. By targeting mRNAs, these notable molecules can modulate the processes related to male infertility. On the other side, the outstanding potential of male germline stem cells, SSCs, includes their application in infertility treatment. SSCs retain normal spermatogenesis and fertility by adjusting both SSC self-renewal and differentiation. Therefore, for the characterization and manipulation of SSCs, effective and efficient in vitro culture methods are essential in supporting their maintenance and development. In this regard, the present investigation was undertaken to evaluate the impact of one of the recently conspicuous miRNAs, miR-106b, in SSCs enrichment. As a result, we first found that the SSCs induced with miR-106b-5p highly express TGF-β1, which is known as a regulator of epigenetic modifiers and downstream genes. We next sought to show that self-renewal markers, including c-Myc, Oct-4, and Sox2, are increased in the induced SSC group. The intended miRNA also induced the inhibitor of differentiation 4 (ID4) and aided to remain unmethylated in SSCs. Additionally, for the tumorigenicity possibility of the manipulation, we indicated that PTEN, a tumor-suppressor gene, expressed remarkably in the induced SSCs. In conclusion, our findings showed that miR-106b-5p enhances the proliferative potential of SSCs, making it a substantial factor for therapeutic strategies of male infertility.

The Effect of miR-106b-5p Expression in The Production of iPS-Like Cells from Mice SSCs during The Formation of Teratoma and The Three Embryonic Layers

<strong>Objective:</strong> According to the mounting data, microRNAs (miRNAs) may play a key role in reprogramming. miR-106b<br />is considered as an enhancer in reprogramming efficiency. Based on induced pluripotent stem cells (iPSCs), cell treatments have a huge amount of potential. One of the main concerns about using iPSCs in therapeutic settings is the possibility of tumor formation. It is hypothesized that a procedure that can reprogram cells with less genetic manipulation reduces the possibility of tumorigenicity.<br /><strong>Materials and Methods:</strong> In this experimental study, miR-106b-5p transduced by pLV-miRNA vector into mice isolated spermatogonial stem cells (SSCs) to achieve iPS-like cells. Then the transduced cells were cultured in specific conditions to study the formation of three germ layers. The tumorigenicity of these iPS-like cells was investigated by transplantation into male BALB/C mice.<br /><strong>Results:</strong> We show that SSCs can be successfully reprogrammed into induced iPS-like cells by pLV-miRNA vector to transduce the hsa-mir-106b-5p into SSCs and generating osteogenic, neural and hepatoblast lineage cells in vitro as a result of pluripotency. Although these iPS-like cells are pluripotent, they cannot form palpable tumors in vivo.<br /><strong>Conclusion:</strong> These results demonstrate that infection of hsa-mir-106b-5p into SSCs can reprogram them into iPSCs<br />and advanced germ cell lineages without tumorigenicity. Also, a novel approach for studying the generation of iPSCs<br />and the application of iPS or iPS-like cells in regenerative medicine is presented.

Investigation of cholestasis-related changes in characteristics of spermatogonial stem cells in testis tissue of male Wistar rats

Paternal metabolic status is an important factor in the health status of offspring. Cholestasis, as a metabolic disorder, significantly disrupts spermatogenesis. Spermatogonial stem cells (SSCs) are considered the dividing germ cells, which maintain spermatogenesis throughout the lifespan. Here, we investigated the in vivo and in vitro effect(s) of cholestasis on SSCs. Cholestasis was induced in rats by bile duct ligation. Four weeks after the cholestasis induction, testicular tissues were analysed using histopathological examinations. The expression of SSC markers, including Plzf and Thy-1, was determined using the immunofluorescent technique. Also, SSCs were isolated from animals, and their proliferation was examined in vitro. The histological examinations revealed that cholestasis caused irregularities in the structure of seminal tubes. Immunostaining showed that the total number of Thy-1- and Plzf-expressing cells was declined in the cholestasis group compared with the control group. In vitro culture of SSCs indicated that the number of SSC colonies and those expressing Plzf were significantly reduced in the culture medium of the cholestasis group. Our results indicated that cholestasis affects the functionality of SSCs and reduces the number and proliferation of them. This finding may be of interest to the effect of metabolic diseases such as cholestasis on spermatogenesis.