Although somatic cells can be reprogrammed to pluripotent stem cells (PSCs) with pure chemicals, authentic pluripotency of chemically induced pluripotent stem cells (CiPSCs) has never been achieved through tetraploid complementation assay. Spontaneous reprogramming of spermatogonial stem cells (SSCs) was another non-transgenic way to obtain PSCs, but this process lacks mechanistic explanation. Here, we reconstructed the trajectory of mouse SSC reprogramming and developed a five-chemical combination, boosting the reprogramming efficiency by nearly 80- to 100-folds. More importantly, chemical induced germline-derived PSCs (5C-gPSCs), but not gPSCs and chemical induced pluripotent stem cells, had authentic pluripotency, as determined by tetraploid complementation. Mechanistically, SSCs traversed through an inverted pathway of in vivo germ cell development, exhibiting the expression signatures and DNA methylation dynamics from spermatogonia to primordial germ cells and further to epiblasts. Besides, SSC-specific imprinting control regions switched from biallelic methylated states to monoallelic methylated states by imprinting demethylation and then re-methylation on one of the two alleles in 5C-gPSCs, which was apparently distinct with the imprinting reprogramming in vivo as DNA methylation simultaneously occurred on both alleles. Our work sheds light on the unique regulatory network underpinning SSC reprogramming, providing insights to understand generic mechanisms for cell-fate decision and epigenetic-related disorders in regenerative medicine.
Male ; Mice ; Animals ; Cellular Reprogramming/genetics* ; Tetraploidy ; Pluripotent Stem Cells/metabolism* ; Induced Pluripotent Stem Cells/metabolism* ; DNA Methylation ; Spermatogonia/metabolism* ; Germ Cells/metabolism*

Understanding the regulatory networks for germ cell fate specification is necessary to developing strategies for improving the efficiency of germ cell production in vitro. In this study, we developed a coupled screening strategy that took advantage of an arrayed bi-molecular fluorescence complementation (BiFC) platform for protein-protein interaction screens and epiblast-like cell (EpiLC)-induction assays using reporter mouse embryonic stem cells (mESCs). Investigation of candidate interaction partners of core human pluripotent factors OCT4, NANOG, KLF4 and SOX2 in EpiLC differentiation assays identified novel primordial germ cell (PGC)-inducing factors including BEN-domain (BEND/Bend) family members. Through RNA-seq, ChIP-seq, and ATAC-seq analyses, we showed that Bend5 worked together with Bend4 and helped mark chromatin boundaries to promote EpiLC induction in vitro. Our findings suggest that BEND/Bend proteins represent a new family of transcriptional modulators and chromatin boundary factors that participate in gene expression regulation during early germline development.
Animals ; Cell Differentiation/genetics* ; Chromatin/metabolism* ; Embryonic Stem Cells ; Germ Cells/metabolism* ; Germ Layers/metabolism* ; Mice

It is not fully clear why there is a higher contribution of pluripotent stem cells (PSCs) to the chimera produced by injection of PSCs into 4-cell or 8-cell stage embryos compared with blastocyst injection. Here, we show that not only embryonic stem cells (ESCs) but also induced pluripotent stem cells (iPSCs) can generate F0 nearly 100% donor cell-derived mice by 4-cell stage embryo injection, and the approach has a "dose effect". Through an analysis of the PSC-secreted proteins, Activin A was found to impede epiblast (EPI) lineage development while promoting trophectoderm (TE) differentiation, resulting in replacement of the EPI lineage of host embryos with PSCs. Interestingly, the injection of ESCs into blastocysts cultured with Activin A (cultured from 4-cell stage to early blastocyst at E3.5) could increase the contribution of ESCs to the chimera. The results indicated that PSCs secrete protein Activin A to improve their EPI competency after injection into recipient embryos through influencing the development of mouse early embryos. This result is useful for optimizing the chimera production system and for a deep understanding of PSCs effects on early embryo development.
Activins ; metabolism ; Animals ; Cells, Cultured ; Embryonic Development ; Germ Layers ; metabolism ; Mice ; Pluripotent Stem Cells ; cytology ; metabolism

The adult gut microbiota comprises 10~100 trillion microorganisms, which is equivalent to 10 times the number of total somatic and germ cells. Further, the collective genomes of gut microbiota (microbiome) contain 100~150-fold more genes than the human genome. The gut microbiota has coevolved with humans and has shown profound effects on various host responses. Recent findings have suggested that an altered gut microbial composition is associated with metabolic diseases, including obesity, diabetes, and non-alcoholic fatty liver disease. These findings indicate that the gut microbiota should be considered as an important factor to modulate host metabolism and metabolic disorders. If we could understand the alterations of the gut microbiota, in combination with dietary patterns, this might provide insights into how the gut microbiota contributes to disease progression and whether it could be a potential diagnostic, prognostic, and therapeutic target.
Adult ; Diet ; Disease Progression ; Gastrointestinal Microbiome* ; Genome ; Genome, Human ; Germ Cells ; Humans ; Metabolic Diseases ; Metabolism ; Non-alcoholic Fatty Liver Disease ; Obesity

OBJECTIVETo perform a genome-wide alternative polyadenylation (APA) profiling in both mouse female germline stem cells (FGSCs) and embryonic stem cells (ESCs) and explore the role of germline-specific APA in the biological behaviors of FGSCs.

METHODSWe used a high-throughput sequencing-based method 3T-Seq to profile the genome-wide 3' termini of the transcripts and delineate all the APA sites in mouse FGSCs and ESCs. The genes with altered APA sites in FGSCs compared with ESCs were analyzed with DAVID Gene Ontology tool for their biological roles.

RESULTSWe identified a total of 50243 APA sites in 16973 genes. In FGSCs, 1148 genes were shown to have alterations in 3'UTR length, among which 795 ( 66%) genes had shortened and 353 (34%) had lengthened 3'UTR. Some of the genes with shortened 3'UTR were involved in germ cell development.

CONCLUSIONSOur genome-wide APA profiling analysis reveals a cell type-specific APA alternation in FGSCs, and APA-mediated 3'UTR alteration contributes to germline-related biological process. This study provides a framework for understanding the post-transcriptional regulation mechanisms in FGSCs.

3' Untranslated Regions ; Animals ; Cell Differentiation ; Embryonic Germ Cells ; metabolism ; Embryonic Stem Cells ; metabolism ; Female ; Gene Expression Regulation ; Genome ; Mice ; Polyadenylation

OBJECTIVETo observe the effects of Qiangjing Tablets (QJT) on the semen quality and Fas/FasL signaling pathway in male SD rats with infertility.

METHODSModels of infertility were made in 50 male SD rats by intragastric administration of Tripterygium (GTW) for 3 weeks, and another 20 rats were taken as blank controls. Then 40 successfully established rat models were randomly divided into four groups, model control, low-dose QJT, medium-dose QJT, and high-dose QJT, the latter three groups treated intragastrically with QJT at 58 mg, 105 mg, and 233 mg per kg of the body weight per day, respectively. After 4 weeks of medication, the rats were killed for examination of semen quality and determination of the expression of the apoptosis factor FasL in the testis tissue.

RESULTSCompared with the blank controls, the model rats showed significant decreases in sperm concentration ([71.99 ± 9.72] vs [10.94 ± 3.58] x 10⁶/ml, P < 0.01), motility ([48.95 ± 4.10] vs [9.31 ± 5.79]%, P < 0.01), and viability ( [82.06 ± 6.16] vs [24.03 ± 6.93]%, P < 0.01). In comparison with the model controls, the rats in the QJT groups exhibited remarkably increased sperm concentration, motility, and viability, more significantly in the high-dose group ([59.66 ± 4.53] x 10⁶/ml, [35.45 ± 5.21] %, and [61.97 ± 9.75]%) and medium-dose group ([40.89 ± 4.90] x 10⁶/ml, [24.41 ± 4.79]%, and [60.06 ± 10.62]%) (P < 0.05 or P < 0.01). The expression of FasL was markedly reduced in the low-, medium-, and high-dose QJT groups (0.5215 ± 0.0189, 0.5371 ± 0.0364, and 0.4556 ± 0.0215) as compared with that of the model controls (0.5989 ± 0.0448 ) (P < 0.05 or P < 0.01).

CONCLUSIONBy upregulating the Fas/FasL signaling pathway, Tripterygium glycosides may induce the apoptosis of spermatogenic cells and reduce sperm concentration, motility and viability, resulting in infertility. The Chinese medicine Qiangjing Tablets can improve the reproductive function of male rats by decreasing the expression of the apoptosis factor FasL in the testis.

Animals ; Apoptosis ; drug effects ; Drugs, Chinese Herbal ; pharmacology ; Fas Ligand Protein ; drug effects ; metabolism ; Germ Cells ; Glycosides ; Infertility, Male ; chemically induced ; drug therapy ; metabolism ; Male ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Semen ; drug effects ; Semen Analysis ; Signal Transduction ; Sperm Count ; Sperm Motility ; drug effects ; Tablets ; Testis ; drug effects ; metabolism ; Tripterygium

CRISPR-Cas Systems ; Embryo, Mammalian ; cytology ; metabolism ; Germ Cells ; cytology ; metabolism ; Humans ; RNA Editing ; genetics

To monitor the trans-differentiation from adult stem cells to germ cells, we analyzed the vasa expression of goat testicular tissues in different ages and constructed the germ cell specific reporting vector pVASA-EGFP. The expression of vasa was verified by RT-PCR and immunofluorescence. The vector pVASA-EGFP was constructed by molecular technology, then transfected into goat bone mesenchymal stem cells (BMSCs) by Lipofectamine 2000. Moreover, we observed the expression of the vector through green fluorescent protein (GFP). Immunofluorescence results show that Vasa was expressed in all groups of goat testicular tissues, RT-PCR results show that the levels of vasa mRNA in 3-month group and 10-month group were significantly higher than that in 10-day group. Sequencing and restriction enzyme results show that the vector was successfully constructed. After transfection and RA treatment, GFP expression was observed, which proved the validity of our reporting system. All the results proved that vasa was expressed in different ages in goat testicular tissues, and the vector pVASA-EGFP is efficient in monitoring the trans-differentiation in vitro, which paves the way for further characterization and screening of the trans-differentiation of goat BMSCs.
Animals ; Cell Transdifferentiation ; Genes, Reporter ; Genetic Vectors ; Germ Cells ; cytology ; Goats ; Green Fluorescent Proteins ; Male ; Mesenchymal Stromal Cells ; RNA, Messenger ; Testis ; metabolism ; Transfection

OBJECTIVETo observe the histological features of tumor-bearing tissues formed by human fibroblasts after reprograming by spermatogonial stem cell self-renewal key regulating gene Piwil2 (Piwil2-iCSC).

METHODSPiwil2-iCSC tumor spheroids-like colonies were selected for tumor formation assay in four nude mice. Pathological features of Piwil2-iCSC tumors were observed by histology. Stem cell markers and common triploblastic markers were detected by reverse transcriptase-polymerase chain reaction (RT-PCR) assay and immunohistochemistry. Germ cell tumor markers were detected by immunohistochemical examination.

RESULTSTwo weeks after inoculation, subcutaneous tumors were formed in all the four nude mice with a tumor formation rate of 100%. In the Piwil2-iCSC tumor tissues, Piwil2-GFP(+) cells showed high-density nuclear expression and were widely observed in DAPI-stained sections. Numerous mitotic figure of the neoplastic cells were seen (>10 cells/field of vision under high magnification) in HE-stained sections. Enlarged abnormal cell nuclei were observed. RT-PCR assay showed that Piwil2-iCSC tumors still expressed Piwil2 and some self-renewal and pluripotent markers of stem cells and some markers of triploblastic differentiation. Immunohistochemical staining showed that the tumors expressed stem cell markers, triploblastic markers and germ cell tumor markers AFP and HCG.

CONCLUSIONSPiwil2-iCSC tumors are probably undifferentiated embryonic small cell carcinoma, most likely to be immature teratoma, mixed with yolk sac tumor and choriocarcinoma components. It can be used as a useful model for the research of origin or genesis mechanism of cancer stem cells and the treatment of relevant tumors.

Adult Stem Cells ; Animals ; Argonaute Proteins ; genetics ; Cellular Reprogramming Techniques ; Choriocarcinoma ; pathology ; Endodermal Sinus Tumor ; pathology ; Fibroblasts ; metabolism ; pathology ; Humans ; Immunohistochemistry ; Mice ; Mice, Nude ; Neoplasms, Germ Cell and Embryonal ; chemistry ; genetics ; pathology ; Neoplastic Stem Cells ; chemistry ; pathology ; Real-Time Polymerase Chain Reaction ; Spheroids, Cellular ; Teratoma ; pathology ; Time Factors

OBJECTIVETo investigate the effects and mechanisms of diethylhexylphthalate (DEHP) on morphology and function of progenitor Leydig cells (PLC) in rats.

METHODSTwenty pregnant SD rats were randomly divided into 4 groups ( n = 5): normal control group, DEHP low dose group , middle dose group, and high dose group, which were treated from postnatal day (PND) 1 to PND 21 of the pubs with DEHP at the doses of 0, 10, 100, 750 mg/(kg · d) in 0.5 ml of corn oil by gavage respectively. At the end of the treatment, the male pups were killed and blood samples were collected for determination of serum testosterone concentration by chemiluminescence method. The body weight, testis weight and anogenital distance (AGD) were measured. The morphology of PLC was observed by light and transmission electron microscopy. The protein expression of steroidogenic acute regulatory protein(StAR) in PLC was determined by immunohistochemistry. The mRNA expression of insulin-like growth factor-I (IGF-I) in the testis was assayed by real-time PCR.

RESULTSCompared with normal control group, the serum testosterone and AGD of male pubs from the middle and high dose groups were declined significantly (P < 0.01), the testis weight and body weight from high dose group were decreased significantly (P < 0.01), while the testis weight increased in the low dose group (P < 0.05). Under light microscope, PLC showed hyperplasia and cluster aggregation in the low dose group and focal hyperplasia in the middle and high dose group. The spermatogenic cells in seminiferous tubules showed decrease, apoptosis and unfix in the high dose group. Under transmission electron microscope, the PLC showed decreased lipid droplets, smooth endoplasmic reticulum and mitochondriae in the treated group. The mRNA expression of IGF-I increased in the low dose group, and the protein expression of StAR decreased in the middle and high dose group.

CONCLUSIONLactating exposure to DEHP may interfere with the synthesis of testosterone of PLC in male pubs, the decrease of StAR and the damage of PLC may be involved in it.

Animals ; Body Weight ; Diethylhexyl Phthalate ; adverse effects ; Female ; Germ Cells ; drug effects ; Insulin-Like Growth Factor I ; metabolism ; Lactation ; Leydig Cells ; cytology ; drug effects ; Male ; Organ Size ; Phosphoproteins ; metabolism ; Pregnancy ; Rats ; Rats, Sprague-Dawley ; Stem Cells ; cytology ; drug effects ; Testis ; Testosterone ; blood