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BACKGROUND: The International Agency for Research on Cancer has classified arsenic as a class I carcinogen. Oxidative DNA damage is a typical early precursor to recognized malignancies. The most sensitive early independent marker of oxidative DNA damage is believed to be 8-hydroxy-2 deoxyguanosine (8-OHdG). To date, research on the link between urinary arsenic and 8-OHdG has not been consistent. OBJECTIVE: This study was aimed at exploring the effects of urinary arsenic on 8-OHdG in human urine. METHODS: A literature search until January 2023 was performed on the PubMed, Cochrane Library, Web of Science, Embase, and Scopus databases through a combination of computer and manual retrieval. Stata 12.0 was used to examine the degree of heterogeneity among included studies. The percentage change and 95 % confidence interval (95 % CI) of 8-OHdG were calculated between populations exposed to different doses. We used a random effect model because the degree of heterogeneity exceeded 50 %. Sensitivity analysis and testing for publication bias were performed. RESULTS: This meta-analysis included nine studies, most of which were performed in China. After exposure to arsenic, urinary arsenic (per 10 µg/g creatinine increase) was associated with the increased 8-OHdG (% change = 41.49 %, 95 % CI: 19.73 %, 63.25 %). Subgroup analysis indicated that the percentage change in 8-OHdG in urine was more pronounced in people exposed to arsenic <50 µg/L (% change = 24.60 %, 95 % CI: 17.35 %, 37.85 %). In studies using total urinary arsenic content as an indicator, the percentage change in 8-OHdG in urine was more significant (% change = 60.38 %, 95 % CI: 15.08 %, 105.68 %). CONCLUSION: The 8-OHdG levels in human urine significantly increased after exposure to environmental arsenic, thus suggesting that arsenic exposure is correlated with oxidative DNA damage.

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The widespread use of neodymium oxide nanoparticles (NPs-Nd2O3) has caused environmental pollution and human health problems, thus attracting significant attention. Understanding the mechanisms of NPs- Nd2O3-induced genetic damage is of great significance for identifying early markers for NPs- Nd2O3-induced lung injury. At present, the mechanisms underlying DNA damage induced by NPs- Nd2O3 remain unclear. In this study, we performed functional assays on human bronchial epithelial cells (16HBEs) exposed to various concentrations of NPs-Nd2O3 and SD rats administered with a single intratracheal instillation with NPs-Nd2O3. Exposure to NPs-Nd2O3 could lead to DNA damage in 16HBE cells and rat lung tissue cells. We found a novel long non-coding RNA, named CNTFR-AS1, which was highly expressed after exposure to NPs-Nd2O3. Our data verified that transcription factor TP63 mediates the high expression levels of CNTFR-AS1, which in turn regulates NPs-Nd2O3-induced DNA damage in cells by inhibiting HR repair. Moreover, the levels of CNTFR-AS1 were correlated with the number of years worked by occupational workers. Collectively, these results demonstrate that CNTFR-AS1 acts as a novel DNA damage regulator in bronchial epithelial cells exposed to NPs-Nd2O3. Hence, our data provide a basis for the identification of lncRNAs as early diagnostic markers for rare earth lung injury.

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Mesenchymal stem cells (MSCs) are able to self-renew and have multi-lineage differentiation potential. However, studies on ovine umbilical cord-derived MSCs (UC-MSCs) are limited. Our study aimed to isolate and characterize ovine UC-MSCs. We successfully isolated ovine UC-MSCs and defined their surface marker profile using immunofluorescence analysis. Ovine UC-MSCs were found to be positive for cell surface markers CD13, CD29, CD44, CD90, and CD106, and negative for cell surface marker CD45. Assessment of the proliferation potential of ovine UC-MSCs showed that from day 3 of cultivation a plateau phase was reached. And compare to passage 10, 15, 20 cells, passage 5 cells proliferating the fastest. Differentiation of ovine UC-MSCs into adipocytes, osteocytes, and chondrocytes was also demonstrated by staining for tissue-specific markers and using quantitative real-time polymerase chain reaction for specific marker gene expression. This study demonstrates the existence of a MSC population within the ovine umbilical cord, which maintained a normal karyotype up to passage 20.

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In our previous work, we isolated Arbas Cashmere goat hair follicle stem cells (gHFSCs) and explored the pluripotency. In this study, we investigated the expression and putative role of Sox9 in the gHFSCs. Immunofluorescence staining showed that Sox9 is predominantly expressed in the bulge region of the Arbas Cashmere goat hair follicle, and also positively expressed in both nucleus and cytoplasm of the gHFSCs. When the cells were transfected using Sox9-shRNA, cell growth slowed down and the expression of related genes decreased significantly, cell cycle was abnormal, while the expression of terminal differentiation marker loricrin was markedly increased; cells lost the typical morphology of HFSCs; the mRNA and protein expression of gHFSCs markers and stem cell pluripotency associated factors were all significantly decreased; the expression of Wnt signaling pathway genes LEF1, TCF1,c-Myc were significantly changed. These results suggested that Sox9 plays important role in gHFSCs characteristics and pluripotency maintenance.

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Mesenchymal stem cells (MSCs) are one of the most promising cell populations for tissue engineering and regenerative medicine. Of utmost importance to MSC research is identification of MSC sources that are easily obtainable and stable. Several studies have shown that MSCs can be isolated from amniotic fluid. The sheep is one of the main types of farm animal, and it has many biophysical and biochemical similarities to humans. Here, we obtained MSCs from ovine amniotic fluid and determined the expansion capacity, surface and intracellular marker expression, karyotype, and multilineage differentiation ability of these ovine amniotic fluid mesenchymal stem cells (oAF-MSCs). Moreover, expression levels of differentiation markers were measured using reverse transcription-qPCR (RT-qPCR). Our phenotypic analysis shows that the isolated oAF-MSCs are indeed MSCs.

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Various factors affect the process of obtaining stable Arbas cashmere goat embryonic stem cells (ESCs), for example, the difficulty in isolating cells at the appropriate stage of embryonic development, the in vitro culture environment, and passage methods. With the emergence of induced pluripotent stem cell (iPSC) technology, it has become possible to use specific genes to induce somatic cell differentiation in PSCs. We transferred OCT4, SOX2, c-MYC, and KLF4 into Arbas cashmere goat fetal fibroblasts, then induced and cultured them using a drug-inducible system to obtain Arbas goat iPSCs that morphologically resembled mouse iPSCs. After identification, the obtained goat iPSCs expressed ESC markers, had a normal karyotype, could differentiate into embryoid bodies in vitro, and could differentiate into three germ layer cell types and form teratomas in vivo. We used microarray gene expression profile analysis to elucidate the reprogramming process. Our results provide the experimental basis for establishing cashmere goat iPSC lines and for future in-depth studies on molecular mechanism of cashmere goat somatic cell reprogramming.

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The trophoblast (TR) is the first to differentiate during mammalian embryogenesis and play a pivotal role in the development of the placenta. We used a dual inhibitor system (PD0325901 and CHIR99021) with mixed feeders to successfully obtain bovine trophoblast stem-like (bTS) cells, which were similar in phenotype to mouse trophoblast stem cells (TSCs). The bTS cells that were generated using this system continually proliferated, displayed a normal diploid karyotype, and had no signs of altered morphology or differentiation even after 150 passages. These cells exhibited alkaline phosphatase (AP) activity and expressed pluripotency markers, such as OCT4, NANOG, SOX2, SSEA-1, SSEA-4, TRA-1-60, and TRA-1-81, and TR lineage markers such as CDX2, as determined by both immunofluorescence and reverse transcription-polymerase chain reaction (RT-PCR). Additionally, these cells generated dome-like structures, formed teratomas when injected into NOD-SCID mice, and differentiated into placenta TR cells in vitro. The microarray analysis of bTS cells showed high expression levels of many TR markers, such as TEAD4, EOMES, GATA3, ETS2, TFAP2A, ELF5, SMARCA4 (BRG1), CDH3, MASH2, HSD17B1, CYP11A1, PPARG, ID2, GCM1, HAND1, TDK, PAG, IFN-τ, and THAP11. The expression of many pluripotency markers, such as OCT4, SOX2, NANOG, and GDF3, was lower in bTS cells compared with in vitro-produced blastocysts; however, compared with bovine fetal fibroblasts, the expression of these pluripotency markers was elevated in bTS cells. The DNA methylation status of the promoter regions of OCT4, NANOG, and SOX2 was investigated, which were significantly higher in bTS cells (OCT4 23.90%, NANOG 74.40%, and SOX2 8.50%) compared with blastocysts (OCT4 8.90%, NANOG 34.4%, and SOX2 3.80%). In contrast, two promoter regions of CDX2 were hypomethylated in bTS cells (13.80% and 3.90%) compared with blastocysts (18.80% and 9.10%). The TSC lines that were established in this study may be used either for basic research that is focused on peri-implantation and placenta development or as donor cells for transgenic animal production.

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The technology to reprogram human somatic cells back to pluripotency allows the production of patient-specific induced pluripotent stem cells (iPSCs) and holds a great promise for regenerative medicine. Choosing the most suitable cell type for induction and reducing the risk of viral transgene activation, especially oncogene activation, are important for iPSC research. To date, human dermal fibroblasts (HDFs) are the most frequent cell source used for iPSC generation, but they have several limitations. An invasive skin biopsy must be performed to obtain HDFs, and HDFs must be cultured for a prolonged period before they can be used for experiments. Thus, in an effort to develop a suitable source for iPSC studies to avoid the limitations mentioned above, we have here identified stromal cells derived from menstrual blood (MenSCs) as suitable candidates. In the present study, we found that MenSCs can be reprogrammed to pluripotent status by doxycycline-inducible lentiviral transduction of OCT4, SOX2, and KLF4. Additionally, we found that MenSCs have a significantly higher reprogramming efficiency than HDFs. The combination of OCT4 and SOX2 is sufficient to reprogram MenSCs into iPSCs without the use of c-MYC or KLF4. The resulting MenSC-iPSCs showed the same characteristics as human embryonic stem cells with regard to morphology, pluripotent markers, gene expression, and the epigenetic status of pluripotent-cell-specific genes. These cells were able to differentiate into various cell types of all 3 germ layers both in vitro and in vivo. Therefore, MenSCs may be a preferred candidate for generation of iPSCs.

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