Rno_circRNA_008646 regulates formaldehyde induced lung injury through Rno-miR-224 mediated FOXI1/CFTR axis.

Formaldehyde (FA) serves as a prevailing air pollutant, which has seriously threatened public health in recent years. Of all the known health effects, lung injury is one of the most severe risks. However, little is known about the circRNAs related molecular mechanism in the development of lung injury induced by FA. This study was designed to explore the potential roles of dysregulated circRNAs as well as its mechanism in FA-induced lung injury. In the present study, 24 male SD rats were exposed to formaldehyde (control, 0.5, 2.46 and 5 mg/m3) for 8 h per day for 8 weeks to induce lung injury. We used H&E staining to evaluate the histopathological changes of lung injury indifferent groups. The expression of circRNAs in lung tissue was detected by real-time PCR. Meanwhile, circRNA/miRNA/mRNA interaction networks were predicted by bioinformatics analysis. Our study revealed that formaldehyde exposure resulted in abnormal histopathological changes in lung tissues. Moreover, the expression of rno_circRNA_008646 was significantly higher in lung tissues of formaldehyde exposure rats than in control. Bioinformatics analysis showed that one potential target miRNA/mRNA for rno_circRNA_008646 was rno-miR-224/Forkhead Box I1 (FOXI1). Besides, luciferase report gene confirmed that there was targeted binding relationship between rno_circRNA_008646 and rno-miR-224, rno-miR-224 and FOXI1. Further verification experiments indicated that the expression of rno_circRNA_008646 was negatively correlated rno-miR-224, while it was positively correlated with FOXI1. JASPAR database showed transcription factor FOXI1 located in promotor of CF Transmembrane Conductance Regulator (CFTR). Both FOXI1 and CFTR were up-regulated in lung tissues after formaldehyde exposure. In conclusion, our findings suggested that formaldehyde may induce lung injury, and this may be caused by up-regulatedrno_circRNA_008646, which medicated rno-miR-224/FOXI1/CFTR axis.

Temporal trends in semen concentration and count among 327 373 Chinese healthy men from 1981 to 2019: a systematic review.

STUDY QUESTION: Are there temporal trends of sperm concentration (SC) and total sperm count (TSC) in Chinese healthy males from 1981 to 2019? SUMMARY ANSWER: Our result indicated a temporal decrease in SC and TSC among 327 373 healthy Chinese men in the recent four decades. WHAT IS KNOWN ALREADY: A review of 61 papers reported a temporal decline in SC and TSC from 1938 to 1990. This trend was later confirmed by a systematic review of 185 published papers from 1981 to 2013. However, the majority of the included individuals were from western countries. In China, whether SC and TSC have declined remains controversial. STUDY DESIGN, SIZE, DURATION: This systematic review of published articles used data extracted from Pubmed, Science Direct, Embase, China-National-Knowledge-Infrastructure (CNKI) and Wanfang Data to assess changes in SC and TSC in China from 1981 to 2019. PARTICIPANTS/MATERIALS, SETTING, METHODS: A total of 111 studies including 327 373 individuals who provided semen samples from 1981 to 2019 were extracted for the present analysis. Study selection and data extraction were performed by two independent researchers. The trends in SC and TSC were analysed using liner-regression and meta-regression before and after adjusting for potential covariates. Moreover, subgroups, categorised based on geographic region, fertility status or recruitment source, were also analysed. MAIN RESULTS AND THE ROLE OF CHANCE: SC declined significantly (slope liner-regression = -0.748 million/ml/year; P = 0.005; slope meta-regression = -0.824 million/ml/year; P < 0.001) between 1981 and 2019 in China. Trends for TSC was similar to that for SC (slope liner-regression = -2.073 million/year; P = 0.032; slope meta-regression = -2.188 million/year; P = 0.003). In subgroup meta-regression analyses, males with definite fertility had continuous declines in SC (slope northern group=-2.268, P = 0.009; slope southern group=-1.014, P = 0.009) and TSC (slope northern group=-9.675, P = 0.010; slope southern group=-3.215, P = 0.042). However, in the unselected group, where fertility status was unknown, the obvious downward trend in SC was only seen in males from Northern regions (slope = -0.836, P = 0.003). Another subgroup analysis demonstrated that obvious decreases in SC (slope = -1.432, P < 0.001) and TSC (slope=-4.315, P = 0.001) were only seen in volunteer groups but not in pre-pregnancy examination groups and other recruitment groups. The results changed minimally in multiple sensitivity analyses. LIMITATIONS, REASONS FOR CAUTION: The validity of the meta-analysis results was limited mainly by the quality of the included studies. Additionally, our study spanned many decades and the recommended criteria for some semen parameter assessments have significantly changed, which may bring about some unavoidable bias. Moreover, the data remain insufficient especially in some provinces of China. WIDER IMPLICATIONS OF THE FINDINGS: The present study is the first study to report significant decreases in SC and TSC in 327 373 healthy Chinese men between 1981 and 2019, indicating a serious reproductive health warning. Further studies on the causes of the declines are urgently needed. STUDY FUNDING/COMPETING INTEREST(S): D.Z. is supported by the National Natural Science Funding of China, Natural Science Funding of Shaanxi Province, Science Funding of Health Department, Shaanxi Province, Fundamental Research Funds for the Central University and the Project of Independent Innovative Experiment for Postgraduates in Medicine in Xi'an Jiaotong University. The authors have no conflicts of interests to declare. TRIAL REGISTRATION NUMBER: N/A.

Long-term exposure to formaldehyde induced down-regulation of SPO11 in rats.

Objective: Formaldehyde, a ubiquitous environmental contaminant, has long been suspected of causing male reproductive injury, but the underlying molecular mechanism remains largely unknown. SPO11 is a meiosis-related gene, whose absence can cause spermatogenesis arrest. Materials and methods: The present study aimed to explore the role of SPO11 in male reproductive injury induced by long-term formaldehyde exposure, so as to further understand the molecular mechanism of formaldehyde-induced male reproductive toxicity. Adult male Sprague-Dawley rats (n = 24, 245 ± 22 g) were randomly divided into four groups of six (n = 6) and were exposed to formaldehyde gas at doses of 0 (control), 0.5, 2.46 and 5 mg/m3, respectively, via inhalation for 8 consecutive weeks. Results and dissussion: The expression levels of SPO11 were detected in testicular tissues by real-time quantitative polymerase chain reaction, immunofluorescence, and Western blot. The results indicated that the expression of SPO11 was inhibited by formaldehyde exposure in a dose-dependent manner. Furthermore, the histopathological results showed that testicular seminiferous tubules were atrophied, spermatogenic cells were decreased and the lumina were oligozoospermic in the 2.46 and 5 mg/m3 formaldehyde exposure groups. Combined with the morphometric results, we found that the downregulated expression levels of SPO11 were consistent with the changes of testicular seminiferous tubule diameter and seminiferous epithelium height in testicular tissue, suggesting that SPO11 might be one of the main targets of formaldehyde reproductive toxicity. Conclusions: In conclusion, our findings indicated that SPO11 might be related to male reproductive injuries induced by long-term formaldehyde exposure.

Circular RNA-CDR1as is involved in lung injury induced by long-term formaldehyde inhalation.

OBJECTIVE: Formaldehyde (FA) is known to induce lung injury, but the underlying molecular mechanism remains largely unclear. CDR1as is an important member of the circular RNAs (circRNAs) family and functions as miRNA sponges with gene-regulatory potential. Our earlier circRNA microarray data showed CDR1as was highly expressed in lung tissue exposed to FA. However, the mechanism of circRNA-CDR1as mediates the FA-exposed lung injury is still unclear. This study aimed to explore the role of CDR1as in lung injury. MATERIALS AND METHODS: In this study, FA was inhaled at doses of 0.5, 2.46, and 5 mg/m3, respectively. After exposure 8 weeks, lung histopathological examination, lung injury score, and IL-1ß in bronchoalveolar lavage fluid (BALF) were determined. The expressions of CDR1as, rno-miR-7b and Atg7 were detected and the potential interaction of circRNA/miRNA/mRNA was predicted by bioinformatics analysis, including drawing circRNA/miRNA/mRNA interaction network, GO and KEGG analysis. RESULTS: Our results indicated FA inhalation upregulated the expression of CDR1as in lung tissues in a dose-dependent manner while the expression of rno-miR-7b decreased and Atg7 increased. Moreover, the alteration of CDR1as was positively correlated with lung injury. DISCUSSION AND CONCLUSIONS: CircRNA/miRNA/mRNA prediction further explained the possible effect mechanisms of CDR1as. These data implicated that CDR1as might be a critical regulator involved in lung injury induced by FA.

Association between X-ray repair cross-complementing group 1 Arg399Gln polymorphism and male infertility: An update meta-analysis.

Numerous studies concentrate on the association between X-ray repair cross-complementing group 1 (XRCC1) gene polymorphism and male infertility; however, the results remain inconclusive and inconsistent. Hence, this meta-analysis was conducted to get a precise estimation of the correlation. PubMed, Web of Science, Embase, Scopus and China National Knowledge Infrastructure (CNKI) databases were searched to identify the all relevant studies before 3 May 2020. Summary odds ratios (ORs) and 95% confidence intervals (95% CIs) were used to assess the strength of the association. Finally, six studies with 1,886 cases and 1,212 controls were included in our study. The result indicated that XRCC1 Arg399Gln polymorphism was significantly associated with male infertility under allelic model (A-allele vs. G-allele: OR = 1.183, p = .003), heterozygote genetic model (AA vs. GA: OR = 1.256, p = .027), recessive genetic model (AA vs. GG + GA: OR = 1.279, p = .012) and dominant genetic model (AA + GA vs. GG: OR = 1.218, p = .026). In addition, in Asian subgroup, statistic correlation remained significant in allelic model (A-allele vs. G-allele: OR = 1.145, p = .025) with rare heterogeneity (I2  = 0%). In summary, our meta-analysis suggested that XRCC1 Arg399Gln polymorphism was significantly associated with male infertility and the A-allele might be a risk factor for this disease, especially in Asians.

Pregnancy outcomes after day 5 versus day 6 blastocyst-stage embryo transfer: A systematic review and meta-analysis.

AIM: To compare the pregnancy outcomes after day 5 blastocyst-stage embryo transfers (BET) versus day 6 BET following vitrified-warmed cycle and to evaluate whether the number of embryos transferred and the chromosomal status of embryo influence effect estimates. METHODS: A literature search (PubMed, Embase and MEDLINE) up to January 2019 was conducted to identify studies where women with day 6 BET were compared to women with day 5 BET. Only studies published in English language, on peer-reviewed journal were considered eligible. The following subgroup analyses were performed: (i) number of embryos transferred and (ii) chromosomal status of embryo. RESULTS: From a total of 1956 articles identified, 23 observational studies were included in the meta-analysis. We observed that day 6 BET were associated with lower implantation rate (risk ratio, RR: 1.17, 95% confidence interval, CI: 1.10-1.24), clinical pregnancy rate (RR: 1.17, 95% CI: 1.10-1.24), ongoing pregnancy rate (RR: 1.15, 95% CI: 1.07-1.24) and live birth rate (RR: 1.22, 95% CI: 1.11-1.33) than day 5 BET following vitrified-warmed cycle. The subgroup analysis found that the superiority of day 5 BET compared with day 6 BET is influenced by the number of embryos transferred and chromosomal status of embryos. CONCLUSION: Current evidence shows that day 5 BET is superior to day 6 BET following vitrified-warmed cycle in clinical practice. Due to the overall low quality of available evidence, more larger and well-conducted studies are needed to compare the pregnancy outcomes between day 5 and day 6 BET before drawing a clear conclusion.

Is vanishing twin syndrome associated with adverse obstetric outcomes of ART singletons? A systematic review and meta-analysis.

PURPOSE: The objective of our meta-analysis was to estimate the effect of VTS on obstetric outcomes of ART singletons. METHODS: PubMed, Embase, MEDLINE, and ClinicalTrials.gov were searched up to January 2019 to find studies reporting the obstetric outcomes of ART singletons with VTS. Dichotomous data were expressed as odds ratios (OR) with 95% confidence intervals (CI). Continuous data were expressed as weighted mean difference (WMD) with 95% CI. RESULTS: A total of 17 observational studies encompassing more than 60,000 ART singletons were included in this meta-analysis. The impact of VTS on singletons was highly dependent on the definition of VTS, precisely, the vanishing timing and intrauterine growth stage. When VTS happened at or before 14 weeks, regardless of intrauterine growth stage, there were no differences in terms of gestational age (GA) [WMD = - 0.08, 95% CI = - 0.27, 0.10], preterm birth (< 37 weeks) (PTB) [OR = 1.23, 95% CI = 0.89, 1.70], and low birth weight (< 2.5 kg) (LBW) [OR = 1.56, 95% CI = 1.00, 2.43] in original singletons versus singleton with VTS. On the contrary, VTS occurred after 14 weeks was associated with significantly shorter GW and lower BW, as well as higher risks of PTB and LBW. When the sac reduced in VTS was an empty gestational sac, there would be no differences in GW, PTB, and LBW between singletons versus singletons with VTS, whereas the loss of a fetus with cardiac-activity was associated with adverse obstetric outcomes. CONCLUSIONS: This meta-analysis suggests whether or not VTS is harmful to obstetric outcomes is highly dependent on the vanishing timing and intrauterine growth stage.

CircRNA expression profile and functional analysis in testicular tissue of patients with non-obstructive azoospermia.

BACKGROUND: Non-obstructive azoospermia (NOA) is a multifactorial disorder whose molecular basis remains largely unknown. Circular RNAs (CircRNAs), a novel class of endogenous RNAs, have been recognized to play important roles in many biological processes. However, little is known about the expression patterns and functions of circRNAs in human testes involved in NOA. METHODS: In this study, the testicular circRNA expression profile were explored in NOA patients and the controls by high-throughput circRNA microarray. Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) was performed to confirm the microarray data. Bioinformatics analyses including the circRNA/miRNA/mRNA interaction network, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were used to predict the functions of differentially expressed circRNAs. RESULTS: A total of 368 differentially down-regulated and 526 up-regulated circRNAs were detected in NOA patients. These findings have been verified by qRT-PCR on 6 selected circRNAs. Among these differentially expressed circRNAs, the hsa_circRNA_0023313 was obviously up-regulated in testicular tissue of NOA patients. The most likely potential target miRNA for hsa_circRNA_0023313 include hsa-miR-520d-3p, hsa-miR-373-3p, hsa-miR-372-3p, hsa-miR-302c-3p and hsa-miR-130b-5p. Function analysis indicated that hsa_circRNA_0023313 was ubiquitin-protein transferase activity and chromatin binding. KEGG analysis revealed that the top five pathways related to hsa_circRNA_0023313 were endocytosis, meiosis, FoxO signaling pathway, ubiquitin mediated proteolysis and AMPK signaling pathway. CONCLUSIONS: This is the first report that the testicular circRNA expression profile is altered in NOA patients indicating circRNAs might play important roles in regulating spermatogenesis and be potential biomarkers for the diagnosis and treatment of NOA.

Formaldehyde inhalation triggers autophagy in rat lung tissues.

Formaldehyde (FA), a ubiquitous environmental contaminant, has long been suspected of causing lung injury. However, the molecular and cellular mechanisms underlying this phenomenon remain elusive. The aim of this study was to elucidate the role of autophagy in lung injury induced by FA inhalation. In this study, lung weight coefficient, interleukin 8 in bronchoalveolar fluid, and histopathological examination were used to evaluate the lung injury. Moreover, electron microscopy, Western blotting for the ratio of LC3-II/LC3-I were used to detect autophagy in lung tissues. Our results indicated that the lung toxicity of FA inhalation is dose dependent. Lung weight coefficient, inflammatory response, and histopathological structure in the 0.5 mg/m3 FA exposure group showed no obvious changes compared with the control. However, exposure to 5 and 10 mg/m3 FA produced lung injury including pulmonary edema, histological changes, and inflammatory responses. Furthermore, the alterations of autophagy correlated with lung injury. Taken together, these data indicate that FA exposure triggers autophagy of alveolar epithelial cells, which might play a pivotal role in lung injury.

Formaldehyde exposure inhibits the expression of mammalian target of rapamycin in rat testis.

Formaldehyde (FA), a ubiquitous environmental pollutant, has long been suspected of causing adverse male reproductive effects. However, the molecular and cellular mechanisms underlying this phenomenon remain elusive. The overall aim of this study is to clarify the role of mammalian target of rapamycin (mTOR) in male reproductive injuries induced by FA exposure, by which we can further understand the molecular mechanism of FA male reproductive toxicity. In this study, immunohistochemistry, Western blotting, and reverse transcription polymerase chain reaction analysis were used to detect the expression of mTOR molecule in testicular tissues. We found that FA exposure inhibits the expression of mTOR in a dose-dependent manner. Combined with our earlier finding, we found the decreasing expression of mTOR in testicular tissue were consistent with the changes of testicular structure and autophagy levels. In summary, our data suggested that mTOR molecule might be involved in male reproductive injuries induced by FA exposure.

The role of KCa3.1 channels in cardiac fibrosis induced by pressure overload in rats.

The intermediate-conductance Ca(2+)-activated K(+) (KCa3.1) channels play a pivotal role in the proliferation and collagen secretion of cardiac fibroblasts. However, their contribution in cardiac fibrosis remains unknown. This study was designed to investigate whether KCa3.1 channels mediate the development of cardiac fibrosis. Pressure-overloaded rats were induced by abdominal aortic constriction and treated without or with KCa3.1 blocker (TRAM-34) or angiotensin type 1 receptor blocker (losartan) for 2 weeks. Besides the increase of blood pressure, angiotensin (Ang) II level in the plasma and myocardium, left ventricle mass and hydroxyproline concentration, myocardial hypertrophy, as well as significant collagen deposition in the perivascular regions and interstitium of the myocardium were observed in pressure-overloaded rats. The expression of leukocyte differentiation antigens (CD45 and CD3), macrophage surface marker (F4/80), tumor necrosis factor alpha, and monocyte chemotactic protein-1 (MCP-1) also significantly increased. All these alterations were prevented by losartan and TRAM-34. TRAM-34 also reduced the increase of renin and angiotensinogen in the plasma and myocardium of pressure-overloaded rats. Ang II promoted the migration of monocytes through endothelial cells and the secretion of MCP-1 from human umbilical vein endothelial cells in vitro, which was inhibited by TRAM-34. In conclusion, the present study demonstrates that TRAM-34 alleviates cardiac fibrosis induced by pressure overload, which is related to its inhibitory action on KCa3.1 channels and Ang II level. Our findings indicate that the inhibition of KCa3.1 channels may represent a novel approach of preventing the progression of cardiac fibrosis, and also add to the already developing literature of promising targets for TRAM-34.

Formaldehyde exposure induces autophagy in testicular tissues of adult male rats.

Formaldehyde, a ubiquitous environmental pollutant, has long been suspected of causing adverse male reproductive effects. However, the molecular and cellular mechanisms underlying this phenomenon remain elusive. The overall aim of this study is to clarify the role of autophagy in male reproductive injuries induced by formaldehyde exposure, by which we can further understand the molecular mechanism of spermatogenesis and develop new targets for prevention and treatment of male infertility. In this study, electron microscopy, Western blot, and RT-PCR analysis were used to detect autophagy in testicular tissues. Moreover, testicular weights, histopathology, and morphometry were used to evaluate the reproductive injuries of formaldehyde exposure. We found that formaldehyde exposure-induced autophagy in testicular tissues was dose dependent. Increasing autophagosomes in spermatogenetic cells was observed by electron microscopy in formaldehyde exposure group. In addition, RT-PCR and Western blot analysis showed the transcription levels of the LC3-II, as well as the conversion from LC3-I to LC3-II, an indicator of autophagy, significantly increased in testicular tissue of formaldehyde exposure group in a dose dependent manner when compared with those in control group. Furthermore, the alterations of autophage were basically consistent with the changes in testicular weight and morphologic findings. In summary, formaldehyde exposure triggered autophagy, and autophagy may be a scathing factor responsible for male reproductive impairment induced by formaldehyde.

Association between DNA repair genes (XPD and XRCC1) polymorphisms and susceptibility to age-related cataract (ARC): a meta-analysis.

BACKGROUND: DNA repair gene (XPD and XRCC1) polymorphisms have been considered as risk factors for the development of age-related cataract (ARC). To confirm the association between DNA repair gene (XPD and XRCC1) polymorphisms and the risk of ARC, a meta-analysis was conducted. METHODS: A search was made of published literature from Institute for Scientific Information (ISI) Web of Knowledge, PubMed, Google Scholar, China National Knowledge Infrastructure (CNKI), and Wanfang Data. In addition, all studies evaluating the association between DNA repair genes (XPD and XRCC1) polymorphisms and the risk for ARC were included in our analysis. Pooled odds ratio (OR) and 95 % confidence interval (CI) were calculated by using fixed- or random-effects model. The Egger's test was used to check the publication bias. RESULTS: Six studies on XRCC1 Arg399Gln (1,300 cases, 1,222 controls) and five studies on XPD Lys751Gln (1,092 cases, 1,061 controls) were included. For the XPD Lys751Gln (A/C) SNP, the overall analysis demonstrated that the CC genotype showed a significant association with a decreased risk for ARC compared with the AA genotype (OR = 0.59, 95 % CI, 0.38-0.92, P = 0.019). Similarly, the CC genotype showed a significant association with a decreased risk for ARC compared with the (AA + AC) genotype (OR = 0.65, 95 % CI, 0.43-0.98, P = 0.040). Subgroup analysis showed that the association between the CC genotype and decreased risk for ARC is statistically significant in Caucasians (OR = 0.41, 95 % CI, 0.24-0.73, P = 0.002) but not in Asians (OR = 1.06, 95 % CI, 0.51-2.19, P = 0.877). For the XRCC1 Arg399Gln (G/A) SNP, the overall analysis demonstrated that the A allele showed a significant association with an increased risk for ARC compared with the G allele (OR = 1.16, 95 % CI, 1.03-1.31, P = 0.015). Subgroup analyses exhibited that the association between the A allele and the risk for ARC was statistically significant in Asians (OR = 1.23, 95 % CI, 1.07-1.41, P = 0.003) but not in Caucasians (OR = 0.94, 95 % CI, 0.73-1.22, P = 0.660). Compared with the GG genotype, the GA genotype showed a significant association with an increased risk for ARC in Asians (OR = 1.32, 95 % CI, 1.08-1.61, P = 0.006) but not in Caucasians (OR = 0.58, 95 % CI, 0.27-1.26, P = 0.171). The Egger's test did not reveal an obvious publication bias among the included studies. CONCLUSIONS: Our meta-analysis suggested that the CC genotype of XPD Lys751Gln (A/C) SNP seemed to portend a decreased risk for ARC in Caucasian populations but not in Asian populations. The A allele and GA genotype of XRCC1 Arg399Gln (G/A) SNP might increase risk for ARC in Asian populations but not in Caucasian populations. More researches with larger and more different ethnic populations on this issue are therefore necessary.

A detection model of testis-derived circular RNAs in serum for predicting testicular sperm retrieval rate in non-obstructive azoospermia patients.

BACKGROUND: Microdissection testicular sperm extraction is an effective method to retrieve sperm from non-obstructive azoospermia patients. However, its successful rate is less than 50%. OBJECTIVES: To identify the predictive value of circular RNAs in serum for sperm retrieval rate in non-obstructive azoospermia patients. MATERIALS AND METHODS: 180 non-obstructive azoospermia patients were recruited in this study, including 84 individuals with successful sperm retrieval and 96 individuals with failed sperm retrieval. Our study contained two phases. First, 20 patients, selected from the 180 patients, were included in screening cohort. In this cohort, the top 20 circular RNAs from our previous testicular circRNA profiles were verified between successful and failed sperm retrieval groups using real-time polymerase chain reaction. Six circular RNAs with the most significantly different expressions were selected for further verification. Second, the 180 patients were included as discovery cohort to verify the six circular RNAs. Circular RNAs were extracted from serum in each participant. Logistic regression analysis was further performed to identify the predictive value and the area under the curve analysis was used to evaluate diagnostic efficiency, sensitivity, and specificity. RESULTS: Six circular RNAs including hsa_circ_0058058, hsa_circ_0008045, hsa_circ_0084789, hsa_circ_0000550, hsa_circ_0007422, and hsa_circ_0004099 showed aberrant expressions between the successful and failed sperm retrieval group. In addition, both single-circular RNA panels and multi-circular RNA panels were finally verified to be significant in predicting sperm retrieval rate. Notably, multi-circular RNAs panels demonstrated better predictive abilities compared with single-circRNA panels, and the combined panel of six-circular RNAs (risk score = 1.094×hsa_circ_0058058+0.697×hsa_circ_0008045+0.718×hsa_circ_0084789-0.591×hsa_circ_0000550-0.435×hsa_circ_0007422-1.017×hsa_circ_0004099-1.561) exhibited the best predictive ability in the present study with an AUC of 0.977, a sensitivity of 91.7% and a specificity of 86.5%. A higher risk score indicated a higher risk of failure in sperm retrieval. DISCUSSION AND CONCLUSION: Our study was the first to report that testis-derived circular RNAs in serum have the ability to predict sperm retrieval rate in non-obstructive azoospermia patients, whether it is a single-circular RNA or a combination of multi-circular RNAs.

Participation of autophagy in acute lung injury induced by seawater.

Seawater drowning can lead to acute lung injury (ALI). However, the molecular and cellular mechanisms underlying this phenomenon remain elusive. The overall aim of this study is to clarify the role of autophagy in seawater-induced ALI, by which we can further understand the molecular mechanism and develop new methods for prevention and treatment of seawater-induced ALI. In this study, electron microscopy, western blot analysis, and RT-PCR were used to detect autophagy in lung tissues. Moreover, arterial blood gas analysis, lung weight coefficient, TNF-α, IL-8 in bronchoalveolar fluid (BALF), histopathology were used to detect the lung injury of seawater exposure. An inhibitor of autophagy (3-Methyladenine, 3-MA) was injected intraperitoneally before seawater exposure to further explore the role of autophagy in ALI. Electron microscopy revealed increasing autophagosomes in alveolar epithelial cell in seawater group compared with the control. The transcription and expression levels (mRNA and protein levels) of the LC3 II significantly increased in lung tissue of seawater group compared with those in control group. Furthermore, the alterations of autophage were basically consistent with the changes in arterial blood gas, lung weight coefficient, TNF-α, IL-8 in BALF and morphologic findings. In addition, inhibition of autophagy by 3-MA partly ameliorated seawater-induced ALI, as indicated by reduced lung weight coefficient and TNF-α in BALF, as well as increased PaO2. In conclusion, seawater aspiration triggered autophagy, and autophagy may be a scathing factor responsible for ALI induced by seawater.

Effects of low-dose, long-term formaldehyde exposure on the structure and functions of the ovary in rats.

Formaldehyde (FA) is a ubiquitous environmental pollutant. However, the effects of FA exposure on reproduction are still a matter of scientific controversy. In this study, we assessed the ovarian toxicity of long-term, low-dose FA exposure in rats and explored the potential oxidative stress mechanisms. A total of 30 Sprague-Dawley female rats were randomly allotted to three groups, in which rats were exposed to FA at a dose of 0 mg/m(3) (control), 0.5 mg/m(3) and 2.46 mg/m(3), respectively, by inhalation consecutively for 60 days. The results showed that the ovarian toxicity of FA is dose dependent. Ovarian structure and function in the group of rats exposed to 0.5 mg/m(3) FA showed no obvious difference when compared with those in the control group. However, the activity of superoxide dismutase was significantly decreased, whereas the level of malondialdehyde was significantly increased in ovaries of rats exposed to 2.46 mg/m(3) FA. Moreover, histopathological results demonstrated that the number and size of mature follicles significantly decreased, vascular congestion and interstitial edema in the ovaries of rats exposed to 2.46 mg/m(3) FA. In conclusion, this study may suggest that the FA level of 0.5 mg/m(3) can be considered as a safe level for FA exposure, but long-term FA exposure at a dose of 2.46 mg/m(3) has a harmful effect on ovary by inducing oxidative stress.

GRPR down-regulation inhibits spermatogenesis through Ca2+ mediated by PLCß/IP3R signaling pathway in long-term formaldehyde-exposed rats.

Formaldehyde (FA), which is known as an air pollutant, has been proven to induce male infertility. However, the underlying mechanism of FA-induced male infertility remains elusive. In this study, 24 male SD rats were exposed to different levels of FA (0, 0.5, 2.46, and 5 mg/m3) for eight consecutive weeks. Through HE staining and sperm smear, we observed that FA exposure resulted in spermatogenic injury and the sperm quality decreased in rats. The qRT-PCR and Western blot analysis further revealed that GRPR was down-regulated in testicular tissues of FA-exposed rats as well as primary spermatogenic cells. Meanwhile, ZDOCK uncovered an interaction between GRPR and PLCß. In addition, the CCK8, Fluo 3-AM and Flow cytometry results showed that FA exposure suppressed the expression of GRPR, PLCß and IP3R, consequently reducing the Ca2+ concentration in spermatogenic cells, inducing apoptosis and inhibiting proliferation of spermatogenic cells. Moreover, rescue experiments confirmed that promoting GRPR could improve intracellular Ca2+ concentration by upregulating PLCß and IP3R, partially reducing the apoptosis and promoting the proliferation of FA-treated spermatogenic cells. These findings revealed that GRPR participates in spermatogenesis through Ca2+ mediated by the PLCß/IP3R signaling pathway in FA-exposed rats.

Rno_circRNA_006061 participates in apoptosis induced by formaldehyde via activating p38/ATF3 pathway.

Formaldehyde, a common indoor air pollutant, is significantly toxic to the respiratory system, whereas its mechanism is unclear. CircRNAs exert critical functions via sponging microRNAs (miRNAs). To evaluate the effect of long-term formaldehyde exposure on rno_circRNA_006061 expression profiles, the downstream targets and signaling pathways associated with rno_circRNA_006061 were predicted and validated using bioinformatics methods and dual-luciferase reporter assay. Previously, our circRNA microarray showed that rno_circRNA_006061 was up-regulated in the formaldehyde-exposed lung tissue. Subsequently, bioinformatics analysis predicted that rno_circRNA_006061 bound to rno-miR-128-3p and co-regulated the p38/ATF3 signaling pathway. Meanwhile, the expressions of rno_circRNA_006061, rno-miR-128-3p and p38 were correlated with the lung histomorphopathological injury assessment. Furthermore, TUNEL and Bax/Bcl-2 ratio results revealed that up-regulated rno_circRNA_00606 induced by formaldehyde stimulated apoptosis in the lung. After the knockdown of rno_circRNA_006061, the expression of rno-miR-128-3p increased and the expression of p38 decreased slightly, which partially restored formaldehyde-induced apoptosis in alveolar epithelial cells. In conclusion, our study hinted that the rno_circRNA_006061 might enhance p38/ATF3 pathway expression via sponging the rno-miR-128-3p, thus significantly promoting apoptosis in lung tissues, which may provide potential new targets for preventing and treating lung injury by formaldehyde inhalation.

Association between XRCC1 single-nucleotide polymorphisms and infertility with idiopathic azoospermia in northern Chinese Han males.

X-ray repair cross-complementing group 1 (XRCC1) is a scaffold protein that plays a critical role in DNA base excision repair. To explore the association between XRCC1 single-nucleotide polymorphisms and infertility with idiopathic azoospermia in a northern Chinese Han population, PCR restriction fragment length polymorphism was used to genotype a SNP locus (rs25487) of XRCC1 in 112 patients with idiopathic azoospermia and 156 healthy controls. Furthermore, nucleotide sequences were sequenced. The results showed that, compared with GG genotype, the GA and GA+AA genotypes showed a significant association with an increased risk of idiopathic azoospermia (OR 2.119, 95% CI 1.245-3.606, P=0.005), (OR 2.052, 95% CI 1.227-3.431, P=0.006) respectively. Meanwhile, the A allele frequency was significantly higher in azoospermic patients than that in controls (OR 1.472, 95% CI 1.029-2.105, P=0.034). The substitutions bring about an amino acid alteration: G→A changes the arginine residue into glutamine. In conclusion, the SNP locus rs25487 of XRCC1 could be a marker for genetic susceptibility to idiopathic azoospermia and the A allele might be a risk gene of idiopathic azoospermia in the northern Chinese Han population.

Semen Quality Following Long-term Occupational Exposure to Formaldehyde in China.

Importance: The potential effects of long-term occupational exposure to formaldehyde (FA) on human semen quality is not clear. Objective: To assess whether long-term occupational exposure to FA is associated with semen quality. Design, Setting, and Participants: This population-based cohort study was conducted from June 1 to June 30, 2021, in Xi'an, China. Participants were adults aged 23 to 40 years who had lived in the study area for 24 months or longer. Data analysis was performed from September 1 to October 1, 2021. Exposures: Long-term occupational exposure to FA was measured using a formaldehyde detector, and the FA exposure index (FEI) was calculated as follows: FEI = final concentration of FA (mg/m3) × work time during a workday (hour) × cumulative workdays (year). Main Outcomes and Measures: Semen samples were collected by masturbation after 3 to 7 days of abstinence and were then assessed by the computer-automated semen analysis system, Baso-Papanicolaou staining, and sperm-chromatin structure assay. Results: A total of 205 men (mean [SD] age, 29.49 [3.64] years), with 124 individuals in the FA exposure group (mean [SD] FEI, 73.72 [54.86]) and 81 age-matched controls, were included in the final analysis. Long-term personal occupational exposure to FA was significantly associated with poor semen quality. Specifically, a 1-unit increase in FEI was associated with a change of -0.99% (95% CI, -1.00% to -0.98%) in total sperm motility, -0.99% (95% CI, -0.99% to -0.97%) in progressive sperm motility, -0.05% (95% CI, -0.08% to -0.02%) in curvilinear velocity, -0.07% (95% CI, -0.10% to -0.04%) in straight line velocity, -0.07% (95% CI, -0.10% to -0.04%) in time-average velocity, -0.98% (95% CI, -0.99% to -0.93%) in normal sperm morphology, -0.24% (95% CI, -0.35% to -0.11%) in seminal neutral glucosidase, -0.61% (95% CI, -0.66% to -0.56%) in seminal plasma zinc, 0.52% (95% CI, 0.15% to 1.02%) in beat cross frequency, and 0.10% (95% CI, 0.06% to 0.14%) in the DNA fragmentation index. These associations remained significant after adjusting for confounding factors. Furthermore, subgroup analysis found that high levels of oxidative stress might promote the associations between FA exposure and semen quality. Conclusions and Relevance: This study found an association between long-term occupational exposure to FA and semen quality. This deterioration was dose and time dependent and might be induced by oxidative stress.