Varieties of RNA modification form the epitranscriptome for post-transcriptional regulation. 5-Methylcytosine (5-mC) is a sparse RNA modification in messenger RNA (mRNA) under physiological conditions. The function of RNA 5-hydroxymethylcytosine (5-hmC) oxidized by ten-eleven translocation (Tet) proteins in Drosophila has been revealed more recently. However, the turnover and function of 5-mC in mammalian mRNA have been largely unknown. Tet2 suppresses myeloid malignancies mostly in an enzymatic activity-dependent manner, and is important in resolving inflammatory response in an enzymatic activity-independent way. Myelopoiesis is a common host immune response in acute and chronic infections; however, its epigenetic mechanism needs to be identified. Here we demonstrate that Tet2 promotes infection-induced myelopoiesis in an mRNA oxidation-dependent manner through Adar1-mediated repression of Socs3 expression at the post-transcription level. Tet2 promotes both abdominal sepsis-induced emergency myelopoiesis and parasite-induced mast cell expansion through decreasing mRNA levels of Socs3, a key negative regulator of the JAK-STAT pathway that is critical for cytokine-induced myelopoiesis. Tet2 represses Socs3 expression through Adar1, which binds and destabilizes Socs3 mRNA in a RNA editing-independent manner. For the underlying mechanism of Tet2 regulation at the mRNA level, Tet2 mediates oxidation of 5-mC in mRNA. Tet2 deficiency leads to the transcriptome-wide appearance of methylated cytosines, including ones in the 3' untranslated region of Socs3, which influences double-stranded RNA formation for Adar1 binding, probably through cytosine methylation-specific readers, such as RNA helicases. Our study reveals a previously unknown regulatory role of Tet2 at the epitranscriptomic level, promoting myelopoiesis during infection in the mammalian system by decreasing 5-mCs in mRNAs. Moreover, the inhibitory function of cytosine methylation on double-stranded RNA formation and Adar1 binding in mRNA reveals its new physiological role in the mammalian system.

Autophagy is a complex ''self-eating'' process and could be utilized for cell survival under stresses. Statins, which could reduce apoptosis in mesenchymal stem cells (MSCs) during both ischemia and hypoxia/serum deprivation (H/SD), have been proved to induce autophagy in some cell lines. We have previously shown that atorvastatin (ATV) could regulate AMP-activated protein kinase (AMPK), a positive modulator of autophagy, in MSCs. Thus, we hypothesized that autophagy activation through AMPK and its downstream molecule mammalian target of rapamycin (mTOR) may be a novel mechanism of ATV to protect MSCs from apoptosis during H/SD. Here, we demonstrated that H/SD induced autophagy in MSCs significantly as identified by increasing acidic vesicular organelle-positive cells, type II of light chain 3 (LC3-II) expression, and autophagosome formation. The levels of H/SD-induced apoptosis were increased by autophagy inhibitor 3-methyladenine (3-MA) while decreased by rapamycin, an autophagic inducer. ATV further enhanced the autophagic activity observed in MSCs exposed to H/SD. Treatment with 3-MA attenuated ATV-induced autophagy and abrogated the protective effects of ATV on MSC apoptosis, while rapamycin failed to cause additional effects on either autophagy or apoptosis compared with ATV alone. The phosphorylation of AMPK was upregulated whereas the phosphorylation of mTOR was downregulated in ATV-treated MSCs, which were both attenuated by AMPK inhibitor compound C. Further, treatment with compound C reduced the ATV-induced autophagy in MSCs under H/SD. These data suggest that autophagy plays a protective role in H/SD-induced apoptosis of MSCs, and ATV could effectively activate autophagy via AMPK/mTOR pathway to enhance MSC survival during H/SD.

Substantial studies indicated that fetal macrosomia was associated with detrimental pregnancy outcomes, and increased susceptibility to metabolic diseases in later life. However, investigations into the association between placental microbiota and fetal macrosomia are limited. We aimed to profile the placental microbiota of fetal macrosomia and study whether they relate to clinical characteristics. Placenta samples were collected from fetal macrosomias and newborns with normal birth weight. The clinical characteristics, umbilical cord blood parameters were measured, and placental microbiota were sequenced and further analysed. The clinical characteristics of infants and mothers and umbilical cord blood parameters were significantly different between macrosomias and controls. The relative abundance of microbiota sequences revealed that microbial structures of the placenta differed significantly between macrosomia and controls. Regression analysis showed a cluster of key operational taxonomic unit (OTUs), phyla and genera were significantly correlated with body length, ponderal index and placenta weight, body weight increase during pregnancy of mothers, and cord blood IGF-1 and leptin concentrations. In conclusion, our study for the first time explored the relationship between placental microbiota profile and fetal macrosomia. It is novel in showing that a distinct placental microbiota profile is present in fetal macrosomia, and is associated with clinical characteristics of mothers and newborns.

The innate immune response is a rapid response to pathogens or danger signals. It is precisely activated not only to efficiently eliminate pathogens but also to avoid excessive inflammation and tissue damage. cis-Regulatory element–associated chromatin architecture shaped by epigenetic factors, which we define as the epiregulome, endows innate immune cells with specialized phenotypes and unique functions by establishing cell-specific gene expression patterns, and it also contributes to resolution of the inflammatory response. In this review, we focus on two aspects: ( a) how niche signals during lineage commitment or following infection and pathogenic stress program epiregulomes by regulating gene expression levels, enzymatic activities, or gene-specific targeting of chromatin modifiers and ( b) how the programed epiregulomes in turn mediate regulation of gene-specific expression, which contributes to controlling the development of innate cells, or the response to infection and inflammation, in a timely manner. We also discuss the effects of innate immunometabolic rewiring on epiregulomes and speculate on several future challenges to be encountered during the exploration of the master regulators of epiregulomes in innate immunity and inflammation. Expected final online publication date for the Annual Review of Immunology, Volume 39 is April 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

: In contrast to cardiomyocytes, autophagy in cardiac microvascular endothelial cells (CMECs) during ischemia/reperfusion (I/R) injury has not been fully investigated. Tongxinluo (TXL), a traditional Chinese medicine, was shown to be vascular protective. We aimed to elucidate the role of autophagy and its regulatory mechanisms by TXL in CMECs subjected to I/R injury. CMECs were exposed to different treatments for 30 minutes and subjected to hypoxia/reoxygenation each for 2 hours. The results indicated that hypoxia/reoxygenation significantly induced autophagy, as identified by an increased number of monodansylcadaverine-positive CMECs, increased autophagosome formation, and a higher type II/type I of light chain 3 ratio, but not Beclin-1 expression. Autophagy inhibition using 3-methyladenine was proapoptotic, but rapamycin-induced autophagy was antiapoptotic. TXL enhanced autophagy and decreased apoptosis in a dose-dependent manner, reaching its largest effect at 800 μg/mL. 3-methyladenine attenuated the TXL-promoted autophagy and antiapoptotic effects, whereas rapamycin had no additional effects compared with TXL alone. TXL upregulated mitogen-activated protein kinase and extracellular signal-regulated kinase (ERK) phosphorylation; however, PD98059 abrogated ERK phosphorylation and decreased autophagy and increased apoptosis compared with TXL alone. These results suggest that autophagy is a protective mechanism in CMECs subjected to I/R injury and that TXL can promote autophagy through activation of the mitogen-activated protein kinase/ERK pathway.

ObjectiveTo explore the genotype distribution of high-risk human papillomavirus (HR-HPV) and its attribution to different grades of cervical lesions in rural China, which will contribute to type-specific HPV screening tests and the development of new polyvalent HPV vaccines among the Chinese population.MethodsOne thousand two hundred ninety-two subjects were followed based on the Shanxi Province Cervical Cancer Screening Study I (SPOCCS-I), and screened by HPV DNA testing (hybrid capture® 2 [HC2]), liquid-based cytology (LBC), and if necessary, directed or random colposcopy-guided quadrant biopsies. HPV genotyping with linear inverse probe hybridization (SPF10-PCR-LiPA) was performed in HC2 positive specimens. Attribution of specific HR-HPV type to different grades of cervical lesions was estimated using a fractional contribution approach.ResultsAfter excluding incomplete data, 1,274 women were included in the final statistical analysis. Fifteen point two percent (194/1,274) of women were HR-HPV positive for any of 13 HR-HPV types (HPV16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, and 68) and the most common HR-HPV types were HPV16 (19.1%) and HPV52 (16.5%). The genotypes most frequently detected in HR-HPV-positive cervical intraepithelial neoplasia grade 1 (CIN1) were HPV52 (24.1%), HPV31 (20.7%), HPV16 (13.8%), HPV33 (13.8%), HPV39 (10.3%), and HPV56 (10.3%); in HR-HPV-positive cervical intraepithelial neoplasia grade 2 or worse (CIN2+): HPV16 (53.1%), HPV58 (15.6%), HPV33 (12.5%), HPV51 (9.4%), and HPV52 (6.3%). HPV52, 31, 16, 33, 39, and 56 together contributed to 89.7% of HR-HPV-positive CIN1, and HPV16, 33, 58, 51, and 52 together contributed to 87.5% of CIN2+.ConclusionIn summary, we found substantial differences in prevalence and attribution of CINs between different oncogenic HPV types in a rural Chinese population, especially for HPV16, 31, 33, 52, and 58. These differences may be relevant for both clinical management and the design of preventive strategies.

Dendritic cells (DCs) are critical to initiate the immune response and maintain tolerance, depending on different status and subsets. The expression profiles of microRNAs (miRNAs) in various DC subsets and haematopoietic stem cells (HSCs), which generate DCs, remain to be fully identified. Here we examine miRNomes of mouse bone marrow HSCs, immature DCs, mature DCs and IL-10/NO-producing regulatory DCs by deep sequencing. We identify numerous stage-specific miRNAs and histone modification in HSCs and DCs at different differentiation stages. miR-30b, significantly upregulated via a TGF-beta/Smad3-mediated epigenetic pathway in regulatory DCs, can target Notch1 to promote IL-10 and NO production, suggesting that miR-30b is a negative regulator of immune response. We also identify miRNomes of in vivo counterparts of mature DCs and regulatory DCs and systematically compare them with DCs cultured in vitro. These results provide a resource for studying roles of miRNAs in stem cell biology, development and functional regulation of DC subsets.

Risk stratification of human papillomavirus (HPV)-positive women is needed to avoid excessive colposcopy and overtreatment in cervical cancer screening. We aimed to evaluate the predictive value of type-specific HPV in detecting cervical cancer and precancers in a Chinese population-based cohort and provide evidence of HPV genotyping to triage HPV-positive women. We typed all Hybrid Capture 2-positive cytologic samples of 1,742 women in Shanxi Province Cervical Cancer Screening Study cohort. Cumulative risks of cervical intraepithelial neoplasia grade 2 or worse (CIN2+) among HPV-positive women and cumulative detection rates of CIN2+ among general women by type-specific HPV were estimated during the course of 10-year follow-up. HPV 16 and HPV 52 were most prevalent types among the screening population. Ten-year cumulative risk of CIN2+ was 47.5% [95% confidence interval (CI), 31.6-62.3] for HPV 16-positive women and 46.3% (95% CI, 15.3-75.4) for HPV 31-positive women. Ten-year cumulative risks of CIN2+ among HPV 58, 39, 33, 18, and 52 positive women ranged from 34.3% to 12.0% in a decreasing order. CIN2+ risks were found to be positively associated with infection times of the same genotypes of HPV 16, 31, 33, and 58 (all < 0.001). Cumulative detection rates of CIN2+ within 10 years were predominantly contributed by HPV 16, 31, and 58. Our results support the risk-based management of HPV-positive women using HPV genotyping and also indicate the significance of including HPV 31 and 58 apart from commonly acknowledged HPV 16 and HPV 18 in achieving better risk stratification. .