Tissue-specific profiling of age-dependent miRNAomic changes in Caenorhabditis elegans.

Ageing exhibits common and distinct features in various tissues, making it critical to decipher the tissue-specific ageing mechanisms. MiRNAs are essential regulators in ageing and are recently highlighted as a class of intercellular messengers. However, little is known about the tissue-specific transcriptomic changes of miRNAs during ageing. C. elegans is a well-established model organism in ageing research. Here, we profile the age-dependent miRNAomic changes in five isolated worm tissues. Besides the diverse ageing-regulated miRNA expression across tissues, we discover numerous miRNAs in the tissues without their transcription. We further profile miRNAs in the extracellular vesicles and find that worm miRNAs undergo inter-tissue trafficking via these vesicles in an age-dependent manner. Using these datasets, we uncover the interaction between body wall muscle-derived mir-1 and DAF-16/FOXO in the intestine, suggesting mir-1 as a messenger in inter-tissue signalling. Taken together, we systematically investigate worm miRNAs in the somatic tissues and extracellular vesicles during ageing, providing a valuable resource to study tissue-autonomous and nonautonomous functions of miRNAs in ageing.

Serum interleukin-6 levels are increased in post-herpetic neuralgia: a single-center retrospective study

Abstract Background: Studies have shown that the overall incidence rate of herpeszoster (HZ) in China is 6.64 cases per 1000 people, despite such harms brought by postherpetic neuralgia (PHN), the mechanism of the disease remains unclear in China. Currently, effective biomarkers to predict PHN remain unavailable, which makes it difficult to prevent and successfully treat PHN. Objectives: The aim of the study was to determine the serum interleukin-6 level in PHN. Methods: The serum levels of interleukin 6 (IL-6) were measured by multi-antibody sandwich ELISA. The likert scale was used to represent the degree of neuralgia in the patients. Patients with PHN were divided into a mild PHN group and a severe PHN group according to the Likert scale. ROC curve was performed for evaluating the diagnostic efficiency of IL6 for PHN. The correlation between the IL6 level and the Likert scale before and after treatment with gabapentin and mecobalamin was analyzed. Results: IL6 levels in PHN patients resulted higher compared to volunteers. Patients in the severe PHN group had a higher serum IL6 level than in the mild PHN group. The Likert scale score was related to the serum IL6 levels and the frequency of IL6 levels above the cutoff value (4.95pg/mL) in PNH groups before and after treatment (p<0.05). Study limitations: Pain is subjective. Some mental states, such as anxiety and depression, greatly influence an individual's perception of pain, and pain tolerance can vary between people. Therefore, pain scores can be affected by different individual factors. Conclusions: The serum IL6 levels may be used as a biochemical indicator of the severity of PNH.

Serum interleukin-6 levels are increased in post-herpetic neuralgia: a single-center retrospective study.

BACKGROUND: Studies have shown that the overall incidence rate of herpeszoster (HZ) in China is 6.64 cases per 1000 people, despite such harms brought by postherpetic neuralgia (PHN), the mechanism of the disease remains unclear in China. Currently, effective biomarkers to predict PHN remain unavailable, which makes it difficult to prevent and successfully treat PHN. OBJECTIVE: The aim of the study was to determine the serum interleukin-6 level in PHN. METHODS: The serum levels of interleukin 6 (IL-6) were measured by multi-antibody sandwich ELISA. The likert scale was used to represent the degree of neuralgia in the patients. Patients with PHN were divided into a mild PHN group and a severe PHN group according to the Likert scale. ROC curve was performed for evaluating the diagnostic efficiency of IL6 for PHN. The correlation between the IL6 level and the Likert scale before and after treatment with gabapentin and mecobalamin was analyzed. RESULTS: IL6 levels in PHN patients resulted higher compared to volunteers. Patients in the severe PHN group had a higher serum IL6 level than in the mild PHN group. The Likert scale score was related to the serum IL6 levels and the frequency of IL6 levels above the cutoff value (4.95 pg/mL) in PNH groups before and after treatment (p < 0.05). STUDY LIMITATIONS: Pain is subjective. Some mental states, such as anxiety and depression, greatly influence an individual's perception of pain, and pain tolerance can vary between people. Therefore, pain scores can be affected by different individual factors. CONCLUSIONS: The serum IL6 levels may be used as a biochemical indicator of the severity of PNH.

KCNQ1OT1 promotes genome-wide transposon repression by guiding RNA-DNA triplexes and HP1 binding.

Transposon (de)repression and heterochromatin reorganization are dynamically regulated during cell fate determination and are hallmarks of cellular senescence. However, whether they are sequence specifically regulated remains unknown. Here we uncover that the KCNQ1OT1 lncRNA, by sequence-specific Hoogsteen base pairing with double-stranded genomic DNA via its repeat-rich region and binding to the heterochromatin protein HP1α, guides, induces and maintains epigenetic silencing at specific repetitive DNA elements. Repressing KCNQ1OT1 or deleting its repeat-rich region reduces DNA methylation and H3K9me3 on KCNQ1OT1-targeted transposons. Engineering a fusion KCNQ1OT1 with an ectopically targeting guiding triplex sequence induces de novo DNA methylation at the target site. Phenotypically, repressing KCNQ1OT1 induces senescence-associated heterochromatin foci, transposon activation and retrotransposition as well as cellular senescence, demonstrating an essential role of KCNQ1OT1 to safeguard against genome instability and senescence.

Ageing induces tissue-specific transcriptomic changes in Caenorhabditis elegans.

Ageing is a complex process with common and distinct features across tissues. Unveiling the underlying processes driving ageing in individual tissues is indispensable to decipher the mechanisms of organismal longevity. Caenorhabditis elegans is a well-established model organism that has spearheaded ageing research with the discovery of numerous genetic pathways controlling its lifespan. However, it remains challenging to dissect the ageing of worm tissues due to the limited description of tissue pathology and access to tissue-specific molecular changes during ageing. In this study, we isolated cells from five major tissues in young and old worms and profiled the age-induced transcriptomic changes within these tissues. We observed a striking diversity of ageing across tissues and identified different sets of longevity regulators therein. In addition, we found novel tissue-specific factors, including irx-1 and myrf-2, which control the integrity of the intestinal barrier and sarcomere structure during ageing respectively. This study demonstrates the complexity of ageing across worm tissues and highlights the power of tissue-specific transcriptomic profiling during ageing, which can serve as a resource to the field.

Non-muscle myosin heavy chain 9 maintains intestinal homeostasis by preventing epithelium necroptosis and colitis adenoma formation.

Non-muscle myosin IIA plays an important role in cell adhesion, cell migration, and tissue architecture. We previously showed that low activity of the heavy chain of non-muscle myosin II Myh9 is beneficial to LGR5+ intestinal stem cell maintenance. However, the function of Myh9 in adult mouse intestinal epithelium is largely unclear. In this study, we used the inducible Villin-creERT2 knockout approach to delete Myh9 in adult mouse intestinal epithelium and observed that homozygous deletion of Myh9 causes colitis-like morphologic changes in intestine, leads to a high sensitivity to dextran sulfate sodium and promotes colitis-related adenoma formation in the colon. Myh9 deletion disturbs cell junctions and impairs intestinal lumen barrier integrity, promoting the necroptosis of epithelial cells. Consistently, these changes can be partially rescued by Ripk3 knockout. Our results indicate that Myh9 is required for the maintenance of intestinal epithelium integrity and the prevention of cell necroptosis.

Individual variation of the SARS-CoV-2 receptor ACE2 gene expression and regulation.

The COVID-19 coronavirus is now spreading worldwide. Its pathogen, SARS-CoV-2, has been shown to use angiotensin-converting enzyme 2 (ACE2) as its host cell receptor, same as the severe acute respiratory syndrome coronavirus (SARS-CoV) in 2003. Epidemiology studies found males although only slightly more likely to be infected than females account for the majority of the severely ill and fatality, which also bias for people older than 60 years or with metabolic and cardiovascular diseases. Here by analyzing GTEx and other public data in 30 tissues across thousands of individuals, we found a significantly higher level in Asian females, an age-dependent decrease in all ethnic groups, and a highly significant decrease in type II diabetic patients of ACE2 expression. Consistently, the most significant expression quantitative loci (eQTLs) contributing to high ACE2 expression are close to 100% in East Asians, >30% higher than other ethnic groups. A shockingly common enrichment of viral infection pathways was found among ACE2 anti-expressed genes, and multiple binding sites of virus infection related transcription factors and sex hormone receptors locate at ACE2 regulatory regions. Human and mice data analysis further revealed ACE2 expression is reduced in T2D patients and with inflammatory cytokine treatment and upregulated by estrogen and androgen (both decrease with age). Our findings revealed a negative correlation between ACE2 expression and COVID-19 fatality at both population and molecular levels. These results will be instrumental when designing potential prevention and treatment strategies for ACE2 binding coronaviruses in general.

Widespread roles of enhancer-like transposable elements in cell identity and long-range genomic interactions.

A few families of transposable elements (TEs) have been shown to evolve into cis-regulatory elements (CREs). Here, to extend these studies to all classes of TEs in the human genome, we identified widespread enhancer-like repeats (ELRs) and find that ELRs reliably mark cell identities, are enriched for lineage-specific master transcription factor binding sites, and are mostly primate-specific. In particular, elements of MIR and L2 TE families whose abundance co-evolved across chordate genomes, are found as ELRs in most human cell types examined. MIR and L2 elements frequently share long-range intra-chromosomal interactions and binding of physically interacting transcription factors. We validated that eight L2 and nine MIR elements function as enhancers in reporter assays, and among 20 MIR-L2 pairings, one MIR repressed and one boosted the enhancer activity of L2 elements. Our results reveal a previously unappreciated co-evolution and interaction between two TE families in shaping regulatory networks.

Aging and Alzheimer's disease: Comparison and associations from molecular to system level.

Alzheimer's disease is the most prevalent cause of dementia, which is defined by the combined presence of amyloid and tau, but researchers are gradually moving away from the simple assumption of linear causality proposed by the original amyloid hypothesis. Aging is the main risk factor for Alzheimer's disease that cannot be explained by amyloid hypothesis. To evaluate how aging and Alzheimer's disease are intrinsically interwoven with each other, we review and summarize evidence from molecular, cellular, and system level. In particular, we focus on study designs, treatments, or interventions in Alzheimer's disease that could also be insightful in aging and vice versa.

Immune mechanisms induced by an HSV-1 mutant strain: Discrepancy analysis of the immune system gene profile in comparison with a wild-type strain.

Herpes simplex virus is a prevalent pathogen of humans of various age groups. The fact that no prophylactic or therapeutic vaccine is currently available suggests a significant need to further investigate the immune mechanisms induced by the virus and various vaccine candidates. We previously generated an HSV-1 mutant strain, M3, with partial deletions in ul7, ul41 and LAT that produced an attenuated phenotype in mice. In the present study, we performed a comparative analysis to characterize the immune responses induced by M3 versus wild-type HSV-1 in a mouse model. Infection with wild-type HSV-1 triggered an inflammatory-dominated response and adaptive immunity suppression and was accompanied by severe pathological damage. In contrast, infection with M3 induced a systematic immune response involving full activation of both innate and adaptive immunity and was accompanied by no obvious pathological changes. Furthermore, the immune response induced by M3 protected mice from lethal challenge with wild-type strains of HSV-1 and restrained virus proliferation and impaired latency. These data are useful for further HSV-1 vaccine development using a mutant strain construction strategy.

CXXC5 suppresses hepatocellular carcinoma by promoting TGF-ß-induced cell cycle arrest and apoptosis.

Evading TGF-ß-mediated growth inhibition is often associated with tumorigenesis in liver, including hepatocellular carcinoma (HCC). To better understand the functions and the underlying molecular mechanisms of TGF-ß in HCC initiation and progression, we carried out transcriptome sequencing (RNA-Seq) to identify the target genes of TGF-ß. CXXC5, a member of the CXXC-type zinc finger domain-containing protein family, was identified as a novel TGF-ß target gene in Hep3B HCC cells. Knockdown of CXXC5 attenuated the expression of a substantial portion of TGF-ß target genes and ameliorated TGF-ß-induced growth inhibition or apoptosis of Hep3B cells, suggesting that CXXC5 is required for TGF-ß-mediated inhibition of HCC progression. Analysis of the TCGA database indicated that CXXC5 expression is reduced in the majority of HCC tissue samples in comparison to that in normal tissues. Furthermore, CXXC5 associates with the histone deacetylase HDAC1 and competes its interaction with Smad2/3, thereby abolishing the inhibitory effect of HDAC1 on TGF-ß signaling. These observations together suggest that CXXC5 may act as a tumor suppressor by promoting TGF-ß signaling via a positive feedback loop, and reveal a strategy for HCC to bypass TGF-ß-mediated cytostasis by disrupting the positive feedback regulation. Our findings shed new light on TGF-ß signaling regulation and demonstrate the function of CXXC5 in HCC development.