Transition of allele-specific DNA hydroxymethylation at regulatory loci is associated with phenotypic variation in monozygotic twins discordant for psychiatric disorders.

BACKGROUND: Major psychiatric disorders such as schizophrenia (SCZ) and bipolar disorder (BPD) are complex genetic mental illnesses. Their non-Mendelian features, such as those observed in monozygotic twins discordant for SCZ or BPD, are likely complicated by environmental modifiers of genetic effects. 5-Hydroxymethylcytosine (5hmC) is an important epigenetic mark in gene regulation, and whether it is linked to genetic variants that contribute to non-Mendelian features remains largely unexplored. METHODS: We combined the 5hmC-selective chemical labeling method (5hmC-seq) and whole-genome sequencing (WGS) analysis of peripheral blood DNA obtained from monozygotic (MZ) twins discordant for SCZ or BPD to identify allelic imbalances in hydroxymethylome maps, and examined association of allele-specific hydroxymethylation (AShM) transition with disease susceptibility based on Bayes factors (BF) derived from the Bayesian generalized additive linear mixed model. We then performed multi-omics integrative analysis to determine the molecular pathogenic basis of those AShM sites. We finally employed luciferase reporter, CRISPR/Cas9 technology, electrophoretic mobility shift assay (EMSA), chromatin immunoprecipitation (ChIP), PCR, FM4-64 imaging analysis, and RNA sequencing to validate the function of interested AShM sites in the human neuroblastoma SK-N-SH cells and human embryonic kidney 293T (HEK293T) cells. RESULTS: We identified thousands of genetic variants associated with AShM imbalances that exhibited phenotypic variation-associated AShM changes at regulatory loci. These AShM marks showed plausible associations with SCZ or BPD based on their effects on interactions among transcription factors (TFs), DNA methylation levels, or other epigenomic marks and thus contributed to dysregulated gene expression, which ultimately increased disease susceptibility. We then validated that competitive binding of POU3F2 on the alternative allele at the AShM site rs4558409 (G/T) in PLLP-enhanced PLLP expression, while the hydroxymethylated alternative allele, which alleviated the POU3F2 binding activity at the rs4558409 site, might be associated with the downregulated PLLP expression observed in BPD or SCZ. Moreover, disruption of rs4558409 promoted neural development and vesicle trafficking. CONCLUSION: Our study provides a powerful strategy for prioritizing regulatory risk variants and contributes to our understanding of the interplay between genetic and epigenetic factors in mediating SCZ or BPD susceptibility.

Prohibitin1 facilitates viral replication by impairing the RIG-I-like receptor signaling pathway.

IMPORTANCE: Type I interferon (IFN-I), produced by the innate immune system, plays an essential role in host antiviral responses. Proper regulation of IFN-I production is required for the host to balance immune responses and prevent superfluous inflammation. IFN regulatory factor 3 (IRF3) and subsequent sensors are activated by RNA virus infection to induce IFN-I production. Therefore, proper regulation of IRF3 serves as an important way to control innate immunity and viral replication. Here, we first identified Prohibitin1 (PHB1) as a negative regulator of host IFN-I innate immune responses. Mechanistically, PHB1 inhibited the nucleus import of IRF3 by impairing its binding with importin subunit alpha-1 and importin subunit alpha-5. Our study demonstrates the mechanism by which PHB1 facilitates the replication of multiple RNA viruses and provides insights into the negative regulation of host immune responses.

LncRNA RP5-998N21.4 promotes immune defense through upregulation of IFIT2 and IFIT3 in schizophrenia.

Schizophrenia is a complex polygenic disease that is affected by genetic, developmental, and environmental factors. Accumulating evidence indicates that environmental factors such as maternal infection and excessive prenatal neuroinflammation may contribute to the onset of schizophrenia by affecting epigenetic modification. We recently identified a schizophrenia-associated upregulated long noncoding RNA (lncRNA) RP5-998N21.4 by transcriptomic analysis of monozygotic twins discordant for schizophrenia. Importantly, we found that genes coexpressed with RP5-998N21.4 were enriched in immune defense-related biological processes in twin subjects and in RP5-998N21.4-overexpressing (OE) SK-N-SH cell lines. We then identified two genes encoding an interferon-induced protein with tetratricopeptide repeat (IFIT) 2 and 3, which play an important role in immune defense, as potential targets of RP5-998N21.4 by integrative analysis of RP5-998N21.4OE-induced differentially expressed genes (DEGs) in SK-N-SH cells and RP5-998N21.4-coexpressed schizophrenia-associated DEGs from twin subjects. We further demonstrated that RP5-998N21.4 positively regulates the transcription of IFIT2 and IFIT3 by binding to their promoter regions and affecting their histone modifications. In addition, as a general nuclear coactivator, RMB14 (encoding RNA binding motif protein 14) was identified to facilitate the regulatory role of RP5-998N21.4 in IFIT2 and IFIT3 transcription. Finally, we observed that RP5-998N21.4OE can enhance IFIT2- and IFIT3-mediated immune defense responses through activation of signal transducer and activator of transcription 1 (STAT1) signaling pathway in U251 astrocytoma cells under treatment with the viral mimetic polyinosinic: polycytidylic acid (poly I:C). Taken together, our findings suggest that lncRNA RP5-998N21.4 is a critical regulator of immune defense, providing etiological and therapeutic implications for schizophrenia.

[Repair of electrical burns on hands with flaps].

OBJECTIVE: To summarize the experiences and shortcomings of repair of wounds on hands due to electrical burns with flaps, aiming at further improvement. METHODS: Clinical data of 425 patients with electrical burn of hands admitted to Burn Institute of Wuhan, City Hospital NO. 3 & Tongren Hospital of Wuhan University from January 2000 to December 2006 were collected and summarized. Therapeutic methods and outcomes of all patients were statistically analyzed. Flap types, complications after surgery and problems existed in patients having undergone flap transplantation were summarized. Patients were divided into surgery within 7days post burn (PBD) group (SW) and surgery after PBD 7 group (SA) according to the timing of surgery. Survival rate of flaps and incidence of complications in patients of two groups were compared. RESULTS: Out of the 425 patients, 348 (90.2%) patients underwent surgery, among which 248 flaps of different types were transplanted in 209 patients, including 202 (81.5%) distant pedicle flaps, 19 (7.7%) local flaps, 12 (4.8%) free flaps, and 15 (6.0%) other kinds of tissue flaps. Five flaps failed because of necrosis of torn off, and the resulting wounds were treated with other methods. Eight flaps showed necrosis of distal margin, and the wound healed with dressing changing or skin grafting. All the remaining flaps survived with satisfactory cosmetic and functional results. In SW group (n = 170) and SA group (n = 78), survival rate of flaps was respectively 98.8% (168/170) and 96.2% (75/78), incidence of complications was respectively 10.6% (18/170) and 12.8% (10/78). There was no statistical difference between above two sets of data (with chi(2) value respectively 0.81 and 0.27, and P values both above 0.05). CONCLUSIONS: There are many types of flaps that can be used to repair electric burn wounds on hands. Appropriate choice and design of flaps, skillful operation, and careful post-operation observation and treatment are key points for good therapeutic effect.