DDB1- and CUL4-associated factor 8 plays a critical role in spermatogenesis / 医学前沿

Cullin-RING E3 ubiquitin ligase (CRL)-4 is a member of the large CRL family in eukaryotes. It plays important roles in a wide range of cellular processes, organismal development, and physiological and pathological conditions. DDB1- and CUL4-associated factor 8 (DCAF8) is a WD40 repeat-containing protein, which serves as a substrate receptor for CRL4. The physiological role of DCAF8 is unknown. In this study, we constructed Dcaf8 knockout mice. Homozygous mice were viable with no noticeable abnormalities. However, the fertility of Dcaf8-deficient male mice was markedly impaired, consistent with the high expression of DCAF8 in adult mouse testis. Sperm movement characteristics, including progressive motility, path velocity, progressive velocity, and track speed, were significantly lower in Dcaf8 knockout mice than in wild-type (WT) mice. However, the total motility was similar between WT and Dcaf8 knockout sperm. More than 40% of spermatids in Dcaf8 knockout mice showed pronounced morphological abnormalities with typical bent head malformation. The acrosome and nucleus of Dcaf8 knockout sperm looked similar to those of WT sperm. In vitro tests showed that the fertilization rate of Dcaf8 knockout mice was significantly reduced. The results demonstrated that DCAF8 plays a critical role in spermatogenesis, and DCAF8 is a key component of CRL4 function in the reproductive system.

Zfyve16 regulates the proliferation of B-lymphoid cells / 医学前沿

Zfyve16 (a.k.a. endofin or endosome-associated FYVE-domain protein), a member of the FYVE-domain protein family, is involved in endosomal trafficking and in TGF-β, BMP, and EGFR signaling. The FYVE protein SARA regulates the TGF-β signaling pathway by recruiting Smad2/3 and accelerating their phosphorylation, thereby altering their susceptibility to TGF-β-mediated T cell suppression. Zfyve16 binds to Smad4 and their binding affects the formation of Smad2/3-Smad4 complex in TGF-β signaling. However, the in vivo function of Zfyve16 remains unknown. In this study, we generated a Zfyve16 knockout mouse strain (Zfyve16) and examined its hematopoietic phenotypes and hematopoietic reconstruction ability. The proportion of Tcells in the peripheral blood of Zfyve16 mice increases compared with that in wild-type mice. This finding is consistent with the role of Zfyve16 in facilitating TGF-β signaling. Unpredictably, B cell proliferation is inhibited in Zfyve16 mice. The proliferation potential of Zfyve16 B-lymphoid cells also significantly decreases in vitro. These results suggest that Zfyve16 inhibits the proliferation of T cells, possibly through the TGF-β signaling, but upregulates the proliferation of B-lymphoid cells.

Efficient Strategy to Identify Gene-Gene Interactions and Its Application to Type 2 Diabetes

Over the past decade, the detection of gene-gene interactions has become more and more popular in the field of genome-wide association studies (GWASs). The goal of the GWAS is to identify genetic susceptibility to complex diseases by assaying and analyzing hundreds of thousands of single-nucleotide polymorphisms. However, such tests are computationally demanding and methodologically challenging. Recently, a simple but powerful method, named “BOolean Operation-based Screening and Testing” (BOOST), was proposed for genome-wide gene-gene interaction analyses. BOOST was designed with a Boolean representation of genotype data and is approximately equivalent to the log-linear model. It is extremely fast, and genome-wide gene-gene interaction analyses can be completed within a few hours. However, BOOST can not adjust for covariate effects, and its type-1 error control is not correct. Thus, we considered two-step approaches for gene-gene interaction analyses. First, we selected gene-gene interactions with BOOST and applied logistic regression with covariate adjustments to select gene-gene interactions. We applied the two-step approach to type 2 diabetes (T2D) in the Korea Association Resource (KARE) cohort and identified some promising pairs of single-nucleotide polymorphisms associated with T2D.

Correlation analysis of hyperarousal, personality characteristics, coping strategy with the vulnerability to stress-related sleep disturbance / 中华行为医学与脑科学杂志

Objective To explore the influence factors of hyperarousal,personality characteristics and coping strategies on the vulnerability to stress-related sleep disturbance.Methods A total of 345 sleep good healthy volunteers were recruited bypurposive sampling technique.Every participant completed an extensive survey that included the general condition questionnaire,Ford Insomnia Response to Stress Test (FIRST),PreSleep Arousal Scale (PSAS),NEO Personality Inventory-Revised (NEOPI-R),Coping Inventory for Stressful Situations (CISS) and Heart Rate Variability(HRV).All participants were classified as High risk group andLow risk group by using the FIRST criterion.Results The high risk group was younger than the low risk group (27.91±8.22 vs 24.82±7.73,P＜0.01),and had a higher percentage of females (34.7％ vs 53.4％,P＜0.05).The high risk group showed significantly higher scores in PSAS total (30.11±6.22),pesleep cognitive arousal (17.73± 4.51),presleep somatic arousal (12.78 ± 3.23),neuroticism (3.13 ± 0.51),emotion oriented (48.98 ± 10.54),but lower score in extraversion (2.96±0.54),then those indicators of the low risk group (28.52±5.82,16.32±4.32,11.41±2.75; 3.11±0.56,2.87±0.47,46.23±11.21,3.11±0.56,P＜0.01 or 0.05).There were significant difference between the two group in LF/HF (1.51 ±0.19 vs 1.17±0.11,P＜0.01),HF((311.21 ±72.32) ms2/Hz vs (490.43 ± 91.74)ms2/Hz,P＜0.01),LF((469.49±85.67)ms2/Hzvs (573.21±98.75) ms2/Hz,P＜0.01) in HRV.Results of linear regression analysis showed that gender,and scores of PSAS total,cognitive arousal,presleep cognitive arousal,presleep somatic arousal,neuroticism,emotion oriented and LF/HF were significant correlation with FIRST score (P＜0.01 or 0.05).Conclusion Presleep cognitive and somatic arousal,neurotic character may be the premorbid characteristics of stress-related sleep disturbance,and bad stress coping strategies are easy to promote the development of insomnia.