A novel mutation in the STK11 gene causes heritable Peutz-Jeghers syndrome - a case report.

BACKGROUND: Peutz-Jeghers syndrome (PJS) is a rare disorder characterized by multiple gastrointestinal hamartomatous polyps and mucocutaneous pigmentation. STK11 has been identified as a causative gene for this disease. CASE PRESENTATION: Herein we report a Chinese Han kindred with PJS. Onset for the PJS signs in three of the patients was rarely as early as at birth. We identified a novel heterozygous mutation (c.440_441delGT, p.Arg147Leufs*15) in the gene STK11, causing a short frameshift followed by a deletion of 63% of the amino acids in the STK protein. This mutation co-segregated with the PJS phenotype, and was absent in two hundred of unrelated ethnicity-matched controls. The mutation led to expression decrease of unaffected STK11 protein in patients than in controls, as well in PJ polyps than in circulating leucocytes from the patients. Phosphorylation levels of the downstream kinase AMPKα altered according with the expression of STK11. These results indicated the possibility that haploinsufficiency and epigenetic reduction of STK11 contributed to the pathogenesis of the disease. CONCLUSION: This study identifies a novel mutation in the pathogenic gene STK11 leading to PJS.

Endophilin A2 Influences Volume-Regulated Chloride Current by Mediating ClC-3 Trafficking in Vascular Smooth Muscle Cells.

BACKGROUND: Previous research has demonstrated that ClC-3 is responsible for volume-regulated Cl-current (ICl.vol) in vascular smooth muscle cells (VSMCs). However, it is still not clear whether and how ClC-3 is transported to cell membranes, resulting in alteration ofICl.vol.Methods and Results:Volume-regulated chloride current (ICl.vol) was recorded by whole-cell patch clamp recording, and Western blotting and co-immunoprecipitation were performed to examine protein expression and protein-protein interaction. Live cell imaging was used to observe ClC-3 transporting. The results showed that an overexpression of endophilin A2 could increaseICl.vol, while endophilin A2 knockdown decreasedICl.vol. In addition, the SH3 domain of endophilin A2 mediated its interaction with ClC-3 and promotes ClC-3 transportation from the cytoplasm to cell membranes. The regulation of ClC-3 channel activity was also verified in basilar arterial smooth muscle cells (BASMCs) isolated from endophilin A2 transgenic mice. Moreover, endophilin A2 increase VSMCs proliferation induced by endothelin-1 or hypo-osmolarity. CONCLUSIONS: The present study identified endophilin A2 as a ClC-3 channel partner, which serves as a new ClC-3 trafficking insight in regulatingICl.volin VSMCs. This study provides a new mechanism by which endophilin A2 regulates ClC-3 channel activity, and sheds light on how ClC-3 is transported to cell membranes to play its critical role as a chloride channel in VSMCs function, which may be involved in cardiovascular diseases. (Circ J 2016; 80: 2397-2406).

Endophilin-A2-mediated increase in scavenger receptor expression contributes to macrophage-derived foam cell formation.

BACKGROUND AND AIMS: Macrophage-derived foam cell formation (MFCF) is a crucial step in the pathogenesis of atherosclerosis. Uptake of oxidized low-density lipoprotein (oxLDL) by scavenger receptors is indispensable for MFCF. Endophilin-A2 has been reported to regulate clathrin-mediated endocytosis (CME). In this study, we tested the hypothesis that endophilin-A2 regulates oxLDL uptake and MFCF by mediating CME of oxLDL-scavenger receptor complexes. METHODS: In vitro MFCF was induced by oxLDL treatment. Involvement of endophilin-A2 in oxLDL cytomembrane binding, cellular uptake, and MFCF was evaluated by manipulation of endophilin-A2. RESULTS: Endophilin-A2 was involved in MFCF via scavenger receptor CD36 and scavenger receptor-A (SR-A)-mediated positive feedback pathways. We observed that oxLDL triggered interaction of endophilin-A2 with CD36 or SR-A, and induced an endophilin-A2-dependent activation of the apoptosis signal-regulating kinase-1 (ASK1)/Jun N-terminal kinase (JNK)/p38 signaling pathway. The activation of ASK1-JNK/p38 signal increased expression of both CD36 and SR-A, which promoted oxLDL cytomembrane binding, cellular uptake, and MFCF. In the absence of oxLDL, endophilin-A2 up-regulated the expression of receptors and Dil-oxLDL binding and uptake, but not the intracellular accumulation of lipids. In the presence of oxLDL, the CME inhibitors pitstop2 and ikarugamycin mimicked the inhibiting effect of endophilin-A2 knockdown and eliminated the elevating effect of endophilin-A2 overexpression on oxLDL uptake and MFCF. CONCLUSIONS: Endophilin-A2 was identified as a novel molecule regulating MFCF by mechanisms attributable to CME and beyond CME.

Investigation of associations between ten polymorphisms and the risk of coronary artery disease in Southern Han Chinese.

A large-scale meta-analysis of 14 genome-wide association studies has identified and replicated a series of susceptibility polymorphisms for coronary artery disease (CAD) in European ancestry populations, but evidences for the associations of these loci with CAD in other ethnicities remain lacking. Herein we investigated the associations between ten (rs579459, rs12413409, rs964184, rs4773144, rs2895811, rs3825807, rs216172, rs12936587, rs46522 and rs3798220) of these loci and CAD in Southern Han Chinese (CHS). Genotyping was performed in 1716 CAD patients and 1572 controls using mass spectrography. Both allelic and genotypic associations of rs964184, rs2895811 and rs3798220 with CAD were significant, regardless of adjustment for covariates of gender, age, hypertension, type 2 diabetes, blood lipid profiles and smoking. Significant association of rs12413409 was initially not observed, but after the adjustment for the covariates, both allelic and genotypic associations were identified as significant. Neither allelic nor genotypic association of the other six polymorphisms with CAD was significant regardless of the adjustment. Our results indicated that four loci of the total 10 were associated with CAD in CHS. Therefore, some of the CAD-related loci in European ancestry populations are indeed susceptibility loci for the risk of CAD in Han Chinese.

Common Variants in Promoter of ADTRP Associate with Early-Onset Coronary Artery Disease in a Southern Han Chinese Population.

The first genome-wide association study for coronary artery disease (CAD) in the Han Chinese population, we reported recently, had identified rs6903956 in gene ADTRP on chromosome 6p24.1 as a novel susceptibility locus for CAD. The risk allele of rs6903956 was associated with decreased mRNA expression of ADTRP. To further study the correlation of ADTRP expression and CAD, in this study we evaluated the associations of eight common variants in the expression-regulating regions of ADTRP with CAD in the Southern Han Chinese population. Rs169790 in 3'UTR, rs2076189 in 5'UTR, four SNPs (rs2076188, rs7753407, rs11966356 and rs1018383) in promoter, and two SNPs (rs3734273, rs80355771) in the last intron of ADTRP were genotyped in 1716 CAD patients and 1572 controls. The correlations between these loci and total or early-onset CAD were investigated. None of these loci was discovered to associate with total CAD (P > 0.05). However, with early-onset CAD, significant both allelic and genotypic associations of rs7753407, rs11966356 and rs1018383 were identified, after adjustment for risk factors of age, gender, hypertension, diabetes, lipid profiles and smoking (adjusted P < 0.05). A haplotype AGCG (constructed by rs2076188, rs7753407, rs11966356 and rs1018383) was identified to protect subjects from early-onset CAD (OR = 0.332, 95% CI = 0.105-0.879, adjusted P = 0.010). Real-time quantitative reverse transcription polymerase chain reaction assay showed that the risk alleles of the associated loci were significantly associated with decreased expression of ADTRP mRNA. Moreover, the average level of ADTRP mRNA expression in early-onset CAD cases was significantly lower than that in controls. Our results provide new evidence supporting the association of ADTRP with the pathogenesis of early-onset CAD.

[Death caused by anaphylactic shock: a forensic pathological analysis of 142 cases].

OBJECTIVE: To explore the forensic pathological features of death caused by anaphylactic shock. METHODS: One hundred and forty-two death cases of anaphylactic shock were retrospectively analyzed. The IgE level in the serum of anaphylactic shock cases were statistically compared with that of 62 non-anaphylactic shock cases. RESULTS: Most cases (77.46%) of anaphylactic shock death occurred in the medical institutes, with intravenous drug administration accounting for 53.53% of anaphylactic shock death. ß-Lactam antibiotics, glucocorticoid and herbal medications were responsible for a significant proportion of such cases. Although characteristic histopathological changes were absent in vast majority of these anaphylactic shock cases, the differences of IgE levels in the serum between anaphylactic shock group and non-anaphylactic shock group were statistically significant (P<0.05). CONCLUSION: Combined information including clinical data, autopsy results, IgE level, and other specific test results should be evaluated together in the forensic pathological diagnosis of anaphylactic shock.

EEN regulates the proliferation and survival of multiple myeloma cells by potentiating IGF-1 secretion.

The molecular mechanisms of multiple myeloma are not well defined. EEN is an endocytosis-regulating molecule. Here we report that EEN regulates the proliferation and survival of multiple myeloma cells, by regulating IGF-1 secretion. In the present study, we observed that EEN expression paralleled with cell proliferation, EEN accelerated cell proliferation, facilitated cell cycle transition from G1 to S phase by regulating cyclin-dependent kinases (CDKs) pathway, and delayed cell apoptosis via Bcl2/Bax-mitochondrial pathway. Mechanistically, we found that EEN was indispensable for insulin-like growth factor-1 (IGF-1) secretion and the activation of protein kinase B-mammalian target of rapamycin (Akt-mTOR) pathway. Exogenous IGF-1 overcame the phenotype of EEN depletion, while IGF-1 neutralization overcame that of EEN over-expression. Collectively, these data suggest that EEN may play a pivotal role in excessive cell proliferation and insufficient cell apoptosis of bone marrow plasma cells in multiple myeloma. Therefore, EEN may represent a potential diagnostic marker or therapeutic target for multiple myeloma.

Decrease of intracellular chloride concentration promotes endothelial cell inflammation by activating nuclear factor-κB pathway.

Recent evidence suggested that ClC-3 channel/antiporter is involved in regulation of nuclear factor (NF)-κB activation. However, the mechanism explaining how ClC-3 modulates NF-κB signaling is not well understood. We hypothesized that ClC-3-dependent alteration of intracellular chloride concentration ([Cl(-)](i)) underlies the effect of ClC-3 on NF-κB activity in endothelial cells. Here, we found that reduction of [Cl(-)](i) increased tumor necrosis factor-α (TNFα)-induced expression of intercellular adhesion molecule 1 and vascular cell adhesion molecule 1 and adhesion of monocytes to endothelial cells (P<0.05; n=6). In Cl(-) reduced solutions, TNFα-evoked IκB kinase complex ß and inhibitors of κBα phosphorylation, inhibitors of κBα degradation, and NF-κB nuclear translocation were enhanced. In addition, TNFα and interleukin 1ß could activate an outward rectifying Cl(-) current in human umbilical vein endothelial cells and mouse aortic endothelial cells. Knockdown or genetic deletion of ClC-3 inhibited or abolished this Cl(-) conductance. Moreover, Cl(-) channel blockers, ClC-3 knockdown or knockout remarkably reduced TNFα-induced intercellular adhesion molecule 1 and vascular cell adhesion molecule 1expression, monocytes to endothelial cell adhesion, and NF-κB activation (P<0.01; n=6). Furthermore, TNFα-induced vascular inflammation and neutrophil infiltration into the lung and liver were obviously attenuated in ClC-3 knockout mice (P<0.01; n=7). Our results demonstrated that decrease of [Cl(-)](i) induced by ClC-3-dependent Cl(-) efflux promotes NF-κB activation and thus potentiates TNFα-induced vascular inflammation, suggesting that inhibition of ClC-3-dependent Cl(-) current or modification of intracellular Cl(-) content may be a novel therapeutic approach for inflammatory diseases.

Vinpocetine inhibits breast cancer cells growth in vitro and in vivo.

Vinpocetine is a clinically used drug for cerebrovascular disorders as well as age-related memory impairment. Of note, vinpocetine has been recently identified as a novel anti-inflammatory agent; however, its effects on cancer cells remain to be investigated. In the present study, we found that vinpocetine potently inhibited proliferation of multiple types of human breast cancer cells by arresting cell cycle at G(0)/G(1) phase. It was also revealed that vinpocetine induced cell apoptosis via mitochondria-dependent pathway. Moreover, vinpocetine impaired the migration of the strongly metastatic cell MDA-MB-231. In xenograft model of human breast cancer in nude mice, both systemic and local administration of vinpocetine significantly suppressed the tumor growth without observed toxicity. Interestingly, vinpocetine markedly attenuated the activation of Akt and signal transducer and activator of transcription factor 3 (STAT3), but had no effects on MAP kinases pathways. Collectively, the data suggest that vinpocetine possesses significant yet previously unknown antitumor properties that may be utilized for the treatment of breast cancer.

Genome-wide association identifies a susceptibility locus for coronary artery disease in the Chinese Han population.

Coronary artery disease (CAD) causes more than 700,000 deaths each year in China. Previous genome-wide association studies (GWAS) in populations of European ancestry identified several genetic loci for CAD, but no such study has yet been reported in the Chinese population. Here we report a three-stage GWAS in the Chinese Han population. We identified a new association between rs6903956 in a putative gene denoted as C6orf105 on chromosome 6p24.1 and CAD (P = 5.00 × 10⁻³, stage 2 validation; P = 3.00 × 10⁻³, P = 1.19 × 10⁻8 and P = 4.00 × 10⁻³ in three independent stage 3 replication populations; P = 4.87 × 10⁻¹², odds ratio = 1.51 in the combined population). The minor risk allele A of rs6903956 is associated with decreased C6orf105 mRNA expression. We report the first GWAS for CAD in the Chinese Han population and identify a SNP, rs6903956, in C6orf105 associated with susceptibility to CAD in this population.