Cardiac Disease Associated Genetic Variants in Yi Nationality in Regions with High Incidence of Yunnan Sudden Unexplained Death.

ABSTRACT: Objective To explore the association of cardiac disease associated genetic variants and the high incidence of Yunnan sudden unexplained death （YNSUD） in Yi nationality. Methods The genomic DNA was extracted from peripheral blood samples collected from 205 Yi villagers from YNSUD aggregative villages （inpatient group） and 197 healthy Yi villagers from neighboring villages （control group）. Fifty-two single nucleotide variants （SNVs） of 25 cardiac disease associated genes were genotyped using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry （MALDI-TOF-MS）. The SPSS 17.0 was used to analyze data. The pathogenicities of variants with differences between the two groups that have statistical significance were predicted by protein function prediction software PolyPhen-2 and SIFT. All villagers from inpatient group were given electrocardiogram （ECG） examination using a 12-lead electrocardiograph. Results The allele frequency and the genotype frequency of missense mutation DSG2 （rs2278792, c.2318G>A, p.R773K） of pathogenic genes of arrhythmogenic right ventricular cardiomyopathy （ARVC） in inpatient group was higher than that in control group （P<0.05）. Abnormal ECG changes were detected in 71 individuals （34.6%） in the inpatient group, among which 54 individuals carried R773K mutation, including clockwise （counterclockwise） rotation, left （right） axis deviation, ST segment and T wave alteration and heart-blocking. Conclusion Definite pathogenic mutations have not been found in the 52 cardiac disease genes associated SNVs detected in Yi nationality in regions with high incidence of YNSUD. The cause of high incidence of YNSUD in Yi nationality needs further study.

Forensic Pathology Analysis of 363 Sudden Death Cases in Yunnan Province.

OBJECTIVES: To study the epidemiological and pathological features of sudden death （SD） in Yunnan Province and to provide scientific evidence for prevention and forensic identification of sudden death. METHODS: Totally 363 SD cases were collected from the autopsies between 2009 and 2017 in the Forensic Centre of Kunming Medical University. The related factors such as etiology, age, inducing factor, time interval between the onset of disease and death, morbidity season and pathological change were retrospectively analysed. RESULTS: The incidence of SD in males was significantly higher than that of females. The peak age was ≥35-55 years. The mortality rate was relatively high within 6 h after the onset of disease. The season order with descending number of deaths was spring, summer, winter and autumn. The top ten causes of SD were coronary heart disease, sudden unexplained death （SUD）, cerebral hemorrhage, acute hemorrhagic necrotic pancreatitis, aortic dissection rupture, cardiomyopathy, pneumonia, pulmonary thromboembolism, amniotic fluid embolism and allergy. Exercise, infusion, surgery, medication and minor injury were the most common predisposing factors of sudden coronary death. Consciousness disorder or coma, chest pain or chest tightness, and abdominal pain were the most common premortem symptoms of sudden coronary death. CONCLUSIONS: The SD is more common in middle-aged males, which is the key population for the prevention of SD. For the forensic identification and prevention of SD, the attention on SUD should be paid.

[Analysis of 124 Suicide Cases in Wuhua District in Kunming].

OBJECTIVES: To analyze the relationship between the suicide method and the sex, age, education background and cause of suicide to provide reference for the forensic identification of suicide. METHODS: After scene investigation, external body examination, autopsy and case investigation, 124 identified suicide cases which happened in recent three years in Wuhua district in Kunming were collected. Analytical methods as chi-square test and descriptive statistics were performed by SPSS 22.0. RESULTS: In all the suicide cases, male to female ratio was 1.53∶1. The suicide methods were mainly fatal fall, hanging and drowning. The ratio of local to non-native residents was 1∶1. The suicide rate in the people with primary school or junior middle school education level was highest. The group of >10-50 years tended to choose fatal fall suicide and people over 60 years were more likely to choose hanging. People with different academic background tended to choose fatal fall suicide. The suicide methods as fatal fall and hanging were chosen because of mental and physical diseases and economic problems, while the suicides with emotional problems were more likely to choose fatal fall and poisoning. CONCLUSIONS: Suicide belongs to a kind of complex cases. For the cases of suspected suicide, complete exploration and overall consideration should be done to determine the nature of cases based on comprehensive analysis of all the influence factors.

Regulation of intestinal apolipoprotein B mRNA editing levels by a zinc-deficient diet and cDNA cloning of editing protein in hamsters.

This study was conducted to investigate the influence of dietary zinc on intestinal apoB mRNA editing in hamsters. Apolipoprotein B-48 (apoB-48) is synthesized from the same gene as apoB-100 by a post-transcriptional, site-specific cytidine deamination, a process known as apoB mRNA editing. A cDNA encoding the hamster apoB mRNA editing enzyme was obtained by reverse transcriptase-polymerase chain reaction (RT-PCR) and the deduced amino acid sequence was found to possess high amino acid sequence identity to apoB mRNA editing enzymes from several other species. Editing activity was detected in the small intestine and colon but, like humans, none was detected in the liver. Analysis by RT-PCR indicated that the small intestine possessed the highest expression of editing enzyme mRNA abundance, whereas both liver and small intestine expressed relatively high levels of apoB mRNA. The influence of dietary zinc on intestinal apoB mRNA editing levels was examined in Golden Syrian hamsters (7 wk old) assigned to one of the following three dietary treatments: Zn-adequate (ZA, 30 mg Zn/kg diet), Zn-deficient (ZD, <0. 5 mg Zn/kg diet), or Zn-replenished (ZDA, ZD hamsters receiving ZA diet for last 2 d) for 7 wk. Hamsters consuming the ZD diet had modestly but significantly lower intestinal editing activity than ZA hamsters. Intestinal editing activity in the ZDA group was not different from that of ZA hamsters. Data derived from these studies contribute to the understanding of lipoprotein metabolism in hamsters, a suitable model for the study of atherosclerosis.

Apolipoprotein A-I gene expression is regulated by cellular zinc status in hep G2 cells.

The influence of Zn on the expression of the apolipoprotein A-I (apoA-I) gene in Hep G2 cells was examined. Zn depletion was achieved with a low-Zn (ZD) medium prepared from Zn-free growth medium (Opti), a ZD medium containing Chelex 100-extracted fetal bovine serum (CHE), and a medium containing chelator 1, 10-phenanthroline (OP). Compared with those for their respective controls, cellular Zn levels were reduced by 55, 48, and 46% and apoA-I mRNA abundances were reduced by 20, 29, and 28% in Opti, CHE, and OP systems, respectively, after one passage in ZD media or 24 h in OP medium. To establish the specificity of Zn treatment, groups of ZD cells were treated with their respective control media for the last 24 h (ZDA) or normal cells were cultured with OP medium supplemented with Zn (OP-Zn). ZDA treatments partially normalized cellular Zn levels in the Opti system and restored or elevated apoA-I mRNA levels in the Opti or CHE system, respectively. Similarly, the OP-Zn treatment restored the cellular Zn and apoA-I mRNA levels. Furthermore, one passage of culture with Zn-supplemented media in both the Opti and CHE systems resulted in higher cellular Zn and apoA-I mRNA levels than those for controls. Most significantly, short-term high-Zn induction to normal cells markedly elevated the cellular Zn (3-fold) and apoA-I mRNA (5-fold) levels. Data derived from this study strongly suggest that the expression of apoA-I is regulated by cellular Zn status.

Zinc deficiency decreases plasma level and hepatic mRNA abundance of apolipoprotein A-I in rats and hamsters.

The influence of Zn deficiency on the plasma level as well as the hepatic and intestinal gene expression of apolipoprotein (apo) A-I was examined in rats and hamsters. Male Sprague-Dawley rats (8 wk old) and Golden Syrian hamsters (7 wk old) were assigned to three dietary treatments: Zn adequate (ZA, 30 mg Zn/kg diet), Zn deficient (ZD, <0.5 mg Zn/kg diet), and Zn replete (ZDA, ZD animals fed the ZA diet for the last 2 days). The dietary treatments lasted for 18 days for rats or 6 wk for hamsters. For the measurement of apoA-I mRNA abundance, hamster apoA-I cDNA was cloned from the small intestine. The full-length 905-base pair cDNA shared approximately 80% similarity with the human, rat, and mouse apoA-I cDNAs. Hepatic and plasma Zn levels were reduced in ZD animals but normalized in ZDA rats and increased in ZDA hamsters compared with ZA animals. Zn deficiency reduced plasma apoA-I and hepatic apoA-I mRNA levels 13 and 38%, respectively, in ZD rats. The 2 days of Zn replenishment raised plasma apoA-I and hepatic apoA-I mRNA levels in ZDA rats by 34 and 28%, respectively, higher than ZA rats. Similarly, these levels were decreased by 18 and 25%, respectively, in ZD hamsters but normalized in ZDA hamsters compared with ZA hamsters. In contrast to the alterations of hepatic apoA-I mRNA levels, neither Zn deficiency nor subsequent Zn repletion produced alterations in the intestinal apoA-I mRNA abundance. Data from this study demonstrated that Zn deficiency specifically decreases hepatic apoA-I gene expression, which may at least be partly responsible for the reduction of plasma apoA-I levels.

Regulation of apolipoprotein A-I gene expression in Hep G2 cells depleted of Cu by cupruretic tetramine.

Studies were designed to examine the regulation of apolipoprotein (apo) A-I gene expression in Cu-depleted Hep G2 cells. The cupruretic chelator N,N'-bis(2-aminoethyl)-1,3-propanediamine 4 HCl (2,3,2-tetramine or TETA) was used to maintain a 77% reduction in cellular Cu in Hep G2 cells. After two passages of TETA treatment, the relative abundance of apoA-I mRNA was elevated 52%. In TETA-treated cells, the rate of apoA-I mRNA decay measured by an actinomycin D chase study was accelerated 108%, and the synthesis of apoA-I mRNA determined by a nuclear runoff assay was enhanced 2.5-fold in TETA-treated cells. All of those changes could be reverted toward the control values with Cu supplementation for only 2 days. In transient transfection assays, a 26.7% increase in chloramphenicol O-acetyltransferase (CAT) activity for the reporter construct -256AI-CAT was observed in the treated cells. However, the ability of apoA-I regulatory protein 1 (ARP-1) to repress the CAT activity was not affected by the depressed Cu status. In addition, gel retardation experiments demonstrated that Cu depletion enhanced the binding of hepatocyte nuclear factor 4 (HNF-4) and other undefined nuclear factors to oligonucleotides containing site A, one of three regulatory sites of the apoA-I gene promoter. Moreover, the relative abundance of HNF-4 mRNA was increased 58% in the Cu-depleted cells. Thus the observed increase in apoA-I gene transcription may be mediated mostly by an elevated level of the regulatory factor, HNF-4. In summary, the present findings established the mechanism by which a depressed cellular Cu status can enhance apoA-I mRNA production and subsequently increase apoA-I synthesis.