Heteroplasmy levels of mtDNA1555A>G mutation is positively associated with diverse phenotypes and mutation transmission in a Chinese family.

The mtDNA 1555A>G mutation was considered to be one of the most common causes of aminoglycoside-induced and non-syndromic hearing loss. However, this mutation was always found in homoplasmy with high phenotypic heterogeneity. Recently this mutation in heteroplasmy has been reported in several studies. In the present study, we have collected a large Chinese family harboring heteroplasmic mtDNA 1555A>G mutation with diverse clinical phenotypes. To investigate the relationship between the mutation load and the severity of hearing loss under Eastern Asian background, we performed clinical, molecular, genetic and phylogenic analysis. This pedigree was characterized by coexistence of eight subjects with homoplasmic mutation and ten subjects with various degrees of heteroplasmy, and the results suggested that there was a strong correlation between the mutation load and the severity/age-onset of hearing loss (r=0.758, p<0.001). We noticed that the mutation level of offspring was associated with their mothers' in this pedigree, which indicated that maybe exist a regular pattern during the process of the heteroplasmic transmission. In addition, analysis of the complete mtDNA genome of this family revealed that it belonged to Eastern Asian haplogroup B4C1. In addition, a rare homoplasmic mtDNA 9128T>C variant was identified, it located at a strictly conserved site of mtDNA ATP6 gene.

[In vitro study on the anti-HSV-1 and HBV activities of extracts from the fruit of Eucalyptus maidenii].

OBJECTIVE: To investigate the antiviral activities of three kinds of extracts from the fruit of Eucalyptus maidenii against herpes simplex virus typel and Hepatitis B Virus. METHODS: Cytotoxicity of extracts on Vero cell lines were estimated using MTT method and anti-HSV-1 activity was observed and determined with CPE and plaque reduction assay. The inhibitory effects of extracts on HBsAg and HBeAg secretion in HepG2.2.15 cell culture were detected using ELISA. RESULTS: Aqueous extract (pl8-E3) had conspicuous anti-HSV-1 activity, the IC50 was 126.77 microg/mL,but the EtOAc extracts( pl8-E1 )and MeOH extracts (pl8-E2) showed little anti-HSV-1 activity. None of these extracts had significant inhibitory eflect on HBsAg and HBeAg secretion in HepG2.2.15 cell culture. CONCLUSION: Aqueous extract(p18-E3) from the fruit of Eucalyptus maidenii has conspicuous anti-HSV-1 activity. It could inactivate virus directly,and inhibit virus attachment,but had no influence on virus penetration. The mechanism that p18-E3 inactivates virus might involve in viral envelope alteration.

BJ-B11, a novel Hsp90 inhibitor, induces apoptosis in human chronic myeloid leukemia K562 cells through the mitochondria-dependent pathway.

In the past few years heat shock protein 90 (Hsp90) inhibitors have been reported to possess significant antitumor activity. We investigated, for the first time, the antitumor activity of a novel Hsp90 inhibitor 2-(4-acetyloxycyclohexylamino)-4-(3, 6, 6-trimethyl-4-oxo-4, 5, 6, 7-tetrahydro-1H-indazol-1-yl)-benzamide (BJ-B11) and the molecular mechanism underlying the apoptosis it induces in human chronic myeloid leukemia K562 cells. The results revealed that BJ-B11 triggered growth inhibition in K562 cells and other malignant cell lines in vitro with only minor toxicity in a normal human cell line. BJ-B11 inhibited the proliferation of K562 cells in a concentration- and time-dependent manner, with IC(50) values of 1.1 ± 0.2 µM and 0.4 ± 0.1 µM after 48 and 72 h incubations respectively. This most likely results from cell cycle arrest at the G(0)/G(1) phase and the induction of apoptosis. In addition, BJ-B11 degraded the Hsp90 client proteins Bcr-Abl and Akt, induced activation of caspase-9 and caspase-3, and subsequent cleavage of PARP. The caspase signals may originate from mitochondrial dysfunction, which is supported by the finding of cytochrome c release. In addition, inactivation of the Akt signaling pathway may be involved in the process of BJ-B11-induced apoptosis. Taken together, our data provide a putative molecular mechanism for the anticancer effect of BJ-B11 on K562 cells, and suggest a potential application for BJ-B11 in chronic myeloid leukemia therapy.

Synthesis and in vitro anti-HSV-1 activity of a novel Hsp90 inhibitor BJ-B11.

In this study, a novel Hsp90 inhibitor BJ-B11, was synthesized and evaluated for in vitro antiviral activity against several viruses. Possible anti-HSV-1 mechanisms were also investigated. BJ-B11 displayed no antiviral activity against coxsackievirus B(3) (CVB(3)), human respiratory syncytial virus (RSV) and influenza virus (H1N1), but exhibited potent anti-HSV-1 and HSV-2 activity with EC(50) values of 0.42±0.18 µM and 0.60±0.21 µM, respectively. Additionally, the inhibitory effects of BJ-B11 against HSV-1 were likely to be introduced at early stage of infection. Our results indicate that BJ-B11 with alternative mechanisms of action is potent as an anti-HSV clinical trial candidate.

Large-scale mtDNA screening reveals a surprising matrilineal complexity in east Asia and its implications to the peopling of the region.

In order to achieve a thorough coverage of the basal lineages in the Chinese matrilineal pool, we have sequenced the mitochondrial DNA (mtDNA) control region and partial coding region segments of 6,093 mtDNAs sampled from 84 populations across China. By comparing with the available complete mtDNA sequences, 194 of those mtDNAs could not be firmly assigned into the available haplogroups. Completely sequencing 51 representatives selected from these unclassified mtDNAs identified a number of novel lineages, including five novel basal haplogroups that directly emanate from the Eurasian founder nodes (M and N). No matrilineal contribution from the archaic hominid was observed. Subsequent analyses suggested that these newly identified basal lineages likely represent the genetic relics of modern humans initially peopling East Asia instead of being the results of gene flow from the neighboring regions. The observation that most of the newly recognized mtDNA lineages have already differentiated and show the highest genetic diversity in southern China provided additional evidence in support of the Southern Route peopling hypothesis of East Asians. Specifically, the enrichment of most of the basal lineages in southern China and their rather ancient ages in Late Pleistocene further suggested that this region was likely the genetic reservoir of modern humans after they entered East Asia.

Mitochondrial DNA polymorphisms in Gelao ethnic group residing in Southwest China.

Gelao ethnic group, an aboriginal population residing in southwest China, has undergone a long and complex evolutionary process. To investigate the genetic structure of this ancient ethnic group, mitochondrial DNA (mtDNA) polymorphisms of 102 Gelao individuals were collected and analyzed in this study. With the aid of the information extracted from control-region hypervariable segments (HVSs) I and II as well as some necessary coding-region segments, phylogenetic status of all mtDNAs under study were determined by means of classifying into various defined haplogroups. The southern-prevalent haplogroups B, R9, and M7 account for 45.1% of the gene pool, whereas northern-prevalent haplogroups A, D, G, N9, and M8 consist of 39.2%. Haplogroup distribution indicates that the Gelao bears signatures of southern populations and possesses some regional characters. In the PC map, Gelao clusters together with populations with Bai-Yue tribe origin as well as the local Han and the Miao. The results demonstrate the complexity of Gelao population and the data can well supplement the China mtDNA database.

[GJB2 gene mutation in deaf patients].

OBJECTIVE: To detect the GJB2 gene mutation in patients with autosomal-recessive deafness, and analyze the relationship between clinical phenotype and gene mutation. METHODS: Forty-two patients were examined clinically by pure tone audiometry, acoustic impedance and auditory brainstem response. The complete coding region of the GJB2 gene was amplified by polymerase chain reaction (PCR) and the PCR products were subjected to automatic DNA sequencing. RESULTS: Two cases had homozygous mutation of 235delC. One of them had sensorineural hearing loss while the other had mixed hearing loss. Heterozygous mutation of 176del16bp was detected in a pair of twins who had mixed hearing loss. The 109G to A, 79G to A and 341A to G mutations were observed in both the patients and the controls. CONCLUSION: Homozygous 235delC mutation is one of the pathogeni c mutations which could occur in patients with mixed hearing loss. The heterozygous 176del16bp mutation combined with environmental factor may cause hearing loss. The 109G to A, 79G to A and 341A to G variants were considered to be polymorphisms of the GJB2 gene.

Analysis of mitochondrial DNA polymorphisms in Guangdong Han Chinese.

Previous investigations on Chinese mitochondrial DNA (mtDNA) variation revealed that the matrilineal gene pool of southern Han Chinese is rather complex, with much higher genetic diversity and more basal/ancient lineages than the northern Hans. The extreme case is Guangdong Han populations, among which pronounced (matrilineal) differentiation has been observed, indicative of complex demography of the region. To get more insights into the maternal makeup of southern Han Chinese, mtDNA variation of a total of 106 individuals sampled from Dongguan, Guangdong Province, China, was analyzed in this study. With the aid of the information from control-region hypervariable segments I and II (HVS-I and -II) as well as some necessary coding-region segments, the phylogenetic status of all mtDNAs under examination were determined according to the reconstructed East Asian mtDNA tree. In this way, the mtDNAs have been classified into various haplogroups or sub-haplogroups. The southern-prevalent haplogroups, such as R9 (20.8%), B (17.9%), M7b (14.2%), show relatively high distribution frequencies in Dongguan Hans; whereas the frequencies of Northern-prevalent haplogroups (with the exception of D) are quite low: C (1.9%), G2 (1.9%) and Z (1.9%), indicating the southern-origin of Dongguan Hans.

[The relationship between the effect of amlodipine on carotid intimal-medial thickness and angiotensin converting enzyme genotypes in elderly hypertensive patients].

OBJECTIVE: To investigate the association between the anti-atherosclerotic effects of amlodipine and angiotensin converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism in elderly essential hypertensive (EH) patients. METHODS: A total of 220 EH patients were treated with amlodipine (2.5 - 10 mg, once daily) for twelve months and complete data were obtained from 208 patients with genotypes of II (n = 90), ID (n = 91) and DD (n = 27). The indices of carotid arterial were compared before and post amlodipine treatment in patients with identical genotype and among different ACE genotypes and each genotype post therapy. RESULTS: The carotid mean intimal-medial thickness (MIMT) was slightly decreased in EH patients with ID and DD genotypes and significantly decreased in EH patients with II genotype (0.96 +/- 0.12 vs. 0.92 +/- 0.13, P < 0.01) compared to pre-treatment values. The decreased degree of MIMT (DeltaMIMT) in II genotype was significantly higher in II genotype than those in ID or DD genotype (0.05 +/- 0.03 vs. 0.01 +/- 0.02, 0.01 +/- 0.03 respectively, P < 0.01). The post treatment plaque score (PS) in patients with II genotype was significantly reduced (4.85 +/- 2.51 vs. 3.90 +/- 2.36, P < 0.05). Multivariate linear regression analysis showed the baseline SBP, the decreased degree of SBP (DeltaSBP) and the II genotype were the major factors affecting the DeltaMIMT. CONCLUSION: Hypertensive patients carrying II genotype ACE genotype are the best responders for the anti-atherosclerotic effects of amlodipine.

[Effect of endogeneous gangliosides on integrin alpha2beta1-mediated adhesion of neuroblastoma cells to collagen].

OBJECTIVE: To study the effect of endogeneous gangliosides (Gls) on integrin alpha2beta1-mediated adhesion of neuroblastoma cells to collagen (Col). METHODS: Neuroblastoma SK-N-SH cell line was cultured in the modified eagle's medium with the presence of 10 mum D-threo-1-phenyl-2-decanolamino-3-morphinolin-1-propanol (D-PDMP), an inhibitor of glucosylceramide synthase. Flow cytometry was used to detect the expression of integrin alpha2beta1 in the cell line. The effects of Mg2(+) and monoclonal antibodies to integrin alpha2beta1 on the adhesion of the cell line to immobilized Col were observed. The adhesion cell number was measured with the BCA method and presented with absorptance A570. RESULTS: There was a high expression of integrin alpha2beta1 in the SK-N-SH cell line without D-PDMP treatment. Endogenous Gls in the cells were almost depleted after 6-day exposure to D-PDMP, but the integrin alpha2beta1 expression was not significantly changed. 1 mmoL/L Mg2(+) treatment increased significantly the number of adhesion cells in the SK-N-SH cell line. The adhesion to Col of the SK-N-SH cells exposed to D-PDMP which Gls was depleted was significantly reduced compared with the control SK-N-SH cells treated with 1 mmoL/L Mg2(+) (A570: 0.33 +/- 0.016 vs 0.57 +/- 0.033; P < 0.01). After endogeneous Gls was added into the Gls-depleted SK-N-SH cells, the adhesion of the cells was restored (A570: 0.52 +/- 0.035). The adhesion of SK-N-SH cells was significantly blocked by anti-alpha2 and anti-beta1 monoclonal antibodies, with A570 of 0.31 +/- 0.018 and 0.36 +/- 0.021 respectively. CONCLUSIONS: Endogenous tumor Gls increases neuroblastoma cell adhesion to Col by regulating the function of integrin alpha2beta1, but has no effects on the integrin expression. It is suggested that tumor Gls may play a role in migration, invasion and metastasis of tumor cells.

[Genotyping of HBV DNA in Shenzhen and clinical manifestations].

OBJECTIVE: To detect HBV DNA and its genotypes. METHODS: The 6 isoforms of HBV DNA was detected out using of different probes by Polymerase Chain Reaction and Nucleic Acid hybridization. RESULTS: Of 150 HBV DNA positive patients who lived in Shenzhen, 50 samples (33%) are type B, 36 samples (24%) are type C, 13 samples (9%) are type D, 3 samples is type F, 1 sample is type A, 48 samples (31%) are mixed type. The ALT value was significantly higher in genotype B than in genotype C. HBe positivity were higher in genotype B than genotype C. HBeAg positivity were higher in genotype C than in genotype B. There are not obvious relations between genotype and age or sex. CONCLUSION: In the detected samples, the major genotype of HBV DNA is type B, several are type C, D. The type E haven't been found. There are some relations between all kinds of genotypes and the severity of hepatitis B.

[Effects of bu yang huan wu decoction on astrocytes after cerebral ischemia and reperfusion].

OBJECTIVE: To study the effects of Bu Yang Huan Wu Decoction on astrocytes after cerebral ischemia and reperfusion. METHOD: Cerebral ischemia model in gerbils was produced by ligating bilateral common carotid artery. The dynamic expressin of GFAP were determined by immunochemistry after cerebyal ischemia for 15 min followed by reperfusion for 24 hours and 48 hours. RESULT: GFAP positive reactions reached a peak after cerebral ischemia for 15 min followed by reperfusion for 24 hours. Bu Yang Huan Wu Decoction decreased the expression. GFAP positive reactions decreased after cerebral ischemia for 15 min followed by reperfusion for 48 hours, Bu Yang Huan Wu Decoction increased the expression. CONCLUSION: The regulation of Bu Yang Huan Wu Decoction on astrocytes after cerebral ischemia and reperfusion may be related to repairing process after cerebral ischemia.