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Preeclampsia is a gestational hypertensive disease; however, preeclampsia remains poorly understood. Bioinformatics analysis was applied to find novel genes involved in the pathogenesis of preeclampsia and identified CLDN1 as one of the most differentially expressed genes when comparing patients with preeclampsia and healthy controls. The results of the qRT-PCR, Western blotting and immunohistochemistry experiments demonstrated that CLDN1 was significantly downregulated in the chorionic villi in samples from patients with preeclampsia. Furthermore, knockdown of CLDN1 in HTR-8/SVneo cells resulted in the inhibition of proliferation and induction of apoptosis, and overexpression of CLDN1 reversed these effects. In addition, RNA-seq assays demonstrated that the gene BIRC3 is potentially downstream of CLDN1 and is involved in the regulation of apoptosis. Knockdown of CLDN1 confirmed that the expression level of BIRC3 was obviously decreased and was associated with a significant increase in cleaved PARP. Interestingly, the apoptotic effect in CLDN1 knockdown cells was rescued after BIRC3 overexpression. Overall, these results indicate that a decrease in CLDN1 inhibits BIRC3 expression and increases cleaved PARP levels thus participating in the pathogenesis of preeclampsia.

Protein disulfide isomerase 3 (PDIA3) is a chaperone protein that modulates the folding of newly synthesized glycoproteins, has isomerase and redox activity, and has been implicated in the pathogenesis of many diseases. However, the role of PDIA3 in pregnancy-associated diseases remains largely unknown. Our present study reveals a key role for PDIA3 in the biology of placental trophoblasts from women with preeclampsia (PE). Immunohistochemistry and Western blot analysis revealed that PDIA3 expression was decreased in villous trophoblasts from women with PE compared to normotensive pregnancies. Further, using a Cell Counting Kit-8 assay, flow cytometry, and 5-ethynyl-2’-deoxyuridine (EdU) staining, we found that siRNA-mediated PDIA3 knockdown significantly promoted apoptosis and inhibited proliferation in the HTR8/SVneo cell line, while overexpression of PDIA3 reversed these effects. Furthermore, RNA sequencing and Western blot analysis demonstrated that knockdown of PDIA3 inhibited MDM2 protein expression in HTR8 cells, concurrent with marked elevation of p53 and p21 expression. Conversely, overexpression of PDIA3 had the opposite effects. Immunohistochemistry and Western blot further revealed that MDM2 protein expression was downregulated and p21 was increased in trophoblasts of women with PE compared to women with normotensive pregnancies. Our findings indicate that PDIA3 expression is decreased in the trophoblasts of women with PE, and decreased PDIA3 induces trophoblast apoptosis and represses trophoblast proliferation through regulating the MDM2/p53/p21 pathway.

Myasthenia gravis (MG) is a chronic autoimmune disorder resulting from autoantibodies against neuromuscular junction components. Research shows that this disease might be a primary bone marrow (BM) stem cell disorder. Autophagy protects the dynamics and homeostasis of the host cells by removing damaged mitochondria, protein aggregates and other intercellular materials. Dysfunctional autophagy is associated with autoimmune diseases. However, the autophagy activity and mechanisms in BM stem cell from MG patients remain largely uncharacterized. We evaluated the autophagy activity in bone marrow mononuclear cells (BM-MNCs) and the effects of autophagy on cell survival from patients with MG and healthy controls. Our results revealed that autophagy was significantly decreased in patients with MG before immunomodulation treatment compared with that in age-/sex-matched controls, and was lower in generalized MG (GMG) patients than in ocular MG (OMG) patients. Immunomodulatory treatment partially increased autophagy activity of BM-MNCs in MG patients and improved the symptoms. Furthermore, defective BM-MNCs differentiation, proliferation and apoptosis were observed due to dysfunctional autophagy. These findings suggest for the first time that BM-MNCs autophagy is impaired in patients with MG before immunomodulation therapy, and that autophagy is indispensable for the survival of BM-MNCs, implicating autophagy might be a potential pathogenic mechanism of MG and a novel therapeutic strategy for MG treatment.

Pumilio (PUM) proteins are members of a highly conserved RNA-binding protein family that posttranscriptionally regulate gene expression in many organisms. However, their roles in the placenta are unclear. In the present study, we report the requirement for the PUM homolog 1 (PUM1) gene in preeclampsia (PE). Immunofluorescence and immunohistochemical data showed that PUM1 was highly expressed in human placental villi from women with PE compared to healthy controls (HCs). Further, PUM1 overexpression repressed, and knockdown enhanced, the invasion and proliferation of trophoblasts. Interestingly, PUM1 knockdown promoted trophoblast invasion in a villous explant culture model, while PUM1 overexpression repressed these effects. Furthermore, lncRNA transcriptome sequencing coupled with RNA immunoprecipitation (RIP) revealed that PUM1 inhibits trophoblast invasion in PE by downregulating the expression of lncRNA HOTAIR. Moreover, PUM1 regulates HOTAIR expression via a posttranscriptional mechanism. Using RNA-protein pull-down and mRNA stability assays, we identified PUM1 as a specific binding partner that decreased the half-life of HOTAIR and lowered the steady-state level of HOTAIR expression, suggesting a novel posttranscriptional regulatory mechanism. Collectively, these findings identified a novel RNA regulatory mechanism, revealing a new pathway governing the regulation of PUM1/HOTAIR in trophoblast invasion in the pathogenesis of PE.

Recurrent respiratory papillomatosis (RRP) is mainly caused by Human Papillomavirus (HPV) 6 and 11. While various adjuvant therapies have been reported, no effective therapy has been documented to universally “cure” this disease. In the era of precision medicine, it would be valuable to identify effective intervention based on drug sensitivity testing and/or molecular analysis. It is essential to be able to successfully carry out in vitro culture and expand tumor cells directly from patients to accomplish this goal. Here we report the result of successful culture of HPV-infected cell lines (successful rate 70%, 9/13) that express the E6/E7 RNA transcript, using pathologic tissue biopsies from patients treated at our institution. The availability of such a system would enable ex vivo therapeutic testing and disease modeling.

Nuclear modifier genes have been proposed to modify the phenotypic expression of mitochondrial DNA mutations. Using a targeted exome-sequencing approach, here we found that the p.191Gly>Val mutation in mitochondrial tyrosyl-tRNA synthetase 2 (YARS2) interacts with the tRNA(Ser(UCN)) 7511A>G mutation in causing deafness. Strikingly, members of a Chinese family bearing both the YARS2 p.191Gly>Val and m.7511A>G mutations displayed much higher penetrance of deafness than those pedigrees carrying only the m.7511A>G mutation. The m.7511A>G mutation changed the A4:U69 base-pairing to G4:U69 pairing at the aminoacyl acceptor stem of tRNA(Ser(UCN)) and perturbed tRNA(Ser(UCN)) structure and function, including an increased melting temperature, altered conformation, instability, and aberrant aminoacylation of mutant tRNA. Using lymphoblastoid cell lines derived from symptomatic and asymptomatic members of these Chinese families and control subjects, we show that cell lines harboring only the m.7511A>G or p.191Gly>Val mutation revealed relatively mild defects in tRNA(Ser(UCN)) or tRNA(Tyr) metabolism, respectively. However, cell lines harboring both m.7511A>G and p.191Gly>Val mutations displayed more severe defective aminoacylations and lower tRNA(Ser(UCN)) and tRNA(Tyr) levels, aberrant aminoacylation, and lower levels of other tRNAs, including tRNA(Thr), tRNA(Lys), tRNA(Leu(UUR)), and tRNA(Ser(AGY)), than those in the cell lines carrying only the m.7511A>G or p.191Gly>Val mutation. Furthermore, mutant cell lines harboring both m.7511A>G and p.191Gly>Val mutations exhibited greater decreases in the levels of mitochondrial translation, respiration, and mitochondrial ATP and membrane potentials, along with increased production of reactive oxygen species. Our findings provide molecular-level insights into the pathophysiology of maternally transmitted deafness arising from the synergy between tRNA(Ser(UCN)) and mitochondrial YARS mutations.

Problem Preeclampsia (PE) is a unique gestational disorder leading to maternal and neonatal morbidity and mortality. AnnexinA7 (ANXA7) is a calcium-dependent phospholipid-binding protein that promotes membrane fusion during exocytosis. However, the function of ANXA7 in placental trophoblast is poorly understood. The present study aimed to investigate a possible association between ANXA7 and human trophoblast apoptosis. Methods We collected human placental tissues from patients with PE and normal pregnant women to elucidate the expression level of ANXA7. The ANXA7-knockdown and ANXA7-overexpressing HTR8/SVneo cells were utilized for studying the function of ANXA7 in trophoblast. The proliferation and apoptosis levels of trophoblast were examined with Western blot assay, flow cytometry, Cell Counting Kit-8 assay, and immunohistochemistry. Results ANXA7 expression was significantly lower in placentas from patients with PE patients compared with that in from normal pregnant controls. Knockdown of ANXA7 induced cell apoptosis and inhibited cell proliferation in HTR-8 via by downregulating BCL2 protein levels. Overexpression of ANXA7 reduced apoptosis and promoted HTR8 proliferation. Further analyses showed that ANXA7 knockdown inhibited the activation of the JAK1/STAT3 pathway in HTR-8 cells. Conclusion Our findings revealed a new regulatory pathway of ANXA7/JAK1/STAT3 in trophoblast apoptosis in preeclampsia, suggesting that ANXA7 is a potential therapeutic target for preeclampsia.

Trophoblast dysfunction is one mechanism implicated in the etiology of recurrent miscarriage (RM). Regulation of trophoblast function, however, is complex and the mechanisms contributing to dysregulation remain to be elucidated. Herein, we found EIF5A1 expression levels to be significantly decreased in cytotrophoblasts in RM villous tissues compared with healthy controls. Using the HTR-8/SVneo cell line as a model system, we found that overexpression of EIF5A1 promotes trophoblast proliferation, migration and invasion in vitro. Knockdown of EIF5A1 or inhibiting its hypusination with N1-guanyl-1,7-diaminoheptane (GC7) suppresses these activities. Similarly, mutating EIF5A1 to EIF5A1K50A to prevent hypusination abolishes its effects on proliferation, migration and invasion. Furthermore, upregulation of EIF5A1 increases the outgrowth of trophoblasts in a villous explant culture model, whereas knockdown has the opposite effect. Suppression of EIF5A1 hypusination also inhibits the outgrowth of trophoblasts in explants. Mechanistically, ARAF mediates the regulation of trophoblast migration and invasion by EIF5A1. Hypusinated EIF5A1 regulates the integrin/ERK signaling pathway via controlling the translation of ARAF. ARAF level is also downregulated in trophoblasts of RM villous tissues and expression of ARAF is positively correlated with EIF5A1. Together, our results suggest that EIF5A1 may be a regulator of trophoblast function at the maternal–fetal interface and low levels of EIF5A1 and ARAF may be associated with RM.

The 1555A→G mutation in mitochondrial 12S rRNA has been associated with aminoglycoside-induced and non-syndromic deafness in many individuals worldwide. Mitochondrial genetic modifiers are proposed to influence the phenotypic expression of m.1555A→G mutation. Here, we report that a deafness-susceptibility allele (m.4317A→G) in the tRNA(Ile) gene modulates the phenotype expression of m.1555A→G mutation. Strikingly, a large Han Chinese pedigree carrying both m.4317A→G and m.1555A→G mutations exhibited much higher penetrance of deafness than those carrying only the m.1555A→G mutation. The m.4317A→G mutation affected a highly conserved adenine at position 59 in the T-loop of tRNA(Ile). We therefore hypothesized that the m.4317A→G mutation alters both structure and function of tRNA(Ile). Using lymphoblastoid cell lines derived from members of Chinese families (three carrying both m.1555A→G and m.4317A→G mutations, three harboring only m.1555A→G mutation, and three controls lacking these mutations), we found that the cell lines bearing both m.4317A→G and m.1555A→G mutations exhibited more severe mitochondrial dysfunctions than those carrying only the m.1555A→G mutation. We also found that the m.4317A→G mutation perturbed the conformation, stability, and aminoacylation efficiency of tRNA(Ile). These m.4317A→G mutation-induced alterations in tRNA(Ile) structure and function aggravated the defective mitochondrial translation and respiratory phenotypes associated with the m.1555A→G mutation. Furthermore, mutant cell lines bearing both m.4317A→G and m.1555A→G mutations exhibited greater reductions in the mitochondrial ATP levels and membrane potentials and increasing production of reactive oxygen species than those carrying only the m.1555A→G mutation. Our findings provide new insights into the pathophysiology of maternally inherited deafness arising from the synergy between mitochondrial 12S rRNA and tRNA mutations.

Coronary heart disease (CHD) is the leading cause of death worldwide. Mitochondrial genetic determinant for the development of CHD remains poorly explored. We report there the clinical, genetic, molecular and biochemical characterization of a four-generation Chinese family with maternally inherited CHD. Thirteen of 32 adult members in this family exhibited variable severity and age-at-onset of CHD. Mutational analysis of their mitochondrial genomes identified the tRNA(Thr) 15927G>A mutation belonging to the Eastern Asian haplogroup B5. The anticipated destabilization of a highly conserved base-pairing (28C-42G) by the 15927G>A mutation affects structure and function of tRNA(Thr). Northern analysis revealed ≈80% decrease in the steady-state level of tRNA(Thr) in the mutant cell lines carrying the 15927G>A mutation. The 15927G>A mutation changed the conformation of tRNA(Thr), as suggested by slower electrophoretic mobility of mutated tRNA with respect to the wild-type molecule. In addition, ∼39% reduction in aminoacylated efficiency of tRNA(Thr) was observed in mutant cells derived from this Chinese family. An in vivo mitochondrial protein labeling analysis showed ∼53% reduction in the rate of mitochondrial translation in mutant cells. The impaired mitochondrial protein synthesis leads to defects in overall respiratory capacity or malate/glutamate-promoted respiration or succinate/glycerol-3-phosphate-promoted respiration, or N,N,N',N'-tetramethyl-pphenylenediamine/ascorbate-promoted respiration in mutant cells. An increasing production of reactive oxygen species was observed in the mutant cells carrying the 15927G>A mutation. These results provide the direct evidence that the tRNA(Thr) 15927G>A mutation is associated with CHD. Our findings may provide new insights into pathophysiology and intervention targets of this disorder.

Mitochondria have the profound impact on vascular function in both health and disease. However, mitochondrial genetic determinants for the development of hypertension remain poorly explored.The Sanger sequence analysis of 22 mitochondrial tRNA genes were performed in a cohort of 2070 Han Chinese hypertensive and 512 control subjects. This analysis identified 165 variants among 22 tRNA genes. These variants were evaluated for the pathogenicity using the following criteria: (1) present in1% of the controls; (2) evolutional conservation; (3) potential structural and functional alterations. We identified 47 (5 known and 42 novel/putative) hypertension-associated tRNA variants in 80 hypertensive subjects. These variants could have potential structural alterations and functional significance of tRNAs. By using lymphoblastoid cell lines derived from 6 probands carrying one of 6 represented variants (tRNA(Ala) 5655TC, tRNA(Gly) 10003TC, tRNA(Leu(UUR)) 3253TC, tRNA(Asp) 7551AG, tRNA(Glu) 14692AG, tRNA(Thr) 15909AG) and 6 control subjects lacking these variants, we showed marked reductions in the steady-state level of corresponding 5 tRNAs, but not tRNA(Thr), in mutant cell lines, compared with control cells lines. The various decreases in the activities of complexes I, III and IV were observed in mutant cells carrying one of five tRNA variants, except tRNA(Thr) 15909AG variant. The deficient respirations were responsible for the decrease in the mitochondrial ATP production and increasing production of reactive oxygen species in mutant cell lines carrying one of five tRNA variants.Mitochondrial tRNA variants are the important causes of hypertension, accounting for 3.9% cases of 2070 Han Chinese hypertensive subjects. Our findings may provide new insights into the pathophysiology of hypertension that were manifested by mitochondrial dysfunction.

We report here the clinical, genetic, molecular, and biochemical evaluations in two Han Chinese families with maternally inherited hypertension. Fourteen of 20 adult matrilineal relatives of these families exhibited a wide range of severity in hypertension, while none of offspring of affected fathers had hypertension. The age-at-onset of hypertension in matrilineal relatives varied from 37 years to 83 years, with an average of 55 and 66 years, respectively. Mutational analysis of their mitochondrial genomes identified the m.4353T>C mutation in the tRNA, in conjunction with the known m.593C>T mutation in the tRNA(Phe) and m.5553C>T mutation in the tRNA(Trp). Northern analysis revealed that m.4353T>C, m.593C>T and m.5553C>T mutations caused ∼66%, 65%, and 12% reductions in the steady-state level of tRNA(Gln), tRNA(Phe) and tRNA(Trp), respectively. An in vivo protein labeling analysis showed ∼35% reduction in the rate of mitochondrial translation in cells carrying these tRNA mutations. Impaired mitochondrial translation is apparently a primary contributor to the reduced rates of overall respiratory capacity, malate/glutamate-promoted respiration, succinate/glycerol-3-phosphate-promoted respiration, or N,N,N',N'-tetramethyl-p-phenylenediamine/ascorbate-promoted respiration and the increasing level of reactive oxygen species in the cells carrying these mtDNA mutations. These data demonstrate that mitochondrial dysfunction caused by mitochondrial tRNA mutations is associated with essential hypertension in these families.

We reported here clinical, genetic evaluations and molecular analysis of mitochondrial DNA (mtDNA) in two Han Chinese families carrying the known mitochondrial 12S rRNA A1555G mutation. In contrast with the previous data that hearing loss as a sole phenotype was present in the maternal lineage of other families carrying the A1555G mutation, matrilineal relatives among these two Chinese families exhibited both hearing loss and hypertension. Of 21 matrilineal relatives, 9 subjects exhibited both hearing loss and hypertension, 2 individuals suffered from only hypertension and 1 member had only hearing loss. The average age at onset of hypertension in the affected matrilineal relatives of these families was 60 and 46 years, respectively, whereas those of hearing loss in these two families were 33 and 55 years, respectively. Molecular analysis of their mtDNA identified distinct sets of variants belonging to the Eastern Asian haplogroup D5a. In contrast, the A1555G mutation occurred among other mtDNA haplogroups D, B, R, F, G, Y, M and N, respectively. Our data further support that the A1555G mutation is necessary but by itself insufficient to produce the clinical phenotype. The other modifiers are responsible for the phenotypic variability of matrilineal relatives within and among these families carrying the A1555G mutation. Our investigation provides the first evidence that the 12S rRNA A1555G mutation leads to both of hearing loss and hypertension. Thus, our findings may provide the new insights into the understanding of pathophysiology and valuable information for management and treatment of maternally inherited hearing loss and hypertension.

The authors report here the clinical, genetic, molecular and biochemical characterisation of a large five-generation Han Chinese pedigree with maternally transmitted non-syndromic hearing loss. 17 of 35 matrilineal relatives exhibited variable severity and age at onset of sensorineural hearing loss. The average age at onset of hearing loss in matrilineal relatives of this family is 29 years, while matrilineal relatives among families carrying other mitochondrial DNA mutations developed hearing loss with congenital conditions or early age at onset. Molecular analysis of their mitochondrial genome identified the novel heteroplasmic T12201C mutation in the transfer RNA (tRNA)(His) gene. The levels of T12201C mutation in matrilineal relatives of this family correlated with the severity and age at onset of non-syndromic hearing loss. By contrast, other heteroplasmic mitochondrial DNA mutations often cause syndromic hearing loss. The T12201C mutation destabilises a highly conservative base-pairing (5A-68U) on the acceptor stem of tRNA(His). tRNA northern analysis revealed that the T12201C mutation caused an ∼75% reduction in the steady-state level of tRNA(His). An in vivo protein labeling analysis showed an ∼47% reduction in the rate of mitochondrial translation in cells carrying the T12201C mutation. Impaired mitochondrial translation is apparently a primary contributor to the marked reduction in the rate of overall respiratory capacity, malate/glutamate-promoted respiration, succinate/glycerol-3-phosphate-promoted respiration or N,N,Ń,Ń-tetramethyl-p-phenylenediamine/ascorbate-promoted respiration. These data provide the first direct evidence that mitochondrial dysfunctions caused by the heteroplasmic tRNA(His) mutation lead to late-onset non-syndromic deafness. Thus, the authors' findings provide new insights into the understanding of pathophysiology and valuable information on the management and treatment of maternally inherited hearing loss.

Rational: Despite maternal transmission of hypertension in some pedigrees, pathophysiology of maternally inherited hypertension remains poorly understood. Objective: To establish a causative link between mitochondrial dysfunction and essential hypertension. Method and Results: A total of 106 subjects from a large Chinese family underwent clinical, genetic, molecular, and biochemical evaluations. Fifteen of 24 adult matrilineal relatives exhibited a wide range of severity in essential hypertension, whereas none of the offspring of affected fathers had hypertension. The age at onset of hypertension in the maternal kindred varied from 20 years to 69 years, with an average of 44 years. Mutational analysis of their mitochondrial genomes identified a novel homoplasmic 4263A>G mutation located at the processing site for the tRNA Ile 5′-end precursor. An in vitro processing analysis showed that the 4263A>G mutation reduced the efficiency of the tRNA Ile precursor 5′-end cleavage catalyzed by RNase P. tRNA Northern analysis revealed that the 4263A>G mutation caused ≈46% reduction in the steady-state level of tRNA Ile . An in vivo protein-labeling analysis showed ≈32% reduction in the rate of mitochondrial translation in cells carrying the 4263A>G mutation. Impaired mitochondrial translation is apparently a primary contributor to the reductions in the rate of overall respiratory capacity, malate/glutamate-promoted respiration, succinate/glycerol-3-phosphate-promoted respiration, or N , N , N′ , N′ -tetramethyl- p -phenylenediamine/ascorbate–promoted respiration and the increasing level of reactive oxygen species in cells carrying the 4263A>G mutation. Conclusions: These data provide direct evidence that mitochondrial dysfunction caused by mitochondrial tRNA Ile 4263A>G mutation is involved in essential hypertension. Our findings may provide new insights into pathophysiology of maternally transmitted hypertension.

We report here on the characterization of a three-generation Chinese family with aminoglycoside-induced and nonsyndromic hearing impairment. Ten of 17 matrilineal relatives exhibited bilateral and sensorineural hearing impairment. Of these, nine matrilineal relatives, who had a history of exposure to aminoglycosides, exhibited variable severity and audiometric configuration of hearing loss. The dose and age at the time of drug administration seemed to be correlated with the severity of the hearing loss experienced by affected individuals. Sequence analysis of the complete mitochondrial genome in the pedigree showed the presence of homoplasmic A1555G mutation and 37 variants belonging to haplogroup D4a. Of those variants, the G7444A mutation is of special interest as the mutation at this position results in a read-through of the stop condon AGA of the COI message, thereby adding three amino acids (Lys-Gln-Lys) to the C-terminal of the polypeptide. Alternatively, the G7444A mutation is adjacent to the site of 3' end endonucleolytic processing of L-strand RNA precursor, spanning tRNA(Ser(UCN)) and ND6 mRNA. Thus, the G7444A mutation, similar to the deafness-associated A7445G mutation, may lead to a defect in the processing of the L-strand RNA precursor, thus influencing the phenotypic expression of the A1555G mutation. These data also imply that nuclear background plays a role in the aminoglycoside ototoxicity associated with the A1555G mutation in this Chinese pedigree.

In this report, we investigate molecular pathogenic mechanism of a diabetes-associated homoplasmic mitochondrial tRNA mutation in a Han Chinese family with maternally transmitted diabetes mellitus. Of 10 adult matrilineal relatives, 5 individuals suffered from diabetes (4 subjects with only diabetes, one subject with both diabetes and hearing impairment), while other five matrilineal relatives (one with hearing loss) had glucose intolerance. The average age at onset of diabetes in matrilineal relatives was 50 years. Molecular analysis of their mitochondrial genomes identified the novel homoplasmic T10003C mutation in the tRNA(Gly) gene belonging to haplogroup M11b. The T10003C mutation is expected to form a base-pairing (13C-22G) at the highly conserved D-stem of tRNA(Gly), thereby affecting secondary structure and function of this tRNA. A tRNA Northern analysis revealed that the T10003C mutation caused ~70% reduction in the steady-state level of tRNA(Gly). An in vivo translation analysis showed ~33% reduction in the rate of mitochondrial translation in mutant cells. Oxygen consumption analysis showed the defects in overall respiratory capacity or the ATP-linked, proton leak, and maximal respiration in mutant cells. As a result, the cellular energy deficiency contributes to the development of diabetes in subjects carrying the T10003C mutation. These data provide the first direct evidence that the tRNA(Gly) mutation might be associated with diabetes. Thus, our findings may provide new insights into the understanding of pathophysiology of maternally inherited diabetes.

Background Coronary heart disease is the leading cause of death worldwide. Mitochondrial genetic determinants for the development of this disorder remain less explored. Methods and Results We performed a clinical and genetic evaluation and mutational screening of 22 mitochondrial tRNA genes in a cohort of 80 genetically unrelated Han C hinese subjects and 125 members of 4 families with coronary heart disease and 512 C hinese control subjects. This analysis identified 16 nucleotide changes among 9 tRNA genes. Of these, the T5592C mutation creates a highly conservative base pairing (5G‐68C) on the acceptor stem of tRNA Gln , whereas the G15927A mutation destabilizes a highly conserved base pairing (28C‐42G) in the anticodon stem of tRNA Thr . However, the other tRNA variants were polymorphisms. The pedigrees of BJH24 carrying the T5592C mutation, BJH15, and BJH45 harboring the G15927A mutation exhibited maternal transmission of coronary heart disease. Sequence analysis of their mitochondrial genomes revealed the presence of T5592C or G15927A mutation but the absence of other functionally significant mutations in all matrilineal relatives of these families. Conclusions Our previous observations showed that altered structures of tRNA s by these mt DNA mutations caused mitochondrial dysfunction. These may be the first evidence that mt DNA mutations increase the risk of coronary heart disease. Our findings may provide new insights into the pathophysiology of this disorder.

To investigate the pathophysiology of Leber's hereditary optic neuropathy (LHON), a cohort of 1164 Han Chinese subjects with LHON were screened for ND1 G3460A mutation. A total of 295 subjects from 16 Han Chinese families carrying the G3460A mutation underwent a clinical and genetic evaluation and molecular analysis of mitochondrial (mt)DNA. The incidence of G3460A mutation was 1.4% in this cohort of Chinese subjects with LHON. Twenty-seven (20 males/7 females) of 109 matrilineal relatives among 10 Chinese pedigrees carrying this mutation exhibited a wide range of severity and age-at-onset in visual impairment. Penetrances of optic neuropathy ranged from 7.1% to 50%, with the average of 24.5%. The age-at-onset of 27 affected matrilineal relatives varied from 10 to 40 years, with the average of 22 years. Molecular analysis identified the homoplasmic G3460A mutation and distinct sets of variants belonging to eight haplogroups. Haplogroup M with G3460A mutation was of higher frequency than those in controls. The penetrances of visual loss in families carrying mitochondrial DNA haplogroups A, B and M were higher than those in other families. Furthermore, haplogroup-specific variants tRNA(Ser(AGY)) A12223G, tRNA(Thr) G15927A and tRNA(Glu) A14693G may enhance the penetrance of visual loss in these families. The G3460A mutation occurred through recurrent origins and founder events in Chinese population. Mitochondrial modifiers may modulate the penetrance and expressivity of optic neuropathy among Chinese pedigrees carrying the G3460A mutation. Thus, our findings may provide new insights into the understanding of pathophysiology and valuable information on the management of LHON.

Mitochondrial m.14484T>C ( MT-ND6 ) mutation has been associated with Leber's hereditary optic neuropathy. Previous investigations revealed that the m.14484T>C mutation is a primary factor underlying the development of optic neuropathy but is not sufficient to produce a clinical phenotype. However, mitochondrial haplogroups have been proposed to modulate the phenotypic manifestation of the m.14484T>C mutation. Here, we performed the clinical, genetic evaluation and complete mitochondrial genome sequence analysis of 41 Han Chinese pedigrees carrying the m.14484T>C mutation. These families exhibited a wide range of penetrances and expressivities of optic neuropathy. The average ratio between affected male/female matrilineal relatives from 41 families was 2:1. The penetrance of optic neuropathy in these Chinese pedigrees ranged from 5.6% to 100%, with the average of 23.8%. Furthermore, the age-of-onset for optic neuropathy varied from 4 to 44 years, with the average of 19.3 years. Sequence analysis of their mitochondrial genomes identified distinct sets of polymorphisms belonging to ten Eastern Asian haplogroups, indicating that the m.14484T>C mutation occurred through recurrent origins and founder events. We showed that mitochondrial haplogroups M9, M10 and N9 increased the penetrance of optic neuropathy in these Chinese families. In particular, these mitochondrial haplogroup specific variants: m.3394T>C ( MT-ND1 ), m.14502T>C ( MT-ND4 ) and m.14693A>G ( MT-TE ) enhanced the penetrance of visual loss in these Chinese families. These data provided the direct evidence that mitochondrial modifiers modulate the variable penetrance and expressivity of optic neuropathy among Chinese pedigrees carrying the m.14484T>C mutation.

Purpose To investigate the pathophysiology of Leber's hereditary optic neuropathy (LHON). Methods Seventy-one subjects from three Chinese families with LHON underwent clinical, genetic, molecular, and biochemical evaluations. Biochemical characterizations included the measurements of the rates of endogenous, substrate-dependent respirations, the adenosine triphosphate (ATP) production and generation of reactive oxygen species using lymphoblastoid cell lines derived from five affected matrilineal relatives of these families and three control subjects. Results Ten of 41 matrilineal relatives exhibited variable severity and age at onset of optic neuropathy. The average age at onset of optic neuropathy in matrilineal relatives of the three families was 5, 11, and 24 years, respectively. Molecular analysis identified the ND1 T3866C (I187T) mutation and distinct sets of polymorphisms belonging to the Eastern Asian haplogroups D4a, M10a, and R, respectively. The I187T mutation is localized at the highly conserved isoleucine at a transmembrane domain of the ND1 polypeptide. The marked reductions in the rate of endogenous, malate/glutamate-promoted and succinate/glycerol-3-phosphate-promoted respiration were observed in mutant cell lines carrying the T3866C mutation. The deficient respiration is responsible for the reduced ATP synthesis and increased generation of reactive oxygen species. Conclusions Our data convincingly show that the ND1 T3866C mutation leads to LHON. This mutation may be insufficient to produce a clinical phenotype. Other modifier factors may contribute to the phenotypic manifestation of the T3866C mutation. The T3866C mutation should be added to the list of inherited factors for molecular diagnosis of LHON. Thus, our findings may provide new insights into the understanding of pathophysiology and valuable information on the management of LHON.

Mutations in mitochondrial DNA (mtDNA) have been associated with hypertension in several pedigrees with maternal inheritance. However, the pathophysiology of maternally inherited hypertension remains poorly understood. We reported here clinical, genetic evaluations and molecular analysis of mtDNA in a three-generation Han Chinese family with essential hypertension. Eight of 17 matrilineal relatives exhibited a wide range of severity in essential hypertension, whereas none of the offsprings of the affected father had hypertension. The age-at-onset of hypertension in the maternal kindred varied from 31 to 65 years, with an average of 52 years. Sequence analysis of mtDNA in this pedigree identified the known homoplasmic 4435A>G mutation, which is located at immediately 3′ end to the anticodon, corresponding to the conventional position 37 of tRNAMet, and 41 variants belonging to the Asian haplogroup G2a1. In contrast, the 4435A>G mutation occurred among mtDNA haplogroups B5a, D, M7a2 and J. The adenine (A37) at this position of tRNAMet is extraordinarily conserved from bacteria to human mitochondria. This modified A37 was shown to contribute to the high fidelity of codon recognition, structural formation and stabilization of functional tRNAs. However, 41 other mtDNA variants in this pedigree were the known polymorphisms. The occurrence of the 4435A>G mutation in two genetically unrelated families affected by hypertension indicates that this mutation is involved in hypertension. Our present investigations further supported our previous findings that the 4435A>G mutation acted as an inherited risk factor for the development of hypertension. Our findings will be helpful for counseling families of maternally inherited hypertension.

To study the effects of gonadotroph-releasing hormone (GnRH) agonist (GnRH-a) and GnRH antagonist (GnRH-ant) on cyclophosphamide (CTX)-induced follicle apoptosis in female rats.Thirty-six female Sprague- Dawley rats were randomized into 6 groups, namely normal saline (NS), CTX, GnRH-a+NS, GnRH-a+CTX, GnRH-ant+NS, and GnRH-ant+CTX groups. The rats were sacrificed between the first and second week after the treatments., and the follicle apoptosis was investigated using TUNEL assay and transmission electron microscopy.The apoptosis rate of the granulose cells in the follicles in late development was significantly higher than that in early follicles, and the apoptosis rate of the oocytes and granulose cells in rats with CTX treatment was significantly higher than that in rats without CTX treatment (P0.05). The apoptosis rate of the granulose cells in GnRH-a groups (ranging from 33.40 - or + 4.59 to 73.25 - or + 5.35) was significantly higher than that in GnRH-ant groups (27.46 - or + 4.52 to 49.38 - or + 5.02, P0.05), but there was no significant difference in the oocytes of early follicles between GnRH-a groups (23.48 - or + 4.25 to 36.15 - or + 4.23) and GnRH-ant groups (21.47 - or + 3.81 to 34.04 - or + 5.54, P0.05). Electron microscopy revealed characteristic apoptotic changes of the oocytes in early follicles and granulose cells in early and late follicles. The apoptotic changes were especially typical in the granulose cells showing the formation of the apoptotic bodies, and the oocytes only showed chromatin condensation and aggregation.In the rat mode, GnRH-a promotes while GnRH-ant suppressed follicle apoptosis induced by CTX. GnRH analogues regulates mainly granulose cell apoptosis, but have little effect on oocyte apoptosis.

This study was designed to investigate the correlationship between plasma metastin and pathogenesis of adolescent women with polycystic ovary syndrome (PCOS).From Jan. 2006 to Jun. 2006, 42 PCOS patients including 19 adolescent women and 23 adults with syndrome were treated in Second Affiliated Hospital of Sun Yat-Sen University. According to the range of age, those patients were divided into 19 cases in adolescent group (/= 19 years) and 23 cases in adult group (19 years). Meanwhile, 20 adolescent women were matched as controls. Blood samples were collected between day 1 and day 5 of a spontaneous bleeding episode in the PCOS groups and a menstrual cycle of the controls. The levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone (T), free T (FT), dehydroepiandrosterone sulfate (DHEAS), sex hormone-binding globulin (SHBG), insulin, glucose, and metastin were detected from day 1 to day 5 of spontaneous bleeding or withdrawal bleeding by progesterone. On the next day, oral glucose tolerance test (75 g) and insulin release test were performed on those above patients and controls. The area under curve (AUC), the ratio of fasting blood glucose to insulin (GIR) and homeostasis model assessment insulin resistance index (HOMA-IR) were calculated.(1) The level of hormone: the level of LH was in (12 +/- 7) U/L in adult group and (12 +/- 8) U/L in adolescent PCOS group, which were significantly higher than (6 +/- 4) U/L in controls (P0.05). The level of FT was (2.3 +/- 1.2) pmol/L in adult group, which was significantly higher than (1.3 +/- 0.8) pmol/L in adolescent group and (1.1 +/- 0.5) pmol/L in control group (P0.05). It was observed that the level of (3.1 +/- 2.7)micromol/L in adolescent group was significantly lower than (6.3 +/- 2.7) micromol/L in control group (P0.05). Meanwhile, the level of FAI of 5.6 +/- 4.1 in adult group was significantly higher than 3.0 +/- 1.3 in control group (P0.05). No significant difference in FSH, T and SHBG levels among three groups were observed (P0.05). (2) Metastin and metabolism: Both the levels of fasting blood insulin, 2-hour insulin and AUC of insulin were (13 +/- 7) mU/L, (88 +/- 59) mU/L and (133 +/- 80) mUxL(-1)xmin(-1) in adolescent group, which were significantly higher than (7 +/- 3) mU/L, (57 +/- 29) mU/L and (82 +/- 34) mUxL(-1)xmin(-1) in control group. The fasting blood insulin of (13 +/- 7) mU/L in adolescent group was significantly higher than (9 +/- 5) mU/L in adult group. The level of fasting blood glucose and 2-hour glucose were (5.01 +/- 0.44) mmol/L and (6.48 +/- 1.16) mmol/L in adult group, which were significantly higher than (4.68 +/- 0.29) mmol/L and (5.44 +/- 0.83) mmol/L in control group and (4.67 +/- 0.30) mmol/L and (5.93 +/- 1.44) mmol/L in adolescent group. The glucose AUC of (9.99 +/- 1.85) mmolxL(-1)xmin(-1) in adult group was significantly higher than (8.42 +/- 1.53) mmolxL(-1)xmin(-1) in control group (P0.05). HOMA-IR of 2.6 +/- 2.0 in adolescent group was significantly higher than 1.4 +/- 0.7 in control group. GIR of 10 +/- 8 in adolescent group was significantly lower than 16 +/- 10 in control group (P0.05). The metastin level of (0.25 +/- 0.19) pmol/L in adolescent group and (0.29 +/- 0.29) pmol/L in adult group were all significantly higher than (0.18 +/- 0.23) pmol/L in control group (PPh glucose were observed (r = 0.256, 0.286 and 0.267. P = 0.044, 0.025 and 0.043).The expression of metastin in adolescent PCOS women was significantly higher that of normal adolescent women. The increased level of metastin might be associated with pathogenesis of adolescent women with PCOS.

To investigate the effect of anti-Müllerian hormone (AMH) on hormone secretion and P450 aromatase mRNA expression from cultured human luteinized granulosa cells.Human luteinized granulose cells were derived from 10 patients treated by in vitro fertilization-embryo transplantation (IVF-ET) in the Second Affiliated Hospital of Sun Yat-sen University from June to December 2006. Granulose cells were divided into group A, B, C, D, E depending on different concentration of AMH, testosterone group and blank group. 1x10(-7) mol/L testosterone and 1, 5, 10, 20, 50 microg/L AMH were added into the culture medium of group A, B, C, D and E. 1x10(-7) mol/L testosterone was added into the culture medium of testosterone group while no other ingredient was added into the medium of blank group. Estrogen levels in supernates were measured at 24, 48, 72 hours after cell incubation. RT-PCR was performed to detect the P450 aromatase mRNA expression in group B, C, D, E and testosterone group at 72 hours after cell incubation.(1) Estrogen levels in supernates of granulose cell culture at 24, 48, 72 hours were (8.529+/-0.381)x10(4), (10.977+/-0.436)x10(4), (13.309+/-0.506)x10(4) pmol/L in group A, (7.027+/-0.276)x10(4), (9.167+/-0.300)x10(4), (10.794+/-0.555)x10(4) pmol/L in group B, (6.039+/-0.226)x10(4), (7.585+/-0.548)x10(4), (8.797+/-0.518)x10(4) pmol/L in group C, (5.118+/-0.460)x10(4), (5.716+/-0.496)x10(4), (6.205+/-0.667)x10(4) pmol/L in group D, (4.932+/-0.148)x10(4), (5.323+/-0.184)x10(4), (5.629+/-0.212)x10(4) pmol/L in group E. When compared with blank group [(0.001+/-0.001)x10(4), (0.006+/-0.003)x10(4), (0.029+/-0.011)x10(4) pmol/L], the statistical differences were observed in group A, B, C, D, E (P0.01); when compared with testosterone group [(8.418+/-0.569)x10(4), (10.841+/-0.689)x10(4), (13.301+/-0.637)x10(4) pmol/L], the statistical differences were observed in group B, C, D and E (P0.01); statistical differences were also observed in group C, D and E when compared with group B, and also group D and E when compared with group C (P0.01). No significant difference was observed between group D and E (P0.05). In group A, B, C, D, E and testosterone group, the estrogen levels at 24 hours after cell culture were significantly lower than those at 48 and 72 hours (P0.01); statistical difference was observed between estrogen levels at 48 and 72 hours (P0.01). No significant difference was observed among 24, 48 and 72 hours in blank group (P0.05). (2) Relative ratios of intensity of P450 aromatase/beta-actin at 72 hours of cell culture in group B, C, D and E were 0.6148+/-0.0046, 0.5156+/-0.0012, 0.4698+/-0.0027 and 0.4282+/-0.0017, respectively, which were statistically lower than that in testosterone group (0.8224+/-0.0021, P0.01); statistical differences were also observed in group C, D and E when compared with group B, and also group D and E when compared with group C (P0.01). No significant difference was observed between group D and E (P0.05).It is suggested that AMH might affect estrogen synthesis by inhibiting P450 aromatose activity so that lead to hyperandrogenism microenvironment in local ovary.

To investigate ovarian follicular damage induced by chemotherapeutic agents and gonadotropin- releasing hormone receptor (GnRHR) expression in the damaged ovaries in rats.Two groups of adult SD rats were subjected to intraperitoneal injection of a single-dose cyclophosphamide and saline, respectively, and 8 weeks later, the ovaries were taken for observing the ovarian damages. The distribution of GnRHR was detected with immunohistochemistry, and RT-PCR was used to determine the expression of GnRHR mRNA in the rat ovaries.Massive primordial follicular loss occurred in the ovaries of rats exposed to cyclophosphamide with also evident stromal ovarian blood vessel damages and focal fibrosis. Both the protein and mRNA expressions of GnRHR were detected in normal rat ovaries, but in rats exposed to cyclophosphamide, the expressions were significantly lowered in the ovaries (P0.05).Low-level GnRHR expressions in the ovaries of rats with cyclophosphamide exposure suggest microenvironment disturbances in the damaged rat ovaries in advanced stage of chemotherapy.

To investigate the effects of gonadotropin releasing hormone agonist (GnRH-a) and antagonist (GnRH-ant) on cyclophosphamide (CTX)-induced ovarian damage in rats.Seventy-two Sprague-Dawley female rats were divided randomly into six groups, which received normal saline (NS), CTX, GnRH-a + NS, GnRH-a + CTX, GnRH-ant + NS, and GnRH-ant + CTX respectively. Levels of serum follicle-stimulating hormone (FSH), luteinizing hormone (LH) and estradiol (E(2)) were measured successively by the enzyme-linked immunosorbent assay method, and half of the rats were killed in the first week and between the fourth and the fifth week after stop of medication, respectively to compare the weight of the ovaries and the number of the primordial follicles and the growth follicles.(1) Throughout experiment, the serum levels of FSH, LH and E(2) of the control group fluctuated slightly, while those in the CTX group kept rising. During medication treatment, compared with the control group [(118 +/- 16) microg/L, (350 +/- 35) microg/L] and the CTX group [(113 +/- 15) microg/L, (289 +/- 42) microg/L], the concentrations of LH [(42 +/- 8) - (47 +/- 7) microg/L, (31 +/- 5) - (36 +/- 7) microg/L] and FSH [(124 +/- 45) - (136 +/- 32) microg/L, (178 +/- 54) - (198 +/- 27) microg/L] in the GnRH-a groups and the GnRH-ant groups were maintained at low levels significantly and the levels of LH in the GnRH-ant groups were significantly lower than that in the GnRH-a groups, but the levels of FSH in the GnRH-ant groups were significantly higher than that in the GnRH-a groups (P0.05); and extremely different from the GnRH-a groups [(0.98 +/- 0.18) - (1.46 +/- 0.22) ng/L], the level of E(2) of the GnRH-ant groups [(3.58 +/- 0.43) - (3.98 +/- 0.74) ng/L] did not significantly decrease (P0.01). After stop of therapy, the concentrations of LH, FSH and E(2) in the GnRH-a groups and the GnRH-ant + NS group rose gradually and were similar to the levels of the control group (P0.05), but the levels of FSH, LH and E(2) of the GnRH-ant + CTX group rose obviously and were similar to the levels of the CTX group, especially the FSH , and the levels of LH and FSH of the GnRH-ant + CTX group [(156 +/- 12) microg/L, (520 +/- 44) microg/L] and the CTX group [(178 +/- 18) microg/L, (546 +/- 36) microg/L] were significantly higher than that of the other four groups [(121 +/- 15) - (132 +/- 13) microg/L, (335 +/- 35) - (359 +/- 26) microg/L] at the 4(th) - 5(th) week after stop of treatment (P0.05). (2) At the 1(st) week after stopping therapy, the GnRH-a + NS group [(12 +/- 5) mg/100 g]and the GnRH-a + CTX group [(18 +/- 8) mg/100 g] had the lowest weight of ovaries which was significantly different from the other groups [(30 +/- 9) - (37 +/- 8) mg/100 g, P0.05]. At the 4(th) - 5(th) week after stopping therapy, the GnRH-ant + CTX group [(22 +/- 6) mg/100 g] and the CTX group [(20 +/- 4) mg/100 g] had the lowest weight of ovaries which were significantly different from the other groups [(29 +/- 5) - (31 +/- 9) mg/100 g, P0.05]. (3) At the 1(st) week after stopping therapy, there were the largest number of primordial follicles [(824 +/- 45), (689 +/- 39)] and the lowest number of growth follicles [(15 +/- 1), (21 +/- 3)] in the GnRH-a + NS group and the GnRH-a + CTX group, but there were the lowest number of primordial follicles [(255 +/- 24), (343 +/- 29)] and the largest number of growth follicles [(110 +/- 21), (87 +/- 17)] in the GnRH-ant + CTX group and the CTX group. At the 4(th) - 5(th) week after stopping therapy, the number of growth follicles in the GnRH-a + NS group (58 +/- 11) and the GnRH-a + CTX group (56 +/- 16) recovered to almost the level of the control group (57 +/- 9, P0.05), but the number of all kinds of follicles declined significantly in the GnRH-ant + CTX group [(195 +/- 15), (36 +/- 12)] and the CTX group [(212 +/- 11), (36 +/- 9)] compared to the other four groups [(302 +/- 15) - (690 +/- 43), (44 +/- 12) - (58 +/- 11), P0.05].In rat model, GnRH-a prevents the ovarian function damage induced by CTX, but GnRH-ant does not show similar protective effect.

To investigate the possible pathways for ovarian injury after administration of cyclophosphamide in rats.Adult SD rats received a single injection of saline vehicle or chemotherapeutic agent cyclophosphamide, and 8 weeks later, the ovaries were removed, fixed and serially sectioned for pathological examination and ovarian follicle counting. The expression of stem cell factor (SCF) protein was evaluated by immunohistochemistry and immunoreactive score, and SCF mRNA expression determined by RT-PCR in rat ovaries.Cyclophosphamide had a detrimental effect on ovarian stromal function and lead to primordial follicle loss. Immunoreactive SCF antigens were expressed on the oocytes in the primordial and primary follicles of rat ovaries, and also in the granulosa cells of the secondary follicles and early antral follicles. There was a higher granulosa SCF, lower oocyte SCF and higher SCF mRNA level in the ovaries of the rats exposed to cyclophosphamide as compared with those in control rat ovaries (P0.05).Altered SCF expression in the ovaries of rats exposed to cyclophosphamide can be helpful for understanding the mechanisms for chemotherapeutic drug-induced ovarian damage.

PURPOSE. To investigating the role of mitochondrial haplotypes in the development of Leber's hereditary optic neuropathy (LHON) associated with the ND4 G11778A mutation in Chinese families. METHODS. A three-generation Chinese family with LHON was studied by clinical and genetic evaluation as well as molecular and biochemical analysis of mitochondrial (mt)DNA. RESULTS. This family exhibits a high penetrance and expressivity of visual impairment. The average age at onset was 13.9 years in this family. Of the family members, 86% of the male and 29% of the female matrilineal relatives had visual loss, with a wide range of severity, from blindness to nearly normal vision. Molecular analysis of mtDNA identified the homoplasmic ND4 G11778A mutation and 35 other variants, belonging to the Asian haplogroup D5. Of other variants, the novel homoplasmic A4435G mutation absent in 164 Chinese controls is localized at 3' end adjacent to the anticodon, at conventional position 37 (A37), of tRNA Met . The adenine (A37) at this position of tRNA Met is extraordinarily conserved from bacteria to human mitochondria. This modified A37 was shown to contribute to the high fidelity of codon recognition and to the structural formation and stabilization of functional tRNAs. In fact, the significant reduction of the steady state levels in tRNA Met was observed in cells carrying the both the A4435G and G11778A mutations but not cells carrying only the G11778A mutation. Thus, a failure in mitochondrial tRNA metabolism, caused by the A4435G mutation, may worsen the mitochondrial dysfunction associated with the primary G11778A mutation. CONCLUSIONS. The novel tRNA Met A4435G mutation has a potential modifier role in increasing the penetrance and expressivity of the primary LHON-associated G11778A mutation in this Chinese family.

We report here a simple and effective method to assess the CAG repeat size of HD gene for gene diagnosis of Huntington disease. Genomic DNA sequences in polymorphic CAG repeat HD gene was amplified by PCR with TaKaRa LA Taq DNA polymerase and GC buffer. To distinguish normal alleles from HD alleles, DNA fragments of affected alleles were recovered as templates for secondary PCR. The secondary PCR products were cloned into T vector for sequencing to determine CAG repeat size. A total of 20 normal individuals and 3 members from a HD pedigree were included in this study. Results showed that the CAG repeat numbers in 20 normal individuals and 3 normal alleles from the HD pedigree varied in normal range, while in 3 HD alleles, the copy numbers of CAG repeat were 39, 40, 41 respectively. There was no overlap between the copy number of the normal and affected alleles. In conclusion, the TaKaRa LA Taq DNA polymerase with GC buffer can be used to effectively amplified CAG repeat of HD gene, which combined DNA sequencing can diagnose HD accurately. In addition, these finding suggested that the dynamic mutation in HD gene responsible for the genetic defect in Chinese HD patients.

Familial hemophagocytic lymphohistiocytosis (HLH) is an autosomal recessive disorder of immune regulation characterized by fever, splenomegaly, cytopenia, hypertriglyceridemia, hypofibrinogenemia, and hyperferritinemia. Although presentation usually occurs during the first 2 years of life, congenital presentation is rare. We report siblings with a presumptive diagnosis of familial HLH who presented with hydrops fetalis and severe hepatic involvement ultimately resulting in their deaths. This report emphasizes the difficulty of confirming the diagnosis of HLH. However, establishing the diagnosis has important implications for genetic counseling and family planning. HLH should be considered in the setting of perinatal liver failure. The immunologic basis of the disease is incompletely understood but testing for natural killer cell function, and perforin defects may be helpful in establishing a diagnosis. HLH can be treated with chemotherapy, immunotherapy, and stem cell transplantation.

We report here the characterization of a three-generation Han Chinese family with Leber's hereditary optic neuropathy (LHON). This Chinese family exhibited high penetrance and expressivity of visual impairment. The average age-of-onset was 19 years in this family. All male and 33% female matrilineal relatives in this Chinese family developed visual loss with a wide range of severity, ranging from blindness to normal vision. Sequence analysis of the complete mitochondrial DNA in this pedigree revealed the presence of the ND4 G11778A mutation and 40 other variants, belonging to the Asian haplogroup D4. The G11778A mutation is present at homoplasmy in matrilineal relatives of this Chinese family. Of other variants, the homoplasmic A15951G mutation is of special interest as it is located adjacent to 3' end, at conventional position 71 of tRNA(Thr). The adenine (A71) at this position of tRNA(Thr), highly conserved from bacteria to human mitochondria, has been implicated to be important for tRNA identity and pre-tRNA processing. In fact, the significant reduction of the steady-state levels in tRNA(Thr) was observed in cells carrying both the A15951G and G11778A mutations but not cells carrying only G11778A mutation. Thus, the A15951G mutation most probably leads to a failure in mitochondrial tRNA metabolism, worsening the mitochondrial dysfunction associated with the primary G11778A mutation. These imply that the tRNA(Thr) A15951G mutation may have a potential modifier role in increasing the penetrance and expressivity of the primary LHON-associated G11778A mutation in this Chinese family.

We report here the clinical, genetic, and molecular characterization of three Chinese families (WZ4, WZ5, and WZ6) with Leber's hereditary optic neuropathy (LHON). Clinical and genetic evaluations revealed the variable severity and age-of-onset in visual impairment in these families. Penetrances of visual impairment in these Chinese families were 33.3%, 35.7%, and 35.5%, respectively, with an average 34.8%. Furthermore, the average age-at-onset in those Chinese families was 17, 20, and 18 years. In addition, the ratios between affected male and female matrilineal relatives in these Chinese families were 3:0, 1:1, and 1.2:1, respectively. Sequence analysis of the complete mitochondrial genomes in these pedigrees showed the distinct sets of mtDNA polymorphism, in addition to the identical G11778A mutation associated with LHON in many families. The fact that mtDNA of those pedigrees belonged to different haplogroups F1, D4, and M10 suggested that the G11778A mutation occurred sporadically and multiplied through evolution of the mtDNA in China. However, there was the absence of functionally significant mutations in tRNA and rRNAs or secondary LHON mutations in these Chinese families. The I187T mutation in the ND1, the S99A mutation in the A6, the V254I in CO3, and I58V in ND6 mutation, showing high evolutional conservation, may contribute to the phenotypic expression of the G11778A mutation in the WZ6 pedigree. By contrast, none of mtDNA variants are evolutionarily conserved and implicated to have significantly functional consequence in WZ4 and WZ5 pedigrees. Apparently, these variants do not have a potential modifying role in the development of visual impairment associated with G11778A mutation in those two families. Thus, nuclear modifier gene(s) or environmental factor(s) seem to account for the penetrance and expressivity of LHON in these three Chinese families carrying the G11778A mutation.

To investigate the molecular mechanism of a Chinese patient with 46, XY sex reversal.DNA fragments of the SRY gene from the typical XY female sex reversal patient and her father were amplified by polymerase chain reaction (PCR). The amplified PCR fragments were cloned into the pUCm-T vector, and direct sequencing was carried out on an ABI 377-3 automated DNA sequencer to detect the mutation. PCR-restriction enzyme digestion was applied to detect the results of DNA sequencing.A novel mutation of the SRY gene was identified in the XY sex reversal patient of this study. A T is replaced by an A in codon 129 at position +387, resulting in the replacement of the polar amino acid tyrosine (TAT) by the stop code (TAA) in the HMG-box, whereas her father was proved to have the wild-type sequence. Because the mutation introduced an enzyme site of MaeIII, the PCR-restrict enzyme digestion showed that there were three bands (131 bp,231 bp and 247 bp) in the patient, whereas two bands (131 bp and 478 bp) in normal man. It verified the results of sequencing analysis. The results after searching the Human Gene Mutation Database showed that this mutation was not described before and should be a new mutation.The novel mutation in SRY gene has provided valuable information for the understanding of molecular mechanism of the patient with 46,XY female sex reversal.

PURPOSE To investigate the molecular pathogenesis of Leber's hereditary optic neuropathy (LHON) in Chinese families. METHODS A cohort of 1218 Han Chinese subjects with LHON and 316 control subjects underwent the clinical and genetic evaluation and molecular analysis of mitochondrial (mt)DNA. RESULTS The age at onset of optic neuropathy in these subjects ranged from 5 to 55 years, with the average of 18 years. Mutational analysis of ND6 gene identified 92 (73 known and 19 novel) variants in these subjects. These variants included 29 (9 novel and 20 known) missense mutations and 63 silence variants. A total of 94 subjects carrying one of the known T14484C, T14502C, and G14459A mutations accounted for 7.7% cases of this cohort, particularly 4.4% for T14484C mutation. Furthermore, eight putative LHON-associated ND6 mutations accounted for 1.1% case of this cohort. Thus, 106 subjects carrying one of ND6 mutations accounted for 8.7% cases of this cohort. Low penetrance of optic neuropathy in pedigrees carrying one of eight putative mutations indicated that the mutation(s) is necessary, but itself insufficient to produce a clinical phenotype. Mitochondrial DNAs in 98 probands carrying the ND6 mutation(s) were widely dispersed among 12 Eastern Asian subhaplogroups. In particular, the occurrences of haplogroups M9, M10, M11, and H2 in patients carrying the ND6 mutations were higher than those in controls. CONCLUSIONS These data further support that the ND6 gene is the hot spot for mutations associated with LHON. Thus, our findings may provide valuable information for the further understanding of pathophysiology and management of LHON.