Human prion-like proteins often correspond to nucleic acid binding proteins,displaying both globular domains and long intrinsically disordered regions(IDRs)(Harrison and Shorter,2017).Their IDRs are of low complexity ...Human prion-like proteins often correspond to nucleic acid binding proteins,displaying both globular domains and long intrinsically disordered regions(IDRs)(Harrison and Shorter,2017).Their IDRs are of low complexity and resemble in amino acid composition to the disordered yeast prion domains,being usually enriched in Gln and Asn residues and depleted in hydrophobic and charged residues.Accordingly,these sequence stretches are named prion-like domains(PrLDs).Prion-like proteins can aggregate into amyloid fibrils,which can accommodate incoming protein monomers,propagating thus the polymeric fold,both processes being。展开更多
Muscular dystrophies(MD) comprise a heterogeneous group of hereditary myopathic diseases.In this group,myotonic MD is associated with an increased cancer risk.However,the cancer risk in other types of MD is unclear.To...Muscular dystrophies(MD) comprise a heterogeneous group of hereditary myopathic diseases.In this group,myotonic MD is associated with an increased cancer risk.However,the cancer risk in other types of MD is unclear.To address this gap in knowledge,we assessed data obtained from the Taiwan Health Insurance Program database.A total of 1,272 patients with MD diagnosed between 1997 and 2009 were enrolled.They were followed up for cancer during the same period by record linkage with the cancer certification in Taiwan.Age-and sex-standardized incidence ratios(SIRs) of overall and site-specific cancers were calculated.For congenital and progressive hereditary MD,there were 685 and 505 cases(males:69.5% and 80.6%),the median ages at diagnosis were 16 and 13 years,and the mean follow-up durations were 7.12 and 5.06 years,respectively.In addition,cancers were developed in 10 patients with congenital MD and 3 patients with progressive hereditary MD.Female MD patients exhibited an increased cancer risk,yielding an SIR of 3.37 [95% confidence interval(CI) = 1.38-8.25] in congenital MD and 2.95(95% CI = 0.95-9.19) in hereditary progressive MD.Site-specific cancer SIRs were not powered to be significantly different.In conclusion,genetic defects in hereditary MD may increase cancer risks in females and a sex difference should be further investigated.展开更多
Background Mutations of the LMNA gene encoding lamin A and C are associated with dilated cardiomyopathy （DCM）, conduction system defects and skeletal muscle dystrophy. Here we report a family with a mutation of the ...Background Mutations of the LMNA gene encoding lamin A and C are associated with dilated cardiomyopathy （DCM）, conduction system defects and skeletal muscle dystrophy. Here we report a family with a mutation of the LMNA gene to identify the relationship between genotype and phenotype. Methods All 30 members of the family underwent clinical and genetic evaluation. A mutation analysis of the LMNA gene was performed. All of the 12 exons of LMNA gene were extended with polymerase chain reaction （PCR） and the PCR products were screened for gene mutation by direct sequencing. Results Ten members of the family had limb-girdle muscular dystrophy （LGMD） and 6 are still alive. Two patients suffered from DCM. Cardiac arrhythmias included atrioventricular block and atrial fibrillation; sudden death occurred in 2 patients. The pattern of inheritance was autosomal dominant. Mutation c.73C〉G （R25G） in exon 1 encoding the globular domains was confirmed in all of the affected members, resulting in the conversion of arginine （Arg） to glycine （Gly）. Conclusions The mutation R25G in exon 1 of LMNA gene we reported here in a Chinese family had a phenotype of malignant arrhythmia and mild LGMD, suggesting that patients with familial DCM, conduction system defects and skeletal muscle dystrophy should be screened by genetic testing for the LMNA gene.展开更多
The relative frequencies of different subtypes of limb-girdle muscular dystrophies vary widely among different populations. We estimated the percentage of limb-girdle muscular dystrophy subtypes in Chinese people base...The relative frequencies of different subtypes of limb-girdle muscular dystrophies vary widely among different populations. We estimated the percentage of limb-girdle muscular dystrophy subtypes in Chinese people based on 68 patients with limb-girdle muscular dystrophy from the Myology Clinic, Neurology Department, First Hospital of Jilin University, China. A diagnosis of calpainopathy was made in 12 cases （17%）, and dysferlin deficiency in 10 cases （15%）. Two biopsies revealed α-sarcoglycan deficiency （3%）, and two others revealed a lack of caveolin-3 （3%）. A diagnosis of unclassified limb-girdle muscular dystrophy was made in the remaining patients （62%）. The ap-pearances of calpain 3- and dysferlin-deficient biopsies were similar, though rimmed vacuoles were unique to dysferlinopathy, while inflammatory infiltrates were present in both these limb-girdle muscular dystrophy type 2D biopsies. Macrophages were detected in seven dysferlinopathy biop-sies. The results of this study suggest that the distribution of limb-girdle muscular dystrophy sub-types in the Han Chinese population is similar to that reported in the West. The less necrotic, re-generating and inflammatory appearance of limb-girdle muscular dystrophy type 2A, but with more lobulated fibers, supports the idea that calpainopathy is a less active, but more chronic disease than dysferlinopathy. Unusual features indicated an extended limb-girdle muscular dystrophy disease spectrum. The use of acid phosphatase stain should be considered in suspected dysferlinopathies. To the best of our knowledge, this is the first report to define the relative proportions of the various forms of limb-girdle muscular dystrophy in China, based on protein testing.展开更多
Duchenne muscular dystrophy (DMD) is a lethal X-linked recessive neuromuscular disorder caused by mutations in the dystrophin encoding gene, with the characteristics of a severe and progressive destruction of muscle s...Duchenne muscular dystrophy (DMD) is a lethal X-linked recessive neuromuscular disorder caused by mutations in the dystrophin encoding gene, with the characteristics of a severe and progressive destruction of muscle structure and function. Skeletal muscle fibrosis is one of the pathological features of DMD. Tetramethylpyrazine (2,3,5,6-tetramethylpyrazine, TMP) has been demonstrated to reduce heart and liver fibrosis. Meanwhile, previous studies showed that Tetramethylpyrazine nitrone (TBN), a nitrone derivative of TMP, has promising therapeutic effects in several neurodegenerative models and is more potent than TMP. In this study, we investigated the potential effect of TBN on the <em>mdx</em> mouse model of DMD. Eight-week-old <em>mdx</em> mice were administered with TBN (30 mg/kg) intragastrically twice daily, with deflazacort (1 mg/kg) once a day as a positive control, for a total of 24 weeks. Behavioral tests including pole-climbing open-field test were monitored every 4 weeks. Histopathological assessment was conducted in the gastrocnemius and diaphragm muscles. The effects of TBN on protein levels of dysferlin were measured by immunohistochemistry. TBN significantly reduced the climbing time in pole test and increased the total distance moved in an open-field test of <em>mdx</em> mice. TBN attenuated fibrosis in the gastrocnemius and diaphragmatic muscles. In addition, TBN protected gastrocnemius muscle fibers via increasing expression of the dysferlin in <em>mdx </em>mice. In conclusion, this study demonstrated that TBN could improve the motor deficits and muscle pathology of <em>mdx</em> mouse, and it is worth further exploring the mechanism of action of TBN for DMD treatment.展开更多
文摘Human prion-like proteins often correspond to nucleic acid binding proteins,displaying both globular domains and long intrinsically disordered regions(IDRs)(Harrison and Shorter,2017).Their IDRs are of low complexity and resemble in amino acid composition to the disordered yeast prion domains,being usually enriched in Gln and Asn residues and depleted in hydrophobic and charged residues.Accordingly,these sequence stretches are named prion-like domains(PrLDs).Prion-like proteins can aggregate into amyloid fibrils,which can accommodate incoming protein monomers,propagating thus the polymeric fold,both processes being。
文摘Muscular dystrophies(MD) comprise a heterogeneous group of hereditary myopathic diseases.In this group,myotonic MD is associated with an increased cancer risk.However,the cancer risk in other types of MD is unclear.To address this gap in knowledge,we assessed data obtained from the Taiwan Health Insurance Program database.A total of 1,272 patients with MD diagnosed between 1997 and 2009 were enrolled.They were followed up for cancer during the same period by record linkage with the cancer certification in Taiwan.Age-and sex-standardized incidence ratios(SIRs) of overall and site-specific cancers were calculated.For congenital and progressive hereditary MD,there were 685 and 505 cases(males:69.5% and 80.6%),the median ages at diagnosis were 16 and 13 years,and the mean follow-up durations were 7.12 and 5.06 years,respectively.In addition,cancers were developed in 10 patients with congenital MD and 3 patients with progressive hereditary MD.Female MD patients exhibited an increased cancer risk,yielding an SIR of 3.37 [95% confidence interval(CI) = 1.38-8.25] in congenital MD and 2.95(95% CI = 0.95-9.19) in hereditary progressive MD.Site-specific cancer SIRs were not powered to be significantly different.In conclusion,genetic defects in hereditary MD may increase cancer risks in females and a sex difference should be further investigated.
基金This study was supported by the grant from Natural Science Foundation of Guangdong Province, China, 2005 （No. 5001673）.
文摘Background Mutations of the LMNA gene encoding lamin A and C are associated with dilated cardiomyopathy （DCM）, conduction system defects and skeletal muscle dystrophy. Here we report a family with a mutation of the LMNA gene to identify the relationship between genotype and phenotype. Methods All 30 members of the family underwent clinical and genetic evaluation. A mutation analysis of the LMNA gene was performed. All of the 12 exons of LMNA gene were extended with polymerase chain reaction （PCR） and the PCR products were screened for gene mutation by direct sequencing. Results Ten members of the family had limb-girdle muscular dystrophy （LGMD） and 6 are still alive. Two patients suffered from DCM. Cardiac arrhythmias included atrioventricular block and atrial fibrillation; sudden death occurred in 2 patients. The pattern of inheritance was autosomal dominant. Mutation c.73C〉G （R25G） in exon 1 encoding the globular domains was confirmed in all of the affected members, resulting in the conversion of arginine （Arg） to glycine （Gly）. Conclusions The mutation R25G in exon 1 of LMNA gene we reported here in a Chinese family had a phenotype of malignant arrhythmia and mild LGMD, suggesting that patients with familial DCM, conduction system defects and skeletal muscle dystrophy should be screened by genetic testing for the LMNA gene.
基金supported by the Chinese Scholarship Counsel's International Students Grant,No.404080022426
文摘The relative frequencies of different subtypes of limb-girdle muscular dystrophies vary widely among different populations. We estimated the percentage of limb-girdle muscular dystrophy subtypes in Chinese people based on 68 patients with limb-girdle muscular dystrophy from the Myology Clinic, Neurology Department, First Hospital of Jilin University, China. A diagnosis of calpainopathy was made in 12 cases （17%）, and dysferlin deficiency in 10 cases （15%）. Two biopsies revealed α-sarcoglycan deficiency （3%）, and two others revealed a lack of caveolin-3 （3%）. A diagnosis of unclassified limb-girdle muscular dystrophy was made in the remaining patients （62%）. The ap-pearances of calpain 3- and dysferlin-deficient biopsies were similar, though rimmed vacuoles were unique to dysferlinopathy, while inflammatory infiltrates were present in both these limb-girdle muscular dystrophy type 2D biopsies. Macrophages were detected in seven dysferlinopathy biop-sies. The results of this study suggest that the distribution of limb-girdle muscular dystrophy sub-types in the Han Chinese population is similar to that reported in the West. The less necrotic, re-generating and inflammatory appearance of limb-girdle muscular dystrophy type 2A, but with more lobulated fibers, supports the idea that calpainopathy is a less active, but more chronic disease than dysferlinopathy. Unusual features indicated an extended limb-girdle muscular dystrophy disease spectrum. The use of acid phosphatase stain should be considered in suspected dysferlinopathies. To the best of our knowledge, this is the first report to define the relative proportions of the various forms of limb-girdle muscular dystrophy in China, based on protein testing.
文摘Duchenne muscular dystrophy (DMD) is a lethal X-linked recessive neuromuscular disorder caused by mutations in the dystrophin encoding gene, with the characteristics of a severe and progressive destruction of muscle structure and function. Skeletal muscle fibrosis is one of the pathological features of DMD. Tetramethylpyrazine (2,3,5,6-tetramethylpyrazine, TMP) has been demonstrated to reduce heart and liver fibrosis. Meanwhile, previous studies showed that Tetramethylpyrazine nitrone (TBN), a nitrone derivative of TMP, has promising therapeutic effects in several neurodegenerative models and is more potent than TMP. In this study, we investigated the potential effect of TBN on the <em>mdx</em> mouse model of DMD. Eight-week-old <em>mdx</em> mice were administered with TBN (30 mg/kg) intragastrically twice daily, with deflazacort (1 mg/kg) once a day as a positive control, for a total of 24 weeks. Behavioral tests including pole-climbing open-field test were monitored every 4 weeks. Histopathological assessment was conducted in the gastrocnemius and diaphragm muscles. The effects of TBN on protein levels of dysferlin were measured by immunohistochemistry. TBN significantly reduced the climbing time in pole test and increased the total distance moved in an open-field test of <em>mdx</em> mice. TBN attenuated fibrosis in the gastrocnemius and diaphragmatic muscles. In addition, TBN protected gastrocnemius muscle fibers via increasing expression of the dysferlin in <em>mdx </em>mice. In conclusion, this study demonstrated that TBN could improve the motor deficits and muscle pathology of <em>mdx</em> mouse, and it is worth further exploring the mechanism of action of TBN for DMD treatment.
