The mutations of TTN gene that encodes titin are the most common mutation type among the genetic causes of dilated cardiomyopathy (DCM). This article reviews the worldwide studies on potential molecular pathogenesis (transcription, post-translational modification, etc.), clinical phenotypes, and gene therapies of pediatric DCM caused by TTN mutations, with the hope of providing a reference for the precision treatment of pediatric DCM caused by TTN mutations.
Humans ; Cardiomyopathy, Dilated/therapy* ; Connectin/genetics* ; Genetic Therapy ; Mutation ; Phenotype

Titin, the largest known protein in the body expressed in three isoforms (N2A, N2BA and N2B), is essential for muscle structure, force generation, conduction and regulation. Since the 1950s, muscle contraction mechanisms have been explained by the sliding filament theory involving thin and thick muscle filaments, while the contribution of cytoskeleton in force generation and conduction was ignored. With the discovery of insoluble protein residues and large molecular weight proteins in muscle fibers, the third myofilament, titin, has been identified and attracted a lot of interests. The development of single molecule mechanics and gene sequencing technology further contributed to the extensive studies on the arrangement, structure, elastic properties and components of titin in sarcomere. Therefore, this paper reviews the structure, isforms classification, elastic function and regulatory factors of titin, to provide better understanding of titin.
Connectin/genetics* ; Muscle Proteins/metabolism* ; Protein Isoforms/genetics* ; Sarcomeres/metabolism* ; Muscle Fibers, Skeletal/metabolism*

OBJECTIVETo investigate TCAP gene mutation and clinical features of a Chinese patient with limb-girdle muscular dystrophy type 2G(LGMD 2G).

METHODSClinical data of the patient was analyzed. Exons of the TCAP gene were amplified and sequenced.

RESULTSThe patient has presented clinically as LGMD and pathologically as vacuolar myopathy. Genetic analysis has identified compound heterozygous mutations of exons 1 and 2 of the TCAP gene(c.100delC, c.166insG).

CONCLUSIONLGMD is a group of neuromuscular disorders with substantial phenotypic heterogeneity. Genetic diagnosis has become indispensable for accurate diagnosis for patients suspected to have the disease.

Adult ; Base Sequence ; Connectin ; genetics ; Exons ; Female ; Humans ; Molecular Sequence Data ; Muscular Dystrophies, Limb-Girdle ; genetics ; Young Adult

OBJECTIVE: To explore the correlation between DSG2, TTN and GATA4 genes and Brugada syndrome in Henan Province of China. METHODS: From February 2017 to February 2019, 100 patients with Brugada syndrome and 100 healthy individuals were selected as the study and the control groups, respectively. Electrocardiogram and echocardiography were carried out, and peripheral blood samples was collected. Coding regions of DSG2, TTN and GATA4 genes were amplified by PCR and sequenced. The results were compared with standard sequences from GenBank. RESULTS: Electrocardiogram showed that all patients from the study group had ventricular arrhythmia, 87 cases (87%) presented ventricular tachycardia (VT), 84 cases (84%) presented T wave inversion, and 51 cases (51%) presented Epsilon wave. Echocardiography showed that the right ventricle in the study group was enlarged with the inner diameter of the right ventricle being (40.0±13.3) mm, and the right ventricle showed various degree of abnormal systolic function. The enlargement of right atrium accounted for 64%, and the involvement of the left ventricle accounted for 27%. The right ventricular diameter and left ventricular diastolic diameter of the study group were significantly greater than those of the control group (P< 0.05). DNA sequencing showed that 60 patients carried DSG2 gene variants, among which 18 had missense variant of exon 8. Fifty patients carried TTN gene variants, including 8 in the A-band domain and 3 in the I-band domain. Twenty patients carried 3 variants of the GATA4 gene. CONCLUSION Variants of the DSG2, TTN and GATA4 genes in Henan region are correlated with the onset of Brugada syndrome.
Arrhythmogenic Right Ventricular Dysplasia ; Brugada Syndrome/genetics* ; China ; Connectin ; Desmoglein 2/genetics* ; GATA4 Transcription Factor ; Humans ; Pedigree ; Sequence Analysis, DNA

From July 1, 1981 to August 31, 1984, 59 patients who had radiation therapy for carcinoma of cervix had CTscanning at Departement of Diagnostic Radiology, Kosin Medical College. The authors analysed the CT findings ofthe patients in regard to the recurrence of the disease and postradiation changes. The results are as followings:1. The incidence of recurrence was most common in advanced stage over IIb. 77% 2. Changes in pelvic cavity were asfollowings; ; Widening of presacral space 78% ; Increased perirectal fat space 81% ; Symmetrical thickening ofperirectal fascia 97% ; Fibrous connectin between sacrum and rectum 92% ; Anterior conncetion between rectum andperirectal fascia 47% ; Increased bowel wall thickness 44% ; Increased bladder wall thickness with trabeculations51% 3. In most patients who had CT scanning within 3 months after radiation therapy, CT did not demonstratepostradiation changes characterized by an increased pelvic fibrous and fatty tissue. 4. In 10 patients who hadpostoperative radiation therapy, 8 patients show increased bowel wall thickness. 5. 30 patients with recurrentcarcinoma of cervix were as followings; ; Pelvic tumor recurrence 90% ; Parametrial and side wall extension 53% ;Pelvic and paraaortic lymphadenopathy 40% ; Hydronephrosis 23% ; Bladder involvement 23% ; Lumbar spineinvolvement 10% And 1 patient shows distant metastasis to paraaortic lymph node, 1 patient to lumbar spine, and 1patient to liver without recurrent tumor mass in pelvic cavity. 6. 2 patients showing mass wihout other sign inthe pelvic cavity were unable to be differentiated between irradiated uterus and recurrent tumor.
Adipose Tissue ; Cervix Uteri ; Connectin ; Fascia ; Female ; Humans ; Hydronephrosis ; Incidence ; Liver ; Lymph Nodes ; Lymphatic Diseases ; Neoplasm Metastasis ; Rectum ; Recurrence ; Sacrum ; Spine ; Tomography, X-Ray Computed ; Urinary Bladder ; Uterus

OBJECTIVETo investigate the molecular mechanisms of diaphragm injury in rats with liver cirrhosis.

METHODSThirty adult male Sprague-Dawley rats were randomized into control group (n=10) and carbon tetrachloride-induced liver cirrhosis group (LC group, n=20). In the 9th week, the rat body weight and diaphragm to body weight ratio were measured, and the parameters of diaphragm contractility including peak twitch tension (Pt), maximum tetanic tension (Po), time to peak contraction (CT), half relaxation time (1/2RT), and force-frequency curve were assessed using a Medlab-U/4C biological signal collecting system. The activities of superoxide dismutase (SOD), succinic dehydrogenase (SDH) and myeloperoxidase (MPO) and malondiadehyde (MDA) content in the diaphragm were detected. The mRNA expression levels of sarcoplasmic reticulum calcium ATPase (SERCA) and cytoskeletal proteins (titin and nebulin) in the diaphragm were detected by RT-PCR, and the diaphragm ultrastructure was examined with electron microscopy.

RESULTSCompared with those in the control group, body weight, diaphragm to body weight ratio, Pt, Po, and tetanic force under the stimulus frequency of 10, 20, 40, 60, 100 Hz were all significantly decreased (P<0.01), while CT and 1/2RT were significantly prolonged in LC group (P<0.01). SOD and SDH activities were significantly lowered (P<0.01) while the contents of MDA and MPO activity were significantly increased in LC group (P<0.01) with significantly decreased SERCA, titin and nebulin mRNA expressions in the diaphragm (P<0.01). Electron microscopy of the diaphragm in LC group revealed myofibrillar degeneration, absence of the Z line, and mitochondria swelling and edema.

CONCLUSIONLiver cirrhosis increases free radicals and aggravates inflammatory response and lipid peroxidation in the diaphragm, thus leading to mitochondrial damages and decreased expressions of cytoskeletal proteins and SERCA to cause diaphragmatic dysfunction.

Animals ; Body Weight ; Carbon Tetrachloride ; Connectin ; metabolism ; Diaphragm ; metabolism ; Lipid Peroxidation ; Liver ; enzymology ; pathology ; Liver Cirrhosis ; metabolism ; Male ; Muscle Contraction ; Muscle Proteins ; metabolism ; Oxidation-Reduction ; Rats ; Rats, Sprague-Dawley ; Sarcoplasmic Reticulum Calcium-Transporting ATPases ; metabolism

OBJECTIVETo study the clinical significance of serum anti-titin antibody level in the diagnosis of myasthenia gravis (MG) with thymoma.

METHODThe serum anti-titin antibody was analysed by ELISA method in 40 cases of health control group, 90 cases of MG, 17 cases of MG with thymoma and 7 cases of no-MG thymoma. The positive rate was compared among these groups.

RESULTSThe positive rate of anti-titin antibody was significantly higher in MG with thymoma patients than MG patients (94% and 3%, P < 0.01). According to the Osserman's classification, anti-titin antibody was present mostly in patients (43%) in IV stage, and also present in 2 cases of 7 who with no-MG thymoma.

CONCLUSIONSerum anti-titin antibody test is helpful in the diagnosis of MG with thymoma.

Adolescent ; Adult ; Aged ; Antibodies ; blood ; Connectin ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Male ; Middle Aged ; Muscle Proteins ; immunology ; Myasthenia Gravis ; complications ; diagnosis ; immunology ; Protein Kinases ; immunology ; Thymoma ; complications ; diagnosis ; immunology ; Thymus Neoplasms ; complications ; diagnosis ; immunology

To investigate whether transcription of hepatitis B virus (HBV) gene occurs in human sperm, total RNA was extracted from sperm of patients with chronic HBV infection (test-1), from donor sperm transfected with a plasmid containing the full-length HBV genome (test-2), and from nontransfected donor sperm (control), used as the template for reverse transcription-polymerase chain reaction (RT-PCR). Positive bands for HBV DNA were observed in the test groups but not in the control. Next, to identify the role of host genes in regulating viral gene transcription in sperm, total RNA was extracted from 2-cell embryos derived from hamster oocytes fertilized in vitro by HBV-transfected (test) or nontransfected (control) human sperm and successively subjected to SMART-PCR, suppression subtractive hybridization, T/A cloning, bacterial amplification, microarray hybridization, sequencing and the Basic Local Alignment Search Tool (BLAST) search to isolate differentially expressed genes. Twenty-nine sequences showing significant identity to five human gene families were identified, with chorionic somatomammotropin hormone 2 (CSH2), eukaryotic translation initiation factor 4 gamma 2 (EIF4G2), pterin-4 alpha-carbinolamine dehydratase 2 (PCBD2), pregnancy-specific beta-1-glycoprotein 4 (PSG4) and titin (TTN) selected to represent target genes. Using real-time quantitative RT-PCR (qRT-PCR), when CSH2 and PCBD2 (or EIF4G2, PSG4 and TTN) were silenced by RNA interference, transcriptional levels of HBV s and x genes significantly decreased (or increased) (P < 0.05). Silencing of a control gene in sperm did not significantly change transcription of HBV s and x genes (P > 0.05). This study provides the first experimental evidence that transcription of HBV genes occurs in human sperm and is regulated by host genes.
Animals ; Connectin/genetics* ; Cricetinae ; Eukaryotic Initiation Factor-4G/genetics* ; Gene Expression Regulation/genetics* ; Gene Silencing ; Growth Hormone/genetics* ; Hepatitis B Surface Antigens/genetics* ; Hepatitis B virus/genetics* ; Hepatitis B, Chronic/virology* ; Humans ; Hydro-Lyases/metabolism* ; Male ; Pregnancy-Specific beta 1-Glycoproteins/genetics* ; RNA, Viral/analysis* ; Spermatozoa/virology* ; Trans-Activators/genetics* ; Transcription, Genetic ; Transfection ; Viral Regulatory and Accessory Proteins