VPS35, the core component of the retromer complex, and Parkinson's disease.

Parkinson's disease (PD) is a neurodegenerative disease that is common in middle-aged and elderly people, and its onset is related to multiple factors, such as heredity, environment, and age. The vesicle protein sorting 35 (VPS35) gene was found to be a late-onset autosomal dominant familial PD (PARK17) causative gene. The protein encoded by this gene is located in the endosome and aggregates with other membrane proteins to form a retromer complex, which participates in the membrane protein cycle between the endosome and the Golgi network. Increasing evidence shows that VPS35 may participate in the pathogenesis of PD by affecting autophagy, mitochondria, neurosynaptic transmission, dopamine signaling pathways, and so forth, and it can interact with other disease-causing genes of familial PD. This article aimed to review the functions of VPS35 and the mechanism of its mutations in PD that have been discovered in recent years.

Genetic study of a Chinese pedigree with early onset Parkinson's disease caused by novel compound heterozygous mutations in PARKIN gene.

Objective: To explore the genetic basis for a Chinese pedigree where two siblings were affected with early-onset Parkinson's disease (EOPD). Methods: Clinical examinations and genomic analyses were performed on five subjects belonging to two generations of a Han Chinese family. Target regions capture and high throughput sequencing were used to screen these genes associated with Parkinson's disease (PD), tremor, spinocerebellar ataxia, and dystonia. The multiplex ligation dependent probe amplification (MLPA) method was applied to detect rearrangements and large deletion in PARKIN exons. Results: Two family members were diagnosed with PD by clinical manifestations. Compound heterozygous mutations, consisting of a fragment deletion in exon 2 and 3 of the PARKIN gene, identified by MLPA in II-3, II-5. Individual exon2 deletion mutations were detected in II-1 while individual exon3 deletion mutations were detected in two thirds generations (III-5, III-6). The compound heterozygous mutations have co-segregated with the disease in the pedigree. Other mutations in some genes associated with PD, tremor, dystonia and other movement disorders were not detected. Conclusion: A novel compound heterozygous deletion mutations of the PARKIN gene were identified in a Chinese pedigree and might represent a cause of familial EOPD with autosomal dominant inheritance. Early-onset Parkinson's disease (PD) with PARKIN gene mutation has genetic and clinical heterogeneity.

Utility of Point-of-Care Lung Ultrasound for Clinical Classification of COVID-19.

In this study, the utility of point-of-care lung ultrasound for clinical classification of coronavirus disease (COVID-19) was prospectively assessed. Twenty-seven adult patients with COVID-19 underwent bedside lung ultrasonography (LUS) examinations three times each within the first 2 wk of admission to the isolation ward. We divided the 81 exams into three groups (moderate, severe and critically ill). Lung scores were calculated as the sum of points. A rank sum test and bivariate correlation analysis were carried out to determine the correlation between LUS on admission and clinical classification of COVID-19. There were dramatic differences in LUS (p < 0.001) among the three groups, and LUS scores (r = 0.754) correlated positively with clinical severity (p < 0.01). In addition, moderate, severe and critically ill patients were more likely to have low (≤9), medium (9-15) and high scores (≥15), respectively. This study provides stratification criteria of LUS scores to assist in quantitatively evaluating COVID-19 patients.

SUMO-1 modification on K166 of polyQ-expanded ataxin-3 strengthens its stability and increases its cytotoxicity.

Post-translational modification by SUMO was proposed to modulate the pathogenesis of several neurodegenerative diseases. Spinocerebellar ataxia type 3/Machado-Joseph disease (SCA3/MJD) is an autosomal dominant neurodegenerative disease caused by polyQ-expanded ataxin-3. We have previously shown that ataxin-3 was a new target of SUMOylation in vitro and in vivo. Here we identified that the major SUMO-1 binding site was located on lysine 166. SUMOylation did not influence the subcellular localization, ubiquitination or aggregates formation of mutant-type ataxin-3, but partially increased its stability and the cell apoptosis. Our findings revealed the role of ataxin-3 SUMOylation in SCA3/MJD pathogenesis.

Value of segmental myocardial strain by 2-dimensional strain echocardiography for assessment of scar area induced in a rat model of myocardial infarction.

OBJECTIVES: Two-dimensional strain echocardiography (2DSE) technique has enabled accurate quantification of regional myocardial function. This experimental study was aimed to investigate the value of 2DSE in detection of segmental regional myocardial dysfunction induced by fibrosis following myocardial infarction in a small animal (rat) model. METHODS: A rat model of myocardial infarction was established by ligation of the proximal left anterior descending coronary artery in 17 SD rats. Regional myocardial function was detected by 2DSE at baseline and 4-weeks post-infarction, including end-systolic radial strain and strain rate (SR and SrR) and end-systolic circumferential strain and strain rate (SC and SrC) of each of six segments at papillary level. According to the size of scar found by histologic Masson staining, the optimal cutoff points of parameters for detecting scar area were analyzed and the sensitivity and specificity of every parameter to detect myocardial scar were obtained using ROC. RESULTS: (1) Comparing with parameters measured at baseline, there were significant decreases in SR, SrR, SC and SrC of each segment at 4 weeks post-infarction, with the worst in the infarct area (32.90 ± 8.79 vs 11.18 ± 3.89, 6.28 ± 1.35 vs 3.18 ± 0.47, -14.46 ± 2.21 vs -6.30 ± 2.17 and 4.93 ± 0.95 vs 2.59 ± 1.16, respectively) (all P < 0.05). (2)By 4 weeks, the myocardium of infarct area (anteroseptum, anterior and anterolateral) had fibrosis (31.33 ± 9.89, 73.42 ± 13.21 and 13.99 ± 3.24%, respectively) with minimal fibrosis in inferoseptal segment (0.32 ± 0.19%), no fibrosis was found in the inferior and inferolateral segments. (3)Significant negative correlations were found between the size of segmental scar and 2DSE parameters (r-value -0.61 ~ -0.80, all P < 0.01) with the strongest correlation in SR. SR less than 10% has 84% sensitivity and 98% specificity for detecting segments of scar area greater than 30% with AUC = 0.97. CONCLUSIONS: 2DSE is able to assess regional myocardial dysfunction in a rat model of myocardial infarction and has high accuracy in detecting infarct segments with scar area greater than 30%.

[Metabolic pathways of OGCP and the influence of parkin protein on the metabolism of OGCP].

OBJECTIVE: To study the metabolic pathways of 2-oxoglutarate carrier protein (OGCP)and the influence of parkin protein on the metabolism of OGCP. METHODS: The OGCP metabolic pathways were identified through inhibiting proteasome activities with specific proteasome inhibitors and protease inhibitors. The isotope pulse-chase experiments were performed to measure the turnover rate of OGCP and to study the influence of parkin protein on the metabolism of OGCP. RESULTS: Proteasome inhibitors and protease inhibitors inhibited OGCP degradation. The OGCP metabolism had a half-life of about 8-10 h. Overexpression of parkin protein accelerated the OGCP degradation. CONCLUSION: OGCP degrades through proteasome and lysosome degradation pathways. The degradation of parkin protein can promote the degradation of OGCP.

Novel mutations of the SPG11 gene in hereditary spastic paraplegia with thin corpus callosum.

BACKGROUND: Hereditary spastic paraplegia with thin corpus callosum (HSP-TCC) is a clinically and genetically heterogeneous neurodegenerative disorder with genetic linkage to multi-loci. Recently pathogenic mutations in the KIAA1840 (now named SPG11) for SPG11, the major HSP-TCC locus, were identified; at least 42 different mutations have been detected. OBJECTIVE: To study the clinical features and identify the SPG11 gene mutations in Chinese patients with HSP-TCC. METHODS: Three kindreds with an autosomal recessive HSP-TCC and 5 cases with sporadic HSP-TCC in Chinese Hans were recruited. Detailed clinical history, neurological examination, MRI, electromyography, Mini Mental State Examination (MMSE), Spastic Paraplegia Rating Scale (SPRS) were presented. DNA samples of the 8 families were collected and mutation analysis of SPG11 gene was carried out by direct DNA sequencing. RESULTS: Except for one patient whose age at onset was 3 years old, 10 patients manifested a relatively similar combination of adolescence-onset cognitive decline and spastic paraparesis with TCC on brain MRI. We identified 10 novel and one known mutations in our 8 HSP-TCC families, which were two nonsense mutations (c.5977C>T/p.Q1993X, c.4668T>A/p.Y1556X), three small deletions (c.6898_6899delCT/p.L2300AfsX2338, c.3719_3720delTA/p.I1240VfsX263, c.733_734delAT/p.M245VfsX246), four small insertions (c.7088_7089insATTA/p.Y2363X, c.2163_2164insT/p.I722YfsX731, c.7101_7102insT/p.K2368X, c.6790_6791insC/p.L2264PfsX2339), one deletion/insertion (c.654_655delinsG/p.S218RfsX219), and one splice mutation (c.7151+4_7151+7delAGTA/p.K2384fsX2386). Each family has a different mutation and all the mutations are predicted to cause early protein truncation. CONCLUSION: This study widens the mutation spectrum of the SPG11 gene and the mutations in the SPG11 gene are also the major causative gene for HSP-TCC in the Chinese Hans. Screening of the whole gene is recommended in clinical practice.

[Clinical study on effect of Jianwei Yuyang Granule in treating patients with gastric ulcer].

OBJECTIVE: To observe the clinical effects of Jianwei Yuyang Granule (JYG) in treating patients with gastric ulcer and its influence on interleukin-1beta (IL-1beta) and basic fibroblast growth factor (bFGF) mRNA expression in gastric mucosa for exploring the therapeutic mechanism. METHODS: Fifty-six patients with confirmed gastric ulcer unader gastroscope and differentiated as Gan-stagnant Pi-deficient syndrome were randomly assigned to two groups, the treated group (26 cases) treated with JYG and the control group (30 cases) treated with famotidine and sucralfate, 4 weeks as one therapeutic course. The changes before and after treatment in clinical compliance, symptom integral, ulcer-healing rate, clinical effective rate, and HP-clearance rate were observed. And the gastric mucosa biopsy was fetched for morphological examination and IL-1beta and bFGF mRNA expression detection by RT-PCR as well. RESULTS: The clinical compliance rate in the treated group was 100 %, which was obviously better than that in the control group (86.7 %, P< 0.01); the improvement on symptom integral in the former was also better (P < 0.01); no statistical significance was shown in ulcer-healing rate, clinical effective rate and HP-clearance rate between the two groups. Morphological observation showed markedly decreased inflammatory cell infiltration, epithelial cell regeneration and rather regular glandular arrangement in both groups. The IL-1beta mRNA expression level decreased and that of bFGF increased in both groups after treatment significantly ( P < 0.01), but showed insignificant difference between the two groups. CONCLUSION: JYG, with its good clinical compliance, has favorable effects in relieving clinical symptoms, promoting endoscopic ulcer healing and HP clearance, decreasing the expression of IL-1beta mRNA and increasing the expression of bFGF, therefore, it could promote the recovering of gastric ulcer.

[Frequency of different subtypes of spinocerebellar ataxia in the Han nationality of Hunan province in China].

OBJECTIVE: To determine the frequency of different subtypes of spinocerebellar ataxias (SCAs) in the Han nationality of Hunan province in China. METHODS: The mutations of SCA1, SCA2, SCA3, SCA6, SCA7, SCA17, and dentatorulral-pallidoluysian (DRPLA) were detected with the polymerase chain reaction (PCR), denaturing polyacrylamide gel and DNA sequencing techniques in 139 autosomal dominant SCA families and 61 sporadic SCA patients. RESULTS: Of the 139 families, 11 (7.9%) were positive for SCA1, 9(6.5%) were positive for SCA2, 71 (51.1%) were positive for SCA3, 4 (2.9%) were positive for SCA6, 2 (1.4%) were positive for SCA7, and none was positive for SCA17 and DRPLA. There was 1 SCA2 patient, 3 SCA3 patients, 1 SCA6 patient in the 61 sporadic SCA patients. CONCLUSION: The frequency of SCA3 is substantially higher than that of SCA1 and SCA2 in the autosomal dominant SCA patients in the Han nationality of Hunan province. SCA6 and SCA7 are rare subtypes.

[Clinical characteristics and molecular biology of hereditary spinocerebellar ataxia type 7: study of 3 Chinese families].

OBJECTIVE: To study the clinical characteristics and molecular biology of hereditary spinocerebellar ataxia type 7 (SCA7). METHODS: Peripheral blood samples were collected from 245 with autosomal dominant SCA from 184 families and 71 sporadic SCA patients. Polymerase chain reaction, polyacrylamide gel electrophoresis, and capillary electrophoresis technique were used to detect the SCA7 (CAG) n trinucleotide repeat mutations. 163 healthy persons were used as controls. The abnormal allele fragments were sequenced by ABI 377 DNA sequencing machine. RESULTS: Three SCA families with 15 patients were identified with a positive rate of 1.6%. DNA sequencing showed that the abnormal SCA7 alleles with CAG repeat were expanded to 38 to 71 repeats, and the normal SCA7 alleles were carried from 6 to 15 CAG repeats. Analysis of parent-child couples demonstrated the existence of marked anticipation in 2 families, especially in paternal transmission. Linkage analysis found a maximum two-point LOD score of 2.82 in the microsatellite D3S1300 at recombination fraction (theta = 0.00). CONCLUSION: CAG expansion is the pathogenic cause of SCA7, a rare subtype of SCA. The 38 CAG is the minimum pathological expansion in mainland China.