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Objective To investigate the expression of Parkin protein in colorectal cancer and its clinical significance. Methods Immunohistochemistry was used to detect the expression of Parkin protein in normal and cancerous tissues of 50 patients with colorectal cancer from 2012 to 2015. The relationship between clinicopathological characteristics and Parkin protein expression was analyzed. Results The positive expression rate of Parkin protein in cancerous tissues was significantly lower than that in normal tissues: 36% (18/50) vs. 72% (36/50), and there was statistical difference (P＜0.01). The positive expression of Parkin protein was correlated with the degree of tissue differentiation (P < 0.01);but it was not correlated with sex, age, tumor diameter, tumor type, tumor infiltration, lymph node metastasis and clinical stage (P＞0.05). Conclusions In colorectal cancer tissues, the expression of Parkin gene is absent and decreased. The abnormal expression of Parkin gene may be related to the occurrence and development of colorectal cancer.
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AIM:The effect of acupuncture on mitophagy-related protein expression in skeletal muscle of rats after heavy-load exercise was investigated to explore the role of acupuncture in the repairment of exercise-induced skeletal muscle damage. METHODS:Male adult Sprague-Dawley rats (n=128) were randomly divided into 4 groups:control (C,n=8) group, exercise (E, n=40) group, acupuncture (A, n=40) group, and exercise and acupuncture (EA, n=40) group. The rats in E group and EA group performed an eccentric exercise,and the rats in A group and EA group immediately after exercise received acupuncture treatment. The rats in the latter 3 groups were further divided into 0 h,12 h,24 h,48 h and 72 h sub-groups(n=8),and soleus muscle was collected at each time point. The transmission electron microscopy was used to observe the ultrastructural changes of the mitochondria in skeletal muscle. The content of citrate synthase (CS) was measured by ELISA. The protein expression of skeletal muscle PTEN-induced putative kinase 1 (PINK1),parkin and microtubule-associated protein 1 light chain 3 (LC3) was determined by Western blot. RESULTS:After the heavy-load exercise,the mitochondria swelled and accumulated under cell membrane. The number of mitophago-somes was increased,and the content of CS was significantly decreased(P<0.05). The expression of PINK1,parkin and LC3 was significantly elevated (P<0.05). However,the acupuncture intervention after exercise promoted the recovery of mitochondrial ultrastructure, attenuated mitophagolysosome formation, maintained CS content and down-regulated the ex-pression of PINK1,parkin and LC3 (P<0.05). CONCLUSION:Heavy-load exercise causes the damages of mitochon-drial structure and function in the skeletal muscle and activates PINK1/parkin pathway to induce excessive occurrence of mitophagy. Acupuncture intervention after exercise is able to alleviate the damage of mitochondria in the skeletal muscle through decreasing the expression of mitochondrial outer membrane protein PINK1,reducing the recruitment of downstream cytoplasmic protein parkin,thereby affecting the combination of LC3 and mitochondria to inhibit the overactivation of mito-phagy.
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BACKGROUND: Abnormalities of the parkin gene is the most frequently found genetic abnormality in patients with sporadic young age onset of Parkinson's disease (PD). We investigated the frequency of abnormalities of the parkin gene in Korean patients with young age onset PD (YOPD). METHODS: This study included 18 patients (M : F=10:8) who developed PD before the age of 45. DNA was isolated from peripheral blood leukocytes. Exonal deletion and nucleotide sequence changes in the parkin gene was searched by quantitative PCR and sequencing of all coding regions. RESULTS: Only one patient had a heterozygous mutation at the nucleotide position 1473 in exon 12 (A1473C). The remaining 17 patients showed no mutations in the coding region of the parkin gene. In all 18 patients, we could not find any compound heterozygotic as well as homozygotic exonal deletion. The patient who had the heterozygotic point mutation in the parkin gene did not present any clinical features differentiating the patient from the others with YOPD. The frequency of parkin mutation in patients with YOPD in our series was 5.6 percent. CONCLUSIONS: In Korean patients with YOPD, the frequency of parkin mutation seems to be lower than that of other ethnic groups. Further studies with a larger number of patients with YOPD are needed to support this suggestion.