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ABSTRACT: Autophagy is a highly conserved degradation pathway in cells, which has been involved in many physiological processes and implicated in human age-related diseases. However, autophagy activities have not been systemically investigated with human tissues and cells.
Lysosomal associated membrane protein-2 (LAMP-2) protein is critical for autophagy and chaperone-mediated autophagy. We examined LAMP-2 gene expression and protein levels in the peripheral leukocytes from healthy subjects over 40years old.
Compared to those in group of 40-44years, the LAMP-2 transcript and protein levels in groups of 65-69 (P<0.01) and over 70years (P<0.001) were significantly decreased. No significant difference in LAMP-2 transcript and protein levels were observed between male and female groups.
Our data revealed that there was a progressive and age-related decrease of the LAMP-2 gene expression in the peripheral leukocytes of healthy subjects, indicating a trend of decreasing autophagy activities with aging.
Clinical biochemistry 06/2012; 45(15):1229-32. · 2.02 Impact Factor
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Guanghua Wu, Jian Huang,
Xungang Feng,
Aimei Zhang,
Jifeng Li,
Shuchao Pang,
Kejin Gu,
Haixin Dong,
Junping Zhang,
Huijie Gao,
Bo Yan
[show abstract]
[hide abstract]
ABSTRACT: Parkinson’s disease (PD) is a progressive neurodegenerative disease. To date, the causal genes and variants associated with
sporadic PD are largely unknown. Accumulating evidence demonstrates that autophagy delivers alpha-syncuclein proteins to lysosome
for degradation and dysfunctional autophagy is involved in the PD pathogenesis. We have previously screened a group of lysosomal
hydrolases and found that alpha-galactosidase A (GLA) activity is significantly decreased in the peripheral leukocytes of
sporadic PD patients. In this study, GLA transcript and protein levels were semi-quantitatively examined. The GLA transcript
(P=0.020) and protein (P=0.027) levels in the peripheral leukocytes of sporadic PD patients were significantly decreased, compared to age- and sex-matched
healthy controls. Furthermore, decreased GLA gene expression levels were strongly associated with sporadic PD (OR 3.33, 95%CI
1.17–9.52, P=0.024). Therefore, our data suggest that insufficient GLA activity may contribute to the pathogenesis of sporadic PD. The
underlying molecular mechanisms remain to be determined.
KeywordsParkinson’s disease–Lysosome–Alpha-galactosidase A–Gene expression–Leukocytes
Neurochemical Research 04/2012; 36(10):1939-1944. · 2.24 Impact Factor
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ABSTRACT: Coronary artery disease (CAD) is a common and multifactorial arterial disease that is mainly caused by atherosclerosis. Macrophages, lymphocytes and neutrophils have been implicated in atherosclerotic plaque development. Autophagy, a highly conserved cellular process for the removal of long-lived protein and organelles, plays a variety of pathophysiological roles. However, the roles of autophagy in peripheral leucocytes in atherosclerosis and CAD have not been explored.
LC3 is a marker gene for autophagy, and LC3-II, a conjugated form of LC3 protein, is a membrane marker for autophagosome and autophagolysosomes. In this study, LC3 gene expression levels and LC3-II protein levels in peripheral leucocytes were measured in patients with CAD (n = 146) and healthy controls (n = 87).
In patients with CAD, LC3 gene expression levels in the peripheral leucocytes were significantly decreased compared with age- and sex-matched healthy controls (P < 0·01). LC3-II protein levels were also significantly decreased in patients with CAD (P < 0·01). Multivariate logistic analyses showed that decreased LC3 gene expression levels were strongly associated with CAD. There were no differences in LC3 transcripts and LC3-II protein levels between subgroups of patients with CAD.
LC3 gene expression in the peripheral leucocytes was significantly decreased in patients with CAD, indicating that autophagosome formation is decreased. These data suggest that autophagy in circulating leucocytes may be involved in the pathogenesis of atherosclerosis and CAD.
European Journal of Clinical Investigation 09/2011; 41(9):958-63. · 3.02 Impact Factor
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ABSTRACT: Myocardial infarction (MI) is a common and multifactorial disease. To date, causal genes and underlying mechanisms remain largely unknown. Autophagic-lysosomal system, a highly conserved degradative process in cells, has been implicated in lipid metabolism. In this study, we explored the alterations of the autophagic-lysosomal system in patients with acute MI.
Gene expression of lysosomal associated membrane protein 2 (LAMP-2), a lysosomal marker gene, and microtubule-associated protein 1 light chain 3 (LC3), an autophagy marker gene, in the peripheral leukocytes of MI patients were examined at transcription and protein levels by RT-PCR assay and western blot analysis, respectively.
Compared to age- and sex-matched healthy controls (n=146), levels of LC3 gene expression and LC3-II protein, a cleaved form of LC3 protein, were significantly decreased in MI patients (n=81). LAMP-2 gene expression and protein levels were significantly increased. Decreased LC3 gene expression (OR, 2.150, 95%CI, 1.050-4.405, P=0.036) or increased LAMP-2 gene expression (OR, 3.317, 95%CI, 1.588-6.931, P<0.001) levels were associated with MI.
Our findings indicated that in the peripheral leukocytes of MI patients, autophagy activity is reduced and lysosomal accumulation is increased, which may contribute to the MI pathogenesis. Further genetic analyses of autophagic-lysosomal genes are warranted.
Clinica chimica acta; international journal of clinical chemistry 08/2011; 412(17-18):1567-71. · 2.54 Impact Factor
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ABSTRACT: Parkinson's disease (PD) is a progressive neurodegenerative disease. Majority of PD cases are sporadic, resulting from interaction of genetic and environmental factors. Accumulating evidence indicates that autophagy, which delivers alpha-synuclein to lysosomes for degradation, is involved in the PD pathogenesis. Some lysosomal hydrolases, such as glucocerebrosidase gene and ATP13A2, a lysosomal ATPase gene, have been implicated in PD. We have previously screened the activities of a group of lysosomal hydrolases in sporadic PD patients and found that alpha-galactosidase A (GLA) activities are significantly decreased. In this study, we analyzed GLA gene in sporadic PD patients by sequencing its promoter and exon regions. One single-nucleotide polymorphism (SNP) in the promoter region, rs3027580 (NG_007119.1:g.4292G>C), and two SNPs in the GLA 5'-untranslated region, rs2071225 (NM_000169.2:c.-10C>T) and rs3027585 (NM_000169.2:c.-12G>A), were identified with similar frequencies in sporadic PD patients and healthy controls. A novel variant (NG_007119.1:g.4488C>G) within the promoter region, at the -573 site upstream of the translation start codon (ATG), was found in one male PD patient, but not in female PD patients or healthy controls. Our data suggest that the sequence variant may affect GLA gene expression by altering transcription factor binding sites, contributing to the pathogenesis of sporadic PD.
Neuroscience Letters 06/2011; 500(1):31-5. · 2.11 Impact Factor
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Guanghua Wu,
Xuenan Wang,
Xungang Feng,
Aimei Zhang,
Jifeng Li,
Kejin Gu, Jian Huang,
Shuchao Pang,
Haixin Dong,
Huijie Gao,
Bo Yan
[show abstract]
[hide abstract]
ABSTRACT: Parkinson's disease (PD) is a progressive neurodegenerative disease caused by interaction of genetic and environmental factors. To date, genetic genes and variants causing PD remain largely unknown. Autophagy is a conserved cellular process including three subtypes, macroautophagy (hereafter referred to as autophagy), microautophagy and chaperone-mediated autophagy (CMA). Although reduced CMA and induced autophagy are observed in human PD brain samples, cell and animal PD models, CMA and autophagy have not been systemically studied in sporadic PD patients. In the peripheral leukocytes of sporadic PD patients, we examined gene expression levels of lysosome-associated membrane 2 (LAMP-2), a CMA receptor and a limiting step, and microtubule-associated protein 1 light chain 3 (LC3), product of which is sequentially cleaved and lipidated to form LC3-II as an autophagosome marker. Compared to age- and sex-matched healthy controls, LAMP-2 gene expression and protein levels in sporadic PD patients were significantly decreased, which may lead to reduced CMA activity and impaired fusion of autophagosome and lysosome. LC3 gene expression and LC3-II protein levels were significantly increased in sporadic PD patients, suggesting that autophagosomes are accumulated. Our findings, decreased LAMP-2 gene expression and increased LC3 gene expression, are consistent to the previous studies with dopaminergic neuronal cells in vitro and in vivo, which may contribute to the pathogenesis of sporadic PD by altering CMA and autophagy activities. The genetic causes leading to decreased LAMP-2 gene expression need further investigation and genetic or pharmacological restoration of LAMP-2 might be a novel strategy for treating PD patients.
Brain research 06/2011; 1394:105-11. · 2.46 Impact Factor
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Guanghua Wu, Jian Huang,
Xungang Feng,
Aimei Zhang,
Jifeng Li,
Shuchao Pang,
Kejin Gu,
Haixin Dong,
Junping Zhang,
Huijie Gao,
Bo Yan
[show abstract]
[hide abstract]
ABSTRACT: Parkinson's disease (PD) is a progressive neurodegenerative disease. To date, the causal genes and variants associated with sporadic PD are largely unknown. Accumulating evidence demonstrates that autophagy delivers alpha-syncuclein proteins to lysosome for degradation and dysfunctional autophagy is involved in the PD pathogenesis. We have previously screened a group of lysosomal hydrolases and found that alpha-galactosidase A (GLA) activity is significantly decreased in the peripheral leukocytes of sporadic PD patients. In this study, GLA transcript and protein levels were semi-quantitatively examined. The GLA transcript (P = 0.020) and protein (P = 0.027) levels in the peripheral leukocytes of sporadic PD patients were significantly decreased, compared to age- and sex-matched healthy controls. Furthermore, decreased GLA gene expression levels were strongly associated with sporadic PD (OR 3.33, 95%CI 1.17-9.52, P = 0.024). Therefore, our data suggest that insufficient GLA activity may contribute to the pathogenesis of sporadic PD. The underlying molecular mechanisms remain to be determined.
Neurochemical Research 06/2011; 36(10):1939-44. · 2.24 Impact Factor
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[show abstract]
[hide abstract]
ABSTRACT: Coronary artery disease (CAD) is a common complex disease that is caused by interaction between genetic and environmental factors. Accumulating evidence indicates that foam cells in the atherosclerotic plaques exhibit the characteristics of lysosomal storage diseases, namely lysosomal accumulation of indigested materials. In patients with lysosomal storage diseases, lysosomal accumulation of lipids and cholesterols in atherosclerotic plaque cells has been observed. However, the roles of lysosomal hydrolases and proteins in the pathogenesis of atherosclerosis and CAD remain unclear.
Lysosomal hydrolases and proteins may be involved in the pathogenesis of atherosclerosis and CAD by affecting lipid and cholesterol metabolism.
Expression levels of LAMP-2, a lysosomal membrane marker gene, in the peripheral leukocytes of CAD patients (n = 134) and age- and sex-matched healthy controls (n = 80) were examined at transcription and protein levels with reverse transcriptase-polymerase chain reaction and Western blot analyses, respectively. The results were compared between CAD patients and healthy controls.
LAMP-2 gene expression and LAMP-2 protein levels were significantly increased in the peripheral leukocytes of CAD patients, compared with healthy controls. Furthermore, multivariate logistic regression analyses revealed that CAD is significantly associated with LAMP-2 gene expression levels (odds ratio [OR] 8.84, 95% confidence interval [CI]: 2.15-36.40, P = 0.003) or LAMP-2 protein levels (OR 2.03, 95% CI: 1.15-3.59, P = 0.015).
In CAD patients, LAMP-2 gene expression in the peripheral leukocytes was significantly increased than were controls, which indicates lysosomal accumulation. These data suggest that insufficient lysosomal hydrolases and proteins may lead to abnormal lipid and cholesterol metabolism, which cause initiation and progression of atherosclerosis and CAD.
Clinical Cardiology 04/2011; 34(4):239-43. · 2.15 Impact Factor
