Characterizing the normal proteome of human ciliary body

Background

The ciliary body is the circumferential muscular tissue located just behind the iris in the anterior chamber of the eye. It plays a pivotal role in the production of aqueous humor, maintenance of the lens zonules and accommodation by changing the shape of the crystalline lens. The ciliary body is the major target of drugs against glaucoma as its inhibition leads to a drop in intraocular pressure. A molecular study of the ciliary body could provide a better understanding about the pathophysiological processes that occur in glaucoma. Thus far, no large-scale proteomic investigation has been reported for the human ciliary body.

Results

In this study, we have carried out an in-depth LC-MS/MS-based proteomic analysis of normal human ciliary body and have identified 2,815 proteins. We identified a number of proteins that were previously not described in the ciliary body including importin 5 (IPO5), atlastin-2 (ATL2), B-cell receptor associated protein 29 (BCAP29), basigin (BSG), calpain-1 (CAPN1), copine 6 (CPNE6), fibulin 1 (FBLN1) and galectin 1 (LGALS1). We compared the plasma proteome with the ciliary body proteome and found that the large majority of proteins in the ciliary body were also detectable in the plasma while 896 proteins were unique to the ciliary body. We also classified proteins using pathway enrichment analysis and found most of proteins associated with ubiquitin pathway, EIF2 signaling, glycolysis and gluconeogenesis.

Conclusions

More than 95% of the identified proteins have not been previously described in the ciliary body proteome. This is the largest catalogue of proteins reported thus far in the ciliary body that should provide new insights into our understanding of the factors involved in maintaining the secretion of aqueous humor. The identification of these proteins will aid in understanding various eye diseases of the anterior segment such as glaucoma and presbyopia.     

Regulation of the catalytic behaviour of L-form starch phosphorylase from sweet potato roots by proteolysis

Starch phosphorylase (SP) is an enzyme used for the reversible phosphorolysis of the α-glucan in plant cells. When compared to its isoform in an animal cell, glycogen phosphorylase, a peptide containing 78 amino acids (L78) is inserted in the centre of the low-affinity type starch phosphorylase (L-SP). We found that the amino acid sequence of L78 had several interesting features including the presence of a PEST region, which serves as a signal for rapid degradation. Indeed, most L-SP molecules isolated from mature sweet potato roots were nicked in the middle of a molecule, but still retained their tertiary or quaternary structures, as well as full catalytic activity. The nicking sites on the L78 were identified by amino acid sequencing of these peptides, which also enabled us to propose a proteolytic process for L-SP. Enzyme kinetic studies of L-SP in the direction of starch synthesis indicated that the K_m decreased during the proteolytic process when starch was used as the limiting substrate, but the K_m for the other substrate (Glc-1-P) increased. On the other hand, the maximum velocities (V_max) increased for both substrates. Mobility of the nicked L-SP was retarded on a native polyacrylamide gel containing soluble starch, indicating the increased affinity for starch. Results in this study suggested that L78 and its proteolytic modifications might play a regulatory role on the catalytic behaviour of L-SP in starch biosynthesis.     

FE65 as a link between VLDLR and APP to regulate their trafficking and processing

Background

Loss-of-function mutations in PTEN-induced kinase 1 (PINK1) have been linked to familial Parkinson??s disease, but the underlying pathogenic mechanism remains unclear. We previously reported that loss of PINK1 impairs mitochondrial respiratory activity in mouse brains.

Results

In this study, we investigate how loss of PINK1 impairs mitochondrial respiration using cultured primary fibroblasts and neurons. We found that intact mitochondria in PINK1?/? cells recapitulate the respiratory defect in isolated mitochondria from PINK1?/? mouse brains, suggesting that these PINK1?/? cells are a valid experimental system to study the underlying mechanisms. Enzymatic activities of the electron transport system complexes are normal in PINK1?/? cells, but mitochondrial transmembrane potential is reduced. Interestingly, the opening of the mitochondrial permeability transition pore (mPTP) is increased in PINK1?/? cells, and this genotypic difference between PINK1?/? and control cells is eliminated by agonists or inhibitors of the mPTP. Furthermore, inhibition of mPTP opening rescues the defects in transmembrane potential and respiration in PINK1?/? cells. Consistent with our earlier findings in mouse brains, mitochondrial morphology is similar between PINK1?/? and wild-type cells, indicating that the observed mitochondrial functional defects are not due to morphological changes. Following FCCP treatment, calcium increases in the cytosol are higher in PINK1?/? compared to wild-type cells, suggesting that intra-mitochondrial calcium concentration is higher in the absence of PINK1.

Conclusions

Our findings show that loss of PINK1 causes selective increases in mPTP opening and mitochondrial calcium, and that the excessive mPTP opening may underlie the mitochondrial functional defects observed in PINK1?/? cells.     

步长稳心颗粒治疗功能性早搏60例疗效分析

目的：观察步长稳心颗粒（简称稳心颗粒）治疗功能性早搏的临床疗效及安全性。方法：选择功能性早搏60例病人,随机分为治疗组及对照组,每组各30例。治疗组给予稳心颗粒一包（9克）,每日三次,温开水冲服;对照组给予倍他乐克25毫克,每日二次口服,一个月为一疗程。结果：四周后治疗组显效11例,有效16例,总有效率90％。对照组显效8例,有效18例,总有效率86．7％,p〉0．05,两组比较无显著性差异。对血压、心率影响方面稳心颗粒明显优于倍他乐克结论：稳心颗粒治疗功能性早搏疗效显著,且效果稳定,安全无明显不良反应,值得临床推广应用。     

The abundance of an invasive freshwater snail Tarebia granifera (Lamarck, 1822) in the Nseleni River,South Africa

The invasive freshwater snail Tarebia granifera (Lamarck, 1822) was first reported in South Africa in 1999 and it has become widespread across the country, with some evidence to suggest that it reduces benthic macroinvertebrate biodiversity. The current study aimed to identify the primary abiotic drivers behind abundance patterns of T. granifera, by comparing the current abundance of the snail in three different regions, and at three depths, of the highly modified Nseleni River in KwaZulu-Natal, South Africa. Tarebia granifera was well established throughout the Nseleni River system, with an overall preference for shallow waters and seasonal temporal patterns of abundance. Although it is uncertain what the ecological impacts of the snail in this system are, its high abundances suggest that it should be controlled where possible and prevented from invading other systems in the region.     

三唑酮提高水稻幼苗抗旱性的研究

在-0.5MPa渗透胁迫下三唑酮提高水稻(Oryza sativa L.)幼苗相对含水量,降低丙二醛(MDA)含量,提高了抗旱性。三唑酮(75mg/L)可提高渗透胁迫下水稻幼苗过氧化物酶(POD)和过氧化氢酶(CAT)活性,对超氧物歧化酶(SOD)活性影响不大。加入蛋白质合成抑制剂环己亚胺试验证明,三唑酮对POD的效应是促进酶蛋白的合成。     

放牧对滩涂底栖动物的影响

于2005年5月（春季）和10月（秋季）,调查了放牧对上海市崇明东滩大型底栖动物的影响.调查采样设置3个样区,其中Ⅰ、Ⅱ样区在放牧区,Ⅲ样区在非放牧区,3个样区均在潮间带的中潮带,共计90个样方.采集到底栖动物13种,其中节肢动物7种,软体动物4种,环节动物2种.Ⅰ、Ⅱ和Ⅲ样区春季分别有6、8和10种,秋季6、8和12种.各样区秋季底栖动物的平均密度均高于春季,春、秋季各样区的平均密度又均以Ⅲ样区最高.生物量与密度变化大体相似,以Ⅲ样区最高.与Ⅰ、Ⅱ样区相比,Ⅲ样区的多样性指数、均匀度和丰富度均最高,说明放牧改变了底栖动物种类分布的格局,使底栖动物的密度、生物量均有不同程度的改变,且放牧对崇明东滩底栖动物的生物多样性产生了一定的负面影响.