Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Diabetic retinopathy is one of the common complications of diabetes and is the leading cause for patients' visual dysfunction and sight loss. However, the mechanism of diabetic retinopathy is not clearly defined. The present study was undertaken to investigate neuroretinal apoptosis in different stages in a mouse model for type 2 diabetes mellitus and the mechanism of diabetic retinopathy. KKAY mouse with genetic diabetes, an animal model for type 2 diabetes, was used in this study. Mice were divided into a control group and a diabetic group. The mice in both groups were sacrificed at one month and three months, and the mouse eyeballs were used for making retinal histologic sections. We showed in this study that the apoptotic cell numbers for retinal neural cells in the ganglion cell layer were significantly greater in the diabetic group than in the control group (p<0.01), as determined by the TUNEL assay. In addition, many more apoptotic retinal neuronal cells were found in the retinal ganglion cell layer and medial part of the inner nuclear layer in the diabetic group when the mice were sacrificed at three months as compared to those sacrificed at one month (p<0.01). We also studied the ultrastructure of the retinal nerve cells and microvesseles by electron microscopy and demonstrated that the ultrastructure changes for retinal neural cells and retinal microangiopathy were observed in, as early as, the early stage of diabetes. These findings indicate that: i). retinal neuropathy and microangiopathy occur in the early stage of diabetes, ii). apoptosis may be an important mechanism through which retinal neurodegeneration is developed, and iii). both retinal neurodegeneration and retinal microangiopathy should be considered as the diabetic retinopathy.
Int J Mol Med 2004 Jan
PMID:Neuro-optic cell apoptosis and microangiopathy in KKAY mouse retina. 1465 76

A T8993G point mutation in the mtDNA results in a Leu156Arg substitution in the MTATP6 subunit of the mitochondrial F1F0-ATPase. The T8993G mutation causes impaired oxidative phosphorylation (OXPHOS) in two mitochondrial disorders, NARP (neuropathy, ataxia and retinitis pigmentosa) and MILS (maternally inherited Leigh's syndrome). It has been reported, in some studies, that the T8993G mutation results in loss of assembled F1F0-ATPase. Others reported that the mutation causes impairment of proton flow through F0. In addition, it was shown that fibroblasts from NARP subjects have a tendency to undergo apoptotic cell death, perhaps as a result of increased free radical production. Here, we show that the T8993G mutation inhibits oxidative phosphorylation and results in enhanced free radical production. We suggest that free radical-mediated inhibition of OXPHOS contributes to the loss of ATP synthesis. Importantly, we show that antioxidants restore respiration and partially rescue ATP synthesis in cells harboring the T8993G mutation. Our results indicate that free radicals might play an important role in the pathogenesis of NARP/MILS and that this can be prevented by antioxidants. The effectiveness of antioxidant agents in cultured NARP/MILS cells suggests that they might have a potential beneficial role in the treatment of patients with NARP.
Hum Mol Genet 2004 Apr 15
PMID:The mtDNA T8993G (NARP) mutation results in an impairment of oxidative phosphorylation that can be improved by antioxidants. 1499 33

Hereditary neuropathy with liability to pressure palsies (HNPP) is an autosomal dominant inherited disorder characterized by recurrent pressure palsies. Most HNPP patients have a 1.5 mb deletion in chromosome 17p11.2-p12. The present study aimed at evaluating the deletion of the 17p11.2-p12 region in Korean subjects with families exhibiting HNPP phenotype, and to determine the clinical, electrophysiological and morphological aspects specifically associated with this deletion in HNPP patients. By genotyping six microsatellite markers (D17S921, D17S955, D17S1358, D17S839, D17S122 and D17S261), HNPP with the deletion was observed in 79% (19 of 24) of HNPP families. Nerve conduction studies were performed in 35 HNPP patients from these 19 families. The observed HNPP deletion frequency in Koreans is consistent with findings in other populations. Disease onset occurred at a significantly earlier age in patients with recurrent pressure palsies than in those with a single attack (P < 0.01). Nerve conduction studies demonstrated diffuse mild to moderate slowing of nerve conduction velocities that were worse over the common entrapment sites, regardless of the clinical manifestations. A long duration of compound muscle action potentials without a conduction block or a temporal dispersion is a characteristic of this disease. A sural nerve biopsy with teasing was performed in four patients, and tomacula of the myelin sheath was found in 56.4%. Our findings appear to support the existence of a phenotype/genotype correlation in HNPP patients of Korean ancestry with the deletion, and suggest that HNPP patients with earlier symptom onset face an increased chance of having recurrent attacks.
Exp Mol Med 2004 Feb 29
PMID:Hereditary neuropathy with liability to pressure palsies (HNPP) patients of Korean ancestry with chromosome 17p11.2-p12 deletion. 1503 68

Glaucoma is a progressive blinding disease characterized by gradual loss of vision due to optic neuropathy and retinal ganglion cell death. Increased intraocular pressure is a common feature of glaucoma that is thought to arise from an increased resistance to outflow of aqueous humor through the trabecular meshwork. Mutations of the myocilin gene are one cause of autosomal dominant juvenile- and adult-onset primary open angle glaucoma, but the mechanism by which mutant myocilins cause disease is poorly understood. We have found that disease-causing myocilin mutants are misfolded, are highly aggregation-prone and accumulate in large aggregates in the endoplasmic reticulum (ER) of human embryonic kidney cells and differentiated primary human trabecular meshwork (HTM) cells. In HTM cells, Pro370Leu mutant myocilin is not secreted under normal culture conditions and prolonged expression results in abnormal cell morphology and cell killing. Culturing HTM cells at 30 degrees C, a condition known to facilitate protein folding, promotes secretion of mutant myocilin, normalizes cell morphology and reverses cell lethality. Our results indicate that myocilin-associated glaucoma is an ER storage disease and suggest a progression of events in which chronic expression of misfolded, non-secreted myocilin leads to HTM cell death, trabecular meshwork dysfunction and, ultimately, a dominant glaucoma phenotype. The beneficial effects of facilitating folding and secretion of mutant myocilin suggest a new type of treatment for this form of glaucoma.
Hum Mol Genet 2004 Jun 01
PMID:Reversal of mutant myocilin non-secretion and cell killing: implications for glaucoma. 1506 26

Acute intermittent porphyria (AIP), an inborn error of metabolism, results from the deficient activity of the third enzyme in the heme biosynthetic pathway, porphobilinogen deaminase (PBGD). Clinical symptoms of this autosomal dominant hepatic porphyria include episodic acute attacks of abdominal pain, neuropathy, and psychiatric disturbances. Current therapy based on intravenous heme administration is palliative and there is no way to prevent the attacks. Thus, efforts are focused on methods to replace the deficient activity in the liver to prevent the acute attacks of this hepatic porphyria. Here we explore the efficiency of a non-viral gene delivery to obtain PBGD expression in the liver of AIP transgenic mice. Four vectors were evaluated: naked DNA and DNA complexed to liposomes, polyethylenimine (PEI), and PEI-galactose, using a luciferase construct as reporter gene. The vectors were administered intravenously or directly into the portal vein with transient blood flow blockage. After tail vein injection of the DNA complexes, the liposome vector had the highest luciferase expression in lung and less in liver. When injected into the portal vein, the naked DNA had considerably higher hepatic reporter gene expression; 100 microg of naked DNA had the highest hepatic luciferase expression 24h after portal vein injection. When these vectors were used to deliver the PBGD gene into the AIP mouse model no enhancement of the endogenous PBGD activity in liver was detectable, despite the presence of the PBGD-plasmids as verified by PCR. Thus, more efficient non-viral vectors are needed to express sufficient PBGD activity over the endogenous hepatic level (approximately 30% of normal) in this murine system.
Mol Genet Metab 2004 May
PMID:Non-viral delivery of the porphobilinogen deaminase cDNA into a mouse model of acute intermittent porphyria. 1511 Mar 17

Partial sciatic nerve transection (PST) of the sciatic nerve of rats and mice is described as a model of painful neuropathy. The rationale for developing this model was to establish a simple partial nerve injury without application of foreign material. In contrast to the frequently used model of chronic constriction injury (CCI), PST allows to relate animal behavior and drug effects to endoneurial changes, undisturbed by major epineurial inflammation. PST is easy to perform in rats and mice and leads to reproducible pain-related behavior for 5 wk or longer.
Methods Mol Med 2004
PMID:Partial sciatic nerve transection. 1513 28

Peripheral nerve damage involves inflammation, and is frequently causal to the development of neuropathic pain. However, inflammatory neuropathies often occur in the absence of trauma. We have recently developed an animal model of neuropathic pain where allodynia is induced by nerve inflammation rather than injury. This sciatic inflammatory neuropathy (SIN) model was developed to understand immunologic, neuropathic, and spinal mechanisms underlying allodynia in the territory of the sciatic nerve as well as in extraterritorial and contralateral ("mirror image") sites. A specially designed indwelling catheter system allows immune activators to be selectively injected around one healthy sciatic nerve in awake, behaving rats. Here, we provide detailed procedures on the construction and implantation of chronic indwelling perisciatic catheters used to create SIN. Detailed procedures for implantation of intrathecal catheters via a lumbar vertebra 5 and 6 approach in the same rat are also provided. Methods for testing allodynia and for data analysis are additionally described so to provide all the steps needed for behavioral experimentation.
Methods Mol Med 2004
PMID:Sciatic inflammatory neuropathy in the rat: surgical procedures, induction of inflammation, and behavioral testing. 1513 30

Vincristine belongs to the family of vinca alkaloids used for treatment of malignant tumors. Clinical application of these agents is often associated with dose-dependent painful neuropathy due to damages to the peripheral axons. A rat model of vincristine-induced hyperalgesia was developed through intravenous injection of vincristine by Aley et al. (1996) and was later modified by Nozaki-Taguchi et al. (2001) using continuous intravenous infusion of vincristine. This model provides consistent and long-lasting neuropathic pain states mimicking vincristine-induced pain conditions in human patients. Therefore, this model is a valuable means of studying the mechanisms and pharmacology of vincristine-induced neuropathic pain. In this chapter we describe in detail steps the generation of vincristine-induced neuropathy in rats through continuous intravenous infusion of vincristine.
Methods Mol Med 2004
PMID:A rat pain model of vincristine-induced neuropathy. 1513 31

The dorsal horn of the spinal cord is a key relay in the transmission of sensory information to the brain. Furthermore, this circuitry of spinal-cord neurons, and hence the spinal processing of sensory information, is subject to a great deal of plasticity, both pharmacological and physiological, in persistent pain states. This chapter describes in detail the procedure by which the activity and pharmacological modulation of these dorsal-horn neurons can be recorded in vivo in anesthetized rats, allowing a comprehensive study of spinal sensory processing in an intact and integrated system. The chapter covers the surgical preparation of the animal for electrophysiological recording; isolating and recording the activity of a single dorsal-horn neuron; and identifying the type of dorsal-horn neuron recorded by characterizing the neuronal response to a variety of peripheral stimuli. The study of these neuronal responses in a variety of persistent pain states, such as carrageenan-induced inflammation and neuropathy induced by L5/L6 spinal nerve ligation, together with the study of their pharmacological modulation by locally or systemically administered drugs, is also described.
Methods Mol Med 2004
PMID:In vivo electrophysiology of dorsal-horn neurons. 1513 35

The receptor for advanced glycation end products (RAGE), a multiligand receptor of the immunoglobulin superfamily, has been implicated in the inflammatory response, diabetic angiopathy and neuropathy, neurodegeneration, cell migration, tumor growth, neuroprotection, and neuronal differentiation. We show here that (i) RAGE is expressed in skeletal muscle tissue and its expression is developmentally regulated and (ii) RAGE engagement by amphoterin (HMGB1), a RAGE ligand, in rat L6 myoblasts results in stimulation of myogenic differentiation via activation of p38 mitogen-activated protein kinase (MAPK), up-regulation of myogenin and myosin heavy chain expression, and induction of muscle creatine kinase. No such effects were detected in myoblasts transfected with a RAGE mutant lacking the transducing domain or myoblasts transfected with a constitutively inactive form of the p38 MAPK upstream kinase, MAPK kinase 6, Cdc42, or Rac-1. Moreover, amphoterin counteracted the antimyogenic activity of the Ca(2+)-modulated protein S100B, which was reported to inhibit myogenic differentiation via inactivation of p38 MAPK, and basic fibroblast growth factor (bFGF), a known inhibitor of myogenic differentiation, in a manner that was inversely related to the S100B or bFGF concentration and directly related to the extent of RAGE expression. These data suggest that RAGE and amphoterin might play an important role in myogenesis, accelerating myogenic differentiation via Cdc42-Rac-1-MAPK kinase 6-p38 MAPK.
Mol Cell Biol 2004 Jun
PMID:Amphoterin stimulates myogenesis and counteracts the antimyogenic factors basic fibroblast growth factor and S100B via RAGE binding. 1514 81


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