Effects of ethanol on rat Schwann cell proliferation and myelination in culture

The protective effects of resveratrol on Schwann cells with toxicity induced by ethanol in vitro

Schwann cells (SCs) are the myelin forming cells in the peripheral nervous system, they play a key role in the pathology of various polyneuropathies and provide trophic support to axons via expression of various neurotrophic factors, such as nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF) and glial cell line-derived neurotrophic factor (GDNF). Ethanol (EtOH) adversely affected both SCs proliferation and myelin formation in culture. Resveratrol (Res) has been shown to regulate many cellular processes and to display multiple protective and therapeutic effects. Whether Res has protective effects on SCs with EtOH-induced toxicity is still unclear. The protective efficacy of Res on EtOH-treated SCs in vitro was investigated in the present study. Res improved cell viability of the EtOH-treated SCs. Hoechst 33342 staining and terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate nick-end labeling analysis showed that the EtOH-induced apoptosis was inhibited by Res. The effects of Res were blocked by the 5'-adenosine monophosphate-activated protein kinase inhibitor Compound C and the silencing information regulator T1 inhibitor nicotinamide. Res could increase the mRNA and protein levels of BDNF and GDNF in the EtOH-treated SCs. However, the EtOH-induced increase of NGF in the SCs is inhibited by Res. The data from the present study indicate that Res protects SCs from EtOH-induced cell death and regulates the expression of neurotrophicfactors. Res and its derivative may be effective for the treatment of neuropathic diseases induced by EtOH.

Alcohol-related peripheral neuropathy: nutritional, toxic, or both?

Alcohol-related peripheral neuropathy (ALN) is a potentially debilitating complication of alcoholism that results in sensory, motor, and autonomic dysfunction. Unfortunately, ALN is rarely discussed as a specific disease entity in textbooks because it is widely assumed to primarily reflect consequences of nutritional deficiency. This hypothesis is largely based on observations first made over eight decades ago when it was demonstrated that thiamine deficiency (beriberi) neuropathy was clinically similar to ALN. In recent studies, failure of thiamine treatment to reverse ALN, together with new information demonstrating clinical and electrophysiological distinctions between ALN and nutritional deficiency neuropathies, suggests that alcohol itself may significantly predispose and enhance development of neuropathy in the appropriate clinical setting. We reviewed the evidence on both sides and conclude that ALN should be regarded as a toxic rather than nutritional neuropathy.

The unique simultaneous occurrence of a squamous cell carcinoma and a granular cell tumor of the tongue at the same site: a histological and immunohistochemical study

We report a case of a 47-year-old man with a granular cell tumor (GCT) of the tongue colocalized with a squamous cell carcinoma. To our knowledge, this is the first case to be reported in the literature with such an association. Furthermore, we performed an immunohistochemical analysis with p63 to distinguish pseudoepitheliomatous hyperplasia from invasive squamous cell carcinoma. Clinicians and pathologists must be made aware of this potential diagnostic pitfall so that the workup of a tongue lesion does not end prematurely with a benign diagnosis of granular cell tumor with overlying pseudoepitheliomatous hyperplasia.

A quantitative study of the facial nerve in mice prenatally exposed to ethanol

Pregnant ICR mice were given 20% ethanol intraperitoneally twice on day 13 of gestation and allowed to give birth to offspring. The offspring were killed at 56 days of age and the motor root of their facial nerve was examined histologically and morphometrically. The cross-sectional area of the facial nerve of mice prenatally exposed to ethanol was significantly smaller than that of the control mice. There was no significant difference in the total number of myelinated axons or the mean axonal diameter between control and ethanol-exposed mice, but the mean diameter of myelinated fibers (axon + myelin sheath) and the thickness of myelin sheath were significantly decreased in the treated group. These results suggest that prenatal exposure to ethanol disturbs myelination of the motor root of the facial nerve and may cause permanent neurological effects.

Association of multiple granular cell tumors and squamous carcinoma of the esophagus: case report and review of the literature

This report describes the case of a man who underwent subtotal esophagectomy for the concomitant presence of a multifocal esophageal squamous carcinoma and a granular cell tumor (GCT); he had been previously affected by another metachronous esophageal GCT excised endoscopically. This is the sixth case described in the literature detailing other cases of a combination of malignancies involving additional organs. We emphasize the need for a prolonged surveillance of patients with multiple GCTs in order to promptly recognize the possibility of associated neoplasms.

Combined effects of simultaneous exposure to toluene and ethanol on auditory function in rats

Three experimental groups and one control group of Long-Evans rats were used to study the combined effects of toluene and ethanol on auditory function. The first experimental group was exposed to toluene vapors (1750 ppm, 6 h/day, 5 days/week, 4 weeks), the second one was daily gavaged with a saline solution of ethanol (4 g/kg, 4 weeks), and the last group was simultaneously exposed to both toluene and ethanol. Auditory function was tested by recording brain stem (inferior colliculus) auditory-evoked potentials for audiometric frequencies ranging from 2 to 32 kHz. Urinary hippuric acid was dosed to check the toluene metabolism during the experiments. Ethanol clearly modified the toluene metabolism in the present experimental conditions. As a result, the hearing loss induced by a simultaneous exposure to both ethanol and toluene was larger than that induced by exposure to toluene alone.

Local delivery of ethanol inhibits intimal hyperplasia in pig coronary arteries after balloon injury

BACKGROUND

Smooth muscle cell (SMC) hyperplasia is an important mechanism of restenosis after coronary angioplasty and the primary mechanism of restenosis within coronary stents. Ethanol has been shown to reduce the response of SMCs to local growth stimulants in vitro. This study was carried out to determine whether local delivery of ethanol solution could reduce intimal hyperplasia induced by balloon injury.

METHODS AND RESULTS

Three groups of juvenile domestic pigs underwent oversized balloon dilation injury of the left anterior descending and left circumflex coronary arteries. Immediately after the balloon injury, one of the arteries was randomized to local delivery of 15% ethanol with a local delivery balloon catheter, and the other received no further treatment. Histological and morphometric studies were carried out at 2 weeks in group 1 (n=16) and at 4 weeks in group 2 (n=10). In the third group (n=15), animals were killed at days 4, 8, and 14 after balloon injury, and coronary artery segments were studied by immunohistochemical staining against proliferating cell nuclear antigen (PCNA) and bromodeoxyuridine (BrdU). Histological injury scores were not different between the ethanol-treated and untreated arterial segments in either group 1 or 2. The neointimal areas were significantly smaller in the ethanol-treated arterial segments than in the untreated segments (0.25+/-0.08 versus 0.57+/-0.08 mm2, P=.004, at 2 weeks; 0.33+/-0.05 versus 0.54+/-0.07 mm2, P=.03, at 4 weeks). SMC proliferative activity was significantly lower in ethanol-treated arteries than in untreated arteries at 4 and 8 days after injury by BrdU and PCNA staining.

CONCLUSIONS

Local delivery of 15% ethanol solution to pig coronary arteries significantly decreased the SMC proliferative activity and neointimal formation induced by balloon dilation injury.

Insulin-like growth factor I expression alters acute sensitivity and tolerance to ethanol in transgenic mice

We compared some biobehavioral effects of ethanol in transgenic mice that overexpress insulin-like growth factor I (IGF-I) in brain and in those that exhibit ectopic: brain expression of IGF binding protein I with those in non-transgenic littermate controls. Ethanol-induced sleep in IGF-I transgenic mice was significantly shorter, and in IGF binding protein 1 transgenic mice significantly longer, than in controls. A similar tendency, though not significant, was observed for ethanol-induced hypothermia. The groups did not differ in the degree of ethanol-induced ataxia. IGF-I transgenic mice did not acquire tolerance to either the hypothermic or hypnotic effects of ethanol following 7-day ethanol treatment. In contrast, tolerance in IGF binding protein 1 transgenic mice was significantly more pronounced than in controls. There were no significant differences among the three groups in the peak blood alcohol concentrations or the overall blood alcohol curves following acute ethanol challenge. In general, these data support the prediction made that chronically elevated exposure to IGF-I in IGF-I transgenic mice renders them less susceptible to the effects of ethanol than their non-transgenic siblings, and that overexpression of IGF binding protein 1 has the opposite effect.

Ethanol inhibits human osteoblastic cell proliferation

The habitual consumption of alcoholic beverages is clearly associated with low bone mass and an increased prevalence of skeletal fractures. Microscopic analysis of skeletal tissue from alcoholic patients reveals reduced osteoblast number and suppressed bone formation activity with a relative sparing of resorptive indices. The decreased number of osteoblasts observed in alcoholic subjects results from either impaired proliferation or accelerated senescence. Polyamines and ornithine decarboxylase (ODC), the rate-limiting enzyme for polyamine synthesis, are essential for cell proliferation in a variety of cell types. To determine if the adverse effect of ethanol on osteoblast number involves modulation of polyamine biosynthesis, we examined the effect of ethanol on parameters of cell growth and ODC activity in a human osteoblast-like osteosarcoma cell line (TE-85). Ethanol markedly impaired DNA synthesis and cell proliferation in a dose-dependent fashion, but alkaline phosphatase activity (a marker of differentiated osteoblast function) remained intact, and accelerated apoptosis was not evident. Thus, the reduced osteoblastic cell number was a result of a direct effect on proliferative processes rather than a nonspecific toxic effect of ethanol to accelerate cell death. Induction of ODC activity was impaired in ethanol-exposed cell cultures in a dose-dependent fashion that paralleled the antiproliferative effects. Finally, supplemental polyamine administration substantially improved DNA synthesis in ethanol-exposed UMR 106-01 cell cultures. These data confirm a direct inhibitory effect of ethanol on osteoblast proliferation without overt cellular toxicity that may, in part, explain the reduced bone mass observed in those who consume excessive amounts of alcohol.

Alcohol and white matter development--a review

This is a review of the literature on the effects of alcohol on white matter development. For many years, human and animal studies have reported the vulnerability of developing white matter to the effects of alcohol. However, until recently, studies on alcohol and white matter were limited by existing technology. New technology documenting the presence of neurotransmitter receptors and ion channels on glial cells now provides a new focus for research on alcohol and white matter development. New research using new technology should enlarge our knowledge of the role of glial cells in brain damage associated with alcohol exposure during development.

Volumetric magnetic resonance imaging quantification of longitudinal brain changes in abstinent alcoholics

Magnetic resonance imaging (MRI) of the brain was performed on a group of 24 recently detoxified, male alcoholics approximately 1 month after their date of last drink. The imaging was repeated 3 months later, at which point 9 subjects had resumed drinking and 15 had maintained abstinence. Contrasts between these two drinking groups revealed that, despite comparable baseline values, the Abstainers exhibited volumetric white matter increases and cerebrospinal fluid reductions over the follow-up interval, whereas the Drinkers did not show significant change on either of these MRI indices. These results provide the first evidence suggestive of significant volumetric white matter increase with abstinence.

Cytoplasmic changes in primary cultured adult mouse sensory neurons induced by ethanol and acetaldehyde treatments

Primary cultured sensory neurons prepared from adult mice were maintained for 8 days in vitro. Such cultures were exposed to either a range of ethanol concentrations (50-300 mM) or acetaldehyde (0.5-2 mM) in serum-free medium for up to 24 h. Treated neuronal cultures, together with untreated controls in both the presence and absence of serum, were prepared for transmission electron microscopy. Nuclear morphology was not changed following treatment with either substance at the doses studied. A number of changes were observed, however, in the cytoplasm of neurons, and these were intensified by an increase in concentration and the length of exposure. Acetaldehyde induced effects at a much lower concentration than was required to induce a response with ethanol. Myelin lamellae loosely wound around dense granular core material appeared in multivesicular bodies at low doses. The prevalence of these increased with concentrations of 100 mM ethanol and 1 mM acetaldehyde; the numbers of lamellae in each myelin figure also increased but the core material was less prominent. Electron-dense bodies were also evident at higher dosages together with evidence of vacuolation of the endoplasmic reticulum and Golgi complexes. Mitochondrial profiles similar to those in untreated neurons persisted throughout the exposure periods. The generation of these inclusions may reflect a mechanism of membrane turnover, both of internal systems and cell membrane cycling, as a response to alcohol and aldehyde treatment.

Effects of Guillain-Barré sera containing antibodies against glycolipids in cultures of rat Schwann cells and sensory neurons

Serum samples from 52 patients with the acute Guillain-Barré syndrome (GBS), 19 patients with other neurological disorders, and 18 healthy volunteers were tested for cytotoxicity in cultures of rat Schwann cells and dorsal root ganglion neurons. The samples were also examined by enzyme-linked immunosorbent assay for IgG and IgM antibodies against various acidic and neutral glycolipids. Samples from 16 of the 52 (31%) acute GBS patients and from 1 of the 6 patients with chronic inflammatory demyelinating polyneuropathy produced myelin breakdown in culture. Although 10 of the 16 cytotoxic acute GBS serum samples contained anti-glycolipid immunoglobulins, there was no correlation in individual samples between cytotoxic activity and the presence of antibodies against specific glycolipids. While our results do not exclude a role for anti-glycolipid antibodies in the pathogenesis of the acute GBS, the cytotoxic effects of acute GBS serum in cultures of Schwann cells and sensory neurons are probably not due to these antibodies alone.

Human alpha tumor necrosis factor does not damage cultures containing rat Schwann cells and sensory neurons

The effects of recombinant human alpha tumor necrosis factor (alpha-TNF) were compared with those of cytotoxic serum from patients with the acute Guillain-Barré syndrome (GBS) in myelinated cultures containing only rat Schwann cells and dorsal root ganglion neurons. Alpha-TNF did not damage rat peripheral nervous system tissue in culture. These observations suggest that alpha-TNF is not responsible for the cytotoxic activity of acute GBS serum in culture.