Transplanted hematopoietic stem cells from bone marrow differentiate into neural lineage cells and promote functional recovery after spinal cord injury in mice

Recovery in central nervous system disorders is hindered by the limited ability of the vertebrate central nervous system to regenerate lost cells, replace damaged myelin, and re-establish functional neural connections. Cell transplantation to repair central nervous system disorders is an active area of research, with the goal of reducing functional deficits. Recent animal studies showed that cells of the hematopoietic stem cell (HSC) fraction of bone marrow transdifferentiated into various nonhematopoietic cell lineages. We employed a mouse model of spinal cord injury and directly transplanted HSCs into the spinal cord 1 week after injury. We evaluated functional recovery using the hindlimb motor function score weekly for 5 weeks after transplantation. The data demonstrated a significant improvement in the functional outcome of mice transplanted with hematopoietic stem cells compared with control mice in which only medium was injected. Fluorescent in situ hybridization for the Y chromosome and double immunohistochemistry showed that transplanted cells survived 5 weeks after transplantation and expressed specific markers for astrocytes, oligodendrocytes, and neural precursors, but not for neurons. These results suggest that transplantation of HSCs from bone marrow is an effective strategy for the treatment of spinal cord injury.     

Molecular mechanisms for activation of voltage-independent Ca2+ channels by endothelin-1/endothelin-A receptors

Endothelin-1 (ET-1) activates two types of Ca2+- permeable non-selective cation channels (designated NSCC-1 and NSCC-2) and a store-operated Ca2+ channel (SOCC) in Chinese hamster ovary cells expressing endothelin-A receptors (CHOETAR), which couple with Gq, Gs and G12. The purpose of this study was to identify the G proteins involved in the activation of these Ca channels, using mutated ETARs with coupling to either Gq or Gs/G12 (designated ETAR(Delta)385 and SerETAR, respectively) and a dominant negative mutant of G12 (G12G228A). ETAR(Delta)385 is truncated downstream of Cys385 in the C-terminal as palmitoylation sites, whereas SerET(A)R is unpalmitoylated because of substitution of all the cysteine residues to serine (CysCys --> SerSer). ET-1 activated SOCC in CHO-ET(A)R(Delta)385. In CHO-SerET(A)R or CHO-ET(A)R pretreated with U73122, an inhibitor of phospholipase C, ET-1 activated NSCC-1. ET-1 activated SOCC in CHO-ETAR microinjected with G12G228A. Moreover, ET-1 activated NSCC-1 in CHO-ETAR treated with LY 294002, the phosphoinositide 3-kinase inhibitor. These results indicate that NSCC-1 is activated via a G12-dependent pathway, NSCC-2 via Gq/phospholipase C-dependent and G12-dependent pathways, and SOCC via a Gq-phospholipase C-dependent pathway. In addition, NSCC-2 and SOCC are stimulated by ET-1 via a phosphoinositide 3-kinase-dependent cascade, whereas NSCC-1 is stimulated via a phosphoinositide 3-kinase-independent cascade.     

Short and long-term hypotensive effect of timolol-gel and latanoprost instillation in normal-tension glaucoma

PURPOSE: To confirm the predictive value of the results of a 4-week trial of latanoprost alone, timolol-gel alone, or a combination of the two in normal-tension glaucoma (NTG) patients, when compared with the hypotensive response after a 6-month trial using the same combination of eye drops for the same patients. METHODS: One eye each of 45 NTG patients was used in a prospective 4-week trial of latanoprost alone, timolol-gel alone, or a combination of the two. Patients continued using the eye drops for 6 months, according to the results of the trial. The correlation of the results of the 6-moth use and the baseline data, and the baseline data and the results of the 4-week trial were evaluated by the paired-t test. RESULTS: The intraocular pressure(IOP)s of patients using timolol-gel alone were 13.9 mmHg at the base line, 9.7 mmHg after the trial, and 12.0 mmHg after 6-month use(baseline, trial: p < 0.05). IOPs when using latanoprost alone were 15.3 mmHg at baseline, 11.7 mmHg after the trial, and 11.5 mmHg after 6-month use(baseline: p < 0.05, trial: p = 0.33). IOPs using timolol-gel and latanoprost in combination were 14.8 mmHg at baseline, 11.4 mmHg after the trial, and 12.0 mmHg after 6-month use (baseline: p < 0:05, trial: p = 0.14). CONCLUSION: The result of the 4-weeks trial of latanoprost alone or in combination with timolol-gel can be indicative of the IOP after 6-month use.     

Effect of various anti-glaucoma eyedrops on human corneal epithelial cells

PURPOSE: To investigate the effects of antiglaucoma eyedrops and vehicles on the proliferation of human corneal epithelial cells. MATERIAL AND METHODS: Seven eyedrops[prostaglandin F2 alpha analogs(2), beta blockers(40), topical carbonic anhydrase inhibitor(1)], and six of the eyedrop vehicles, excluding that of Xalatan, were used. Anti-glaucoma eyedrops and vehicles were serially diluted 2-fold with culture medium(10-2,560 fold). The mixture was added to human corneal epithelial cells and incubated for 48 hrs. Cell proliferation was measured by commercial assay kit. Dye-reagents were added to the wells and incubated for 1 h at 37 degrees C. Optical density were measured at 490 nm. The dilution rate for 50% inhibition was calculated as the dilution rate of drugs or vehicles necessary to produce 50% inhibition of cell proliferation. RESULT: All drugs completely inhibited cell proliferation when the dilution rate was low. At 40-fold dilution, Trusopt and Timoptol showed a significant decrease in cell growth inhibition. On the other hand, Rescula showed almost 100% inhibition at 160-fold dilution. Above 640-fold dilution, the inhibition rate of all drugs became 50% or less and there was no significant difference between drugs. Vehicles also inhibited cell growth. The dilution rates for growth inhibition by vehicles were different from those of drugs. The dilution rate at 50% inhibition of anti-glaucoma eyedrops decreased in the following order: Rescula > Xalatan > Betoptic > Hypadil > Mikelan > Timoptol > Trusopt. The dilution rate for 50% inhibition of vehicles decreased in the following order: Rescula vehicle > Hypadil vehicle > Betoptic vehicle > Mikelan vehicle > Timoptol vehicle > Trusopt vehicle. CONCLUSION: All anti-glaucoma eyedrops inhibited cell proliferation. These effects were stronger in prostaglandin F2 alpha analogs and weakest in Trusopt. Furthermore, the inhibition of cell proliferation was caused also by the vehicle of eyedrops, and the influence of the vehicle varied in each type of eyedrops.     

Survey in to the Prevalence of Hearing Loss in Patients Diagnosed with Retinitis Pigmentosa

Sensorineural hearing loss is the most common disease associated with systemic retinitis pigmentosa (RP). We have conducted an epidemiological study to assess the correlation of age at onset of visual symptoms and hearing loss associated with RP. Epidemiological data was derived from a questionnaire-based study of patients who are registered members of the Japanese Retinitis Pigmentosa Society (n = 3200). The questionnaire was mailed to these patients in 2002, and information was requested regarding age at onset of visual disturbance, awareness of hearing loss and the presence of progressive hearing loss, age at onset of hearing loss, awareness of tinnitus, and history of audiometric examination and hearing aid usage. 26.1% of the questionnaires were returned, and data for 828 patients with RP diagnosed by an ophthalmologist were evaluated. Cochlear symptoms were reported by 356 patients (43.0% of the total population), with hearing loss in 29.5%, tinnitus in 31.5% and hearing loss and tinnitus in 39.3% of the 356 patients. Of these 356 patients, progressive hearing loss was reported by 44.9% and was independent of age at onset of cochlear symptoms. The mean age at onset of visual symptoms was higher for patients with progressive hearing loss, and a significant correlation was found between the age at onset of visual symptoms and hearing loss for patients who were older at onset of the symptoms (>30 years of age). Onset of hearing loss occurs later and hearing loss is also more progressive for patients with late onset of RP. This suggests that particular care regarding hearing loss is necessary for this patient population, and that cooperation between opthalmologists and otologists is required for diagnosis of RP-hearing impairment-associated syndromes in this group of patients.