Plos One
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The etiology of chronic prostatitis/chronic pelvic pain syndrome in men is unknown but may involve microbes and autoimmune mechanisms. We developed an infection model of chronic pelvic pain in NOD/ShiLtJ (NOD) mice with a clinical Escherichia coli isolate (CP-1) from a patient with chronic pelvic pain. We investigated pain mechanisms in NOD mice and compared it to C57BL/6 (B6) mice, a strain resistant to CP-1-induced pain. ⋯ Adoptive transfer of ex-vivo expanded IFN-γ or IL-17A-expressing cells was sufficient to induce pelvic pain in naïve NOD recipients. Pelvic pain was not abolished in NOD-IFN-γ-KO mice but was associated with an enhanced IL-17A immune response to CP1 infection. These findings demonstrate a novel role for Th1 and Th17-mediated adaptive immune mechanisms in chronic pelvic pain.
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Striatal transplantation of dopaminergic (DA) neurons or neural stem cells (NSCs) has been reported to improve the symptoms of Parkinson's disease (PD), but the low rate of cell survival, differentiation, and integration in the host brain limits the therapeutic efficacy. We investigated the therapeutic effects of intracranial co-transplantation of mesencephalic NSCs stably overexpressing human glial-derived neurotrophic factor (GDNF-mNSCs) together with fetal DA neurons in the 6-OHDA rat model of PD. ⋯ In addition, survival and differentiation of mNSCs into DA neurons was significantly greater following co-transplantation of GDNF-mNSCs plus fetal DA neurons compared to the other treatment groups as indicated by the greater number of cell expressing both the mNSCs lineage tracer enhanced green fluorescent protein (eGFP) and the DA neuron marker tyrosine hydroxylase. The success of cell-based therapies for PD may be greatly improved by co-transplantation of fetal DA neurons with mNSCs genetically modified to overexpress trophic factors such as GDNF that support differentiation into DA cells and their survival in vivo.
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This study investigated the reversible effects of pulsed radiofrequency (PRF) treatment at 42 °C on the ultrastructural and biological changes in nerve and collagen fibers in the progression of neuropathic pain after rat sciatic nerve injury. Assessments of morphological changes in the extracellular matrices by atomic force microscopy and hematoxylin-eosin, Masson's trichrome and picrosirius-red staining as well as the expressions of two fibril-forming collagens, types-I and -III, and two inflammatory cytokines, TNF-α and IL-6, were evaluated on day 30 after RF exposure. There were four groups for different RF thermal treatments: no treatment, no current, PRF, and continuous RF (CRF). ⋯ The PRF treatment led to excellent performance and high expandability compared to CRF, with effects including slight damage and swelling of myelinated axons, a slightly decreased amount of collagen fibers, swelling of collagen fibril diameters, decreased immunoreactivity of collagen types-I and -III, presence of newly synthesized collagen, and recovery of inflammatory protein immunoreactivity. These evidence-based findings suggest that PRF-based pain relief is responsible for the temporary blockage of nerve signals as well as the preferential destruction of pain-related principal sensory fibers like the Aδ and C fibers. This suggestion can be supported by the interaction between the PRF-induced electromagnetic field and cell membranes; therefore, PRF treatment provides pain relief while allowing retention of some tactile sensation.
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Recent evidence suggests that transient receptor potential melastatin 2 (TRPM2) expressed in immune cells plays an important role in immune and inflammatory responses. We recently reported that TRPM2 expressed in macrophages and spinal microglia contributes to the pathogenesis of inflammatory and neuropathic pain aggravating peripheral and central pronociceptive inflammatory responses in mice. To further elucidate the contribution of TRPM2 expressed by peripheral immune cells to neuropathic pain, we examined the development of peripheral nerve injury-induced neuropathic pain and the infiltration of immune cells (particularly macrophages) into the injured nerve and spinal cord by using bone marrow (BM) chimeric mice by crossing wildtype (WT) and TRPM2-knockout (TRPM2-KO) mice. ⋯ However, the numbers of GFP(-)/Iba1(+) resident microglia did not differ among chimeric mice. These results suggest that TRPM2 plays an important role in the infiltration of peripheral immune cells, particularly macrophages, into the spinal cord, rather than the infiltration of peripheral immune cells into the injured nerves and activation of spinal-resident microglia. The spinal infiltration of macrophages mediated by TRPM2 may contribute to the pathogenesis of neuropathic pain.
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Some hereditary diseases, such as retinitis pigmentosa, lead to blindness due to the death of photoreceptors, though the rest of the visual system might be only slightly affected. Optogenetics is a promising tool for restoring vision after retinal degeneration. In optogenetics, light-sensitive ion channels ("channelrhodopsins") are expressed in neurons so that the neurons can be activated by light. ⋯ We pay particular attention to the operational brightness range and suggest strategies that would allow optogenetic vision over a wider intensity range than currently possible, spanning the brightest 5 orders of naturally occurring luminance. We also discuss the biophysical limitations of channelrhodopsin, and of the expressing cells, that prevent further expansion of this operational range, and we suggest design strategies for optogenetic tools which might help overcoming these limitations. Furthermore, the computational model used for this study is provided as an interactive tool for the research community.