Interleukin-1beta causes a biphasic response in neurons of rat major pelvic ganglia

Allergic Conjunctivitis-induced Retinal Inflammation Promotes Myopia Progression

Myopia is a highly prevalent eye disease. There is limited information suggesting a relationship between myopia and inflammation. We found children with allergic conjunctivitis (AC) had the highest adjusted odds ratio (1.75, 95% confidence interval [CI], 1.72-1.77) for myopia among the four allergic diseases. A cohort study was conducted and confirmed that children with AC had a higher incidence and subsequent risk of myopia (hazard ratio 2.35, 95%CI 2.29-2.40) compared to those without AC. Lower refractive error and longer axial length were observed in an AC animal model. Myopia progression was enhanced by tumor necrosis factor (TNF)-α or interleukin (IL)-6 administration, two cytokines secreted by mast cell degranulation. The TNF-α or IL-6 weakened the tight junction formed by corneal epithelial (CEP) cells and inflammatory cytokines across the layer of CEP cells, which increased the levels of TNF-α, IL-6, and IL-8 secreted by retinal pigment epithelial cells. The expression levels of TNF-α, IL-6, IL-8, monocyte chemoattractant protein-1, and nuclear factor kappa B were up-regulated in eyes with AC, whereas IL-10 and the inhibitor of kappa B were down-regulated. In conclusion, the experimental findings in mice corroborate the epidemiological data showing that allergic inflammation influences the development of myopia.

Hydrochloric acid induced changes in macrophage migration inhibitory factor in the bladder, peripheral and central nervous system of the rat

PURPOSE

We established the presence of the proinflammatory cytokine macrophage migration inhibitory factor (MIF) in the bladder and in nervous system structures innervating the bladder, and evaluated changes in MIF and cyclooxygenase-2 (COX-2) protein levels and expression following chemical cystitis.

MATERIALS AND METHODS

Male Sprague-Dawley rats were anesthetized and a catheter was introduced into the bladder dome. Cystitis was induced by infusing 0.4 N HCl into the bladder. Control rats received a similar volume of saline. Two hours later the bladder, major pelvic ganglia (MPG), L6/S1 dorsal root ganglia (DRG) and L6/S1 spinal cord were removed and assayed for MIF and COX-2 protein, and mRNA using Western blot and quantitative reverse transcriptase-polymerase chain reaction techniques.

RESULTS

Immunohistochemistry showed MIF located mainly in the urothelium of saline treated rats. Instillation of HCl into the bladder resulted in marked epithelial denudation, moderate edema and vasodilatation in the submucosa. MIF protein levels decreased but MIF mRNA expression remained unchanged in bladders treated with HCl compared with controls. However, MIF protein and mRNA levels increased in the MPG, L6/S1 DRG and L6/S1 spinal cord of HCl treated animals. COX-2 protein was not detected in the bladder, DRG or MPG of saline-treated rats. However, a small amount was present in the L6/S1 cord. On the other hand, HCl treated rats showed marked increases in COX-2 protein levels in all tissues examined. Similarly although cox-2 mRNA was constitutively expressed in all tissues examined, expression increased following HCl treatment.

CONCLUSIONS

Chemical cystitis induced by intravesical HCl in rats increases the protein levels and mRNA expression of MIF and COX-2 in central and peripheral nervous system tissues that are involved in innervating the bladder. This finding suggests that MIF may be involved in bladder inflammation and may have a role in the peripheral and central nervous system pathways that regulate bladder reflexes in response to bladder inflammation.

Electrical behaviour of interleukin-1 beta (IL-1 beta) and prostaglandin-E2 (PGE2) on colonic myenteric neurones

Abstract Intracellular recordings were used to examine the effects on electrical and synaptic behaviour of interleukin (IL)-1beta and prostaglandin E2(PGE2) on myenteric neurones of the guinea-pig colon. Application of IL-1beta and PGE2resulted in a concentration-dependent slow depolarization with enhanced spike discharge in, respectively, 45% (21/47) and 83% (33/41) of the impaled colonic neurones. Administration of IL-1beta in three neurones (6%) elicited a hyperpolarization. Responses remained during tetrodotoxin application, indicative of a direct effect of both substances on the impaled neurones. The effects of IL-1beta remained in the presence of indomethacine, a prostaglandin synthase inhibitor. Responses were seen in both nitric oxide synthase- and choline acetyl transferase-immunoreactive neurones. IL-1beta evoked a 26% reduction of the fast excitatory postsynaptic potential. These results indicate that the application of IL-1beta and PGE2evoke direct excitatory actions on a subset of myenteric neurones. For IL-1beta, direct inhibition and presynaptic inhibition of the fast excitatory postsynaptic potential has also been found. In the distal colon, responses to IL-1beta are not mediated through PGE2pathways.