h-89 and Chronic-Disease

Chronic amphetamine intake leads to neurogenic bladder and chronic urinary retention. The mechanism underlying persistent urinary retention is unclear. The pelvic-urethral reflex (PUR) is essential for the urethra to develop sufficient resistance to maintain urine continence, an important function of the urinary system. Recent studies on PUR activities have indicated that repetitive/tetanic stimulation of the pelvic afferent fibers induces spinal reflex potentiation (SRP) in PUR activities, which further increases urinary retention. In this study, results showed that test stimulation (TS, 1/30 Hz) evoked a baseline reflex activity, while repetitive stimulation (RS, 1 Hz) induced reflex potentiation in the external urethral sphincter. Intrathecal d-amphetamine (AMPH, 30 μM) did not but higher AMPH concentration (100 μM) induced SRP in TS-induced reflex activity. H89 (10 μM, a protein kinase A inhibitor), but not chelerythrine chloride (CTC, 10 μM, a protein kinase C inhibitor), prevented the 100 μM AMPH-elicited SRP. At 30 μM, forskolin, an activator of adenylyl cyclase, elicited SRP. The co-administration of 10 μM forskolin and 30 μM AMPH induced SRP in TS-induced reflex activity. These results implied that the repetitive/tetanic stimulation of the pelvic afferent fibers could induce SRP in PUR activities, so that the urethra can produce sufficient resistance and played a significant role in urinary retention. Findings in this study demonstrated that amphetamine could induce bladder dysfunction by triggering protein kinase A activation, and provide a practical basis for the development of treatment for amphetamine-associated urinary retention.

Topics: 6-Cyano-7-nitroquinoxaline-2,3-dione; Afferent Pathways; Amidines; Amphetamine-Related Disorders; Animals; Benzophenanthridines; Central Nervous System Stimulants; Chronic Disease; Colforsin; Dextroamphetamine; Excitatory Amino Acid Agonists; Female; Glutamic Acid; Isoquinolines; N-Methylaspartate; Oxidants; Protein Kinase Inhibitors; Rats, Wistar; Reflex; Spinal Cord; Sulfonamides; Urinary Retention; Urination; Valine

The antipsoriatic dimethylfumarate (DMF) has been anecdotically reported to reduce asthma symptoms and to improve quality of life of asthma patients. DMF decreases the expression of proinflammatory mediators by inhibiting the transcription factor NF-kappaB and might therefore be of interest for the therapy of inflammatory lung diseases. In this study, we determined the effect of DMF on platelet-derived growth factor (PDGF)-BB- and TNFalpha-induced asthma-relevant cytokines and NF-kappaB activation by primary human asthmatic and nonasthmatic airway smooth muscle cells (ASMC). Confluent nonasthmatic and asthmatic ASMC were incubated with DMF (0.1-100 microM) and/or dexamethasone (0.0001-0.1 microM), NF-kappaB p65 siRNA (100 nM), the NF-kappaB inhibitor helenalin (1 microM) before stimulation with PDGF-BB or TNFalpha (10 ng/ml). Cytokine release was measured by ELISA. NF-kappaB, mitogen and stress-activated kinase (MSK-1), and CREB activation was determined by immunoblotting and EMSA. TNFalpha-induced eotaxin, RANTES, and IL-6 as well as PDGF-BB-induced IL-6 expression was inhibited by DMF and by dexamethasone from asthmatic and nonasthmatic ASMC, but the combination of both drugs showed no glucocorticoid sparing effect in either of the two groups. NF-kappaB p65 siRNA and/or the NF-kappaB inhibitor helenalin reduced PDGF-BB- and TNFalpha-induced cytokine expression, suggesting the involvement of NF-kappaB signaling. DMF inhibited TNFalpha-induced NF-kappaB p65 phosphorylation, NF-kappaB nuclear entry, and NF-kappaB-DNA complex formation, whereas PDGF-BB appeared not to activate NF-kappaB within 60 min. Both stimuli induced the phosphorylation of MSK-1, NF-kappaB p65 at Ser276, and CREB, and all were inhibited by DMF. These data suggest that DMF downregulates cytokine secretion not only by inhibiting NF-kappaB but a wider range of NF-kappaB-linked signaling proteins, which may explain its potential beneficial effect in asthma.

Topics: Anti-Inflammatory Agents, Non-Steroidal; Becaplermin; Bronchi; Cells, Cultured; Chemokine CCL11; Chemokine CCL5; Chronic Disease; Cyclic AMP Response Element-Binding Protein; Cytokines; Dexamethasone; Dimethyl Fumarate; Enzyme Inhibitors; Fumarates; Glucocorticoids; Humans; I-kappa B Proteins; Immunosuppressive Agents; Interleukin-6; Isoquinolines; Myocytes, Smooth Muscle; NF-KappaB Inhibitor alpha; Platelet-Derived Growth Factor; Pneumonia; Proto-Oncogene Proteins c-sis; Ribosomal Protein S6 Kinases, 90-kDa; RNA, Small Interfering; Sesquiterpenes; Sesquiterpenes, Guaiane; Sulfonamides; Transcription Factor RelA; Tumor Necrosis Factor-alpha

The etiology of skeletal growth retardation accompanying metabolic acidosis is not clear. Using ex vivo models for endochondral ossification, we showed that the cAMP/PKA pathway, probably triggered by proton sensitive G-protein-coupled receptors, is responsible for impaired skeletal growth in acidosis.. Chronic metabolic acidosis (CMA) is very often accompanied by skeletal growth retardation. We have previously shown in an ex vivo model of endochondral ossification that murine mandibular condyles subjected to acidic conditions exhibit growth retardation accompanied by a decline of insulin-like growth factor-I (IGF-I) and its receptors. PTH-induced ameliorative effects on the CMA-induced growth retardation of the mandibular condyle are partially mediated by protein kinase C (PKC). In this study we explored the mechanisms underlying the acidosis-induced growth retardation; in particular, the involvement of the cyclic adenosine monophosphate/protein kinase A (cAMP/PKA) cellular pathway in the process.. Mandibular condyles from neonatal mice or mandibular condyle derived chondrocytes (MCDCs) were incubated for 3 days under either control or acidic conditions or in the presence of cAMP-regulating factors (cAMPrf) such as forskolin, iso-butyl methyl xanthine (IBMX), or 8-Br cAMP. The effects on proliferation and differentiation of the cultures as well as on phosphorylation of cAMP responsive element binding protein (CREB) and increased expression of the alpha subunit, Gs were determined. The intracellular pH was detected using the acridine orange assay.. Our results show that, under acidic conditions, PKA levels were increased. H89 abolished the adverse effects of acidosis on condylar development and restored IGF-I and IGF-I receptors (IGF-IR) levels. The inhibitory effects of acidosis on proliferation and differentiation of cartilaginous cells were mimicked by cAMPrf. We have also shown that acidosis stimulates activation of Gs trimeric protein and CREB phosphorylation. GDPbetaS--a Gs antagonist--abolished the acidosis-induced condylar growth arrest. Using an acridine orange assay, we showed that the intracellular environment is not acidified under acidic conditions.. Our results indicate that the adverse effects of acidosis on skeletal growth centers are mediated at least in part by the cAMP/PKA cellular pathway. We speculate that high proton concentrations exerted by acidosis conditions stimulate proton sensitive G-protein-coupled receptors, which are mediated by the cellular cAMP/PKA pathway and induce skeletal growth retardation.

Topics: Acidosis; Animals; Animals, Newborn; Blotting, Western; Cell Division; Chronic Disease; Cyclic AMP Response Element-Binding Protein; Cyclic AMP-Dependent Protein Kinases; Electrophoresis, Polyacrylamide Gel; Enzyme Inhibitors; Growth Disorders; GTP-Binding Protein alpha Subunits, Gs; Immunohistochemistry; In Situ Hybridization; Insulin-Like Growth Factor I; Isoquinolines; Mandible; Mice; Phosphorylation; Protein Kinase C; Protons; Receptor, IGF Type 1; Sulfonamides