Abnormal smooth-muscle contractility may be a major cause of disease states such as hypertension, and a smooth-muscle relaxant that modulates this process would be useful therapeutically. Smooth-muscle contraction is regulated by the cytosolic Ca2+ concentration and by the Ca2+ sensitivity of myofilaments: the former activates myosin light-chain kinase and the latter is achieved partly by inhibition of myosin phosphatase. The small GTPase Rho and its target, Rho-associated kinase, participate in this latter mechanism in vitro, but their participation has not been demonstrated in intact muscles. Here we show that a pyridine derivative, Y-27632, selectively inhibits smooth-muscle contraction by inhibiting Ca2+ sensitization. We identified the Y-27632 target as a Rho-associated protein kinase, p160ROCK. Y-27632 consistently suppresses Rho-induced, p160ROCK-mediated formation of stress fibres in cultured cells and dramatically corrects hypertension in several hypertensive rat models. Our findings indicate that p160ROCK-mediated Ca2+ sensitization is involved in the pathophysiology of hypertension and suggest that compounds that inhibit this process might be useful therapeutically.

Schizophrenia is a debilitating psychiatric disease with a strong genetic contribution, potentially linked to altered glutamatergic function in brain regions such as the prefrontal cortex (PFC). Here, we report converging evidence to support a functional candidate gene for schizophrenia. In post-mortem PFC from patients with schizophrenia, we detected decreased expression of MKK7/MAP2K7-a kinase activated by glutamatergic activity. While mice lacking one copy of the Map2k7 gene were overtly normal in a variety of behavioural tests, these mice showed a schizophrenia-like cognitive phenotype of impaired working memory. Additional support for MAP2K7 as a candidate gene came from a genetic association study. A substantial effect size (odds ratios: ~1.9) was observed for a common variant in a cohort of case and control samples collected in the Glasgow area and also in a replication cohort of samples of Northern European descent (most significant P-value: 3 × 10(-4)). While some caution is warranted until these association data are further replicated, these results are the first to implicate the candidate gene MAP2K7 in genetic risk for schizophrenia. Complete sequencing of all MAP2K7 exons did not reveal any non-synonymous mutations. However, the MAP2K7 haplotype appeared to have functional effects, in that it influenced the level of expression of MAP2K7 mRNA in human PFC. Taken together, the results imply that reduced function of the MAP2K7-c-Jun N-terminal kinase (JNK) signalling cascade may underlie some of the neurochemical changes and core symptoms in schizophrenia.

Biological substances with neurotrophic activities, such as nerve growth factor (NGF) and monosialoganglioside GM1, have been considered as agents for diabetic peripheral neuropathy. Because recent studies have suggested that decreased availability of these substances might contribute to the pathogenesis of diabetic peripheral neuropathy, some clinical trials of NGF for diabetic peripheral neuropathy have been conducted and have led to mixed conclusions. The major reasons were its limited delivery to the nervous system and adverse effects induced by subcutaneous injection, which was necessary because NGF is a polypeptide. The current study investigates whether an orally active sialic acid derivative, MCC-257, has neuroprotective properties in diabetic peripheral nerves. MCC-257 augmented NGF activity in cultured dorsal root ganglia and PC12 (pheochromocytoma 12) cells. Treatment with MCC-257 elevated NGF levels in the sciatic nerve, accompanied by improvement in nerve conduction velocity in strepotozotocin-induced diabetic animals. More importantly, MCC-257 ameliorated small fiber dysfunctions, including thermal hypoalgesia, substance P content, and histopthological innervation in the plantar skin of diabetic animals. Thus, the orally active neurotrophin enhancer provides a new option for the clinical treatment of diabetic peripheral neuropathy. Diabetes 55:616 -621, 2006

Communications to the Editor Design, Synthesis, and Antineoplastic Activity of 2/-Deoxy-2'-methylidenecytidine1Sir:l-/3-D-Arabinofuranosylcytosine (ara-C, la) is one of the most potent drugs for the treatment of acute human leukemia.2 However, ara-C has several drawbacks; its half-life is very short because of deamination to chemotherapeutically inactive l-d-D-arabinofuranosyluracil by cytidine deaminase, and it is not effective against solid tumors. In