CXCL10-CXCR3 signaling appears to be a critical factor for the exacerbation of the pathology of ARDS. Thus, the CXCL10-CXCR3 axis could represent a prime therapeutic target in the treatment of the acute phase of ARDS of nonviral and viral origins.

Superoxide excess plays a central role in tissue damage that results from diabetes, but the mechanisms of superoxide overproduction in diabetic nephropathy (DN) are incompletely understood. In the present study, we investigated the enzyme superoxide dismutase (SOD), a major defender against superoxide, in the kidneys during the development of murine DN. We assessed SOD activity and the expression of SOD isoforms in the kidneys of two diabetic mouse models (C57BL/6-Akita and KK/Ta-Akita) that exhibit comparable levels of hyperglycemia but different susceptibility to DN. We observed down-regulation of cytosolic CuZn-SOD (SOD1) and extracellular CuZn-SOD (SOD3), but not mitochondrial Mn-SOD (SOD2), in the kidney of KK/Ta-Akita mice which exhibit progressive DN. In contrast, we did not detect a change in renal SOD expression in DN-resistant C57BL/6-Akita mice. Consistent with these findings, there was a significant reduction in total SOD activity in the kidney of KK/Ta-Akita mice compared with C57BL/6-Akita mice. Finally, treatment of KK/Ta-Akita mice with a SOD mimetic, tempol, ameliorated the nephropathic changes in KK/Ta-Akita mice without altering the level of hyperglycemia. Collectively, these results indicate that down-regulation of renal SOD1 and SOD3 may play a key role in the pathogenesis of DN. Diabetic nephropathy (DN) is the leading cause of end-stage renal disease. Although hyperglycemia is clearly a prerequisite for the development of DN, alone it is insufficient for its development. Epidemiologic studies demonstrate only 10% to 40% of all diabetic patients get DN, despite comparable levels of glucose control in those subjects developing DN versus spared. In addition, sibling studies show a strong familial component for the risk of developing persistent proteinuria, suggesting a genetic basis for DN risk. 1,2 However, the molecular or cellular mechanisms coupled with the genetic susceptibility to DN are incompletely understood.There is compelling evidence that superoxide excess induced by diabetic hyperglycemia plays a central role in diabetic vascular cell damage. 3 High glucose flux increases the production of superoxide anion (O 2•Ϫ ) by mitochondrial electron-transport chain, and the overproduced superoxide enhances the major pathways of hyperglycemic vascular cell

Phosphorylated derivatives of phosphatidylinositol, collectively referred to as phosphoinositides, occur in the cytoplasmic leaflet of cellular membranes and regulate activities such as vesicle transport, cytoskeletal reorganization and signal transduction. Recent studies have indicated an important role for phosphoinositide metabolism in the aetiology of diseases such as cancer, diabetes, myopathy and inflammation. Although the biological functions of the phosphatases that regulate phosphatidylinositol-3,4,5-trisphosphate (PtdIns(3,4,5)P(3)) have been well characterized, little is known about the functions of the phosphatases regulating the closely related molecule phosphatidylinositol-3,4-bisphosphate (PtdIns(3,4)P(2)). Here we show that inositol polyphosphate phosphatase 4A (INPP4A), a PtdIns(3,4)P(2) phosphatase, is a suppressor of glutamate excitotoxicity in the central nervous system. Targeted disruption of the Inpp4a gene in mice leads to neurodegeneration in the striatum, the input nucleus of the basal ganglia that has a central role in motor and cognitive behaviours. Notably, Inpp4a(-/-) mice show severe involuntary movement disorders. In vitro, Inpp4a gene silencing via short hairpin RNA renders cultured primary striatal neurons vulnerable to cell death mediated by N-methyl-d-aspartate-type glutamate receptors (NMDARs). Mechanistically, INPP4A is found at the postsynaptic density and regulates synaptic NMDAR localization and NMDAR-mediated excitatory postsynaptic current. Thus, INPP4A protects neurons from excitotoxic cell death and thereby maintains the functional integrity of the brain. Our study demonstrates that PtdIns(3,4)P(2), PtdIns(3,4,5)P(3) and the phosphatases acting on them can have distinct regulatory roles, and provides insight into the unique aspects and physiological significance of PtdIns(3,4)P(2) metabolism. INPP4A represents, to our knowledge, the first signalling protein with a function in neurons to suppress excitotoxic cell death. The discovery of a direct link between PtdIns(3,4)P(2) metabolism and the regulation of neurodegeneration and involuntary movements may aid the development of new approaches for the treatment of neurodegenerative disorders.

The metabolism of membrane phosphoinositides is critical for a variety of cellular processes. 5)P 2 ] controls multiple steps of the intracellular membrane trafficking system in both yeast and mammalian cells. However, other than in neuronal tissues, little is known about the physiological functions of PtdIns(3,5)P 2 in mammals. Here, we provide genetic evidence that type III phosphatidylinositol phosphate kinase (PIPKIII), which produces PtdIns(3,5)P 2 , is essential for the functions of polarized epithelial cells. PIPKIII-null mouse embryos die by embryonic day 8.5 because of a failure of the visceral endoderm to supply the epiblast with maternal nutrients. Similarly, although intestine-specific PIPKIII-deficient mice are born, they fail to thrive and eventually die of malnutrition. At the mechanistic level, we show that PIPKIII regulates the trafficking of proteins to a cell's apical membrane domain. Importantly, mice with intestine-specific deletion of PIPKIII exhibit diarrhea and bloody stool, and their gut epithelial layers show inflammation and fibrosis, making our mutants an improved model for inflammatory bowel diseases. In summary, our data demonstrate that PIPKIII is required for the structural and functional integrity of two different types of polarized epithelial cells and suggest that PtdIns(3,5)P 2 metabolism is an unexpected and critical link between membrane trafficking in intestinal epithelial cells and the pathogenesis of inflammatory bowel disease.embryogenesis | Crohn's disease

In the process of cancer spreading, different modes of invasion exist. One is expansive invasion, in which a group of cancer cells gradually expands along with cancer cell proliferation. Invasion of cancer cells is also modified by their interaction with stromal cells including cancer-associated fibroblasts (CAFs). Cancer cells co-invade with CAFs, and invasion by CAFs frequently precede invasion by cancer cells, which indicates CAF-led cancer cell invasion. Here, we show that CAFs induce apoptosis in gastric cancer cells, which prevented expansive invasion by cancer cells and instead facilitated CAF-led invasion. Death receptor 4 and activation of caspase-8 in cancer cells mediated cancer cell apoptosis induced by CAFs, which was dependent on contact between cancer cells and CAFs. Apoptotic cancer cells in turn released apoptotic vesicles and stimulated invasion of CAFs. Accordingly, cancer cells followed the migrating CAFs. Treatment with a caspase inhibitor, ZVAD, or forced expression of a death domain fragment in cancer cells prevented cancer cell apoptosis induced by CAFs and increased expansive invasion by cancer cells in extracellular gel invasion assays, while the rate of cancer cell invasion led by CAFs was decreased. Death domain-fragment expression also prevented intramural invasion by gastric cancer cells in the stomach. Because CAF-led invasion is characterized by the movement of individual cancer cells away from the tumour, adequate cancer cell apoptosis may promote cancer dissemination.

Man1, an inner nuclear membrane protein, regulates transforming growth factor ␤ signaling by interacting with receptor-associated Smads. In Man1-deficient (Man1 ⌬/⌬ ) embryos, vascular remodeling is perturbed by misregulation of Smad activity. Here, we show that Man1 ⌬/⌬ embryos exhibit abnormal heart morphogenesis including the looping abnormality. We searched for the molecular basis underlying the heart abnormalities and found that the left side-specific genes responsible for left-right (LR) asymmetry, Nodal, Lefty2, and Pitx2, were expressed bilaterally in the lateral plate mesoderm and that their expression was enhanced significantly in mutants. Notably, Lefty1, a marker for the midline barrier, was maintained in

Natural rubber from Hevea brasiliensis (Hb) is known to have a characteristic network structure, with branch points formed by minor nonrubber components such as proteins and phospholipids that connect the major rubber component, cis‐1,4‐polyisoprene chains. However, the structure of solid rubber from Ficus carica (Fc) is not well known. In this study, we examined the microstructure and protein composition of solid rubber from Fc. Transmission electron microscopy analysis of Fc solid rubber revealed that the nonrubber components formed a nonuniform framework in the rubber matrix, and that many rubber particles were fused together. We determined that ficin, a cysteine endoproteolytic protease, was a major protein in the Fc rubber. It appears that ficin degrades the proteins associated with rubber particles rather than acting as a protein connecting the cis‐1,4‐polyisoprene chains in Fc rubber. We also found that a macrogel fraction, which separated after the dissolution of Hb solid rubber in toluene, was absent in the Fc solid rubber. These results suggest that there are no proteinous branch points in Fc rubber. Furthermore, size exclusion chromatography with multiangle light scattering (SEC‐MALS) analysis of the transesterified rubber demonstrated that no branch points composed of phospholipids were involved in Fc rubber. On the basis of our results, we propose a microstructure for the rubber particles in Fc solid rubber and discuss the relationship between the microstructure and the structure of the rubber chains within it.