This study examined the involvement of store-operated Ca 2+ entry in agonist-stimulation of salivary gland fluid secretion. A recombinant adenovirus (AdCMV-hTrp1) encoding the storeoperated Ca 2+ channel protein, human transient receptor potential 1 (hTrp1), was used to direct expression of HA (hemaglutinin )-tagged hTrp1 in vivo in rat submandibular glands (SMG) and in vitro in the human submandibular gland cell line (HSG). Studies with HSG cells demonstrated that AdCMV-hTrp1 was successful in directing the expression of functional hTrp1 and that it did not affect early Ca 2+ signaling events. AdCMV-hTrp1-infected SMG displayed an increase in the level of Trp1 and a fivefold increase in pilocarpine-stimulated fluid secretion, compared with glands infected with a control adenovirus encoding luciferase (AdCMV-Luc). The expressed hTrp1 demonstrated polarized localization in the basolateral plasma membrane region of SMG acinar cells and was co-immunoprecipitated with IP 3 Rs. Further, acinar cells isolated from AdCMV-hTrp1-infected glands demonstrated a significant increase in carbachol-and Tgstimulated Ca 2+ entry compared with cells isolated from AdCMV-Luc-infected glands. We conclude that in vivo expression of Trp1 in SMG induces an enhancement of agonist-stimulated fluid secretion via increasing store-operated Ca 2+ entry into acinar cells. These data suggest that store-operated Ca 2+ entry has a role in agonist-stimulated fluid secretion from salivary glands.Key words: store-operated calcium influx • calcium channel • fluid secretion • salivary glands • basolateral plasma membrane eurotransmitter stimulation of fluid secretion in salivary glands is suggested to be regulated via an increase in cytosolic [Ca 2+ ] ([Ca 2+ ] i ) (1-5). Lower concentrations of agonists typically induce oscillatory or wavelike elevations in [Ca 2+ ] i that are generated due to Ca 2+ release from, and reuptake into, internal Ca 2+ stores, although sustained [Ca 2+ ] i oscillations display a requirement for external Ca 2+ (3,(6)(7)(8). Higher concentrations of agonists reportedly induce a biphasic increase in [Ca 2+ ] i -an initial rapid, transient increase in [Ca 2+ ] i N followed by a more sustained, although lower, level of [Ca 2+ ] i , which is maintained as long as the cell is stimulated. The first phase of [Ca 2+ ] i elevation is primarily a result of IP 3 -dependent release of Ca 2+ from the internal Ca 2+ store(s) via the IP 3 R. The latter lower, but sustained, [Ca 2+ ] i elevation is primarily due to influx of Ca 2+ into the cytosol from the extracellular medium (1, 2).Studies with dispersed acinar cells, which are the only cells in the salivary gland that secrete water, have demonstrated that agonist-stimulated increases in [Ca 2+ ] i result in the activation of ion channels and ion transporters that are critical to the regulation of fluid secretion; for example, Ca 2+ -dependent K + and Cl -channels, the Na + /K + /2Cl -cotransporter, and aquaporin 5 (2-5, 7-10). Both oscillatory and sustained increases in [Ca 2+ ] i hav...

Objective Hemorrhagic transformation (HT) is a life‐threatening complication of stroke. Whether changes in gut microbial composition underlie the development of HT remains unknown. This study aimed to investigate whether the gut microbiota is altered in HT rats and examine the association between these changes and inflammatory responses. Methods HT was successfully established in rats injected with 50% glucose (6 ml/Kg, i.p.) 15 min before middle cerebral artery occlusion (MCAO, 90 min occlusion) with reperfusion. After 5 days, rats were euthanized, and their brains used to estimate infarct volume. The inflammatory factors, the analysis of gut microbiota, and short‐chain fatty acids (SCFA) were assessed. Results In contrast with non‐HT rats, gut microbiota sequencing showed an elevation in the relative abundance of Proteobacteria and Actinobacteria in HT rats. Total SCFAs, especially butyrate and valeric acid, were significantly lower in the cecal contents of HT rats than in those of non‐HT rats. Hyperglycemia‐induced HT exacerbation was not observed when rats were treated with antibiotics, suggesting that altered microbiota play a critical role in hyperglycemic HT pathogenesis. Furthermore, rats whose gut was colonized with HT rat microbiota showed increased susceptibility to HT. Conclusion This study provides important information about the gut microbiota profiles and SCFA levels of MCAO rats with HT or non‐HT. The susceptibility to HT in MCAO rats is associated with inflammation and gut microbiota modulation.

Nasopharyngeal carcinoma (NPC) has the highest metastasis rate among head and neck cancers with unclear mechanism. WNT5A belongs to the WNT family of cysteine-rich secreted glycoproteins. Our previous high-throughput gene expression profiling revealed that WNT5A was up-regulated in highly metastatic cells. In the present study, we first confirmed the elevated expression of WNT5A in metastatic NPC tissues at both the mRNA and protein levels. We then found that WNT5A promoted epithelial-mesenchymal transition (EMT) in NPC cells, induced the accumulation of CD24-CD44+ cells and side population, which are believed to be cancer stem cell characteristics. Moreover, WNT5A promoted the migration and invasion of NPC cells in vitro, while in vivo treatment with recombinant WNT5A promoted lung metastasis. Knocking down WNT5A diminished NPC tumorigenesis in vivo. When elevated expression of WNT5A coincided with the elevated expression of vimentin in the primary NPC, the patients had a poorer prognosis. Among major signaling pathways, protein kinase C (PKC) signaling was activated by WNT5A in NPC cells. A positive feedback loop between WNT5A and phospho-PKC to promote EMT was also revealed. Taken together, these data suggest that WNT5A is an important molecule in promoting stem cell characteristics in NPC, leading to tumorigenesis and metastasis.

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