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Sleep apnea syndrome (SAS) exposes cells throughout the body to intermittent hypoxia (IH). Intermittent hypoxia is a risk factor not only for hypertension and insulin resistance but also for vascular dysfunction. We have reported correlations between IH, insulin resistance and hypertension. However, the details of why IH leads to vascular dysfunction remain unclear. In this study, we investigated inflammation‐related transcripts in vascular endothelial cells (human HUEhT‐1 and mouse UV2) exposed to IH by real‐time RT‐PCR and found that intercellular adhesion molecule‐1 (ICAM‐1) and endothelial cell‐specific molecule‐1 (ESM1) mRNAs were significantly increased. ELISA confirmed that, in the UV2 cell medium, ICAM‐1 and ESM1 were significantly increased by IH. However, the promoter activities of ICAM‐1 and ESM1 were not upregulated. On the other hand, IH treatment significantly decreased microRNA (miR)‐181a1 in IH‐treated cells. The introduction of miR‐181a1 mimic but not miR‐181a1 mimic NC abolished the IH‐induced upregulation of Ican‐1 and ESM1. These results indicated that ICAM‐1 and ESM1 were upregulated by IH via the IH‐induced downregulation of miR‐181a1 in vascular endothelial cells and suggested that SAS patients developed atherosclerosis via the IH‐induced upregulation of ICAM‐1 and ESM1. [ABSTRACT FROM AUTHOR]

We have recently reported that Pdx1-Cre-mediated whole pancreas inactivation of IGF-1 gene [in pancreatic-specific IGF-I gene-deficient (PID) mice] results in increased [beta]-cell mass and significant protection against both type 1 and type 2 diabetes. Because the phenotype is unlikely a direct consequence of IGF-I deficiency, the present study was designed to explore possible activation of proislet factors in PID mice by using a whole genome DNA microarray. As a result, multiple members of the Reg family genes (Reg2, -3[alpha], and -3[beta], previously not known to promote islet cell growth) were significantly upregulated in the pancreas. This finding was subsequently confirmed by Northern blot and/or real-time PCR, which exhibited 2- to 8-fold increases in the levels of these mRNAs. Interestingly, these Reg family genes were also activated after streptozotocin-induced [beta]-cell damage and diabetes (wild-type T1D mice) when islet cells were undergoing regeneration. Immunohistochemistry revealed increased Reg proteins in exocrine as well as endocrine pancreas and suggested their potential role in [beta]-cell neogenesis in PID or T1D mice. Previously, other Reg proteins (Reg1 and islet neogenesis-associated protein) have been shown to promote islet cell replication and neogenesis. These uncharacterized Reg proteins may play a similar but more potent role, not only in normal islet cell growth in PID mice, but also in islet cell regeneration after T1D. pancreatic islets: DNA microarray; gene-targeted mice: insulin-like growth factor I

Recently, the regenerating gene (Reg) has been documented to play an important role in various regenerating tissues, but it is unknown whether the Reg gene could be activated in the heart. The aim of this study was to reveal the transcriptional activation of Reg in the heart in response to heart stress. We first found REG-1 protein expression in human hearts obtained from autopsied patients who died of myocardial infarction. REG protein was immunohistochemically stained in a fine granular pattern in the cytoplasm of cardiomyocytes. To demonstrate the activation profiles of Reg gene expression in the heart, we quantified the levels of Reg-1 mRNA in rat hearts after coronary artery ligation using real-time RT-PCR. Transient Reg-1 mRNA activation, peaking at 12 h after coronary ligation, was observed mainly in the atria, which was sevenfold higher compared with hearts with pressure overload due to aortic constriction. In contrast, Reg receptor mRNA was expressed intensely in damaged ventricles. Furthermore, Western blot analysis showed the corresponding pattern of Reg protein secretion into the serum after loading, and circulating levels of the protein after myocardial infarction were higher than those after aortic constriction. In conclusion, our results demonstrate for the first time the presence of the Reg/Reg receptor system in damaged hearts. In view of emerging evidence of Reg for tissue regeneration in a variety of tissues/organs, it is proposed that the damaged heart may be a target for Reg action and that Reg may protect against acute heart stress. receptor; heart failure; myocardial infarction; pressure overload

Cyclic ADP-ribose (cADPR), a putative [Ca.sup.2+]-mobilizing second messenger, has been reported to operate in several mammalian cells. To investigate whether cADPR is involved in electrolyte secretion from airway glands, we used a patch-clamp technique, the measurement of microsomal [Ca.sup.2+] release, quantification of cellular cADPR, and RT-PCR for CD38 mRNA in human and feline tracheal glands, cADPR (>6 [micro]M), infused into the cell via the patch pipette, caused ionic currents dependent on cellular [Ca.sup.2+]. Infusions of lower concentrations (2-4 [micro]M) of cADPR or inositol 1,4,5-trisphosphate ([IP.sub.3]) alone were without effect on the baseline current, but a combined application of cADPR and [IP.sub.3] mimicked the cellular response to low concentrations of acetylcfioline (ACh). Microsomes derived from the isolated glands released [Ca.sup.2+] in response to both [IP.sub.3] and cADPR, cADPR released [Ca.sup.2+] from microsomes desensitized to [IP.sub.3] or those treated with heparin. The mRNA for CD38, an enzyme protein involved in cADPR metabolism, was detected in human tissues, including tracheal glands, and the cellular content of cADPR was increased with physiologically relevant concentrations of ACh. We conclude that cADPR, in concert with [IP.sub.3], operates in airway gland acinar cells to mobilize [Ca.sup.2+], resulting in [Cl.sup.-] secretion. patch clamp; CD38; calcium store; inositol 1,4,5-trisphosphate; calcium; acetylcholine