Sjögren's syndrome is an extremely complex and currently incurable autoimmune disorder, which occurs primarily in females, and is associated with lacrimal gland inflammation, meibomian gland dysfunction, and severe dry eye. We hypothesize that androgen deficiency, which reportedly occurs in primary and secondary Sjögren's syndrome (e.g., systemic lupus erythematosus, rheumatoid arthritis), is a critical etiologic factor in the pathogenesis of dry eye syndromes. We further hypothesize that androgen treatment to the ocular surface will promote both lacrimal and meibomian gland function and alleviate both "aqueous-deficient" and "evaporative" dry eye. Our results demonstrate that androgens regulate both lacrimal and meibomian gland function, and suggest that topical androgen administration may serve as a safe and effective therapy for the treatment of dry eye in Sjögren's syndrome.

We have identified an agent (SP-303) that shows efficacy against in vivo cholera toxin-induced fluid secretion and in vitro cAMP-mediated Cl−secretion. Administration of cholera toxin to adult mice results in an increase in fluid accumulation (FA) in the small intestine (FA ratio = 0.63 vs. 1.86 in control vs. cholera toxin-treated animals, respectively). This elevation in FA induced by cholera toxin was significantly reduced (FA ratio = 0.70) in animals treated with a 100 mg/kg dose of SP-303 at the same time as the cholera treatment. Moreover, when SP-303 was administered 3 h after cholera toxin, a dose-dependent inhibition of FA levels was observed with a half-maximal inhibitory dose of 10 mg/kg. In Ussing chamber studies of Caco-2 or T84 monolayer preparations, SP-303 had a significant effect on both basal current and forskolin-stimulated Cl− current. SP-303 also induced an increase in resistance that paralleled the observed decrease in current. These data suggest that SP-303 has an inhibitory effect on cAMP-mediated Cl− and fluid secretion. Thus SP-303 may prove to be a useful broad-spectrum antidiarrheal agent.

Objective-HSPA12B is the newest member of HSP70 family of proteins and is enriched in atherosclerotic lesions. This study focused on HSPA12B expression in mice and its involvement in angiogenesis. Methods and Results-The expression of HSPA12B in mice and cultured cells was studied by: (1) Northern blot; (2) in situ hybridization; (3) immunostaining with HSPA12B-specific antibodies; and (4) expressing Enhanced-Green-Fluorescent-Protein under the control of the HSPA12B promoter in mice. The function of HSPA12B was probed by an in vitro angiogenesis assay (Matrigel) and a migration assay. Interacting proteins were identified through a yeast two-hybrid screening. HSPA12B is predominantly expressed in vascular endothelium and induced during angiogenesis.In vitro angiogenesis and migration are inhibited in human umbilical vein endothelial cells in the presence of HSPA12B-neutralizing antibodies. HSPA12B interacts with multiple proteins in yeast 2-hybrid system. Conclusions-We provide the first evidence to our knowledge that the HSPA12B is predominantly expressed in endothelial cells, required for angiogenesis, and interacts with known angiogenesis regulators. We postulate that HSPA12B provides a new mode of angiogenesis regulation and a novel therapeutic target for angiogenesis-related diseases. Key Words: angiogenesis Ⅲ endothelial cells Ⅲ HSPA12B Ⅲ HSP70 family Ⅲ migration B lood vessel development and formation are essential for organ growth and repair, wound healing, and reproduction cycle, and an imbalance of functional vessels contributes to diseases such cancer and ischemia. 1 During development of the vascular system, vasculogenesis refers to the process in which endothelial progenitors differentiate, proliferate, multiply, and migrate to give rise to a primitive vascular network of arteries and veins; angiogenesis refers to the process of blood vessels expansion/remodeling from the existing endothelial cell (EC) network through proliferating, sprouting, pruning, and remodeling. Pericytes and smooth muscle cells are recruited to cover nascent endothelial channels, which provide strength and regulation of vessel perfusion, a process termed arteriogenesis. 2 The formation and maintenance of functional blood vessels is a complex process involving the interplay of multiple genes. These genes include members of many signaling pathways such as vascular endothelial growth factors/ vascular endothelial growth factor receptors, angiopoietin/Tie families, platelet-derived growth factor, transforming growth factor-␤, Notch pathways, certain integrins, neuronal axon guidance molecules such as ephrin, semaphorins, netrins, and robo, transcriptional factors, and many other genes. 3 In adults, many of the embryonic and early pathways are reactivated in situations of neoangiogenesis.Despite great progresses in finding key regulators in angiogenesis, characterizing new genes is still necessary and greatly beneficial for a full understanding of the process. The precise and delicate coordination, combination, and collaboration o...

Increased osteopontin (OPN) expression associates with increased myocyte apoptosis and myocardial dysfunction. The objective of this study was to identify the receptor for OPN and get insight into the mechanism by which OPN induces cardiac myocyte apoptosis. Adult rat ventricular myocytes (ARVMs) and transgenic mice expressing OPN in a myocyte-specific manner were used for in vitro and in vivo studies. Treatment with purified OPN (20 nM) protein or adenoviral-mediated OPN expression induced apoptosis in ARVMs. OPN co-immunoprecipitated with CD44 receptors, not with β1 or β3 integrins. Proximity ligation assay confirmed interaction of OPN with CD44 receptors. Neutralizing anti-CD44 antibodies inhibited OPN-stimulated apoptosis. OPN activated JNKs and increased expression of Bax and levels of cytosolic cytochrome c, suggesting involvement of mitochondrial death pathway. OPN increased endoplasmic reticulum (ER) stress, as evidenced by increased expression of Gadd153 and activation of caspase-12. Inhibition of JNKs using SP600125 or ER stress using salubrinal or caspase-12 inhibitor significantly reduced OPN-stimulated apoptosis. Expression of OPN in adult mouse heart in myocyte-specific manner associated with decreased left ventricular function and increased myocyte apoptosis. In the heart, OPN expression increased JNKs and caspase-12 activities, and expression of Bax and Gadd153. Thus, OPN, acting via CD44 receptors, induces apoptosis in myocytes via the involvement of mitochondrial death pathway and ER stress.

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Objective Extracellular ubiquitin (Ub) is an immune modulator that plays a role in suppression of inflammation, organ injury, myocyte apoptosis and fibrosis. The purpose of this study was to investigate the effects of extracellular Ub on the process of cardiac angiogenesis. Methods Cardiac microvascular endothelial cells (CMECs) and aortic tissue were isolated from rats to measure changes in angiogenic protein levels and to assess angiogenic responses to extracellular Ub. Results In CMECs, extracellular Ub increased protein levels of vascular endothelial growth factor-A (VEGF-A) and matrix metalloproteinase-2 (MMP-2), known angiogenesis regulators. CMECs demonstrated enhanced rearrangement of fibrillar actin and migration in response to Ub treatment. Ub-treated CMECs demonstrated an increase in tube network formation which was inhibited by the CXCR4 receptor antagonist, AMD3100. Methylated Ub, unable to form polyubiquitin chains, enhanced tube network formation. Aortic ring sprouting assays demonstrated that Ub increases microvessel sprouting in the Matrigel. Conclusion The results of our study suggest a novel role for extracellular Ub in cardiac angiogenesis, providing evidence that extracellular Ub, at least in part acting via the CXCR4 receptor, has the potential to facilitate the process of angiogenesis in myocardial endothelial cells.