Hong Wang - US grants

DESCRIPTION: (Adapted from the applicant's Description) The targeting of opioid receptors, as well as their coordinated interactions with N-methyl-D-aspartate subtype of glutamate receptors (NMDARs), is crucial for normal brain development and motor functions involving patch-matrix compartments in the mammalian caudate-putamen nucleus (CPN). During the critical developmental plasticity period, mu and delta opioid receptors (MOR, DOR) play either complementary or opposite roles that may in part involve functional interaction with NMDAR. The goal of this application is to test the hypothesis that there are age-related differences in the subcellular localization of MOR and/or DOR, which are correlated with synaptogenesis and parallel those of NMDAR in the CPN. The specific aims in each of the three proposed studies will be pursued by examining the localization of sequence specific antipeptide antisera against MOR, DOR, or NMDAR in the rat CPN during postnatal ontogeny. The results obtained from these studies will complement and extend previous knowledge that age-dependent MOR and DOR subcellular distributions are functionally linked to neuronal maturation; that developing NMDAR is largely involved in activity-dependent synaptic plasticity and has a subcellular distribution that parallels the distribution of opioid receptors; and that prenatal opioid availability differentially controls the ontogeny of neurons containing opioid and/or glutamate receptors. Understanding opioid and NMDA receptor targeting during development in the rat model may provide information leading to new approaches for reactivation of developmental plasticity in human brain.

Hyperhomocysteinemia is an independent risk for cardiovascular disease. Most of the reported biological effects of homocysteine (Hcy) in vascular cells have been attributed to oxidative mechanisms, which were observed at Hcy concentrations higher than 1mM, and can be mimicked by cysteine, another non-pathogenic biothiol. Thus, a biochemical mechanism unique to Hcy remains to be identified. Our previous work has demonstrated that Hcy at 10-50 muM, but not cysteine, arrests endothelial cell (EC) p21/ras, suppress cyclin A transcription in cell type specific manner. The basic hypothesis of this proposed project is that Hcy, at growth through a hypomethylation related mechanism, which blocks cell cycle progression and endothelium regeneration. This project will study this hypothesis utilizing three linked specific aims. First, in Aim 1, experiments are designed to elucidate the role of Ras demethylation-independent Ras over-expression on EC growth, and on cyclin A expression and promoter activity. Cell growth will be determine by thymidine uptake, flow cytometry and cell counting. Cyclin A expression and promoter activity will be determined by Northern, Western blot analysis and reporter gene transfection. Alternatively, DNA microarray will be used to identify other potential targets in Hcy signaling. Second, in Aim 2, studies are proposed to determine the biochemical mechanisms by which Hcy suppress cyclin A transcription. Experiments will be performed to study the RB phosphorylation and E2F expression, and the role of E2F and other transcription factors on cyclin A transcription by Western blot, reporter gene transfection, gel mobility shift, adenovirus-transduced E2F expression. The role of cyclin A in maintaining RB phosphorylation will be assessed by RNA interference. The promoter methylation pattern of cyclin A genes will be examined by bisufite genomic sequence and methylation sensitive restriction enzyme digestion. Finally, in Aim 3, a mouse endothelial denudation and regeneration model will be used in cystathionine beta-synthase (CBS) knockout and diet-induced hyperhomocysteinemic mice to assess the effect of Hcy in endothelial regeneration. Mouse blood will e examined for the concentrations of Hcy and SAH/SAM. Immunohistochemistry staining for leukocytes, macrophages, EC and smooth muscle cells will be performed on vessel sections to analyze the cellular composition of the lesion. In situ hybridization of immunohistochemistry staining for cyclin A will be performed to assess its involvement. The broad, long-term objective of this proposal i to elucidate Hcy signaling in EC growth inhibition, and to evaluate its importance on the role of atherogenesis in hyperhomocysteinemia. If we identify the key events in Hcy-induced arteriosclerosis, genetic or biochemical approaches to block these steps could lead to therapeutic advantage.

[unreadable] DESCRIPTION (provided by applicant): Although hyperhomocysteinemia is an independent risk factor for myocardial infarction and stroke, the mechanistic link between homocysteine (Hcy) and arteriosclerosis is unknown. We have proposed hypomethylation as a specific mechanism by which Hcy inhibits endothelial regeneration that leads to cardiovascular disease [11. Our plan in the ongoing research "Inhibition of Endothelial Growth by Homocysteine" (ROl-I-IL67033) is to elucidate the molecular mechanisms by which Hcy inhibits endothelial cell (EC) growth and to evaluate its role in a hyperhomocysteinemic mouse model. EC growth is a key step of vasculogenesis and angiogenesis. The growth inhibitory effect of Hcy on EC growth suggests a role in the development of atherosclerosis and vasculogenesis. The basic hypothesis of this proposed project is that Hcy inhibits EC differentiation and vascular development. This is based on our previous finding that Hcy selectively inhibits EC growth, and our new observation that there is a decrease in vascularization in hyperhomocysteinemic mice. This hypothesis is supported by studies from others showing that Hcy inhibits angiogenesis in vitro and in vivo. We plan to investigate the effect of Hcy on EC differentiation and vasculogenesis using human embryonic stem (ES) cells, and to test the role of the targeting molecules during this process. In Aim 1, we will determine the effect of Hcy on EC differentiation by embryoid body (EB) formation using human ES cell line 1-19 clone (NIH Code: WA09) from WiCell Research Inst (Madison, WI), which has been validated for EC differentiation. In Aim 2, we will assess the status and the role of Ras demethylation and cyclin A inhibition in Hcy signaling in EC derived from human ES cells. We anticipate that our studies will advance the body of knowledge that will establish a mechanistic connection between Hcy and impaired human vasculogenesis, and will help in achieving our primary goal in the ongoing research, which is to understand the effect of Hcy in human endothelial biology. [unreadable] [unreadable]

DESCRIPTION (provided by applicant): Hyperhomocysteinemia is an independent risk factor for myocardial infarction and stroke, yet the mechanisms by which homocysteine (Hcy) promotes arteriosclerosis are not clear. Most of the reported biological effects of Hcy in vascular cells have been attributed to oxidative mechanisms, which were observed at Hcy concentrations higher than 1 mM or higher, and can be mimicked by cysteine, another nonpathogenic biothiol. Thus, a biochemical mechanism unique to Hcy remains to be identified. We have proposed hypomethylation as a specific mechanism by which Hcy induces vascular injury and leads to cardiovascular disease. The basic hypothesis of the ongoing and this proposed projects is that Hcy, at clinically relevant concentrations, selectively inhibits EC growth through a hypomethylation-related mechanism. The ongoing research is designed to investigate the role of Ras demethylation in Hcy-EC growth, to dissect the mechanism in Hcy signaling using cellular and animal models. Because damage to EC is a key feature of arteriosclerosis, the growth inhibition of EC may represent an important mechanism to explain Hcy-induced arteriosclerosis. In the proposed study, we hypothesize that hypomethylation of other molecules may also play an important role in Hcy-related EC growth inhibition. We added two new aims to characterize methylation status of genomic DNA and protein, to examine the activities of histone methyltransferase in Hcy-treated EC (Aim 4), and to identify new functional target genes using retrovirus-mediated genetic screening and radiolabelled methylation sensitive two-dimensional electrophoresis proteomics (Aim 5). These two new aims are expansion of the funded project and would explore key functional molecular mechanisms by which Hcy inhibit EC growth. The broad, long-term objective of this proposal is to elucidate Hcy signaling in EC growth inhibition, and to evaluate its importance in the role of atherogenesis in Hcy pathology. If we can identify the key events in Hcy-induced arteriosclerosis, genetic or biochemical approaches to block these steps could lead to therapeutic advantage.

[unreadable] DESCRIPTION (provided by applicant): Chemosensory disorders, including disorders of taste and smell, are common in the general population and yet they are often overlooked. A broad range of conditions and diseases can cause taste disorders. This includes viral and bacterial infections, cancer, medication, and normal aging. Taste disorders contribute significantly to malnutrition, weight loss, depression, and compromised quality of life. The molecular and cellular bases of taste disorders are poorly understood. To elucidate the underlying mechanisms of taste loss is our long-term goal. In this application, we will focus our research on the roles of interferons in infection-caused taste disorders. Interferons are multi-functional cytokines produced during viral and bacterial infections. They are critical in regulating the activities of the immune system and in fighting against viral and bacterial pathogens. In addition, by regulating the expression of numerous genes, interferons affect cell proliferation, differentiation, and cell death. We have found the expression of interferon signaling pathways in taste tissue. To determine their roles in infection-caused taste disorders, we will pursue the following specific aims: 1) We will thoroughly characterize the expression of interferon signaling components in taste tissue. This analysis will reveal the specific types of taste cells expressing the interferon signaling pathways. 2) We will examine the activation of the interferon pathways in taste tissue under conditions that mimic viral and bacterial infections. We will monitor the induction of the interferon-inducible genes in taste tissue in mouse models of viral and bacterial infections. 3) We will investigate the effects of interferons on taste bud cell turnover. Disturbing the homeostasis of taste bud cell turnover will likely lead to taste disorders. Results from this study may provide new insights into the regulation of taste cell turnover and the molecular and cellular bases of taste disorders. [unreadable] [unreadable]

DESCRIPTION (provided by applicant): In patients with type II diabetes, cardiovascular disease (CVD) is highly prevalent and a major cause of premature mortality and plasma homocysteine (Hcy) levels are increased by 3-4 folds. Hyperhomocysteinemia (hHcy), elevated plasma concentrations of Hcy, has been established as an independent and significant risk factor for CVD, and has been suggested to be responsible for CVD in diabetes that is not explained by traditional risk factors. However, the role of HHcy in diabetic atherosclerosis has not been studied in experimental model. We have previously proposed that Hcy promotes atherosclerosis by stimulating vascular aortic smooth muscle cell (VSMC) proliferation and by inhibiting endothelial cell (EC) growth, and reported that HHcy accelerated spontaneous atherosclerosis in mice. Recently, we found that Hcy potentiated the diabetic inhibitions on EC growth and eNOS activities in human aortic endothelial cells (HAEC). A PKC inhibitor, GFX, reversed these inhibitions. We hypothesize that Hcy potentiates diabetic endothelium damage and eNOS inactivation via PKC activation, which contributes to high prevalence of atherosclerosis in diabetes. This project will study this hypothesis utilizing three linked specific aims. First, in Aim 1, experiments will evaluate the role and mechanisms of Hcy on endothelial cell growth inhibition in diabetes using in vitro and in vivo models. Second, in Aim 2, studies are proposed to determine the role and mechanism of Hcy in eNOS inactivation and PKC activation. Third, in Aim 3, studies will determine the effect of HHcy on endothelial function and atherosclerosis in animal model of diabetes and atherosclerosis. We believe this project will lead to fundamental new insights into the identification of mechanistic links between Hcy and diabetic atherosclerosis. If we can identify the key events in Hcy-induced atherosclerosis in diabetes, genetic or biochemical approaches to block these steps could lead to new therapeutic approaches

DESCRIPTION (provided by applicant): The overall objective of this competitive renewal application is to determine the molecular mechanisms responsible for Hyperhomocysteinemia (HHcy)-accelerated atherosclerosis. Major discoveries in the previous grant period include; 1) HHcy impairs endothelial function in severe HHcy CBS-/- mice by inhibiting eNOS expression and PKC activation, 2) HHcy inhibits post injury endothelial repair and lead to increase vascular remodeling in severe HHcy, 3) HHcy inhibits HDL biosynthesis via apo-AI inhibition in human and mouse CVD, 4) HHcy accelerates spontaneous atherosclerosis in CBS-/-/apoE-/- mice, 5) HHcy increased vessel wall content of cholesteryl ester (CE) and triglyceride (TG) contents and promoted MC uptake of Acetyl-LDL, 6) HHcy promoted inflammatory MC subset differentiation in hCBStg/mCBS-/-/apoE-/-. Collectively, these findings implicate HHcy in the etiology of inflammatory vascular diseases. The hypothesis to be tested in this proposal is that HHcy accelerates atherosclerosis by activating endothelium, promoting vessel wall inflammatory MC differentiation and increasing MC trans-endothelium migration. This project will study this hypothesis utilizing three linked specific aims. In Aim 1, we will examine the effects and mechanism of HHcy on endothelium activation and monocyte trans-endothelium migration using cultured primary endothelial and splenic cells in static condition or under physiological relevant flow. In Aim 2, we will study the role of HHcy on vessel wall MC origin and its relevance to atherogenesis using bone marrow transplantation from GFP mice into our newly developed HHcy mouse (CBS-/?/-). In Aim 3, we will study the effect of homocysteine-lowering on preventing MC trans-endothelium migration into the vessel wall and on reducing spontaneous atherosclerotic lesion formation. MC rolling/adhesion on EC will be examined in cremaster microcirculation model using intravital microscopy technology. We believe that completion of the specific Aims should Completion of the specific aims of this proposal may provide important insights into the role of Hcy in CVD, and identify the mechanistic links between HHcy and atherosclerosis.

DESCRIPTION (provided by applicant): Taste disorders, including taste distortion and taste loss, are associated with diseases, aging, and medications and contribute significantly to anorexia, malnutrition, and depression. Despite recent progress in identifying taste receptors and taste signaling proteins, little is known about the underlying mechanisms of taste disorders. Our long-term objective is to elucidate the molecular and cellular basis of gustatory dysfunction. Several lines of evidence suggest that inflammation is an important contributing factor to the pathogenesis of taste disorders. First, taste abnormality is frequently associated with inflammatory conditions, such as infections and autoimmune diseases. Second, inflammatory stimuli can change taste preference and food intake. Third, taste bud cells express receptors and signaling molecules for inflammatory factors. Fourth, we have shown that inflammatory cytokines, such as interferons, can alter gene expression and induce cell death in taste buds. So far, however, how inflammation affects taste sensation remains largely unknown. In this application, we propose to study the mechanisms of inflammation-induced taste disorders in animal models. We are going to pursue the following specific aims: 1) We will study the effects of acute and chronic inflammation on taste bud cell renewal and turnover. 2) We will determine the roles of cytokines in mediating the effects of inflammation on taste bud cell renewal and turnover. 3) We will investigate the effects of inflammation and cytokines on taste function. Results from these studies will be important for understanding the roles of inflammation in taste disorders, which will be useful for developing new treatment strategies. In addition, this research will further our knowledge on the regulatory mechanisms of taste bud cell turnover.

DESCRIPTION (provided by applicant): Malaria results from infection by one of five species of mosquito-borne parasite. Each year, these protists infect 350-500 million worldwide and kill over one million people. Over three billion people living in tropical regions are exposed to malaria every year. Plasmodium Vivax is the common cause of recurring Malaria, but remains one of the more poorly understood parasites. P. Vivax and other plasmodia have grown increasingly resistant to these common treatments leading to a resurgence of Malaria. Though development of vaccine candidates for vivax malaria has accelerated, it remains hindered by the dearth of relevant experimental models. These parasites preferentially infect reticulocytes, which account for a small fraction of circulating blood cells and difficult to isolate in sufficient quantity for vaccine research. Arteriocyte is developing unique rapid reticulocyte production technology to address this problem. The resulting cells demonstrate functional characteristics similar to circulating reticulocytes. Arteriocyte will adapt and refine its feeder-layer free expansion and differentiation technologies and implement them in a system to produce high volumes of Duffy-antigen positive reticulocytes suitable for vaccine research. The company will then work with experts at the Emory Vaccine Center and CDC to demonstrate feasibility for use in Vaccine Development. This project will lead to a unique platform to jump start research of P. vivax malaria and stimulate rapid development of effective vaccines. Arteriocyte's innovative tools for malaria research will lead to significant improvement in infection prevention for populations living or operating in tropical regions worldwide. This system will bridge the gap between biology and production by providing the biological and technical underpinnings for an automated reticulocyte production system. PUBLIC HEALTH RELEVANCE: The goal of this project is to develop innovative ex vivo reticulocyte production methods to provide vital tools for p. vivax malaria research. This will lead to significant acceleration in vaccine development and eventually malaria infection prevention for populations living or operating in tropical regions worldwide.

DESCRIPTION (provided by applicant): The overall objective of new application is to determine the role and mechanism of NADPH-related oxidative stress in Hyperhomocysteinemia (HHcy)-caused monocyte differentiation and endothelial dysfunction. The hypothesis to be tested in this proposal is that HHcy causes SAH accumulation, resulting in hypomethylative epigenetic modification on NADHP oxidase gene, leading to NADPH oxidase-related oxidative stress and inflammatory MC differentiation, contributing to vascular dysfunction. This project will study this hypothesis utilizing three linked specific aims. In Aim 1, they will characterize MC differentiation/adhesion, and vascular function/inflammation in HHcy mice. In Aim 2, they will examine the role and mechanism of NADPH oxidase activation and epigenetic modification in Hcy-induced MC differentiation in mouse primary splenocytes. In Aim 3, they will define the role of HHcy, SAH accumulation, DNA hypomethylation, and NADPH oxidase activation in inflammatory MC differentiation and vascular dysfunction in Tg-hCBS Cbs-/- mice. It is believed that completion of the specific aims of this proposal may provide important insights into the role of Hcy in CVD, and identify the underline mechanism. PUBLIC HEALTH RELEVANCE: Increased plasma homocysteine (Hcy) level is an independent risk factor for cardiovascular diseases (CVD). However, the underlying mechanism is largely unknown. This project will illustrate mechanism by which how Hcy causes vessel wall inflammation and impair vascular function, both are early events of cardiovascular disease. We anticipate this study will identify biomarker and novel therapeutic target of cardiovascular disease.

DESCRIPTION (provided by applicant): The overall objective of new application is to determine the role and mechanism of NADPH-related oxidative stress in Hyperhomocysteinemia (HHcy)-caused monocyte differentiation and endothelial dysfunction. The hypothesis to be tested in this proposal is that HHcy causes SAH accumulation, resulting in hypomethylative epigenetic modification on NADHP oxidase gene, leading to NADPH oxidase-related oxidative stress and inflammatory MC differentiation, contributing to vascular dysfunction. This project will study this hypothesis utilizing three linked specific aims. In Aim 1, they will characterize MC differentiation/adhesion, and vascular function/inflammation in HHcy mice. In Aim 2, they will examine the role and mechanism of NADPH oxidase activation and epigenetic modification in Hcy-induced MC differentiation in mouse primary splenocytes. In Aim 3, they will define the role of HHcy, SAH accumulation, DNA hypomethylation, and NADPH oxidase activation in inflammatory MC differentiation and vascular dysfunction in Tg-hCBS Cbs-/- mice. It is believed that completion of the specific aims of this proposal may provide important insights into the role of Hcy in CVD, and identify the underline mechanism.

DESCRIPTION (provided by applicant): Hyperhomocysteinemia (HHcy) is an important non-lipid risk factor for cardiovascular disease (CVD). At present, our mechanistic knowledge of HHcy's correlation with dyslipidemia and the development of atherosclerosis is limited. Notwithstanding, it has been suggested that HHcy affects hepatic lipid metabolism, thereby contributing to fatty liver, a condition described in humans and animals with HHcy. Our previous findings suggested that plasma HHcy levels are significant negative correlated with plasma HDL-C and apolipoprotein AI (apoA-I), a predominant structural protein in HDL particles and cofactor for HDL maturation, in patients with coronary heart disease (CHD) and in atherosclerosis mice. We also found that severe HHcy is associated with increased HDL-C turnover and increased protein levels of hepatic/vascular endothelial lipase (EL), an HDL degradation enzyme in mice. Because the mechanistic link between HHcy and HDL dysfunction has never been studied, we plan to investigate the role and mechanism of HHcy-induced HDL dysfunction in our newly established severe HHcy models with double gene deficiency for Cystathionine ¿-synthase (CBS) which degrade homocysteine (Hcy), and either apolipoprotein E (ApoE) or low density lipoprotein receptor (LDLR), and with an inducible human CBS gene (Tg-hCBS ApoE-/- Cbs-/-, Tg- hCBS Cbs-/-, and Ldlr-/- Cbs-/+). These set of transgenic mice can circumvent the potential limitations of different model system and are valid for assessing the role and mechanistic links of HHcy-HDL metabolism with/without hyperlipidemia and with/without apoE deficiency. The central hypothesis to be tested in this proposal is that HHcy causes ApoA1 reduction and EL activation, resulting in reduced HDL maturation and increased HDL degradation, leading to impaired reverse cholesterol transport (RCT) contributing to the development of atherosclerosis. We proposed in Aim 1 to determine the effect of HHcy on HDL biosynthesis, catabolism, and function in our newly three developed HHcy models, in Aim 2 to identify molecular targets and underlying biochemical basis mediating HHcy-altered HDL metabolism, and in Aim 3 to reverse HHcy, ApoA1 deficiency or EL activation, and to examine the effect on HDL-raising/function and atherosclerosis. The goal of this proposal is to investigate the role of HHcy in HDL metabolism, in the hope to identify the underlying molecular mechanisms and novel therapies. If the key steps in Hcy-induced dyslipidemia and atherosclerosis can be identified, new genetic or pharmacological therapeutic targets can be utilized for treatment.

? DESCRIPTION (provided by applicant): Hyperhomocycteinemia (HHcy) is an independent risk factor for cardiovascular disease in the general population and associated with vascular diseases in diabetic patients{Hackam, 2003 #101;Schnyder, 2002 #102;Schnyder, 2002 #102}. When diabetes is compounded HHcy, cardiovascular mortality is about 2-fold greater than in those without HHcy. We have obtained substantial preliminary data showing that the combination of HHcy and Hyperglycemia (HHcy/HG) accelerated the development of atherosclerotic lesion, increased monocyte (MC)/macrophage (MØ) in the lesion, elevated inflammatory subsets of MC and MØ (Ly6Cmiddle+high MC and M1 MØ) in peripheral tissues. It is known that inflammatory MC and MØ contribute to vascular and systemic inflammation. In this proposal, we will examine the role and mechanism of Hcy in MC/MØ differentiation and in vascular inflammation, a key status determining atherosclerosis and cardiovascular disease, in combinatory diseases of HHcy and diabetes. Our central hypothesis is that HHcy promotes inflammatory MC/MØ differentiation via DNA hypomethylation thereby accelerating atherogenesis in diabetes. We will test our hypothesis by using the following three Aims: Aim 1 will examine the effect of HHcy on inflammatory MC/MØ differentiation and vascular diseases in diabetes animals. Aim 2 will access mechanisms contributing to HHcy-induced MC differentiation in T2DM. Aim 3 will identify the role of DNA hypomethylation in mediating HHcy- induced MC differentiation and test a novel DNA methylation therapy in preventing inflammatory MC/MØ differentiation and vascular diseases in diabetes animals. Success of this project will lead to the development of novel therapeutics for HHcy- related diabetic cardiovascular disease.

Project summary/Abstract: Extensive evidence indicates that complement (C), in particular the C membrane attack complex (C/MAC), a key mediator of inflammation and immunity, plays a critical role in atherogenesis. However, mechanisms underlying C/MAC-accelerated atherogenesis is unknown. Recent trails of C-targeted therapeutics to inhibit C/MAC formation presented some benefit to reduce mortality in patients undergoing coronary artery bypass grafting but lack of consist benefit for myocardial infarction. Research to further understand mechanisms underlying C/MAC-accelerated atherogenesis is in great needs and would lead to the development of better therapeutic strategies for cardiovascular disease. We recently discovered that the deficiency of a key C/MAC regulator CD59 (mCd59-/-) induced monocytes (MC, CD11b+), inflammatory MC subset (CD11b+/Ly6C+) and caspase-1 (Casp1) activation in MC. We also demonstrated that Casp-1 activation plays an essential role in sensing metabolic danger signal-associated molecular patterns (DAMPs) and in initiating vascular inflammatory. These results link C/MAC formation with inflammatory MC differentiation, Casp1 activation and inflammasome activation in MC, which may contribute to vascular inflammation and atherogenesis. The effect of C/MAC on inflammatory MC differentiation and Casp-1 activation and its role in atherogenesis have not been studied before. In this project, we proposed four connected aims to investigate 1) the effect of C/MAC on MC expansion and differentiation, and atherosclerosis; 2) the molecular mechanism underlying C/MAC-induced Ly6C+ inflammatory MC differentiation; 3) the role of Casp-1 in C/MAC-induced Ly6C+ inflammatory MC differentiation and atherosclerosis; and 4) the therapeutic effect of C/MAC or Casp-1 inhibitors on C/MAC-induced MC differentiation and atherosclerosis. This study would provide important insights into our understanding about the role of complement system in atherosclerosis and inflammation, will open a new avenue to prevent and treat atherosclerosis, and will foster the development of new therapeutic strategies for cardiovascular disease.

PROJECT SUMMARY The sense of taste has evolved to detect nutrients and toxic substances in food and beverages--it is the sensory system that we rely on to make food choices. Taste dysfunction can substantially affect health: severe taste loss can lead to malnutrition, weight loss, and depression. Taste disorders can develop with various diseases, including many with underlying inflammation, such as infections and autoimmune diseases. The mechanisms of taste disorders associated with infections, autoimmune diseases, and chronic inflammatory diseases are poorly understood. Our recent research indicates that inflammation, characterized by induction of inflammatory cytokines, infiltration and activation of immune cells, may contribute to taste dysfunction. The goal of this research is to determine the molecular and cellular mechanisms of inflammation-triggered taste loss and its recovery and to explore treatment options to accelerate taste bud regeneration. The inflammatory cytokine interferon-? (IFN-?) is highly induced in taste epithelium in multiple disease models that show taste abnormalities. However, whether induction of IFN-? in the taste epithelium contributes to taste loss has not been determined. To directly test the role of IFN-? in taste loss, we have established transgenic mouse strains that allow selective induction of IFN-? in particular cell types in the taste epithelium: taste progenitor/stem cells, sweet and umami receptor cells, and sour receptor cells. Here, we propose to use these mouse models to determine the role of IFN-? in taste loss and to elucidate the molecular and cellular mechanisms that drive taste loss and taste bud regeneration. We will investigate the effects of IFN-? on taste bud cell renewal, cell death, taste pore structure, taste bud permeability, and immune cell trafficking in taste papillae. In addition, we will identify the molecular and cellular processes that are critical to taste bud regeneration following taste loss triggered by inflammation. Furthermore, we will determine whether exogenous growth factors can accelerate taste bud regeneration. This research will improve our understanding of the underlying mechanisms of taste loss and taste bud regeneration and shed new light on fundamental aspects of taste biology.

Summary: Chronic kidney disease (CKD) is a common disease affecting >15% of the US adult population and has cardiovascular mortality10- to 30-folds greater than that in general population. We recently discovered a novel inflammatory monocyte subset the CD40 monocyte (MC) that has strong inflammatory feature and is elevated in CKD patients. We determined CD40+ MC as a novel inflammatory MC subset which is elevated in CKD subjects. Additional preliminary data lead us to hypothesize that CKD and uremic toxins induce CD40+ inflammatory MC differentiation via CD40 ligand induced CD40 expression, DNA hypomethylation on CD40 promoter, and 2) CD40 Inhibition, inflammasome suppression and DNA methylation therapy can reverse CD40+ MC differentiation, vascular inflammation and atherosclerosis. We will test this hypothesis using three connected Aims. Aim 1 will investigate the effect of CKD on CD40+ MC differentiation and tissue inflammation in human and mouse models of CKD, and in uremic toxin-treated human/mouse PBMC. Aim 2 will examine molecular mechanism underlying CKD-induced CD40+ MC differentiation. Aim 3 will test the therapeutic benefit of CD40 blocking, Casp1 inhibition and DNA methylation on CD40+ MC differentiation, atherosclerosis and kidney function in CKD. Accomplishment of the proposed research will lead to the identification of fundamental mechanistic links between CKD and cardiovascular disease, and novel therapeutic targets.