Vascular repair and anti-inflammatory effects of soluble epoxide hydrolase inhibitor

Dual soluble epoxide hydrolase inhibitor - farnesoid X receptor agonist interventional treatment attenuates renal inflammation and fibrosis

Introduction

Renal fibrosis associated with inflammation is a critical pathophysiological event in chronic kidney disease (CKD). We have developed DM509 which acts concurrently as a farnesoid X receptor agonist and a soluble epoxide hydrolase inhibitor and investigated DM509 efficacy as an interventional treatment using the unilateral ureteral obstruction (UUO) mouse model.

Methods

Male mice went through either UUO or sham surgery. Interventional DM509 treatment (10mg/kg/d) was started three days after UUO induction and continued for 7 days. Plasma and kidney tissue were collected at the end of the experimental protocol.

Results

UUO mice demonstrated marked renal fibrosis with higher kidney hydroxyproline content and collagen positive area. Interventional DM509 treatment reduced hydroxyproline content by 41% and collagen positive area by 65%. Renal inflammation was evident in UUO mice with elevated MCP-1, CD45-positive immune cell positive infiltration, and profibrotic inflammatory gene expression. DM509 treatment reduced renal inflammation in UUO mice. Renal fibrosis in UUO was associated with epithelial-to-mesenchymal transition (EMT) and DM509 treatment reduced EMT. UUO mice also had tubular epithelial barrier injury with increased renal KIM-1, NGAL expression. DM509 reduced tubular injury markers by 25-50% and maintained tubular epithelial integrity in UUO mice. Vascular inflammation was evident in UUO mice with 9 to 20-fold higher ICAM and VCAM gene expression which was reduced by 40-50% with DM509 treatment. Peritubular vascular density was reduced by 35% in UUO mice and DM509 prevented vascular loss.

Discussion

Interventional treatment with DM509 reduced renal fibrosis and inflammation in UUO mice demonstrating that DM509 is a promising drug that combats renal epithelial and vascular pathological events associated with progression of CKD.

Multimodal Optical Imaging to Investigate Spatiotemporal Changes in Cerebrovascular Function in AUDA Treatment of Acute Ischemic Stroke

Administration of 12-(3-adamantan-1-yl-ureido)-dodecanoic acid (AUDA) has been demonstrated to alleviate infarction following ischemic stroke. Reportedly, the main effect of AUDA is exerting anti-inflammation and neovascularization via the inhibition of soluble epoxide hydrolase. However, the major contribution of this anti-inflammation and neovascularization effect in the acute phase of stroke is not completely elucidated. To investigate the neuroprotective effects of AUDA in acute ischemic stroke, we combined laser speckle contrast imaging and optical intrinsic signal imaging techniques with the implantation of a lab-designed cranial window. Forepaw stimulation was applied to assess the functional changes via measuring cerebral metabolic rate of oxygen (CMRO₂) that accompany neural activity. The rats that received AUDA in the acute phase of photothrombotic ischemia stroke showed a 30.5 ± 8.1% reduction in the ischemic core, 42.3 ± 15.1% reduction in the ischemic penumbra (p < 0.05), and 42.1 ± 4.6% increase of CMRO₂ in response to forepaw stimulation at post-stroke day 1 (p < 0.05) compared with the control group (N = 10 for each group). Moreover, at post-stroke day 3, increased functional vascular density was observed in AUDA-treated rats (35.9 ± 1.9% higher than that in the control group, p < 0.05). At post-stroke day 7, a 105.4% ± 16.4% increase of astrocytes (p < 0.01), 30.0 ± 10.9% increase of neurons (p < 0.01), and 65.5 ± 15.0% decrease of microglia (p < 0.01) were observed in the penumbra region in AUDA-treated rats (N = 5 for each group). These results suggested that AUDA affects the anti-inflammation at the beginning of ischemic injury and restores neuronal metabolic rate of O₂ and tissue viability. The neovascularization triggered by AUDA restored CBF and may contribute to ischemic infarction reduction at post-stroke day 3. Moreover, for long-term neuroprotection, astrocytes in the penumbra region may play an important role in protecting neurons from apoptotic injury.

[Quantitative proteomics and bioinformatics analyses of human coronary artery endothelial cell injury induced by Kawasaki disease]

OBJECTIVE

To study the biomarkers for human coronary artery endothelial cell (HCAEC) injury induced by Kawasaki disease (KD) using isobaric tags for relative and absolute quantitation (iTRAQ) proteomics.

METHODS

HCAECs cultured with the serum of children with KD were used as the KD group, and those cultured with the serum of healthy children was used as the healthy control group. The iTRAQ technique was used to measure the expression of proteins in two groups. The data on proteins were analyzed by bioinformatics. Western blot was used for the validation of protein markers.

RESULTS

A total of 518 significantly differentially expressed proteins were identified (with an absolute value of difference fold of >1.2, P<0.05). The gene ontology analysis showed that the differentially expressed proteins were significantly enriched in biological processes (including cellular processes, metabolic processes, and biological regulation), cellular components (including cell parts, cells, and organelles), and molecular functions (including binding, catalytic activity, and molecular function regulators). The KEGG analysis showed that the proteins were significantly enriched in the signaling pathways of ribosomes, PI3K-Akt signaling pathway, and transcriptional dysregulation in cancer. The PPI network showed that the top 9 protein markers in relation density were PWP2, MCM4, MCM7, MCM5, MCM3, MCM2, SLD5, HDAC2, and MCM6, which were selected as the protein markers for coronary endothelial injury in KD. Western blot showed that the KD group had significantly lower expression levels of the protein markers HDAC2, PWP2, and MCM2 than the healthy control group (P<0.05).

CONCLUSIONS

The serum of children with KD significantly changes the protein expression pattern of HCAECs and affects the signaling pathways associated with the cardiovascular system, which provides a new basis for the pathophysiological mechanism and therapeutic targets of KD.

[Quantitative proteomics and bioinformatics analyses of human coronary artery endothelial cell injury induced by Kawasaki disease]

OBJECTIVE

To study the biomarkers for human coronary artery endothelial cell (HCAEC) injury induced by Kawasaki disease (KD) using isobaric tags for relative and absolute quantitation (iTRAQ) proteomics.

METHODS

HCAECs cultured with the serum of children with KD were used as the KD group, and those cultured with the serum of healthy children was used as the healthy control group. The iTRAQ technique was used to measure the expression of proteins in two groups. The data on proteins were analyzed by bioinformatics. Western blot was used for the validation of protein markers.

RESULTS

A total of 518 significantly differentially expressed proteins were identified (with an absolute value of difference fold of >1.2, P<0.05). The gene ontology analysis showed that the differentially expressed proteins were significantly enriched in biological processes (including cellular processes, metabolic processes, and biological regulation), cellular components (including cell parts, cells, and organelles), and molecular functions (including binding, catalytic activity, and molecular function regulators). The KEGG analysis showed that the proteins were significantly enriched in the signaling pathways of ribosomes, PI3K-Akt signaling pathway, and transcriptional dysregulation in cancer. The PPI network showed that the top 9 protein markers in relation density were PWP2, MCM4, MCM7, MCM5, MCM3, MCM2, SLD5, HDAC2, and MCM6, which were selected as the protein markers for coronary endothelial injury in KD. Western blot showed that the KD group had significantly lower expression levels of the protein markers HDAC2, PWP2, and MCM2 than the healthy control group (P<0.05).

CONCLUSIONS

The serum of children with KD significantly changes the protein expression pattern of HCAECs and affects the signaling pathways associated with the cardiovascular system, which provides a new basis for the pathophysiological mechanism and therapeutic targets of KD.

Soluble Epoxide Hydrolase Inhibition in Liver Diseases: A Review of Current Research and Knowledge Gaps

Emerging evidence suggests that soluble epoxide hydrolase (sEH) inhibition is a valuable therapeutic strategy for the treatment of numerous diseases, including those of the liver. sEH rapidly degrades cytochrome P450-produced epoxygenated lipids (epoxy-fatty acids), which are synthesized from omega-3 and omega-6 polyunsaturated fatty acids, that generally exert beneficial effects on several cellular processes. sEH hydrolysis of epoxy-fatty acids produces dihydroxy-fatty acids which are typically less biologically active than their parent epoxide. Efforts to develop sEH inhibitors have made available numerous compounds that show therapeutic efficacy and a wide margin of safety in a variety of different diseases, including non-alcoholic fatty liver disease, liver fibrosis, portal hypertension, and others. This review summarizes research efforts which characterize the applications, underlying effects, and molecular mechanisms of sEH inhibitors in these liver diseases and identifies gaps in knowledge for future research.

Epoxy Fatty Acids: From Salt Regulation to Kidney and Cardiovascular Therapeutics: 2019 Lewis K. Dahl Memorial Lecture

Epoxyeicosatrienoic acids (EETs) are epoxy fatty acids that have biological actions that are essential for maintaining water and electrolyte homeostasis. An inability to increase EETs in response to a high-salt diet results in salt-sensitive hypertension. Vasodilation, inhibition of epithelial sodium channel, and inhibition of inflammation are the major EET actions that are beneficial to the heart, resistance arteries, and kidneys. Genetic and pharmacological means to elevate EETs demonstrated antihypertensive, anti-inflammatory, and organ protective actions. Therapeutic approaches to increase EETs were then developed for cardiovascular diseases. sEH (soluble epoxide hydrolase) inhibitors were developed and progressed to clinical trials for hypertension, diabetes mellitus, and other diseases. EET analogs were another therapeutic approach taken and these drugs are entering the early phases of clinical development. Even with the promise for these therapeutic approaches, there are still several challenges, unexplored areas, and opportunities for epoxy fatty acids.

The Anti-inflammatory Effect of Soluble Epoxide Hydrolase Inhibitor and 14, 15-EET in Kawasaki Disease Through PPARγ/STAT1 Signaling Pathway

Soluble epoxide hydrolase (sEH) is responsible for rapid degradation of 14, 15-EET, which is one of the isomers of EETs and plays an important role in cardiovascular diseases. In this study, we investigated the mechanism by which sEH inhibitor AUDA played an anti-inflammatory effect in HCAECs. Our results indicated that AUDA treatment promoted PPARγ expression, while knockdown of PPARγ blocked the cell growth and STAT1 expression inhibition induced by 100 μmol/L AUDA in HCAECs. AUDA also inhibited the overexpression of TNF-α, IL-1 β, and MMP-9 induced by KD sera in HCAECs. Moreover, 30 blood samples from children with Kawasaki disease (KD) were collected with 30 healthy children as the control group. QPCR and ELISA assays were used to detect the level of 14, 15-EET, TNF-α, IL-1β, and MMP-9. We found that the level of 14, 15-EET was higher in peripheral blood of children with KD compared with healthy controls (P < 0.05). In comparison to KD children with non-coronary artery lesion (nCAL), the level of 14, 15-EET was higher in peripheral blood of KD children with coronary artery lesion (CAL) (P < 0.05). Compared with healthy control group, the expression levels of TNF-α, IL-1β, and MMP-9 in patients with KD were significantly up-regulated. Compared with nCAL KD children, the expression levels of TNF-α, IL-1β, and MMP-9 in CAL children were abnormally high (P < 0.05). Our study indicated that AUDA played an anti-inflammatory effect in HCAECs through PPARγ/STAT1 signaling pathway, and 14, 15-EET is up-regulated in children with KD, suggesting that 14, 15-EET involved in the progression of KD.