Tubulointerstitial inflammation plays an important role in the progression of diabetic nephropathy (DN), and tubular epithelial cells (TECs) are crucial promoters of the inflammatory cascade. Exchange protein activated by cAMP (Epac) has been shown to suppress the angiotensin II (Ang-II)-induced release of inflammatory cytokines in tubular cells. However, the role of Epac in TEC-mediated tubulointerstitial inflammation in DN remains unknown. We found that administering the Epac agonist 8-pCPT-2′-O-Me-cAMP (8-O-cAMP) to db/db mice inhibited tubulointerstitial inflammation characterized by macrophage infiltration and increased inflammatory cytokine release and consequently alleviated tubulointerstitial fibrosis in the kidney. Furthermore, 8-O-cAMP administration restored CCAAT/enhancer binding protein β (C/EBP-β) expression and further upregulated the expression of Suppressor of cytokine signaling 3 (SOCS3), while inhibiting p-STAT3, MCP-1, IL-6, and TNF-α expression in the kidney cortex in db/db mice. And in vitro study showed that macrophage migration and MCP-1 expression induced by high glucose (HG, 30 mM) were notably reduced by 8-O-cAMP in human renal proximal tubule epithelial (HK-2) cells. In addition, 8-O-cAMP treatment restored C/EBP-β expression in HK-2 cells and promoted C/EBP-β translocation to the nucleus, where it transcriptionally upregulated SOCS3 expression, subsequently inhibiting STAT3 phosphorylation. Under HG conditions, siRNA-mediated knockdown of C/EBP-β or SOCS3 in HK-2 cells partially blocked the inhibitory effect of Epac activation on the release of MCP-1. In contrast, SOCS3 overexpression inhibited HG-induced activation of STAT3 and MCP-1 expression in HK-2 cells. These findings indicate that Epac activation via 8-O-cAMP ameliorates tubulointerstitial inflammation in DN through the C/EBP-β/SOCS3/STAT3 pathway.

Cinnamaldehyde (CinA) is a phytochemical whose source plants are widely used as a medicine and food spice additive, but its vascular effect and mechanisms remain poorly understood. To study the vasomotor effect and channel pharmacological effect of CinA on the arterial smooth muscle cells (ASMC) of rat coronary artery (RCA). The tensions of rat isolated arteries were recorded with a myograph. Transmembrane currents through Ca²⁺-activated Cl^- channels (CaCC), voltage-gated K⁺ (Kv) channels and inwardly rectifier K⁺ (Kir) channels were evaluated with a whole cell patch clamp. Intracellular Ca²⁺ ([Ca²⁺]_i) levels were measured with fluorescent dye Fluo-4 AM. Ion channel expressions were assayed with immunofluorescent staining and RT-qPCR. CinA relaxed all arteries tested. Among arteries contracted with various vasoconstrictors, 60 mM KCl-precontracted RCAs were more sensitive to the relaxation. Both intracellular Cl^- depletion and CaCC inhibitor T16A_inh-A01 decreased, while Kv inhibitor 4-aminopyridine increased, CinA-induced relaxation in serotonin-precontracted RCA. In RCA ASMC, CinA suppressed KCl-induced [Ca²⁺]_i elevation and decreased currents through CaCC, Kv channels and Kir channels. CinA incubation depressed the contractility of RCA and reduced expressions of VGCC, CaCC, Kv channels and Kir channels in RCA ASMC. CinA induces vasorelaxation in various arteries and its vasorelaxation efficiencies vary with arteries and vasoconstrictors. Down-regulation of VGCC and CaCC contributes to the coronarospasmolysis of CinA, while repression on Kv channels and Kir channels may slightly discount the coronarospasmolysis. Overall, CinA may be a promising candidate to treat or prevent coronarospasmodic diseases.

Humans are ubiquitously exposed to crotonaldehyde (CRA) endogenously and exogenously. Deeper knowledge of the pharmacological and toxicological characteristics and the mechanisms of CRA on vasculature is urgently needed for prevention of its harmfulness. The effects of acute and prolonged exposure to CRA were studied in rat isolated arteries and arterial smooth muscle cells (ASMCs). Instant exposure to CRA (1-300 μM) concentration-dependently declined the tension of pre-constricted arteries with an irreversible depression on the contractility. Prolonged exposure of rat coronary arteries (RCAs) to CRA concentration- and time-dependently depressed the arterial contractile responsiveness to various vasoconstrictors including depolarization, U46619, serotonin and Bay K8644 (an agonist of voltage-gated Ca²⁺ channels (VGCCs)). In fresh RCA ASMCs, CRA abated depolarization-induced elevation of intracellular Ca²⁺ ([Ca²⁺]_i). Electrophysiological study revealed that acute exposure to CRA depressed the functions of Ca²⁺-activated Cl^- channels (CaCCs), voltage-gated K⁺ (Kv) channels and inward rectifier K⁺ (Kir) channels in RCA ASMCs. Prolonged exposure of RCAs to CRA reduced the expressions of these ion channels in RCA ASMCs, disordered tissue frames, injured arterial cells, and increased autophagosomes in both ASMCs and endothelial cells. In rat aortic smooth muscle cells (A7r5), CRA exposure decreased the cell viability, elevated the intracellular levels of reactive oxygen species, reduced the mitochondrial membrane potential, and enhanced autophagy. Taken together, the present study for the first time portrays a clearer panoramic outline of the vascular effects and the mechanisms of CRA on arteries, demonstrates that CRA impairs arterial contractility, depresses VGCCs, CaCCs, Kv channels and Kir channels, reduces cell viability, and destroys the arterial histiocytes, and suggests that excessive oxidative stress, mitochondrial dysfunction and autophagy underlie these vascular damages. These findings are significant for the comprehensive evaluation of the vicious effects of CRA on arteries and suggest potential preventive strategies.

Antibody–drug conjugates (ADCs) are a promising therapeutic modality for treating cancer. TM4SF1 is an integral membrane protein that internalizes from the cell surface along microtubules to the nucleus and is highly expressed on the surface of both tumor endothelium and tumor cells. We previously reported that in human tumor xenografts in mice, an ADC directed to mouse TM4SF1 (2A7A-LP2) effectively regressed tumors through an anti-vascular mechanism, and an ADC directed to human TM4SF1 (v1.10-LP2) effectively regressed tumors through an anti-tumor cell mechanism. In this study, we investigated the actions of the mouse TM4SF1-directed ADC on VEGF-A-provoked angiogenic vessels. We employed an adenovirus expressing mouse VEGF-A¹⁶⁴ (Ad-VEGF-A) to induce surrogate tumor blood vessels in the ears of nude mice. We showed that an immune effector function-ablated ADC, 3m2A7A-LP2, was better tolerated than its parent 2A7A-LP2. Homing of 3m2A7A to Ad-VEGF-A-induced new blood vessels became evident within six hours after intraperitoneal injection. A single dose of 3m2A7A-LP2 at 3 mg/kg disrupted evolving Ad-VEGF-A-provoked blood vessels within forty-eight hours, and three doses of 3m2A7A-LP2 at 48 h intervals caused striking local ear necrosis; in each case, there was no apparent harm to vessels in the corresponding control virus-injected ears and the surrounding tissues of the same mice. Our studies demonstrate that an ADC-directed against mouse TM4SF1 specifically targeted the newly formed blood vessels induced by Ad-VEGF-A at multiple stages of their development. Thus, TM4SF1-directed ADCs, through their ability to target angiogenic vessels, represent an alternative anti-angiogenic approach for treating solid tumors.

Background: Type 1 and type 2 diabetes both cause damage to the cardiovascular system. Hesperetin, a medicinal product found in foods, has been shown to have various cardioprotective effects. However, the effects of this compound on diabetes-related cardiovascular damage have not been evaluated.Methods: In this study, we aimed to investigate the protective effects of hesperetin on the coronary artery in diabetic rats and to explore its effects on the changes in critical proteins in the coronary artery using proteomics analysis. Results: Hesperetin alleviated coronary artery injury and modulated the expression of various proteins, including S100A8 and S100A9, which functioned in Toll-like receptor 4 binding, Toll-like receptor binding, and RAGE receptor binding. Pathways altered by hesperetin included type I diabetes mellitus, cell adhesion molecules, antigen processing and presentation, and interleukin-17 signaling pathway. Conclusions: In this study, we constructed a protein map of SD rats with type 1 diabetes treated with hesperetin, and found significant changes in three important proteins, S100A8, S100A9 and KNG1.Our findings provided important insights into further studies of the cardiovascular protective effects of hesperetin.