Current Issue : October-December Volume : 2026 Issue Number : 4 Articles : 5 Articles
Background/Objectives: Emerging evidence suggests that alterations in lipid metabolism may play a contributing role in the pathogenesis of age-related macular degeneration (AMD). Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, a novel class of lipid-lowering agents, offer anti-inflammatory and antioxidant benefits, which may provide protective effects against AMD. We aimed to evaluate the risk of developing AMD among patients with atherosclerotic cardiovascular disease (ASCVD) who were newly treated with PCSK9 inhibitors compared with those receiving statins. Methods: This retrospective cohort study utilized data from the Global Collaborative Network within the TriNetX Research Network. Patients with ASCVD who were newly initiated on PCSK9 inhibitors or statins were identified and matched for age, sex, race, laboratory data, comorbidities, and concomitant medications. The primary outcomes were the hazard ratios (HRs) for developing AMD, dry AMD, and wet AMD. Propensity score matching (PSM) was used to adjust for baseline demographics and comorbidities. Results: After PSM, 50,102 patients were included in each group (PCSK9 inhibitor users vs. statin users). Compared to statin users, PCSK9 inhibitor users had significantly lower risks of AMD (HR, 0.81; 95% confidence interval [CI], 0.72–0.92) and dry AMD (HR, 0.78; 95% CI, 0.65–0.94), but not wet AMD (HR, 0.90; 95% CI, 0.70–1.16). Stratified and subgroup analyses showed reduced AMD risk among patients aged ≥65 years, White patients, female patients, and evolocumab users. Conclusions: In patients with ASCVD, compared with use of statins, use of PCSK9 inhibitors is associated with reduced risks of AMD and dry AMD, suggesting a potential novel strategy for managing a condition with limited therapeutic options....
Background/Objectives: The ACE2/Ang-(1–7)/Mas receptor axis is a protective, counterregulatory component of the RAAS that opposes Ang II/AT1R-mediated vasoconstriction. The present study evaluated the pharmacological effects of Ang-(1–7) in the rat inferior vena cava (IVC), a venous capacitance vessel involved in the regulation of venous return and cardiac preload. We hypothesized that Ang-(1–7) exerts anti-contractile effects in the rat inferior vena cava through activation of potassium channel-dependent mechanisms in venous smooth muscle. Methods: Isolated IVC rings from Wistar rats were studied using organ bath assays. Ang-(1–7) effects were assessed on pre-constriction induced by angiotensin II (Ang II), phenylephrine (PE), endothelin-1 (ET-1), and thromboxane A2 analog (U46619). Responses were recorded and quantified. Mechanistic involvement of nitric oxide (NO), prostaglandins, soluble guanylate cyclase (sGC), and K+ channels was evaluated using specific pharmacological inhibitors. Results: Ang-(1–7) attenuated Ang II-induced contraction. The effect was markedly reduced by tetraethylammonium (TEA), indicating a predominant role of potassium channel-dependent mechanisms in venous smooth muscle. In contrast, inhibition of nitric oxide synthase, soluble guanylate cyclase, or cyclooxygenase had minimal influence. Ang-(1–7) also produced concentrationdependent relaxation in PE-, ET-1-, and U46619-precontracted vessels, demonstrating agonist-dependent anti-contractile activity. Conclusions: Ang-(1–7) exerts significant anti-contractile effects in the rat inferior vena cava primarily through activation of TEAsensitive K+ channels in venous smooth muscle. These findings demonstrate functional activity of the ACE2/Ang-(1–7)/Mas axis in a major venous capacitance vessel and provide mechanistic insight into Ang-(1–7)-mediated modulation of venous tone, supporting further investigation in in vivo models....
Background/Objectives: Osteotoxicity is a severe complication of Methotrexate (MTX) chemotherapy, characterized by oxidative stress and disrupted bone remodeling. The primary objective of this study was to investigate the cytoprotective mechanisms of the antioxidant Alpha-Lipoic Acid (ALA) against MTX-induced osteotoxicity, specifically focusing on its modulation of oxidative stress, apoptosis, and Mitogen-Activated Protein Kinase (MAPK) signaling pathways. Methods: Murine osteocyte-like MLO-Y4 cells were cultured and exposed to a fixed dose of MTX (10−5 M), either alone or concurrently with ALA (50 μmol/L) for 48 h. Biochemical profiling was performed using specific enzyme-linked immunosorbent assays (ELISA) and colorimetric kits to evaluate pro- and anti-apoptotic proteins (Caspase-3, Bax, Bcl-2,Wee1, GRP78, GADD153, AIF), active MAPK components (p-JNK, p-ERK), and standard oxidative stress parameters (TAS, TOS, SOD, GPx). Results: MTX treatment induced significant cellular stress, evidenced by elevated Caspase-3, Bax, p-JNK, and p-ERK levels, alongside a critical reduction in Bcl-2 expression. MTX also markedly increased TOS while depleting TAS, SOD, and GPx levels. Conversely, co-treatment with ALA significantly mitigated these cytotoxic responses. ALA restored the Bax/Bcl-2 balance, effectively downregulated both p-JNK and p-ERK activation, and substantially reinforced the cellular antioxidant defense system by enhancing TAS, SOD, and GPx activities, although recovery to baseline control levels was partial. Conclusions: ALA exerts robust in vitro cytoprotective effects against MTX-induced osteotoxicity in MLO-Y4 cells by counteracting oxidative stress and inhibiting aberrant apoptotic and MAPK signaling. These findings establish a mechanistic baseline, underscoring the need for subsequent in vivo dose–response studies to validate ALA’s therapeutic potential in chemotherapy management....
Glucagon-like peptide (GLP)-1 receptor (GLP1R) agonists exert a multitude of beneficial cardiovascular effects beyond control of blood glucose levels and obesity reduction. GLP- 1R is a G protein-coupled receptor (GPCR), coupling to adenylyl cyclase (AC)-stimulatory Gs proteins to raise cyclic 3′-5′-adenosine monophosphate (cAMP) levels in cells. cAMP exerts various effects mainly via protein kinase A (PKA) and Exchange protein directly activated by cAMP (Epac). Cardiac GLP-1R has been reported to induce atrial natriuretic peptide (ANP) secretion via Epac2, while ANP is known to inhibit aldosterone secretion from adrenocortical zona glomerulosa (AZG) cells. Herein, we tested the effects of the GLP-1R agonist liraglutide on ANP secretion in H9c2 cardiomyocytes and on angiotensin II (AngII)-induced aldosterone secretion. We also examined whether phosphodiesterase (PDE)-4 inhibition with roflumilast could potentiate liraglutide’s effects. We found that liraglutide stimulated ANP secretion from H9c2 cardiomyocytes, an effect potentiated by roflumilast but blocked by AC inhibition. Epac inhibition with ESI-09 also significantly reduced liraglutide-dependent ANP secretion in H9c2 cardiomyocytes. Moreover, application of medium from liraglutide-treated H9c2 cardiomyocytes, but not from control cardiomyocytes, led to suppression of AngII-dependent aldosterone secretion from H295R cells. This effect was blocked by cyclic guanosine monophosphate (cGMP)-dependent protein kinase inhibition (an effector of ANP) in H295R cells, while direct application of liraglutide to these cells failed to suppress AngII-induced aldosterone secretion. Again, aldosterone suppression was more potent when medium from liraglutide plus roflumilast-treated cardiomyocytes was applied to H295R cells. Taken together, these results suggest that roflumilast enhances the adrenocortical aldosterone suppression induced by GLP-1R agonists via cardiac GLP-1R/cAMP/Epac-dependent ANP secretion. Given the cardio-toxic effects of elevated aldosterone levels in the context of various heart diseases, such as post-myocardial infarction heart failure, combination of a GLP-1R agonist drug with a PDE4 inhibitor drug may be more advantageous than either agent alone in treatment of certain cardiovascular diseases....
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....
Loading....