S1P/S1PR signaling pathway advancements in autoimmune diseases

Chlorogenic acid attenuates cardiac hypertrophy via up-regulating Sphingosine-1-phosphate receptor1 to inhibit endoplasmic reticulum stress

AIMS

Cardiac hypertrophy, an adaptive response of the heart to stress overload, is closely associated with heart failure and sudden cardiac death. This study aimed to investigate the therapeutic effects of chlorogenic acid (CGA) on cardiac hypertrophy and elucidate the underlying mechanisms.

METHODS AND RESULTS

To simulate cardiac hypertrophy, myocardial cells were exposed to isoproterenol (ISO, 10 μM). A rat model of ISO-induced cardiac hypertrophy was also established. The expression levels of cardiac hypertrophy markers, endoplasmic reticulum stress (ERS) markers, and apoptosis markers were measured using quantitative reverse transcription PCR and western blotting. The apoptosis level, size of myocardial cells, and heart tissue pathological changes were determined by terminal deoxynucleotidyl transferase dUTP nick-end labelling staining, immunofluorescence staining, haematoxylin and eosin staining, and Masson's staining. We found that CGA treatment decreased the size of ISO-treated H9c2 cells. Moreover, CGA inhibited ISO-induced up-regulation of cardiac hypertrophy markers (atrial natriuretic peptide, brain natriuretic peptide, and β-myosin heavy chain), ERS markers (C/EBP homologous protein, glucose regulatory protein 78, and protein kinase R-like endoplasmic reticulum kinase), and apoptosis markers (bax and cleaved caspase-12/9/3) but increased the expression of anti-apoptosis marker bcl-2 in a dose-dependent way (0, 10, 50, and 100 μM). Knockdown of sphingosine-1-phosphate receptor 1 (S1pr1) reversed the protective effect of CGA on cardiac hypertrophy, ERS, and apoptosis in vitro (P < 0.05). CGA also restored ISO-induced inhibition on the AMP-activated protein kinase (AMPK)/sirtuin 1 (SIRT1) signalling in H9c2 cells, while S1pr1 knockdown abolished these CGA-induced effects (P < 0.05). CGA (90 mg/kg/day, for six consecutive days) protected rats against cardiac hypertrophy in vivo (P < 0.05).

CONCLUSIONS

CGA treatment attenuated ISO-induced ERS and cardiac hypertrophy by activating the AMPK/SIRT1 pathway via modulation of S1pr1.

1-Phosphate receptor agonists: A promising therapeutic avenue for ischemia-reperfusion injury management

Ischemia-reperfusion injury (IRI) - a complex pathological condition occurring when blood supply is abruptly restored to ischemic tissues, leading to further tissue damage - poses a significant clinical challenge. Sphingosine-1-phosphate receptors (S1PRs), a specialized set of G-protein-coupled receptors comprising five subtypes (S1PR1 to S1PR5), are prominently present in various cell membranes, including those of lymphocytes, cardiac myocytes, and endothelial cells. Increasing evidence highlights the potential of targeting S1PRs for IRI therapeutic intervention. Notably, preconditioning and postconditioning strategies involving S1PR agonists like FTY720 have demonstrated efficacy in mitigating IRI. As the synthesis of a diverse array of S1PR agonists continues, with FTY720 being a prime example, the body of experimental evidence advocating for their role in IRI treatment is expanding. Despite this progress, comprehensive reviews delineating the therapeutic landscape of S1PR agonists in IRI remain limited. This review aspires to meticulously elucidate the protective roles and mechanisms of S1PR agonists in preventing and managing IRI affecting various organs, including the heart, kidney, liver, lungs, intestines, and brain, to foster novel pharmacological approaches in clinical settings.