[Inhibitory effect of downregulating G protein-coupled receptor class C group 5 member A expression on lipopolysaccharide-induced inflammatory response in human gingival fibroblasts].

Objective: To clarify the effect and the mechanism of G protein-coupled receptor class C group 5 member A (GPRC5A) on lipopolysaccharide (LPS)-induced inflammatory response in human gingival fibroblasts (GFs), thus to provide a foundation for delving into the role of G protein coupled receptor (GPCR) in periodontitis. Methods: Gingival tissue samples were collected from 3 individuals periodontally healthy (health group) and 3 patients with periodontitis (periodontitis group) in Shandong Stomatological Hospital from December 2022 to February 2023. The expressions of GPRC5A of the two groups were detected by immunohistochemistry staining. GFs used in this study were isolated from a portion of gingiva for the extraction of impacted teeth in School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University from December 2022 to February 2023. GFs were isolated with enzymic digestion and transfected with 30, 50 and 80 µmol/L small interfering RNA-GPRC5A (siGPRC5A) or small interfering RNA-negative control (siNC), regarded as the experimental group and the negative control one, respectively. The silencing efficiency of siGPRC5A was evaluated by real-time fluorescence quantitative PCR (RT-qPCR). Experiments were then conducted using these cells which were divided into four groups of negative control (NC), LPS, siGPRC5A+LPS and siGPRC5A. The mRNA and protein levels of GPRC5A in GFs under 1 mg/L LPS-induced GFs inflammatory state were evaluated by RT-qPCR and Western blotting analysis after GPRC5A knockdown. RT-qPCR was used to detect the gene expression levels of the inflammatory cytokines in GFs induced by LPS, namely, interleukin (IL)-1ß, IL-6, IL-8, tumor necrosis factor (TNF)-α, prostaglandin endoperoxide synthase 2 (PTGS2) after GPRC5A knockdown. Western blotting analysis and immunofluorescence staining were used to further investigate the activation of nuclear factor-kappa B (NF-κB) signaling pathway. Results: Immunohistochemistry staining showed that the expression of GPRC5A in gingival tissues of periodontitis group (0.132±0.006) increased compared with that in periodontally healthy group (0.036±0.019) (t=8.24, P=0.001). Meanwhile, RT-qPCR results showed that the gene expression levels of GPRC5A at different time point (2, 6, 12, 24 h) in LPS-induced GFs (0.026±0.002, 0.042±0.005, 0.004±0.000, 0.016±0.000) were upregulated compared with those in the NC group (0.004±0.000, 0.004±0.000, 0.002±0.000, 0.007±0.000) (all P<0.001), respectively, and peaked at 6 h. The 50 µmol/L group displayed the most significant decrease in siGPRC5A expression (31.16±3.29) compared with that of the siNC group (100.00±4.88) (F=297.98, P<0.001). The results of RT-qPCR and Western blotting analysis showed that siGPRC5A (0.27±0.03, 0.71±0.00) suppressed the expressions of GPRC5A at both gene and protein levels, while LPS (1.30±0.10, 1.43±0.03) was able to promote the expressions of GPRC5A compared with those of the NC group (1.00±0.01, 1.00±0.00)(all P<0.001). The siGPRC5A+LPS group (0.39±0.03, 1.06±0.16) also inhibited the increase of GPRC5A at both gene and protein levels induced by LPS (1.30±0.10, 1.43±0.03) (F=208.38, P<0.001; F=42.04, P<0.001). RT-qPCR results showed that the expressions of IL-8, IL-1ß, IL-6, TNF-α, and PTGS2 at the gene level in LPS group were highly increased compared with those in the NC group (all P<0.001). siGPRC5A significantly suppressed LPS-induced expressions of these inflammatory cytokines in GFs (all P<0.001). Western blotting analysis showed that the levels of p65 and IκBα protein phosphorylation in the LPS group were highly increased compared with those in the NC group, and siGPRC5A could effectively suppressed LPS-induced protein phosphorylation (all P<0.01). Furthermore, immunofluorescence staining showed that NF-κB p65 in the control group was mainly concentrated in the cytoplasm, and partially translocated to the nucleus under the stimulation of LPS. siGPRC5A was able to inhibit LPS-induced intranuclear translocation of p65 to a certain extent. Conclusions: GPRC5A expression was upregulated in periodontitis, and GPRC5A knockdown inhibited LPS-induced inflammation. Moreover, GPRC5A played a role in inflammation regulation by interacting with NF-κB signaling pathway.

[Role of PI3K/Akt signaling pathway in ischemic rats underwent cardiac shock waves therapy].

Objective: To investigate the role of PI3K/Akt signaling pathway in ischemic rats underwent cardiac shock therapy. Methods: Adult male Sprague Dawley (SD) rats weighing 220-250 g were used to establish a heart failure model by ligation of the left anterior descending coronary artery. Rat models were defined by echocardiographic assessment at 4 weeks post operation and heart failure rats were randomly divided into 4 groups,namely heart failure group (HF group, 9 cases),heart failure+cardiac shock waves therapy group (HF+CSWT group, 9 cases),heart failure+inhibitor(HF+LY294002 group, 9 cases),heart failure+cardiac shock waves therapy group+inhibitor (HF+CSWT+LY294002 group, 9 cases),and another 9 sham-operated SD rats served as control group (sham group, 9 cases). At 8 weeks postoperation, echocardiography was used to evaluate cardiac function in each group,myocardial infarct size was measured by TTC staining,the apoptotic index of rats cardiomyocytes were detected by TUNEL method,the myocardial mRNA expression of apoptosis-related factor was detected by real-time quantitative PCR, the protein expression levels of PI3K/Akt signaling pathway and apoptosis-related pathways were detected by Western blot. Results: (1) Eight weeks after operation, left ventricular end diastolic diameter (LVEDD) and left ventricular end systolic diameter (LVESD) were significantly lower in HF+CSWT group than in HF group (all P<0.05), left ventricular ejection fraction (LVEF) and left ventricular shortening rate (LVFS) were significantly higher in HF+CSWT group than in HF group (all P<0.05),LVEF was significantly lower in the HF+ CSWT+ LY294002 group than in HF+ CSWT group (P<0.05). (2) Myocardial infarct size was significantly lower in the HF+ CSWT group than in HF group ((5.57 ± 0.51)% vs. (25.56 ± 0.56)%, P<0.05), which was significantly higher in the HF+CSWT+LY294002 group than in HF+CSWT group ((12.90±2.34)% vs. (5.57±0.51)%,P<0.05). (3) The cardiomyocyte apoptotic index was significantly lower in the HF+CSWT group than in the HF group ((30.25±6.12)% vs. (53.85±9.89)%,P<0.05), which was significantly higher in the HF+CSWT+LY294002 group than in the HF+CSWT group ((46.12±3.42)% vs.(30.25±6.12)%,P<0.05). (4) The myocardial mRNA expression of Bcl-2 was significantly higher, while myocardial mRNA Bax and Caspase-3 expression were significantly lower in HF+CSWT group than in HF group and HF+CSWT+LY294002 group (all P<0.05). (5) The expression levels of p-Akt, Bcl-2 and pro-Caspase-3 in myocardial tissue were significantly higher in the HF+CSWT group than in the HF group and HF+CSWT+LY294002 group (all P<0.05), which were significantly lower in the HF+LY294002 group than in the HF and HF+CSWT+LY294002 groups (all P<0.05). Myocardial Bax protein expression was significantly lower in the HF+CSWT group than in the HF group and the HF+CSWT+LY294002 group (all P<0.05), which was significantly higher in the HF+LY294002 group than in the HF group (P<0.05). Conclusion: CSWT improves cardiac function and inhibits cardiomyocyte apoptosis through PI3K/Akt signaling pathways in this rat HF model.

Comparison of pharmacodynamic effects of ticagrelor vs prasugrel in type 2 diabetes mellitus patients with coronary heart disease.

WHAT IS KNOWN AND OBJECTIVE: Patients with type 2 diabetes mellitus (T2DM) are at higher risk of thrombotic complications. Studies have indicated that patients with T2DM have impaired clopidogrel-induced antiplatelet effect. Ticagrelor and prasugrel are two latest generation P2Y12 inhibitors with advantageous platelet inhibitory profiles. However, the pharmacodynamic differences between the two drugs in patients with T2DM remain poorly explored. METHODS: This study, involving 140 patients with T2DM following percutaneous coronary intervention (PCI), evaluated the efficacy of aspirin upon concomitant use of prasugrel (10 mg/d) or ticagrelor (90 mg/d). Platelet reactivity was assessed by value of ADP-induced light transmittance aggregometry (LTA) and vasodilator-stimulated phosphoprotein phosphorylation-platelet reactivity index (VASP-PRI) at baseline, 7 and 30 days after randomized P2Y12 inhibitor treatment. RESULTS: The study showed a decreased platelet reactivity after use of P2Y12 inhibitors (both P < .001). On the basis of comparison between regimens, apart from the prasugrel group having a significantly higher LTA value at the 30-day time point (P = .043), there existed no significant differences in platelet reactivity at separate time points (all P > .05). As for intragroup measurements, when compared with 7-day and 30-day time points, similar platelet reactivity was documented in the ticagrelor group (both P > .05), but LTA tests showed a significant increase with time (days 7-30) in the prasugrel group (P = .050). WHAT IS NEW AND CONCLUSION: Although ticagrelor and prasugrel have similar platelet inhibitory effects in patients with T2DM, if a P2Y12 inhibitor is necessitated in patients with T2DM, ticagrelor might exert a more stable antiplatelet effect with 30-day short-term treatment.