[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)-1β, 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-1β, 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.

Acacetin protects against sepsis-induced acute lung injury by facilitating M2 macrophage polarization via TRAF6/NF-κB/COX2 axis

Acute lung injury (ALI) is the leading cause of death in patients with sepsis syndrome and without effective protective or therapeutic treatments. Acacetin, a natural dietary flavonoid, reportedly exerts several biological effects, such as anti-tumor, anti-inflammatory, and anti-oxidative effects. However, acacetin's effect and underlying mechanism on sepsis-induced ALI remain unclear. Here, the mouse model was established to explore the impact of acacetin on sepsis-induced ALI. Acacetin significantly increased ALI murine survival and attenuated lung injury in histological examinations. Additionally, acacetin down-regulated myeloperoxidase activity, protein concentration, and number of neutrophils and macrophages in bronchoalveolar lavage fluid. Subsequently, inflammatory cytokines, including TNF-α, IL-1β, and IL-6, were examined. Results showed that acacetin dramatically suppressed the production of TNF-α, IL-1β, and IL-6. These above results indicated that acacetin attenuated sepsis-induced ALI by inhibiting the inflammatory response. Moreover, acacetin inhibited the expression of markers for M1-type (iNOS, CD86) macrophages and promoted the expression of markers for M2-type (CD206, Arg1) macrophages by western blot. In addition, acacetin down-regulated the expression TRAF6, NF-κB, and Cyclooxygenase-2 (COX2) by western blot. The high concentration of acacetin had a better effect than the low concentration. Besides, over-expression of TRAF6 up-regulated the expression of COX2, CD86, and iNOS, and the ratio of p-NF-κB to NF-κB increased the mRNA levels of TNF-α, IL-1β, and IL-6, down-regulated the expression of CD206 and Arg1. The effects of TRAF6 were the opposite of acacetin. And TRAF6 could offset the impact of acacetin. This study demonstrated that acacetin could prevent sepsis-induced ALI by facilitating M2 macrophage polarization via TRAF6/NF-κB/COX2 axis.

Common salt aggravated pathology of testosterone-induced benign prostatic hyperplasia in adult male Wistar rat

BACKGROUND

Benign prostatic hyperplasia (BPH) is a major health concern associated with lower urinary tract symptoms and sexual dysfunction in men. Recurrent inflammation, decreased apoptotic rate and oxidative stress are some of the theories that explain the pathophysiology of BPH. Common salt, a food additive, is known to cause systemic inflammation and redox imbalance, and may serve as a potential risk factor for BPH development or progression. This study examined the effect of common salt intake on the pathology of testosterone-induced BPH.

METHODS

Forty male Wistar rats were randomly divided into four equal groups of 10: a control and three salt diet groups-low-salt diet (LSD), standard-salt diet (SSD) and high-salt diet (HSD). The rats were castrated, allowed to recuperate and placed on salt-free diet (control), 0.25% salt diet (LSD), 0.5% salt diet (SSD) and 1.25% salt diet (HSD) for 60 days ad libitum. On day 33, BPH was induced in all the rats with daily injections of testosterone propionate-Testost® (3 mg/kg body weight) for 28 days. The rats had overnight fast (12 h) on day 60 and were euthanized the following day in order to collect blood and prostate samples for biochemical, molecular and immunohistochemistry (IHC) analyses. Mean ± SD values were calculated for each group and compared for significant difference with ANOVA followed by post hoc test (Tukey HSD) at p < 0.05.

RESULTS

This study recorded a substantially higher level of IL-6, IL-8 and COX-2 in salt diet groups and moderate IHC staining of COX-2 in HSD group. The prostatic level of IL-17, IL-1β, PGE2, relative prostate weight and serum PSA levels were not statistically different. The concentrations of IGF-1, TGF-β were similar in all the groups but there were multiple fold increase in Bcl-2 expression in salt diet groups-LSD (13.2), SSD (9.5) and HSD (7.9) and multiple fold decrease in VEGF expression in LSD (-6.3), SSD (-5.1) and HSD (-14.1) compared to control. Activity of superoxide dismutase (SOD) and concentration of nitric oxide rose in LSD and SSD groups, and SSD and HSD groups respectively. Activities of glutathione peroxidase and catalase, and concentration of NADPH and hydrogen peroxide were not significantly different. IHC showed positive immunostaining for iNOS expression in all the groups while histopathology revealed moderate to severe prostatic hyperplasia in salt diet groups.

CONCLUSIONS

These findings suggest that low, standard and high salt diets aggravated the pathology of testosterone-induced BPH in Wistar rats by promoting inflammation, oxidative stress, while suppressing apoptosis and angiogenesis.

A single dose of ketamine relieves fentanyl-induced-hyperalgesia by reducing inflammation initiated by the TLR4/NF-κB pathway in rat spinal cord neurons

A large amount of clinical evidence has revealed that ketamine can relieve fentanyl-induced hyperalgesia. However, the underlying mechanism is still unclear. In the current study, a single dose of ketamine (5 mg/kg or 10 mg/kg), TAK-242 (3 mg/kg), or saline was intraperitoneally injected into rats 15 min before four subcutaneous injections of fentanyl. Results revealed that pre-administration of ketamine alleviated fentanyl-induced hyperalgesia according to hind paw-pressure and paw-withdrawal tests. High-dose ketamine can reverse the expression of toll-like receptor-dimer (d-TLR4), phospho- nuclear factor kappa-B (p-NF-κB, p-p65), cyclooxygenase-2 (COX-2), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α) 1 d after fentanyl injection in the spinal cord. Moreover, fentany-linduced-hyperalgesia and changes in the expression of the aforementioned proteins can be attenuated by TAK-242, an inhibitor of TLR4, as well as ketamine. Importantly, TLR4, p-p65, COX-2, and IL-1β were expressed in neurons but not in glial cells in the spinal cord 1 d after fentanyl injection. In conclusion, results suggested that a single dose of ketamine can relieve fentanyl-induced-hyperalgesia via the TLR4/NF-κB pathway in spinal cord neurons.

15-Deoxy-Δ12,14-prostaglandin J2 Upregulates VEGF Expression via NRF2 and Heme Oxygenase-1 in Human Breast Cancer Cells

There is a plethora of evidence to support that inflammation is causally linked to carcinogenesis. Cyclooxygenase-2 (COX-2), a rate-limiting enzyme in the biosynthesis of prostaglandins, is inappropriately overexpressed in various cancers and hence recognized as one of the hallmarks of chronic inflammation-associated malignancies. However, the mechanistic role of COX-2 as a link between inflammation and cancer remains largely undefined. In this study, we found that 15-deoxy-Δ^12,14-prostaglandin J₂ (15d-PGJ₂), one of the final products of COX-2, induced upregulation of vascular endothelial growth factor (VEGF) and capillary formation and migration through nuclear factor erythroid 2-related factor 2 (NRF2)-dependent heme oxygenase-1 (HO-1) induction in MCF-7 cells. Analysis of the publicly available TCGA data set showed that high mRNA levels of both COX-2 and NRF2 correlated with the poor clinical outcomes in breast cancer patients. Moreover, human tissue analysis showed that the levels of 15d-PGJ₂ as well the expression of COX-2, NRF2, and HO-1 were found to be increased in human breast cancer tissues. In conclusion, the elevated levels of 15d-PGJ₂ during inflammatory response activate VEGF expression through NRF2-driven induction of HO-1 in human breast cancer cells, proposing a novel mechanism underlying the oncogenic function of 15d-PGJ₂.

Effect of Concurrent Chemoradiation With Celecoxib vs Concurrent Chemoradiation Alone on Survival Among Patients With Non-Small Cell Lung Cancer With and Without Cyclooxygenase 2 Genetic Variants: A Phase 2 Randomized Clinical Trial

IMPORTANCE

Treatment of locally advanced non-small cell lung cancer (NSCLC) remains challenging. The rationale of combining a cyclooxygenase 2 (COX-2) inhibitor with concurrent chemoradiation (CCRT) was based on results of preclinical research and prospective clinical studies; however, no randomized clinical trial has provided evidence of a direct comparison with CCRT alone.

OBJECTIVE

To determine the effect of combined selective COX-2 inhibition with standard CCRT on survival among patients with unresectable stage III NSCLC.

DESIGN, SETTING, AND PARTICIPANTS

A single-center, open-label, randomized phase 2 clinical trial was performed among 96 patients who had histologically and cytologically confirmed unresectable stage III NSCLC. Participants were enrolled from November 2011 to August 2015. Data were analyzed from February to October 2018.

INTERVENTION

Patients were randomized to receive thoracic radiation, 60 Gy, for 6 weeks concurrent with etoposide and cisplatin or the same regimen of CCRT combined with 200 mg of celecoxib, taken twice daily.

MAIN OUTCOMES AND MEASURES

The primary end point was overall survival. The secondary end points were the proportion of patients with treatment-related toxic effects, progression-free survival, and overall survival in subgroups with and without the COX-2 genotype.

RESULTS

A total of 100 patients were randomized. Following the exclusion of 4 outliers, 96 participants (96.0%) were analyzed (51 randomized to CCRT alone and 45 randomized to CCRT with celecoxib; mean [SD] age, 60.0 [8.3] years; 73.0 [76.0%] male). The median overall survival time was 32.8 (95% CI, 17.0-48.5) months in the group that received CCRT with celecoxib and 35.5 (95% CI, 25.8-45.2) months in the group that received CCRT alone (P = .88). Celecoxib with CCRT was well tolerated; the incidence of symptomatic radiation pneumonitis was 6.6% (95% CI, 1.4%-18.0%) in the group that received CCRT with celecoxib and 11.8% (95% CI, 4.4%-23.9%) in the group that received CCRT alone (P = .49). Among patients with the high-risk genotype, celecoxib plus CCRT was not associated with higher progression-free survival (hazard ratio, 0.36; 95% CI, 0.13-1.04; P = .05) or overall survival (hazard ratio, 0.50; 95% CI, 0.15-1.72; P = .26) compared with CCRT alone.

CONCLUSIONS AND RELEVANCE

In unresectable stage III NSCLC, adding celecoxib to concurrent chemoradiation did not improve survival. A smaller, not statistically significant proportion of patients in the CCRT with celecoxib group compared with the CCRT alone group developed symptomatic radiation pneumonitis. Among patients with the high-risk genotype, adding celecoxib to CCRT did not improve overall or progression-free survival.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT01503385.

The hepatic safety and tolerability of the cyclooxygenase-2 selective NSAID celecoxib: pooled analysis of 41 randomized controlled trials

OBJECTIVE

To assess the hepatic safety and tolerability of celecoxib versus placebo and three commonly prescribed nonselective nonsteroidal anti-inflammatory drugs (NSAIDs).

RESEARCH DESIGN AND METHODS

This was a retrospective, pooled analysis of a 41-study dataset involving patients with osteoarthritis, rheumatoid arthritis, ankylosing spondylitis, chronic low back pain, and Alzheimer's disease. Criteria for selection of studies were: (1) Randomized, parallel-group design and planned treatment duration of > or =2 weeks (2) > or =1 placebo or NSAID comparator (3) > or =1 arm with celecoxib at total daily dose of > or =200 mg (4) Data available as of October 31, 2004 Data were pooled by treatment and subject from the safety analysis population of included studies. Treatment-emergent hepatobiliary adverse events (AEs) were compared for celecoxib <200 mg/day (943 patients), 200 mg/day (12 008 patients), 400 mg/day (7380 patients), and 800 mg/day (4602 patients); placebo (4057 patients); diclofenac 100-150 mg/day (7639 patients); naproxen 1000 mg/day (2953 patients); and ibuprofen 2400 mg/day (2484 patients). Hepatobiliary laboratory abnormalities were also analyzed.

RESULTS

There were no cases of liver failure, treatment-related liver transplant, or treatment-related hepatobiliary death. Incidence of serious hepatic AEs was low, with 13 (0.05%) serious hepatic AEs among 24 933 celecoxib-treated patients, and 16 (0.21%) among 7639 diclofenac-treated patients. No patients receiving celecoxib or any nonselective NSAID met criteria for Hy's rule (alanine aminotransferase [ALT] > or =3 x upper limit of normal [ULN] with bilirubin > or =2 x ULN). The incidence of notable (> or =5 x ULN) and severe (> or =10 x ULN) ALT elevations was similar for all treatment groups except diclofenac. Significantly fewer hepatobiliary AEs were reported for celecoxib (any dose; 1.11%) than for diclofenac (vs. 4.24%, p < 0.0001); for ibuprofen (vs. 1.53%, p = 0.06) and placebo (vs. 0.89%, p = 0.21) the incidence of AEs was comparable to celecoxib.

LIMITATIONS

A number of limitations should be considered when evaluating the results: findings were limited by the quality and reporting of the studies selected; difficulty in estimating the incidence of AEs due to the low frequency of events; acetaminophen not included as an active comparator.

CONCLUSIONS

In this pooled analysis, the incidence of hepatic AEs in patients treated with celecoxib was similar to that for both placebo-treated patients and patients treated with ibuprofen or naproxen, but lower than for diclofenac.