Can pain intensity in osteoarthritis joint be indicator of the impairment of endothelial function?

Protective Effect of Resveratrol on Knee Osteoarthritis and its Molecular Mechanisms: A Recent Review in Preclinical and Clinical Trials

Osteoarthritis (OA) is one of the progressing chronic joint associated with by many complex factors such as age, obesity, and trauma. Knee osteoarthritis (KOA) is the most common type of OA. KOA is characterized by articular cartilage destruction and degeneration, synovial inflammation, and abnormal subchondral bone changes. To date, no practical clinical approach has been able to modify the pathological progression of KOA. Drug therapy is limited to pain control and may lead to serious side effects when taken for a long time. Therefore, searching for safer and more reliable treatments has become necessary. Interestingly, more and more research has focused on natural products, and monomeric compounds derived from natural products have received much attention as drug candidates for KOA treatment. Resveratrol (RES), a natural phenolic compound, has various pharmacological and biological activities, including anti-cancer, anti-apoptotic, and anti-decay. Recently, studies on the effects of RES on maintaining the normal homeostasis of chondrocytes in KOA have received increasing attention, which seems to be attributed to the multi-targeted effects of RES on chondrocyte function. This review summarizes preclinical trials, clinical trials, and emerging tissue engineering studies of RES for KOA and discusses the specific mechanisms by which RES alleviates KOA. A better understanding of the pharmacological role of RES in KOA could provide clinical implications for intervention in the development of KOA.

Predictive Value of Monocyte Chemoattractant Protein-1 in the Development of Diastolic Dysfunction in Patients with Psoriatic Arthritis

We aimed to evaluate the diagnostic accuracy of the proinflammatory monocyte chemotactic protein-1 (MCP-1) in the diagnosis of asymptomatic diastolic dysfunction (DD) in patients with psoriatic arthritis (PsA). The disease activity in psoriatic arthritis (DAPSA) was determined using clinical and laboratory parameters, and echocardiography was performed to estimate DD. Serum MCP-1 concentrations were elevated in PsA patients with DD diagnosed with ultrasound (median (25th percentile, 75th percentile): 366.6 pg/mL (283, 407.1 pg/mL) vs. 277.5 pg/mL (223.5, 319.1 pg/mL) in controls; $P<0.0017$ ). PsA patients with serum MCP-1 concentration higher than the cut-off value of 347.6 pg/mL had a 7.74-fold higher chance of developing DD than PsA patients with lower serum MCP-1 concentrations (controls), with a specificity of 86.36% and sensitivity of 55%, as verified using ultrasound. The group with MCP-1 concentrations above the cut-off value also showed a higher late peak diastolic mitral inflow velocity, A-wave value ( $P=0.000005$ ), E/E ${}^{\prime }$ ratio ( $P=0.00005$ ), and a lower E/A ratio ( $P=0.000002$ ), peak systolic left atrial reservoir strain, SA value ( $P=0.0066$ ), early peak diastolic displacement of the mitral septal annulus, E ${}^{\prime }$ wave value ( $P=0.003$ ), than controls. Systolic blood pressure ( $P=0.01$ ), LDL cholesterol concentration ( $P=0.012$ ), glucose concentration ( $P=0.011$ ), and DAPSA ( $P=0.0000$ ) increased in the PsA group with higher MCP-1 concentrations, although there were no differences in comorbidities and therapy between the groups compared. Thus, the serum MCP-1 concentration was a significant and independent prognostic indicator for asymptomatic DD in PsA patients ( $\text{area}\text{under}\text{the}\text{curve}=0.730$ , $P=0.001$ ). The DAPSA score in PsA patients might indicate the need for echocardiography and adjustment of anti-inflammatory treatment in terms of DD prevention.

Granulysin expression and granulysin-mediated apoptosis in the peripheral blood of osteoarthritis patients

Osteoarthritis (OA) is a chronic joint disease caused by mechanical damage and metabolic factors that support the development of low-grade inflammation. Increased levels of T helper 1 pro-inflammatory cytokines in the serum of OA patients may support granulysin (GNLY) mediated cytotoxicity, which in-turn may contribute to the pathogenesis of OA. In the present study, GNLY expression and cytotoxic/apoptotic mechanisms mediated by GNLY in the peripheral blood of OA patients were assessed. A total of 40 non-obese women (median age of 64 years old) with knee OA, and 40 controls (median age 62 years old) were enrolled in the study. GNLY, IFN-γ and IL-4 expression levels were investigated in peripheral blood lymphocytes (PBLs) using flow cytometry, immunocytochemistry and/or confocal microscopy. Natural killer (NK) GNLY-mediated apoptosis through NK effectors against K-562 targets was analyzed using the PKH-26 18-h cytotoxicity assay. Serum GNLY levels were assessed using ELISA. The percentage of GNLY⁺PBLs was higher in the OA patients than that in the controls due to the increase in the proportions of GNLY⁺ cells in the natural killer (NK), T and natural killer T (NKT) subsets. GNLY localization inside exocytotic lysosomal-associated membrane protein-1⁺ granules was ~40% in both groups. However, the intensity of GNLY labeling in PBLs was higher in OA patients than in the controls, and it was supported by the increased expression of IFN-γ relative to IL-4 in NK and T cells from OA patients. The serum GNLY concentration was <0.3 ng/ml in both groups. RC8 anti-GNLY mAb by itself was unable to significantly alter early apoptosis, whereas RC8 anti-GNLY mAb combined with anti-perforin mAb significantly reduced NK-mediated early apoptosis of K-562 targets in the OA patients, whilst not exerting a notable effect in the controls. Anti-perforin mAb by itself did not affect apoptosis significantly. These results suggest that in women with knee OA, GNLY expression in the PBL subsets and GNLY-mediated early apoptosis of K-562 targets are increased compared with the controls and accompanied by intracellular dominance of IFN-γ over IL-4 in NK cells.

Pain Characteristics, Cardiovascular Risk Factors, and Cardiovascular Disease

BACKGROUND

There is unclear evidence that chronic pain may increase the risk of cardiovascular disease (CVD) incidence and mortality. This work evaluated the association between chronic pain, incidence of CVD and changes in CVD risk factors.

METHODS

Cohort of 1091 community-dwelling individuals ≥60years, free from CVD at baseline, followed up for 6 years. Data on psychosocial factors and CVD risk factors was obtained through validated questionnaires and laboratory measurements. A pain scale ranging from 0 (no pain) to 6 (worst pain) was created according to pain frequency, location and intensity.

RESULTS

The cumulative incidence of CVD was 4.2% at 3 years, and 7.7% at 5-years of follow-up. Compared to individuals without pain in the first 3 years (2012-2015), those with maintained scores ≥2 showed a mean reduction of 3.57 (-5.77,-1.37) METs-h/week in recreational physical activity; a 0.38-point (0.04,0.73) increase in psychological distress; and a 1.79 (1.03,3.11) higher odds of poor sleep. These associations held in the second follow-up period, when individuals with maintained pain also worsened their diet quality. A 1-point increase in the pain scale in 2012 was associated with a 1.21 (1.03,1.42) and 1.18 (0.97,1.44) increased CVD incidence in 2015 and 2017, respectively; none of the studied factors mediated this relationship.

CONCLUSIONS

Older adults with chronic pain show important reductions in recreational physical activity and deterioration in mental health, sleep and diet quality, which may well aggravate pain. Future studies should evaluate whether these factors mediate the increased risk of CVD observed in older adults with chronic pain.

Resveratrol supplementation reduces pain experience by postmenopausal women

OBJECTIVE

Pain is a common complaint among postmenopausal women. It has been postulated that vascular dysfunction caused by estrogen decline at menopause plays a key role in the initiation and progression of degradative joint disease, namely age-related osteoarthritis. We evaluated whether supplementation with resveratrol, a phytoestrogen, could improve aspects of well-being such as chronic pain that is commonly experienced by postmenopausal women.

METHODS

A 14-week randomized, double-blind, placebo-controlled intervention with trans-resveratrol (75 mg, twice daily) was conducted in 80 healthy postmenopausal women. Aspects of well-being, including pain, menopausal symptoms, sleep quality, depressive symptoms, mood states, and quality of life were assessed by Short form-36 at baseline and at the end of treatment. Rating scales were averaged to provide a composite score representing overall well-being. Cerebral vasodilator responsiveness to hypercapnia was also assessed as a surrogate marker for cerebrovascular function.

RESULTS

Compared with placebo treatment, there was a significant reduction in pain and an improvement in total well-being after resveratrol supplementation. Both benefits, including measures of quality of life, correlated with improvements in cerebrovascular function.

CONCLUSIONS

Our preliminary findings indicate potential for resveratrol treatment to reduce chronic pain in age-related osteoarthritis. Resveratrol consumption may also boost perceptions of well-being in postmenopausal women. Further investigation to elucidate underlying mechanisms is warranted.