Platelet mitochondrial respiration and coenzyme Q10 could be used as new diagnostic strategy for mitochondrial dysfunction in rheumatoid diseases

Astaxanthin, Compared to Other Carotenoids, Increases the Efficacy of Methotrexate in Rat Adjuvant Arthritis

This in vivo study performed in rat adjuvant arthritis aims to advance the understanding of astaxanthin's therapeutic properties for the possible treatment of rheumatoid arthritis (RA) in monotherapy and along with the standard RA treatment, methotrexate (MTX), in combination therapy. The main goal was to elucidate astaxanthin's full therapeutic potential, evaluate its dose dependency, and compare its effects in monotherapy with other carotenoids such as β-carotene and β-cryptoxanthin (KXAN). Moreover, potential differences in therapeutic activity caused by using different sources of astaxanthin, synthetic (ASYN) versus isolated from Blakeslea trispora (ASTAP), were evaluated using one-way ANOVA (Tukey-Kramer post hoc test). KXAN was the most effective in reducing plasma MMP-9 levels in monotherapy, significantly better than MTX, and in reducing hind paw swelling. The differences in the action of ASTAP and ASYN have been observed across various biometric, anti-inflammatory, and antioxidative parameters. In combined therapy with MTX, the ASYN + MTX combination proved to be better. These findings, especially the significant anti-arthritic effect of KXAN and ASYN + MTX, could be the basis for further preclinical studies.

Modulatory effects of dietary saturated fatty acids on platelet mitochondrial function following short-term exposure to ambient Particulate Matter (PM2.5)

Exposure to ambient fine particulate matter (PM2.5) was found to produce vascular injury, possibly by activating platelets within days after exposure. The aim of this study was to investigate the modulatory effects of dietary saturated fatty acids on platelet mitochondrial respiratory parameters following short-term inhalational exposure to PM2.5. A total of 22 healthy male volunteers were recruited from the Research Triangle area of North Carolina. Platelets were isolated from fresh whole blood samples and mitochondrial respiratory parameters were measured using an extracellular flux analyzer. Intake of saturated fat was averaged from multiple 24-hr dietary recalls. Daily ambient PM2.5 concentrations were obtained from ambient air quality monitoring stations. Correlation and ANOVA were used in data analyses, along with the pick-a-point method and the Johnson-Neyman technique for probing moderation. After controlling for age and omega-3 index, the intake of dietary saturated fatty acids after reaching 9.3% or higher of the total caloric intake significantly moderated the associations between PM2.5 exposure and several platelet mitochondrial respiratory parameters. In conclusion, dietary saturated fatty acids above 9.3% of total caloric intake influenced the relationship between short-term PM2.5 exposure and platelet mitochondrial respiration. Further research is needed to understand these associations and their implications for cardiovascular health.

Elevated LDL-C, high blood pressure, and low peak V ˙ O2 associate with platelet mitochondria function in children-The Arkansas Active Kids Study

Purpose: To evaluate the association of platelet (PL) mitochondria respiration with markers of cardiovascular health in children ages 7-10 years. Methods: PL mitochondrial respiration (n = 91) was assessed by high resolution respirometry (HRR): Routine (R) respiration, complex (C) I linked respiration (CI), and maximal uncoupled electron transport capacity of CII (CII_E) were measured. The respiratory control ratio (RCR) was calculated as the ratio of maximal oxidative phosphorylation capacity of CI and CI leak respiration (P_CI/L_CI). Peak V ˙ O₂ (incremental bike test) and body composition (dual-energy X-ray absorptiometry) were measured. Multiple generalized linear regression analysis was used to model the association of measures by HRR with variables of interest: adiposity, low-density lipoprotein (LDL-C) and triglyceride (TG) status (normal vs. elevated) HOMA2-IR, blood pressure status (normal vs. high), and demographics. Results: R and CI-linked respiration positively associated with adiposity, high blood pressure (HBP), and peak V ˙ O₂. R and CI-linked respiration had inverse association with age and elevated LDL-C. CII_E was higher in children with elevated LDL-C (log-β = -0.54, p = 0.010). HBP and peak V ˙ O₂ interacted in relation to RCR (log-β = -0.01, p = 0.028). Specifically, RCR was lowest among children with HBP and low aerobic capacity (i.e., mean peak V ˙ O₂ -1SD). HOMA2-IR did not associate with measures of PL mitochondria respiration. Conclusion: In PL, R and CI-linked mitochondrial respiration directly associate with adiposity, peak V ˙ O₂ and HBP. Elevated LDL-C associates with lower CI-linked respiration which is compensated by increasing CII respiration. PL bioenergetics phenotypes in children associate with whole-body metabolic health status.

Why might ovarian rejuvenation fail? Decision analysis of variables impacting reproductive response after autologous platelet-rich plasma

Experience with platelet-rich plasma (PRP) has accumulated from use in dental restoration, post-infarct myocardial repair, tendon surgery, pain management, and aesthetic enhancements. Reproductive medicine joined this arena in 2016, beginning with reports of menopause reversal and fertility recovery after autologous PRP for senescent ovaries. Although recent publications have highlighted benefits of 'ovarian rejuvenation', the absence of randomized placebo-controlled clinical trial data has limited its acceptance. Because selection bias tends to underreport negative outcomes, reliable estimates cannot be calculated for how often intraovarian PRP is unsuccessful. Ample information is available, however, to permit an operational root-cause analysis when failures are considered. This assessment uses a PRP treatment care path with a decision theory model to critique pre-intake screening, baseline audit, sample processing, ovarian tissue placement method, equipment selection, and follow-up monitoring. These branched choice points enable interventions likely to determine outcome. Specimen handling for intraovarian PRP merits particular scrutiny, since enormous variation in platelet protocols already exists across unrelated clinical areas. As a new addition to fertility practice, intraovarian PRP requires validation of safety and efficacy to gain wider support. Borrowing PRP knowledge from other domains can facilitate this goal, ideally with appreciation of aspects unique to intraovarian use.

Platelet Mitochondrial Bioenergetics Reprogramming in Patients with Urothelial Carcinoma

Mitochondrial bioenergetics reprogramming is an essential response of cells to stress. Platelets, an accessible source of mitochondria, have a crucial role in cancer development; however, the platelet mitochondrial function has not been studied in urothelial carcinoma (UC) patients. A total of 15 patients with UC and 15 healthy controls were included in the study. Parameters of platelet mitochondrial respiration were evaluated using the high-resolution respirometry method, and the selected antioxidant levels were determined by HPLC. In addition, oxidative stress was evaluated by the thiobarbituric acid reactive substances (TBARS) concentration in plasma. We demonstrated deficient platelet mitochondrial respiratory chain functions, oxidative phosphorylation (OXPHOS), and electron transfer (ET) capacity with complex I (CI)-linked substrates, and reduced the endogenous platelet coenzyme Q10 (CoQ10) concentration in UC patients. The activity of citrate synthase was decreased in UC patients vs. controls (p = 0.0191). γ-tocopherol, α-tocopherol in platelets, and β-carotene in plasma were significantly lower in UC patients (p = 0.0019; p = 0.02; p = 0.0387, respectively), whereas the plasma concentration of TBARS was increased (p = 0.0022) vs. controls. The changes in platelet mitochondrial bioenergetics are consistent with cell metabolism reprogramming in UC patients. We suppose that increased oxidative stress, decreased OXPHOS, and a reduced platelet endogenous CoQ10 level can contribute to the reprogramming of platelet mitochondrial OXPHOS toward the activation of glycolysis. The impaired mitochondrial function can contribute to increased oxidative stress by triggering the reverse electron transport from the CoQ10 cycle (Q-junction) to CI.