Altered functions of platelets during aging

Platelet-to-lymphocyte ratios as a haematological marker of synovitis in rheumatoid arthritis with normal acute phase reactant level

BACKGROUND

Although normal acute phase reactants (APRs) play an important role in assessing disease activity of rheumatoid arthritis (RA), some studies pointed out the discordance between disease activity and APR level. Neutrophil-to-lymphocyte ratios (NLRs), platelet-to-lymphocyte ratios (PLRs) and lymphocyte-to-monocyte ratios (LMRs) have been reported to be sensitive measures of inflammatory reaction. This study aims to explore the value of these haematological makers in assessment of APR-negative RA patients.

METHODS

Out of a cohort of 418 consecutive patients with RA, we enrolled 135 patients with normal APR for this study. We performed ultrasound assessments to evaluate synovitis and bone erosion in the affected joints. Synovitis was evaluated by ultrasound grey scale (GS) and power Doppler (PD) with semi-quantitative scoring (0-3). Demographic, clinical and laboratory data were collected from the patients. Disease Activity Score-28 joints (DAS28), NLR, MLR and PLR were calculated.

RESULTS

In RA patients with normal APR, PLR exhibited a positive correlation with ultrasound-detected synovitis and bone erosion, whereas NLR, MLR showed no significant correlation with ultrasonography parameters. The area under the ROC curve (AUC) for identifying synovitis with a GS grade ≥2 based on a PLR cutoff value of ≥159.6 was 0.7868 (sensitivity: 80.95%, specificity: 74.24%). For synovitis with a PD grade ≥2, the AUC was 0.7690, using a PLR cutoff value of ≥166.1 (sensitivity: 68.0%, specificity: 83.87%).

CONCLUSIONS

Our findings suggested that PLR might be a reliable and cost-effective marker for identifying moderate-to-severe synovitis in RA patients with normal APR.

Aggregates in apheresis-derived platelet concentrates: A 5-year single-centre experience

BACKGROUND AND OBJECTIVES

The phenomenon of aggregates in apheresis-derived platelet concentrates (APCs) has not yet been fully elucidated. Initially, visible aggregates (IVA) usually dissolve within 24 h after collection, but some persist till the end of the shelf life (persistent aggregates, PA). A study conducted at the Croatian Institute of Transfusion Medicine aimed to identify factors that influence the aggregate occurrence in APCs.

MATERIALS AND METHODS

We conducted a cross-sectional study for the 2018-2022 period and collected data on APCs with IVA. We analysed APCs discarded due to PA separately for two apheresis technologies and compared them to the control group.

RESULTS

Significantly more donations were discarded in the IVA group compared with the control group and total number of discarded APCs. A total of 205 APCs were discarded due to PA (14.7% of IVA APCs and 1.27% of all APCs collected). Amicus APCs with PA had a significantly lower platelet count and mean platelet volume. They were obtained by procedures with less anticoagulant used. In contrast to Amicus APCs, Haemonetics APCs with PA had a significantly higher platelet count. None of the donor-related factors examined was predictive of PA.

CONCLUSION

APCs with IVA are more often discarded, not only due to aggregates, but also for impairment of other quality control parameters. Type of apheresis technology, being one of the most common risk factors for IVA, was not confirmed as the main risk factor for PA. There seem to be some donor-related causal factors.

Aging-related alterations in mechanistic target of rapamycin signaling promote platelet hyperreactivity and thrombosis

BACKGROUND

Aging is an independent risk factor for the development of cardiovascular, thrombotic, and other chronic diseases. However, mechanisms of platelet hyperactivation in aging remain poorly understood.

OBJECTIVES

Here, we examine whether and how aging alters intracellular signaling in platelets to support platelet hyperactivity and thrombosis.

METHODS

Quantitative mass spectrometry with tandem mass tag labeling systematically measured protein phosphorylation in platelets from healthy aged (>65 years) and young human (<45 years) subjects. The role of platelet mechanistic target of rapamycin (mTOR) in aging-induced platelet hyperreactivity was assessed using pharmacologic mTOR inhibition and a platelet-specific mTOR-deficient mouse model (mTORplt-/-).

RESULTS

Quantitative phosphoproteomics uncovered differential site-specific protein phosphorylation within mTOR, Rho GTPase, and MAPK pathways in platelets from aged donors. Western blot confirmed constitutive activation of the mTOR pathway in platelets from both aged humans and mice, which was associated with increased aggregation compared with that in young controls. Inhibition of mTOR with either Torin 1 in aged humans or genetic deletion in aged mice reversed platelet hyperreactivity. In a collagen-epinephrine pulmonary thrombosis model, aged wild-type (mTORplt+/+) mice succumbed significantly faster than young controls, while time to death of aged mTORplt-/- mice was similar to that of young mTORplt+/+ mice. Mechanistically, we noted increased Rac1 activation and levels of mitochondrial reactive oxygen species in resting platelets from aged mice, as well as increased p38 phosphorylation upstream of thromboxane generation following agonist stimulation.

CONCLUSION

Aging-related changes in mTOR phosphorylation enhance Rac1 and p38 activation to enhance thromboxane generation, platelet hyperactivity, and thrombosis.

Identification of the changes in the platelet proteomic profile of elderly individuals

Background

Platelet hyperreactivity is a risk factor for thrombosis in elderly patients with cardiovascular diseases. However, the mechanism of platelet hyperactivation has not been elucidated. This study aims to investigate alterations in the proteomes of platelets and their correlation with platelet hyperreactivity among elderly individuals.

Methods

This study included 10 young (28.1 ± 1.9 years), 10 middle-aged (60.4 ± 2.2 years), and 10 old (74.2 ± 3.0 years) subjects. Washed platelets were used in the present study. Platelet samples were analysed by using data-independent acquisition (DIA) quantitative mass spectrometry (MS).

Results

The results showed that the platelet proteomic profile exhibited high similarity between the young and middle-aged groups. However, there were significant differences in protein expression profiles between the old group and the young group. By exploring the dynamic changes in the platelet proteome with ageing, clusters of proteins that changed significantly with ageing were selected for further investigation. These clusters were related to the initial triggering of complement, phagosome and haemostasis based on enrichment analysis. We found that platelet degranulation was the major characteristic of the differentially expressed proteins between the old and young populations. Moreover, complement activation, the calcium signalling pathway and the nuclear factor-κB (NF-κB) signalling pathway were enriched in differentially expressed proteins.

Conclusions

The present study showed that there are obvious differences in the protein profiles of the elderly compared with young and middle-aged populations. The results provide novel evidence showing changes in platelet hyperactivity and susceptibility to thrombosis in the elderly population.

Perioperative Management of a Frail Patient With Bernard-Soulier Syndrome

Bernard-Soulier syndrome (BSS) is an autosomal recessive inherited bleeding disorder characterized by prolonged bleeding time, thrombocytopenia, and giant platelets. Patients with BSS are at an increased risk of bleeding, especially during traumatic injury and surgical procedures. The literature on the anesthetic management of patients with BSS is limited. In this report, we detail the successful management of a frail patient with BSS who underwent a major surgical procedure. Despite comprehensive clinical monitoring and an extended pharmacological strategy, a hemorrhagic complication occurred in the later postoperative phase, emphasizing the necessity for continued support and vigilant clinical monitoring due to the ongoing bleeding risk associated with these patients. In this case, a combined strategy involving antifibrinolytics, recombinant factor VII, and platelet transfusions proved effective.

Aging and Antithrombotic Treatment

Significance: Several aging-related pathophysiological mechanisms have been described to contribute to increased thrombotic risk in the elderly, including oxidative stress, endothelial dysfunction, and platelet and coagulation cascade activation. Antithrombotic treatment in the elderly should be individualized. Recent Advances: Recent studies have clarified some pathophysiological mechanisms of enhanced oxidative stress and thrombotic alterations in older adults. In the last decade, randomized trials have evaluated different antithrombotic strategies to reduce the risk of cardiovascular events in these patients. Critical Issues: The proportion of elderly patients included in clinical trials is generally low, thus not reflecting the daily clinical practice. There is no consensus on the most appropriate antithrombotic treatment in the elderly, also considering that bleeding risk management may be challenging in this high-risk subgroup of patients. Routine antiplatelet treatment is not a valid strategy for the primary prevention of cardiovascular events given the associated high risk of bleeding. In elderly patients with acute coronary syndrome, low-dose prasugrel or clopidogrel, shorter dual antiplatelet therapy, and no pretreatment before stent placement should be considered. Advanced age should not be the only reason for the underuse of oral anticoagulation in patients with atrial fibrillation, with direct oral anticoagulants preferred over warfarin for stroke prevention. Instead, a case-by-case clinical evaluation is warranted based on patient's bleeding risk also. Future Directions: There is a need for a structured tailored approach to manage thrombotic risk in elderly patients. The choice of the most appropriate antithrombotic treatment should balance efficacy and safety to reduce the risk of bleeding.

Elderly-Onset Rheumatoid Arthritis: Characteristics and Treatment Options

Elderly-onset rheumatoid arthritis (EORA) is a distinct clinical entity defined as the onset of rheumatoid arthritis (RA) in individuals aged over 60 years. EORA presents unique clinical features, including a more equitable distribution of sexes, a potential predilection for male involvement, a higher incidence of acute onset characterized by constitutional symptoms, a propensity for systemic manifestations, elevated sedimentation rates at disease onset, a reduced occurrence of rheumatoid factor positivity, increased titers of anti-citrullinated protein antibodies, a preference for involvement of large joints, elevated disease activity, the presence of bone erosions, and heightened patient disability. RA is recognized to consist of three partially overlapping subsets. One subset mirrors the classical RA clinical presentation, while the remaining subsets exhibit either a polymyalgia rheumatica-like phenotype or present with remitting seronegative symmetrical synovitis accompanied by pitting edema syndrome. In the initial stages of EORA management, non-steroidal anti-inflammatory drugs (NSAIDs) are not typically the first-line treatment choice, because seniors are much more prone to develop side effects due to NSAIDs, and the use of NSAIDs is in reality contraindicated to the majority of seniors due to comorbidities. Disease-modifying antirheumatic drugs (DMARDs), frequently methotrexate, are introduced immediately after the diagnosis is made. In cases where elderly patients demonstrate resistance to conventional DMARD therapy, the introduction of biological or targeted synthetic DMARDs becomes a viable treatment option. EORA presents a unique clinical profile, necessitating tailored treatment strategies. Our study emphasizes the challenges of NSAID use in seniors, highlighting the imperative shift toward DMARDs such as methotrexate. Future research should explore personalized DMARD approaches based on disease activity, comorbidities, and safety considerations, aiming to optimize treatment outcomes and minimize glucocorticoid reliance, thereby enhancing the quality of care for EORA patients.

Morphometric and Nanomechanical Screening of Peripheral Blood Cells with Atomic Force Microscopy for Label-Free Assessment of Alzheimer's Disease, Parkinson's Disease, and Amyotrophic Lateral Sclerosis

Neurodegenerative disorders (NDDs) are complex, multifactorial disorders with significant social and economic impact in today's society. NDDs are predicted to become the second-most common cause of death in the next few decades due to an increase in life expectancy but also to a lack of early diagnosis and mainly symptomatic treatment. Despite recent advances in diagnostic and therapeutic methods, there are yet no reliable biomarkers identifying the complex pathways contributing to these pathologies. The development of new approaches for early diagnosis and new therapies, together with the identification of non-invasive and more cost-effective diagnostic biomarkers, is one of the main trends in NDD biomedical research. Here we summarize data on peripheral biomarkers, biofluids (cerebrospinal fluid and blood plasma), and peripheral blood cells (platelets (PLTs) and red blood cells (RBCs)), reported so far for the three most common NDDs-Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS). PLTs and RBCs, beyond their primary physiological functions, are increasingly recognized as valuable sources of biomarkers for NDDs. Special attention is given to the morphological and nanomechanical signatures of PLTs and RBCs as biophysical markers for the three pathologies. Modifications of the surface nanostructure and morphometric and nanomechanical signatures of PLTs and RBCs from patients with AD, PD, and ALS have been revealed by atomic force microscopy (AFM). AFM is currently experiencing rapid and widespread adoption in biomedicine and clinical medicine, in particular for early diagnostics of various medical conditions. AFM is a unique instrument without an analog, allowing the generation of three-dimensional cell images with extremely high spatial resolution at near-atomic scale, which are complemented by insights into the mechanical properties of cells and subcellular structures. Data demonstrate that AFM can distinguish between the three pathologies and the normal, healthy state. The specific PLT and RBC signatures can serve as biomarkers in combination with the currently used diagnostic tools. We highlight the strong correlation of the morphological and nanomechanical signatures between RBCs and PLTs in PD, ALS, and AD.

The platelet transcriptome and proteome in Alzheimer's disease and aging: an exploratory cross-sectional study

Introduction: Alzheimer's disease (AD) and aging are associated with platelet hyperactivity. However, the mechanisms underlying abnormal platelet function in AD and aging are yet poorly understood. Methods: To explore the molecular profile of AD and aged platelets, we investigated platelet activation (i.e., CD62P expression), proteome and transcriptome in AD patients, non-demented elderly, and young individuals as controls. Results: AD, aged and young individuals showed similar levels of platelet activation based on CD62P expression. However, AD and aged individuals had a proteomic signature suggestive of increased platelet activation compared with young controls. Transcriptomic profiling suggested the dysregulation of proteolytic machinery involved in regulating platelet function, particularly the ubiquitin-proteasome system in AD and autophagy in aging. The functional implication of these transcriptomic alterations remains unclear and requires further investigation. Discussion: Our data strengthen the evidence of enhanced platelet activation in aging and provide a first glimpse of the platelet transcriptomic changes occurring in AD.

Protective Effect of Vitamin D Supplementation on Some Hemogram Derived Inflammatory Indices in Normal and High-Fat Diet Fed Male Wistar Rats

Background

Hematological inflammatory indices are currently suggested to assess systemic inflammation. This study aims to investigate a vitamin D supplementation effect on hematological indices of inflammation in rats.

Method

Forty-eight middle-aged male rats were allocated into a normal diet (ND) group (10% fat) and a high-fat diet (HFD) group (60% fat). The animals were fed for 26 weeks. After this period, each group was randomly divided into three subgroups, each of 8 rats: Group (1): animals were fed the ND and HFD containing 1 IU/g vitamin D for 4 months, group (2): animals were fed the ND and HFD containing 6 IU/g vitamin D for 4 months and group (3): animals were euthanized to evaluate the HFD effect. Serum 25-hydroxyvitamin D level, white blood cell count (WBCs), platelet count, platelet crit (PCT), mean platelet volume (MPV), platelet distribution width (PDW), platelet-to-lymphocyte ratio (PLR), neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR) were measured.

Results

The HFD, significantly increased body weight, PCT, PDW, PLR, NLR, and MLR and significantly reduced serum vitamin D levels compared to the ND (P < 0.05). There was a significant decrease in food intake, MPV, PDW, and NLR after vitamin D supplementation in the ND-fed group (P < 0.05). A significant reduction in platelet count, PCT, and MLR was observed after vitamin D supplementation in HFD-fed rats (P < 0.05).

Conclusions

In our study, some hemogram-derived inflammatory indices were higher in the HFD-fed group, and vitamin D supplementation lowering effects on some hematological indices were seen in both ND and HFD groups.

Hematopoietic Stem Cells and the Immune System in Development and Aging

Hematopoietic stem cells (HSCs) support haematopoiesis throughout life and give rise to the whole variety of cells of the immune system. Developing in the early embryo, passing through the precursor stage, and maturing into the first HSCs, they undergo a fairly large number of divisions while maintaining a high regenerative potential due to high repair activity. This potential is greatly reduced in adult HSCs. They go into a state of dormancy and anaerobic metabolism to maintain their stemness throughout life. However, with age, changes occur in the pool of HSCs that negatively affect haematopoiesis and the effectiveness of immunity. Niche aging and accumulation of mutations with age reduces the ability of HSCs to self-renew and changes their differentiation potential. This is accompanied by a decrease in clonal diversity and a disturbance of lymphopoiesis (decrease in the formation of naive T- and B-cells) and the predominance of myeloid haematopoiesis. Aging also affects mature cells, regardless of HSC, therefore, phagocytic activity and the intensity of the oxidative burst decrease, and the efficiency of processing and presentation of antigens by myeloid cells is impaired. Aging cells of innate and adaptive immunity produce factors that form a chronic inflammatory background. All these processes have a serious negative impact on the protective properties of the immune system, increasing inflammation, the risk of developing autoimmune, oncological, and cardiovascular diseases with age. Understanding the mechanisms of reducing the regenerative potential in a comparative analysis of embryonic and aging HSCs, the features of inflammatory aging will allow us to get closer to deciphering the programs for the development, aging, regeneration and rejuvenation of HSCs and the immune system.

Comparisons of coagulation characteristics between elderly and non-elderly patients with sepsis: A prospective study

BACKGROUND

A blunt host defense response in older patients may contribute to different coagulation responses during sepsis. We aimed to investigate the differences in coagulation parameters between elderly and non-elderly patients with sepsis.

METHODS

Adult patients diagnosed with sepsis within 24 hours after admission to the intensive care unit between September 2018 and December 2020 were prospectively enrolled. Patients were categorized into the adult (18-64 years) and elderly (age ≥65 years) groups. Conventional coagulation parameters and inflammatory markers were measured on intensive care unit admission and on Days 3 and 7. Thromboelastography was performed on intensive care unit admission. The differences in the coagulation parameters between the 2 groups were evaluated. The adult and elderly patients were matched to adjust for baseline characteristics. Correlations between inflammatory markers and coagulation-related parameters were also analyzed.

RESULTS

Of the 567 patients, 303 (53.4%) were elderly. Compared with adult patients, elderly patients had lower prothrombin time elevation, lower fibrinogen, D-dimer, and fibrin/Fib degradation product levels, and lower proportion of disseminated intravascular coagulation on intensive care unit admission; and, they had lower dynamic platelet, lower fibrinogen, and D-dimer levels during the first week in the intensive care unit. Thromboelastography parameters were generally within the normal range, although elderly patients had lower R and K values and a higher alpha angle. Comparisons of coagulation parameters between the 2 groups revealed similar results in the matched cohort. The inflammatory markers correlated with prothrombin time, activated partial thromboplastin time, and antithrombin III.

CONCLUSION

Elderly patients had milder coagulation activation, accompanied by a decreased inflammatory response during sepsis, compared to non-elderly patients.

Age-Related Changes in the Clustering of Blood Populations in Cynomolgus Monkeys Depend on Sex and Immune Status

Non-anthropoid primates cynomolgus monkeys (Macaca fascicularis), also known as crab-eating macaques, are increasingly used in biomedical and preclinical studies due to their evolutionary proximity to humans, sharing similar diets, infectious and senile diseases. Age-related changes and sexual dimorphism of the immune system of C. monkeys have not been sufficiently characterized in literature, though age and sex differences affect the course of diseases and sensitivity to medications. Aging in C. monkeys is accompanied by an increase in CD3+CD4+CD8+ (DP-T) cells, plasma B-cells, and a decrease in platelets. Erythromyeloid bias has also been noticed in older animals. There was an increase in eosinophils, haematocrit (HCT) and haemoglobin concentration (HGB). Senile decline in the function of the immune system had sex differences. An increase in the number of monocytes, cytotoxic lymphocytes (CTL) and a decrease in the T-helper population were more pronounced in older females. A significant reduction in the number of B-cells and activated T-cells was detected in males only. A moderate correlation with the regression model of aging was established for DP-T, HCT and HGB. The reduction in the B cells count in males and the increase in CTL level in females are moderately correlated with age. Other blood cell populations did not show significant correlations in the regression models due to their high sample variability. The novel cell population CD3-CD20loCD16/CD56+, presumably NK-cells subset, was revealed. This cell population demonstrated an increase trend with age in both sexes. Population-statistical age norms for different sexes for young and very old macaques were established. The blood population clusters associated with sex and immune status in older animals were also identified.

Platelets’ Nanomechanics and Morphology in Neurodegenerative Pathologies

The imaging and force–distance curve modes of atomic force microscopy (AFM) are explored to compare the morphological and mechanical signatures of platelets from patients diagnosed with classical neurodegenerative diseases (NDDs) and healthy individuals. Our data demonstrate the potential of AFM to distinguish between the three NDDs—Parkinson’s disease (PD), amyotrophic lateral sclerosis (ALS) and Alzheimer’s disease (AD), and normal healthy platelets. The common features of platelets in the three pathologies are reduced membrane surface roughness, area and height, and enhanced nanomechanics in comparison with healthy cells. These changes might be related to general phenomena associated with reorganization in the platelet membrane morphology and cytoskeleton, a key factor for all platelets’ functions. Importantly, the platelets’ signatures are modified to a different extent in the three pathologies, most significant in ALS, less pronounced in PD and the least in AD platelets, which shows the specificity associated with each pathology. Moreover, different degree of activation, distinct pseudopodia and nanocluster formation characterize ALS, PD and AD platelets. The strongest alterations in the biophysical properties correlate with the highest activation of ALS platelets, which reflect the most significant changes in their nanoarchitecture. The specific platelet signatures that mark each of the studied pathologies can be added as novel biomarkers to the currently used diagnostic tools.

Age-Associated Molecular Changes in Human Hippocampus Subfields as Determined by Quantitative Proteomics

The hippocampus demonstrates age-associated changes in functions, neuronal circuitry, and plasticity during various developmental stages. On the contrary, there is a significant knowledge gap on age-associated proteomic alterations in the hippocampus subfields. Using tandem mass tag-based high-resolution mass spectrometry and quantitative proteomics, we report here age-associated changes in the human hippocampus at the subregional level. We used formalin-fixed paraffin-embedded hippocampal tissue sections from a total of 12 healthy individuals, with 3 individuals from each of the 4 different age groups, specifically, 1-10, 21-30, 31-40, and 81-90 years. We found that lysosome and oxidative phosphorylation were the pathways enriched in the 81- to 90-year age group. On the contrray, nervous system development, synaptic plasticity and transmission, messenger RNA (mRNA) splicing, and electron transport chain (ETC) complex-I activity were the enriched biological processes observed in the younger age groups. In a hippocampus subfield context, our topline findings on age-associated proteome changes include altered expression of proteins associated with adult neurogenesis with age in the dentate gyrus and increased expression of immune response-associated proteins with age in certain cornu ammonis sectors of the hippocampus. Signal peptide analysis predicted hippocampal proteins with secretory potential. While these new findings warrant replication in larger study samples, the current data contribute to (1) our understanding of the molecular basis of proteomic changes across various age groups in hippocampus subfields in healthy individuals, and (2) the design and interpretation of future research on the age-associated neurodegenerative disorders.

A Collagen-Derived Oligopeptide from Salmo salar Collagen Hydrolysates Restrains Atherogenesis in ApoE-/- Mice via Targeting P2 Y12 Receptor

SCOPE

Collagen hydrolysates have been reported with a variety of biological activities. The previous study has separated and identified a series of Hyp-Gly containing antiplatelet peptides from collagen hydrolysates from Salmo salar. But the target and underlying mechanism in platelets remains unknown.

METHODS AND RESULTS

In this study, peptide OGEFG (OG-5) inhibits platelet aggregation especially induced by 2MeS-ADP and attenuates tail thrombosis formation by 30% in a dose-dependent manner, via apparent antagonism effects on P₂ Y₁₂ receptors to regulate Gβγi-PI3K-Akt signaling and Gαi-cAMP-VASP signaling is demonstrated. The molecular docking results also reveal a strong binding energy with the P₂ Y₁₂ receptor of peptide OG-5 (-10.70 kcal mol^-1 ). In vitro study suggests that OG-5 inhibited the release of inflammatory cytokines in endothelial cells and macrophage cells, migration of vascular smooth muscle cell induced by ADP, which is highly released in ApoE^-/- mice. Long-term administration of OG-5 significantly reduces atherosclerotic plaque formation without side effects in ApoE^-/- mice, exhibiting a comparable effect with aspirin.

CONCLUSION

These results reveal that collagen hydrolysates with OG-containing peptides have potential to be developed as an effective diet supplement to prevent the occurrence of atherogenesis and thrombotic disease.

Association between platelet, white blood cell count, platelet to white blood cell ratio and sarcopenia in community-dwelling older adults: focus on Bushehr Elderly Health (BEH) program

BACKGROUND

Sarcopenia is a progressive age-related skeletal muscle disorder associated with harmful impacts on health. The present study aimed to investigate the relation between sarcopenia, platelet (PLT), white blood cell (WBC), and PLT to WBC ratio (PWR) due to the importance of early sarcopenia diagnosis.

METHODS

This cross-sectional study was conducted based on the second stage of the Bushehr Elderly Health (BEH) Program. Sarcopenia was defined based on the revised edition of the European Working Group on Sarcopenia in Older People (EWGSOP2) in accordance with the Iranian cut-off point. Univariate and adjusted multivariate logistic regression and linear regression were used to evaluate the associations.

RESULTS

The prevalence of sarcopenia among participants was 35.73%. PLT count and PWR were statistically higher in severe sarcopenic participants, while no differences were seen in WBC. In crude analysis, sarcopenia was not associated with quartiles of PLT, WBC, and PWR, while after adjusting for age, marital status, and sex, the association was seen in the fourth quartile of PLT and PWR [OR (95%CI) = 1.40 (1.08 to 1.81), p-value = 0.009 for PLT; OR (95%CI) =1.55 (1.20 to 2.00), p-value =0.001 for PWR]. This association remained significant in the fully adjusted model [OR (95%CI) =1.82 (1.20 to 2.78), p-value =0.005 for PLT; OR (95%CI) =1.57 (1.03 to 2.40), p-value =0.035 for PWR]. Among sarcopenia parameters, PLT count was more likely to be associated with handgrip strength and muscle mass. After stratifying the participants by gender, sarcopenia parameters were no longer statistically significant in men.

CONCLUSION

This study showed that PLT and PWR were associated with sarcopenia after considering confounding factors, while this association was not seen in WBC. Moreover, results showed that gender had an important impact on sarcopenia parameters.

Atypical Roles of the Chemokine Receptor ACKR3/CXCR7 in Platelet Pathophysiology

The manifold actions of the pro-inflammatory and regenerative chemokine CXCL12/SDF-1α are executed through the canonical GProteinCoupledReceptor CXCR4, and the non-canonical ACKR3/CXCR7. Platelets express CXCR4, ACKR3/CXCR7, and are a vital source of CXCL12/SDF-1α themselves. In recent years, a regulatory impact of the CXCL12-CXCR4-CXCR7 axis on platelet biogenesis, i.e., megakaryopoiesis, thrombotic and thrombo-inflammatory actions have been revealed through experimental and clinical studies. Platelet surface expression of ACKR3/CXCR7 is significantly enhanced following myocardial infarction (MI) in acute coronary syndrome (ACS) patients, and is also associated with improved functional recovery and prognosis. The therapeutic implications of ACKR3/CXCR7 in myocardial regeneration and improved recovery following an ischemic episode, are well documented. Cardiomyocytes, cardiac-fibroblasts, endothelial lining of the blood vessels perfusing the heart, besides infiltrating platelets and monocytes, all express ACKR3/CXCR7. This review recapitulates ligand induced differential trafficking of platelet CXCR4-ACKR3/CXCR7 affecting their surface availability, and in regulating thrombo-inflammatory platelet functions and survival through CXCR4 or ACKR3/CXCR7. It emphasizes the pro-thrombotic influence of CXCL12/SDF-1α exerted through CXCR4, as opposed to the anti-thrombotic impact of ACKR3/CXCR7. Offering an innovative translational perspective, this review also discusses the advantages and challenges of utilizing ACKR3/CXCR7 as a potential anti-thrombotic strategy in platelet-associated cardiovascular disorders, particularly in coronary artery disease (CAD) patients post-MI.

Divergent Sepsis Pathophysiology in Older Adults

Significance: Both incidence and mortality rates of sepsis significantly increase with advanced age, and the majority of sepsis patients are late middle-aged or older. With the proportion of older adults rapidly increasing in developed countries, age-dependent sepsis vulnerability is an urgent medical issue. Due to an increasing life expectancy, postsepsis complications and health care costs are expected to increase as well. Recent Advances: Older patients suffer from higher sepsis incidence and mortality rates, likely resulting from frequent comorbidities, increased coagulation, dysgylcemia, and altered immune responses. Critical Issues: Despite a large number of ongoing clinical and basic research studies, there is currently no effective therapeutic strategy targeting older patients with severe sepsis. The disparity between clinical and basic studies is a problem, and this is largely due to the use of animal models lacking clinical relevance. Although the majority of sepsis cases occur in older adults, most laboratory animals used for sepsis research are very young. Further, despite the wide use of combination fluid and antibiotic treatment in intensive care unit (ICU) patients, most animal research does not include such treatment. Future Directions: Because sepsis is a systemic disease with multiple organ dysfunction, combined therapy approaches, not those targeting single pathways or single organs, are essential. As for preclinical research, it is critical to confirm new findings using aged animal models with clinically relevant ICU-like medical treatments. Antioxid. Redox Signal. 35, 1358-1375.

Alternative platelet activation pathways and their role in neurodegenerative diseases

PURPOSE OF THE REVIEW

The study of platelets in the context of neurodegenerative diseases is intensifying, and increasing evidence suggests that platelets may play an important role in the pathogenesis of neurodegenerative disorders. Therefore, we aim to provide a comprehensive overview of the role of platelets and their diverse activation pathways in the development of these diseases.

RECENT FINDINGS

Platelets participate in synaptic plasticity, learning, memory, and platelets activated by exercise promote neuronal differentiation in several brain regions. Platelets also contribute to the immune response by modulating their surface protein profile and releasing pro- and anti-inflammatory mediators. In Alzheimer's disease, increased levels of platelet amyloid precursor protein raise the production of amyloid-beta peptides promoting platelet activation, triggering at the same time amyloid-beta fibrillation. In Parkinson's disease, increased platelet α-synuclein is associated with elevated ROS production and mitochondrial dysfunction.

SUMMARY

In this review, we revise different platelet activation pathways, those classically involved in hemostasis and wound healing, and alternative activation pathways recently described in the context of neurodegenerative diseases, especially in Alzheimer's disease.

Management of acute coronary syndromes in older adults

Older patients are underrepresented in prospective studies and randomized clinical trials of acute coronary syndromes (ACS). Over the last decade, a few specific trials have been conducted in this population, allowing more evidence-based management. Older adults are a heterogeneous, complex, and high-risk group whose management requires a multidimensional clinical approach beyond coronary anatomic variables. This review focuses on available data informing evidence-based interventional and pharmacological approaches for older adults with ACS, including guideline-directed management. Overall, an invasive approach appears to demonstrate a better benefit-risk ratio compared to a conservative one across the ACS spectrum, even considering patients' clinical complexity and multiple comorbidities. Conversely, more powerful strategies of antithrombotic therapy for secondary prevention have been associated with increased bleeding events and no benefit in terms of mortality reduction. An interdisciplinary evaluation with geriatric assessment should always be considered to achieve a holistic approach and optimize any treatment on the basis of the underlying biological vulnerability.

Clinical insights into the origins of thrombosis in myeloproliferative neoplasms

Philadelphia chromosome-negative myeloproliferative neoplasms (MPNs), polycythemia vera, essential thrombocythemia, and primary myelofibrosis, are hematopoietic stem cell disorders that are defined by activating mutations in signal transduction pathways and are characterized clinically by the overproduction of platelets, red blood cells, and neutrophils, significant burden of disease-specific symptoms, and high rates of vascular events. The focus of this review is to critically reevaluate the clinical burden of thrombosis in MPNs, to review the clinical associations among clonal hematopoiesis, JAK2V617F burden, inflammation, and thrombosis, and to provide insights into novel primary and secondary thrombosis-prevention strategies.

Systemic Inflammatory Parameters in Patients with Elderly-Onset Rheumatoid Arthritis (EORA) and Young-Onset Rheumatoid Arthritis (YORA)-An Observational Study

BACKGROUND

Rheumatoid arthritis (RA) occurs more often in elderly individuals. Elderly onset RA (EORA) (onset > 60 years) encompasses a specific subset of patients if compared with young onset RA (YORA) (onset at a younger age). There is a need to define reliable, simple markers to properly assess the inflammatory activity of RA. Hematological markers of systemic inflammation (Platelet-To-Lymphocyte (PLR) and Neutrophil-To-Lymphocyte (NLR) ratios) are novel measures of the inflammatory response. The goal of the study was to analyze the course of EORA vs. YORA patients and to assess associations between systemic and clinical disease activity markers, including PLR and NLR, in different subsets of patients. PLR and NLR have not previously been assessed in EORA and YORA.

METHODS

The study group consisted of 113 consecutive patients (63 EORA and 50 YORA). The following assessments were performed: joint counts, Disease Activity Score (DAS28), complete blood cell counts, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP).

RESULTS

EORA was characterized by significantly higher disease activity markers (conventional inflammatory and clinical), a lower rate of remission or low disease activity, and less frequent use of biological drugs and glucocorticoids. The NLR and PLR were positively correlated with disease activity markers. The PLR was significantly lower in EORA compared with in YORA.

CONCLUSION

EORA and YORA patients differed significantly. In EORA, conventional disease activity markers were higher, the PLR was significantly lower.

Platelets in aging and cancer-"double-edged sword"

Platelets control hemostasis and play a key role in inflammation and immunity. However, platelet function may change during aging, and a role for these versatile cells in many age-related pathological processes is emerging. In addition to a well-known role in cardiovascular disease, platelet activity is now thought to contribute to cancer cell metastasis and tumor-associated venous thromboembolism (VTE) development. Worldwide, the great majority of all patients with cardiovascular disease and some with cancer receive anti-platelet therapy to reduce the risk of thrombosis. However, not only do thrombotic diseases remain a leading cause of morbidity and mortality, cancer, especially metastasis, is still the second cause of death worldwide. Understanding how platelets change during aging and how they may contribute to aging-related diseases such as cancer may contribute to steps taken along the road towards a "healthy aging" strategy. Here, we review the changes that occur in platelets during aging, and investigate how these versatile blood components contribute to cancer progression.

Evolutionary medical insights into the SARS-CoV-2 pandemic

The author apply concepts and tools from evolutionary medicine to understanding the SARS-CoV-2 pandemic. The pandemic represents a mismatched conflict, with dynamics and pathology apparently driven by three main factors: (i) bat immune systems that rely on low inflammation but high efficacy of interferon-based defenses; (ii) viral tactics that differentially target the human interferon system, leading to substantial asymptomatic and pre-symptomatic transmission; and (ii) high mortality caused by hyper-inflammatory and hyper-coagulatory phenotypes, that represent dysregulated tradeoffs whereby collateral immune-induced damage becomes systemic and severe. This framework can explain the association of mortality with age (which involves immune life-history shifts towards higher inflammation and coagulation and reduced adaptive immunity), and sex (since males senesce faster than females). Genetic-risk factors for COVID-19 mortality can be shown, from a phenome-wide association analysis of the relevant SNPs, to be associated with inflammation and coagulation; the phenome-wide association study also provides evidence, consistent with several previous studies, that the calcium channel blocking drug amlodipine mediates risk of mortality. Lay Summary: SARS-CoV-2 is a bat virus that jumped into humans. The virus is adapted to bat immune systems, where it evolved to suppress the immune defenses (interferons) that mammals use to tell that they are infected. In humans, the virus can apparently spread effectively in the body with a delay in the production of symptoms and the initiation of immune responses. This delay may then promote overactive immune responses, when the virus is detected, that damage the body as a side effect. Older people are more vulnerable to the virus because they are less adapted to novel infectious agents, and invest less in immune defense, compared to younger people. Genes that increase risk of mortality from SARS-CoV-2 are functionally associated with a drug called amlodipine, which may represent a useful treatment.

Platelets and Their Role in the Pathogenesis of Cardiovascular Events in Patients With Community-Acquired Pneumonia

Community-acquired pneumonia (CAP) remains an important cause of morbidity and mortality throughout the world with much recent and ongoing research focused on the occurrence of cardiovascular events (CVEs) during the infection, which are associated with adverse short-term and long-term survival. Much of the research directed at unraveling the pathogenesis of these events has been undertaken in the settings of experimental and clinical CAP caused by the dangerous, bacterial respiratory pathogen, Streptococcus pneumoniae (pneumococcus), which remains the most common bacterial cause of CAP. Studies of this type have revealed that although platelets play an important role in host defense against infection, there is also increasing recognition that hyperactivation of these cells contributes to a pro-inflammatory, prothrombotic systemic milieu that contributes to the etiology of CVEs. In the case of the pneumococcus, platelet-driven myocardial damage and dysfunction is exacerbated by the direct cardiotoxic actions of pneumolysin, a major pore-forming toxin of this pathogen, which also acts as potent activator of platelets. This review is focused on the role of platelets in host defense against infection, including pneumococcal infection in particular, and reviews the current literature describing the potential mechanisms by which platelet activation contributes to cardiovascular complications in CAP. This is preceded by an evaluation of the burden of pneumococcal infection in CAP, the clinical features and putative pathogenic mechanisms of the CVE, and concludes with an evaluation of the potential utility of the anti-platelet activity of macrolides and various adjunctive therapies.

Brief review: Cardiac complications and platelet activation in COVID-19 infection

COVID-19 pneumonia, much like that of bacterial and viral community-acquired pneumonia before it, is accompanied by a high rate of cardio- and cerebrovascular events that are associated with an increased risk of complications and a greater mortality. Although the mechanisms underlying the pathogenesis of these adverse events are not entirely clear and may be multifactorial, platelets appear to have a prominent aetiologic role and this, together with an overview of the clinical evidence, forms the basis of this short review.

Integrative Analysis of Long Non-Coding RNAs (lncRNAs), miRNAs, and mRNA-Associated ceRNA Network in Lung Tissue of Aging Mice and Changes After Treatment with Codonopsis pilosula

Background

Codonopsis pilosula is a traditional Chinese medicine that has an anti-aging effect. However, the anti-aging effect of Codonopsis pilosula on the lungs remains largely unknown, and the molecular mechanism also needs to be further studied. Thus, we investigated the protective effect of Codonopsis pilosula on the lungs of aging mice, and explored the underlying molecular mechanism.

Material/Methods

We established an aging mouse model and then treated the mice with Codonopsis pilosula. Microarray analysis and bioinformatics methods were used to comprehensively analyze the lncRNA-miRNA-mRNA (ceRNA) network.

Results

Our results showed that we successfully established the aging mouse model. The microarray analysis showed that 138 lncRNAs, 128 mRNAs, and 7 miRNAs were significantly changed after aging, and 282 lncRNAs, 283 mRNAs, and 19 miRNAs were dysregulated after treatment with Codonopsis pilosula. To explore the signaling pathways involved, KEGG pathway analysis was performed. Compared with the ceRNA network in aging mice and after treatment with Codonopsis pilosula, we found that 3 mRNAs (Hif3a, Zbtb16, Plxna2) and 1 lncRNA (NONMMUT063872) were associated with the anti-aging effect of Codonopsis pilosula and they were validated by quantitative real-time polymerase chain reaction (qRT-PCR) analysis.

Conclusions

Our results showed that Codonopsis pilosula has a protective effect on the aging lung, and the ceRNA network plays an important role in the anti-aging effect of Codonopsis pilosula.