Platelet and red blood cell interactions and their role in rheumatoid arthritis

Chronic stress predisposes to the aggravation of inflammation in autoimmune diseases with focus on rheumatoid arthritis and psoriasis

The global incidence of autoimmune diseases is on the rise, and many healthcare professionals believe that chronic stress plays a prominent role in both the aggravation and remission of these conditions. It is believed that prolonged exposure to stress is associated with neuroimmune axis malfunction, which eventually dysregulates multiple immunological factors as well as deregulates autoimmune responses that play a central role in various autoimmune diseases, including rheumatoid arthritis and psoriasis. Herein, we performed validation of an 8-week long rat model of chronic unpredictable stress (CUS) which consisted of exposing groups of rats to random stressors daily for 8 weeks. Additionally, we developed a novel rat model combining 8-week long random stressor-induced CUS with CIA-triggered arthritis and IMQ-triggered psoriasis and have successfully used both these models to assess the role of chronic stress in the aggravation of arthritis and psoriasis, respectively. Notably, the 8-week CUS protocol extensively aggravated and prolonged both arthritis and psoriasis condition in the rat model by upregulating the release of different pro-inflammatory cytokines, dysregulation of immune cell responses and oxidative stress system, which were all related to severe inflammation. Further, CUS aggravated macroscopic features and the increase in destruction of joint tissue and epidermal thickness induced by CIA and IMQ, respectively, in rats. In conclusion, this study suggests that exposure to an 8-week long CUS paradigm aggravates the distinctive characteristics of rheumatoid arthritis and psoriasis in rats via amplifying the inflammatory circuits and immune cell responses linked to these autoimmune diseases.

The Value of Peripheral Blood Cell Ratios in Primary Membranous Nephropathy: A Single Center Retrospective Study

Background

Primary membranous nephropathy (PMN) is a common cause of nephrotic syndrome in adults. Forty percent of the patients continue to progress and eventually develop into chronic renal failure. Although phospholipase A2 receptor (PLA2R) is the major antigen of PMN, the clinical features do not often parallel with the antibody titers. Therefore, it is significant to find relative credible markers to predict the treatment response.

Methods

One hundred and eighteen PMN patients were recruited. The response to treatment was defined as ALB≥30g/L at 6 months and complete remission (CR) or not at the end of the follow-up. Renal outcome endpoint was defined as 50% or more Cr increase at the end.

Results

The patients with poor treatment effects had numerically higher platelet-lymphocytes ratio (PLR). For patients with CR or not, the difference was near to statistic significant (P=0.095). When analyzing CR or not, the fitting of the binary logistic regression model including both PLA2R Ab titer and PLR (Hosmer-Lemeshow test: χ ²=8.328, P = 0.402; OR (PLA2R Ab titer) = 1.002 (95% CI 1.000-1.004, P = 0.042); OR (PLR) = 1.006 (95% CI 0.999-1.013, P = 0.098)) was markedly better than that with only PLA2R Ab titer (Hosmer-Lemeshow test: χ ²=13.885, P = 0.016). The patients with renal function deterioration showed significantly higher monocyte-lymphocyte ratio (MLR) (0.26 (0.22-0.31) vs 0.18 (0.13-0.22), P = 0.012).

Conclusion

PMN patients with poor treatment response tended to have higher PLR at the time of renal biopsy, and a higher MLR was associated with poor renal outcomes. Our findings suggested that PLR and MLR might be used to predict treatment efficacy and prognosis for PMN patients, respectively.

Red Blood Cells Protein Profile Is Modified in Breast Cancer Patients

Metastasis is the primary cause of death for most breast cancer (BC) patients who succumb to the disease. During the hematogenous dissemination, circulating tumor cells interact with different blood components. Thus, there are microenvironmental and systemic processes contributing to cancer regulation. We have recently published that red blood cells (RBCs) that accompany circulating tumor cells have prognostic value in metastatic BC patients. RBC alterations are related to several diseases. Although the principal known role is gas transport, it has been recently assigned additional functions as regulatory cells on circulation. Hence, to explore their potential contribution to tumor progression, we characterized the proteomic composition of RBCs from 53 BC patients from stages I to III and IV, compared with 33 cancer-free controls. In this work, we observed that RBCs from BC patients showed a different proteomic profile compared to cancer-free controls and between different tumor stages. The differential proteins were mainly related to extracellular components, proteasome, and metabolism. Embryonic hemoglobins, not expected in adults' RBCs, were detected in BC patients. Besides, lysosome-associated membrane glycoprotein 2 emerge as a new RBCs marker with diagnostic and prognostic potential for metastatic BC patients. Seemingly, RBCs are acquiring modifications in their proteomic composition that probably represents the systemic cancer disease, conditioned by the tumor microenvironment.

Anti-Eryptotic Activity of Food-Derived Phytochemicals and Natural Compounds

Human red blood cells (RBCs), senescent or damaged due to particular stress, can be removed by programmed suicidal death, a process called eryptosis. There are various molecular mechanisms underlying eryptosis. The most frequent is the increase in the cytoplasmic concentration of Ca²⁺ ions, later exposure of erythrocytes to oxidative stress, hyperosmotic shock, ceramide formation, stimulation of caspases, and energy depletion. Phosphatidylserine (PS) exposed by eryptotic RBCs due to interaction with endothelial CXC-Motiv-Chemokin-16/Scavenger-receptor, causes the RBCs to adhere to vascular wall with consequent damage to the microcirculation. Eryptosis can be triggered by various xenobiotics and endogenous molecules, such as high cholesterol levels. The possible diseases associated with eryptosis are various, including anemia, chronic kidney disease, liver failure, diabetes, hypertension, heart failure, thrombosis, obesity, metabolic syndrome, arthritis, and lupus. This review addresses and collates the existing ex vivo and animal studies on the inhibition of eryptosis by food-derived phytochemicals and natural compounds including phenolic compounds (PC), alkaloids, and other substances that could be a therapeutic and/or co-adjuvant option in eryptotic-driven disorders, especially if they are introduced through the diet.

Prediction of New Risk Genes and Potential Drugs for Rheumatoid Arthritis from Multiomics Data

Rheumatoid arthritis (RA) is an autoimmune and inflammatory disease for which there is a lack of therapeutic options. Genome-wide association studies (GWASs) have identified over 100 genetic loci associated with RA susceptibility; however, the most causal risk genes (RGs) associated with, and molecular mechanism underlying, RA remain unknown. In this study, we collected 95 RA-associated loci from multiple GWASs and detected 87 candidate high-confidence risk genes (HRGs) from these loci via integrated multiomics data (the genome-scale chromosome conformation capture data, enhancer-promoter linkage data, and gene expression data) using the Bayesian integrative risk gene selector (iRIGS). Analysis of these HRGs indicates that these genes were indeed, markedly associated with different aspects of RA. Among these, 36 and 46 HRGs have been reported to be related to RA and autoimmunity, respectively. Meanwhile, most novel HRGs were also involved in the significantly enriched RA-related biological functions and pathways. Furthermore, drug repositioning prediction of the HRGs revealed three potential targets (ERBB2, IL6ST, and MAPK1) and nine possible drugs for RA treatment, of which two IL-6 receptor antagonists (tocilizumab and sarilumab) have been approved for RA treatment and four drugs (trastuzumab, lapatinib, masoprocol, and arsenic trioxide) have been reported to have a high potential to ameliorate RA. In summary, we believe that this study provides new clues for understanding the pathogenesis of RA and is important for research regarding the mechanisms underlying RA and the development of therapeutics for this condition.

Association Between Blood PLT and RBC Related Indices and Disease Activity in Patients with Rheumatoid Arthritis

Background

Platelet (PLT) and red blood cell (RBC) have been demonstrated to play a critical role in inflammatory processes. This study aimed to evaluate the association of blood PLT and RBC related parameters with the disease activity in rheumatoid arthritis (RA) patients, and also to investigate the role of these indices in differentiating among RA patients with different disease activity.

Methods

Clinical data from RA patients were retrospectively analyzed. RA patients were divided into inactive group and active group according to DAS28-CRP. The relationship between blood PLT and RBC counts-related indices and DAS28-CRP was detected by Spearman correlation. ROC curve was used to assess the diagnostic value of these indices in differentiating active RA from inactive RA.

Results

Active RA patients exhibited higher level of PLT counts but significantly lower levels of RBC counts, hemoglobin (Hb), red blood cells-platelet ratio (RPR) and hemoglobin-platelet ratio (HPR) compared with inactive RA. PLT counts were positively but RBC counts, Hb, RPR and HPR were negatively related with DAS28-CRP.

Conclusion

Blood PLT and RBC related indices were significantly associated with RA disease activity. These indices may be used to distinguish active RA from inactive RA.

Metabolic Influences Modulating Erythrocyte Deformability and Eryptosis

Many factors in the surrounding environment have been reported to influence erythrocyte deformability. It is likely that some influences represent reversible changes in erythrocyte rigidity that may be involved in physiological regulation, while others represent the early stages of eryptosis, i.e., the red cell self-programmed death. For example, erythrocyte rigidification during exercise is probably a reversible physiological mechanism, while the alterations of red blood cells (RBCs) observed in pathological conditions (inflammation, type 2 diabetes, and sickle-cell disease) are more likely to lead to eryptosis. The splenic clearance of rigid erythrocytes is the major regulator of RBC deformability. The physicochemical characteristics of the surrounding environment (thermal injury, pH, osmolality, oxidative stress, and plasma protein profile) also play a major role. However, there are many other factors that influence RBC deformability and eryptosis. In this comprehensive review, we discuss the various elements and circulating molecules that might influence RBCs and modify their deformability: purinergic signaling, gasotransmitters such as nitric oxide (NO), divalent cations (magnesium, zinc, and Fe2+), lactate, ketone bodies, blood lipids, and several circulating hormones. Meal composition (caloric and carbohydrate intake) also modifies RBC deformability. Therefore, RBC deformability appears to be under the influence of many factors. This suggests that several homeostatic regulatory loops adapt the red cell rigidity to the physiological conditions in order to cope with the need for oxygen or fuel delivery to tissues. Furthermore, many conditions appear to irreversibly damage red cells, resulting in their destruction and removal from the blood. These two categories of modifications to erythrocyte deformability should thus be differentiated.

Role of Hepcidin in Anemia of Chronic Disease in Rheumatoid Arthritis

Objective Anemia of chronic disease is a frequent consequence in rheumatoid arthritis and is associated with major clinical and patient outcomes. The present cross-sectional study explored the role of hepcidin (HEP) in anemia of chronic disease in rheumatoid arthritis by studying its relationships with markers of anemia, iron metabolism, inflammation, and erythropoiesis. Methods Blood samples from anemic ( n = 43) and nonanemic ( n = 43) rheumatoid arthritis patients were analyzed for markers of anemia (hemoglobin, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, red cells distribution width, and reticulocyte hemoglobin), iron metabolism (iron, total iron binding capacity, ferritin, transferrin saturation, soluble transferrin receptor), inflammation (erythrocyte sedimentation rate, C-reactive protein, and interleukin 6), and erythropoiesis (erythropoietin and HEP). Correlation analysis was used to identify relationships between HEP and all other variables. Principal component analysis was used to identify common underlying dimensions representing linear combinations of all variables. Results HEP had statistically significant mostly moderate-to-large correlations with markers of anemia (0.30-0.70, all p < 0.01), small correlation with markers of iron metabolism and markers of inflammation ( r = 0.20-0.40, all p < 0.01), and moderate correlations with markers of erythropoiesis. Principal component analysis revealed two underlying components (factors) capturing approximately 50% of total variability. Factor 1 comprised mainly of markers of anemia, iron metabolism, and erythropoiesis and was related to "erythrocyte health status," while factor 2 comprised mainly markers of inflammation and iron metabolism and was related to "acute phase reactants." HEP was the only variable demonstrating substantial loadings on both factors. Conclusions HEP is related to markers of anemia, iron metabolism, inflammation, and erythropoiesis. In addition, when all variables are "reduced" to a minimum number of two "latent" factors, HEP is loaded on both, thus underlying its pivotal role in the complex interaction of the erythropoietic response in inflammation-induced anemia and/or functional iron deficiency.

Insights in the Role of Lipids, Oxidative Stress and Inflammation in Rheumatoid Arthritis Unveiled by New Trends in Lipidomic Investigations

Rheumatoid arthritis (RA) is a highly debilitating chronic inflammatory autoimmune disease most prevalent in women. The true etiology of this disease is complex, multifactorial, and is yet to be completely elucidated. However, oxidative stress and lipid peroxidation are associated with the development and pathogenesis of RA. In this case, oxidative damage biomarkers have been found to be significantly higher in RA patients, associated with the oxidation of biomolecules and the stimulation of inflammatory responses. Lipid peroxidation is one of the major consequences of oxidative stress, with the formation of deleterious lipid hydroperoxides and electrophilic reactive lipid species. Additionally, changes in the lipoprotein profile seem to be common in RA, contributing to cardiovascular diseases and a chronic inflammatory environment. Nevertheless, changes in the lipid profile at a molecular level in RA are still poorly understood. Therefore, the goal of this review was to gather all the information regarding lipid alterations in RA analyzed by mass spectrometry. Studies on the variation of lipid profile in RA using lipidomics showed that fatty acid and phospholipid metabolisms, especially in phosphatidylcholine and phosphatidylethanolamine, are affected in this disease. These promising results could lead to the discovery of new diagnostic lipid biomarkers for early diagnosis of RA and targets for personalized medicine.

Accelerated Spatial Fibrin Growth and Impaired Contraction of Blood Clots in Patients with Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an autoimmune disease associated with thrombotic complications. To elucidate pathogenic mechanisms, hemostatic disorders in RA were correlated with other laboratory and clinical manifestations. Hemostasis was assessed using relatively new complementary tests, the spatial growth of a plasma clot (Thrombodynamics assay), and contraction of whole blood clots. Platelet functionality was assessed with flow cytometry that quantified the expression of P-selectin and the fibrinogen-binding capacity of platelets before and after activation with a thrombin receptor-activating peptide. Parameters of fibrin clot growth and the kinetics of contraction of blood clots were significantly altered in patients with RA compared to the control group. In Thrombodynamics measurements, an increase in the clot growth rate, size, and optical density of plasma clots altogether indicated chronic hypercoagulability. The rate and extent of blood clot contraction in patients with RA was significantly reduced and associated with platelet dysfunction revealed by an impaired response to activation. Changes in the parameters of clot growth and contraction correlated with the laboratory signs of systemic inflammation, including hyperfibrinogenemia. These results confirm the pathogenic role of hemostatic disorders in RA and support the validity of fibrin clot growth and the blood clot contraction assay as indicators of a (pro)thrombotic state.

Variation of red blood cell parameters in Behcet's disease: association with disease severity and vascular involvement

INTRODUCTION/OBJECTIVES

Behcet's disease (BD) is a systemic and chronic inflammatory vasculitis with unknown etiology. Diagnosis is determined by evaluating several clinical criteria, but the lack of specific laboratory diagnostic markers makes the diagnosis of BD more difficult. Therefore, the aim of this study was to determine the changes in hematological parameters in BD patients to investigate their relationship with BD clinical features.

METHOD

A total of 48 BD patients and 96 healthy controls were included in this study. The severity of each BD patient was associated to a severity score according to the entire spectrum of disease manifestations. Several laboratory tests were assessed, and the difference in their results between BD patients and healthy controls was evaluated. Correlation analysis was performed to reveal the interaction of these parameters.

RESULTS

C-reactive protein (CRP), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), neutrophil count, platelet count, and plateletcrit significantly increased in BD patients compared with healthy controls (P < 0.05). CRP was higher in patients with skin lesions, MCH and MCHC were lower in patients with vascular involvement, and the neutrophil count was higher in patients with skin lesions and genital ulcers. In addition, higher CRP and lower MCH and MCHC were associated with a severe condition. Besides, MCH and MCHC were negatively correlated with the platelet count, plateletcrit, and neutrophil count.

CONCLUSIONS

This study revealed that MCH and MCHC are valuable parameters for BD. Their levels help assess the disease severity and indicate the vascular involvement in BD. Key Points • This is the first study reporting MCH and MCHC as important biomarkers in BD. • BD patients with vascular involvement and thrombosis potential have lower levels of MCH and MCHC. • MCH and MCHC are negatively correlated with platelet count, plateletcrit, and neutrophil count. • Lower MCH and MCHC are associated with a severe condition.

Significance of serum albumin and derived neutrophil-to-lymphocyte ratio score in assessment of disease activity in rheumatoid arthritis patients

Background

Albumin and derived neutrophil to lymphocyte ratio (dNLR) are known biomarkers that can reflect systemic inflammation and it has been hypothesized that combination of both markers in one score (albumin-dNLR score) can be useful in monitoring rheumatoid arthritis (RA) patients. The current study intended to measure albumin -dNLR score in patients with RA in the order to find whether these new biomarkers could reflect the activity of the disease and the articular activity detected by ultrasonography. We measured serum albumin and dNLR in blood samples obtained from 100 RA patients and from 100 apparently healthy controls (HC). Albumin -dNLR score was calculated according to the presence of hypoalbuminemia (≤ 3.76 gm/dl) and/or raised dNLR (>1.37).

Results

RA patients had a significantly elevated dNLR (p< 0.001) and albumin-dNLR score (p< 0.001) compared to their levels in HC, while serum albumin was significantly decreased (p< 0.001) in RA patients than its level in HC. In RA patients, albumin-dNLR score correlated significantly with DAS28 (p< 0.001), erythrocyte sedimentation rate (ESR) (p< 0.001), C-reactive protein (p< 0.001), grey scale (p< 0.001), power Doppler (p< 0.001) and total ultrasound score (p< 0.001). Also, tender joint count, ESR and albumin-dNLR score were significant predictors of DAS28 in multivariate regression analysis.

Conclusions

Our study settled that albumin - dNLR score is increased in RA patients than in healthy subjects. The score correlated well with DAS28, acute phase reactants, and ultrasonographic synovitis scores implying that it could be an easy valuable biomarker to monitor RA disease activity.

Red cell distribution width and neutrophil-lymphocyte ratio in rheumatoid arthritis

Red cell distribution width (RDW) and neutrophil-lymphocyte ratio (NLR) are potential low-cost markers for detecting rheumatoid arthritis (RA) disease activity, but evidence on their accuracy for this purpose is conflicting. We aimed to determine the relationship between these and the Disease Activity Score of 28 joints (DAS-28) among Filipino RA patients, and to evaluate their ability to discriminate between patients with active RA and those in remission. This was a cross-sectional study done through a 7-year review of medical records of 134 adult patients with RA in a tertiary government hospital. Correlations were analyzed using Spearman analysis, and the receiver operating characteristic (ROC) curve was used to derive the sensitivity, specificity, and optimal cut-off values of RDW and NLR. Most patients were females with a mean disease duration of 7 years. Eighty-one percent (81%) had active disease using DAS-28 ESR. A weak positive correlation was found between NLR and DAS-28 and between NLR and ESR, but RDW did not correlate with either DAS-28 or ESR. The ROC analysis showed that in the differentiation of active RA and inactive RA, both RDW (area under the curve [AUC] 0.516, cut-off of ≥ 14.2% with 55.6% sensitivity and 42.3% specificity) and NLR (AUC 0.629, cut-off of ≥ 2.32 with 54.6% sensitivity and 76.9% specificity) had poor performance. NLR, but not RDW, was positively but weakly correlated with DAS-28 and ESR, making it a helpful marker of disease activity and inflammation in RA. Both NLR and RDW had low sensitivity and specificity for active RA and may not be useful in detecting disease activity.

Platelets: emerging facilitators of cellular crosstalk in rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease in which a variety of circulating pro-inflammatory cells and dysregulated molecules are involved in disease aetiology and progression. Platelets are an important cellular element in the circulation that can bind several dysregulated molecules (such as collagen, thrombin and fibrinogen) that are present both in the synovium and the circulation of patients with RA. Platelets not only respond to dysregulated molecules in their environment but also transport and express their own inflammatory mediators, and serve as regulators at the boundary between haemostasis and immunity. Activated platelets also produce microparticles, which further convey signalling molecules and receptors to the synovium and circulation, thereby positioning these platelet-derived particles as strategic regulators of inflammation. These diverse functions come together to make platelets facilitators of cellular crosstalk in RA. Thus, the receptor functions, ligand binding potential and dysregulated signalling pathways in platelets are becoming increasingly important for treatment in RA. This Review aims to highlight the role of platelets in RA and the need to closely examine platelets as health indicators when designing effective pharmaceutical targets in this disease.

High-throughput phenotyping reveals expansive genetic and structural underpinnings of immune variation

By developing a high-density murine immunophenotyping platform compatible with high-throughput genetic screening, we have established profound contributions of genetics and structure to immune variation (http://www.immunophenotype.org). Specifically, high-throughput phenotyping of 530 unique mouse gene knockouts identified 140 monogenic 'hits', of which most had no previous immunologic association. Furthermore, hits were collectively enriched in genes for which humans show poor tolerance to loss of function. The immunophenotyping platform also exposed dense correlation networks linking immune parameters with each other and with specific physiologic traits. Such linkages limit freedom of movement for individual immune parameters, thereby imposing genetically regulated 'immunologic structures', the integrity of which was associated with immunocompetence. Hence, we provide an expanded genetic resource and structural perspective for understanding and monitoring immune variation in health and disease.

The Platelet-to-Lymphocyte Ratio as an Inflammatory Marker in Rheumatic Diseases

The platelet-to-lymphocyte ratio (PLR) has emerged as an informative marker revealing shifts in platelet and lymphocyte counts due to acute inflammatory and prothrombotic states. PLR has been extensively examined in neoplastic diseases accompanied by immune suppression and thrombosis, which can be predicted by combined blood cell counts and their ratios. Several large observational studies have demonstrated the value of shifts in PLR in evaluating the severity of systemic inflammation and predicting infections and other comorbidities, in inflammatory rheumatic diseases. The value of PLR as an inflammatory marker increases when its fluctuations are interpreted along with other complementary hematologic indices, particularly the neutrophil-to-lymphocyte ratio (NLR), which provides additional information about the disease activity, presence of neutrophilic inflammation, infectious complications, and severe organ damage in systemic lupus erythematosus. PLR and NLR have high predictive value in rheumatic diseases with predominantly neutrophilic inflammation (e.g., Behçet disease and familial Mediterranean fever). High PLR, along with elevated platelet count, is potentially useful in diagnosing some systemic vasculitides, particularly giant-cell arteritis. A few longitudinal studies on rheumatic diseases have demonstrated a decrease in PLR in response to anti-inflammatory therapies. The main limitations of PLR studies are preanalytical faults, inadequate standardization of laboratory measurements, and inappropriate subject selection. Nonetheless, accumulating evidence suggests that PLR can provide valuable information to clinicians who encounter multisystem manifestations of rheumatic diseases, which are reflected in shifts in platelet, lymphocyte, neutrophil, or monocyte counts. Interpretation of PLR combined with complementary hematologic indices is advisable to more accurately diagnose inflammatory rheumatic diseases and predict related comorbidities.

Red Cell Distribution Width and Platelet Count as Biomarkers of Pulmonary Arterial Hypertension in Patients with Connective Tissue Disorders

Introduction/Objective

In the present paper, we aimed to test the value of the red cell distribution width (RDW) coefficient of variation as a candidate biomarker for pulmonary arterial hypertension (PAH) in patients with connective tissue disorders (CTD), correlating it with the degree of cardiopulmonary impairment in these patients.

Methods

The study population included N = 141 patients with CTD and N = 59 patients affected by pulmonary hypertension of other etiologies, all referred to the Pulmonary Hypertension Clinic of the Cardiology Division of an Academic Hospital in Northern Italy for evaluation (including right catheterization). Clinical, instrumental, and laboratory data were collected and related to RDW and other full blood count indexes.

Results

Twenty out of 141 CTD patients (14%) received a diagnosis of PAH. In comparison to those without PAH, CTD patients with PAH displayed a larger RDW (14.9% (13.5-17.2) vs. 13.8% (13.1-15.0); p = 0.02) and a lower platelet count (205 (177‐240) × 10⁹/l vs. 244 (197.5‐304.2) × 10⁹/l; p = 0.005). Moreover, with respect to CTD patients without PAH, RDW was significantly larger also in PH of other etiologies. In contrast, the platelet count was significantly lower only in CTD-related PAH, with a value > 276 × 10⁹/l being 100% sensitive in ruling out PAH. Finally, RDW, but not the platelet count, was related directly to systolic pulmonary arterial pressure (r = 0.381; p = 0.0008) and right ventricle diameter (r = 0.283; p = 0.015) and inversely to diffusing capacity of the lung for carbon monoxide (r = −0.325; p = 0.014).

Conclusion

RDW is a promising candidate biomarker for the screening and the prognostic stratification of PAH in CTD patients.

Cellular and Molecular Networking Within the Ecosystem of Cancer Cell Communication via Tunneling Nanotubes

Intercellular communication is vital to the ecosystem of cancer cell organization and invasion. Identification of key cellular cargo and their varied modes of transport are important considerations in understanding the basic mechanisms of cancer cell growth. Gap junctions, exosomes, and apoptotic bodies play key roles as physical modalities in mediating intercellular transport. Tunneling nanotubes (TNTs)-narrow actin-based cytoplasmic extensions-are unique structures that facilitate direct, long distance cell-to-cell transport of cargo, including microRNAs, mitochondria, and a variety of other sub cellular components. The transport of cargo via TNTs occurs between malignant and stromal cells and can lead to changes in gene regulation that propagate the cancer phenotype. More notably, the transfer of these varied molecules almost invariably plays a critical role in the communication between cancer cells themselves in an effort to resist death by chemotherapy and promote the growth and metastases of the primary oncogenic cell. The more traditional definition of "Systems Biology" is the computational and mathematical modeling of complex biological systems. The concept, however, is now used more widely in biology for a variety of contexts, including interdisciplinary fields of study that focus on complex interactions within biological systems and how these interactions give rise to the function and behavior of such systems. In fact, it is imperative to understand and reconstruct components in their native context rather than examining them separately. The long-term objective of evaluating cancer ecosystems in their proper context is to better diagnose, classify, and more accurately predict the outcome of cancer treatment. Communication is essential for the advancement and evolution of the tumor ecosystem. This interplay results in cancer progression. As key mediators of intercellular communication within the tumor ecosystem, TNTs are the central topic of this article.

Tetrandrine alleviates symptoms of rheumatoid arthritis in rats by regulating the expression of cyclooxygenase-2 and inflammatory factors

The present study aimed to construct a rat model of rheumatoid arthritis (RA) to evaluate changes in pathology, the expression of inflammatory factors and regulation of signaling pathways. The protective effect of tetrandrine (Tet) on tissue lesions induced by RA was also investigated. A total of 60 Wistar rats (100-200 g) were randomly divided into six groups (n=10 per group), namely a blank (NC) group, model group, methotrexate (MTX) group (3 mg/kg body weight), high-dose Tet group (31.25 mg/kg body weight), medium-dose Tet group (18.75 mg/kg body weight) and low-dose Tet group (6.25 mg/kg body weight). A rat model of RA was induced via injection of 0.1 ml complete Freund's adjuvant into the right rear toe. Toe swelling rate, arthritis index and immune organ index were calculated. In addition, cyclooxygenase (COX)-2 expression at the mRNA and protein level in the peripheral blood mononuclear cells (PBMCs) of rats were determined by reverse transcription-quantitative polymerase chain reaction and western blot analysis, respectively. Serum concentrations of inflammatory factors were measured using enzyme-linked immunosorbent assays. It was observed that treatment with Tet alleviated the severity of rear toe swelling associated with RA in rats. Furthermore, Tet exerted anti-inflammatory and immunosuppressive effects in the rat model of RA. Tet also reduced the expression of COX-2 in PBMCs and lowered the concentrations of inflammatory factors in the serum of RA rats. The present data indicate that Tet may exert pharmacological effects in the treatment of RA. The mechanism of action of Tet may be associated with the regulation of inflammatory factors and the inhibition of immune organs.

Roles of microRNA-539 and osteopontin in rheumatoid arthritis

The present study aimed to investigate the role and mechanism of microRNA-539 (miR-539) in rheumatoid arthritis (RA). A total of 68 RA patients and 46 osteoarthritis patients were enrolled into the current study. Peripheral blood and joint fluid were collected prior to treatment. Reverse transcription-quantitative polymerase chain reaction was performed to detect osteopontin (OPN) mRNA and miR-539 expression levels, while ELISA and western blot analysis were applied to detect OPN protein expression. In addition, bioinformatics analysis predicted that miR-539 directly targeted OPN, while dual-luciferase assay was used to validate this finding. Furthermore, agomiR-539 transfection and OPN knockdown by siRNA were conducted in MH7A cells, and MTT assay was used to detect MH7A cell proliferation. The results indicated that OPN was significantly increased in the blood and joint fluid of RA patients, while miR-539 expression was significantly decreased in the two types of specimens (P<0.05). Subsequent to silencing OPN by siRNA, the proliferation of MH7A cells was decreased (P<0.05). Following upregulation of miR-539, OPN expression was significantly decreased and cell proliferation was inhibited. Dual-luciferase assay revealed that miR-539 regulated OPN expression through complementary binding to 3'-untranslated region. OPN was also significantly increased in the blood and joint fluid of RA patients, which may be associated with the downregulation of miR-539. Thus, miR-539 may promote the development and progression of RA through regulating OPN.

Red blood cell distribution width: a potential laboratory parameter for monitoring inflammation in rheumatoid arthritis

Correlation analysis of red blood cell distribution width (RDW) and C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), tumor necrosis factor α (TNF-α), interleukin (IL)-6, and IL-10 in rheumatoid arthritis (RA) to investigate whether RDW can serve as a potential parameter for indicating inflammation in RA patients. A total of 670 RA patients from October 2014 to April 2016 were enrolled in our study. The white blood cell (WBC), red blood cell (RBC), platelet (PLT), hemoglobin (HGB), RDW, CRP, and ESR in peripheral blood of patients with RA were retrospectively analyzed. The relative expression of TNF-α, IL-6, and IL-10 was detected by RT-qPCR. Correlation analysis between RDW and CRP, ESR, TNF-α, IL-6, and IL-10 in RA was conducted by Microsoft Excel. RDW level was significantly increased in RA patients compared to osteoarthritis (OA) patients (P < 0.001) and healthy donors (HDs) (P < 0.001), and RDW was positively associated with inflammatory markers, such as CRP and ESR. In ROC curve analysis, the area under the curve (AUC) of RDW for the identification of RA was 0.881, with a 95% confidence interval (CI) from 0.864 to 0.898. Moreover, correlation analysis showed that RDW level was positively associated with TNF-α and IL-6, however negatively associated with IL-10. RDW was increased in patients with RA which was associated with inflammation in RA, suggesting that RDW may be a potential auxiliary marker for indicating inflammation process in RA conveniently.

HbE/β-Thalassemia and Oxidative Stress: The Key to Pathophysiological Mechanisms and Novel Therapeutics

SIGNIFICANCE

Oxidative stress and generation of free radicals are fundamental in initiating pathophysiological mechanisms leading to an inflammatory cascade resulting in high rates of morbidity and death from many inherited point mutation-derived hemoglobinopathies. Hemoglobin (Hb)E is the most common point mutation worldwide. The βE-globin gene is found in greatest frequency in Southeast Asia, including Thailand, Malaysia, Indonesia, Vietnam, Cambodia, and Laos. With the wave of worldwide migration, it is entering the gene pool of diverse populations with greater consequences than expected.

CRITICAL ISSUES

While HbE by itself presents as a mild anemia and a single gene for β-thalassemia is not serious, it remains unexplained why HbE/β-thalassemia (HbE/β-thal) is a grave disease with high morbidity and mortality. Patients often exhibit defective physical development, severe chronic anemia, and often die of cardiovascular disease and severe infections. Recent Advances: This article presents an overview of HbE/β-thal disease with an emphasis on new findings pointing to pathophysiological mechanisms derived from and initiated by the dysfunctional property of HbE as a reduced nitrite reductase concomitant with excess α-chains exacerbating unstable HbE, leading to a combination of nitric oxide imbalance, oxidative stress, and proinflammatory events.

FUTURE DIRECTIONS

Additionally, we present new therapeutic strategies that are based on the emerging molecular-level understanding of the pathophysiology of this and other hemoglobinopathies. These strategies are designed to short-circuit the inflammatory cascade leading to devastating chronic morbidity and fatal consequences. Antioxid. Redox Signal. 26, 794-813.

Crocin reduces the inflammation response in rheumatoid arthritis

This study is to determine the role and mechanism of crocin in rheumatoid arthritis (RA). Totally 60 Wistar SD rats were randomly divided into control group, RA model group, methotrexate group, crocin high dose, middle dose, and low dose groups. The paw swelling degree, arthritis score, thymus and spleen index, the mRNA and protein levels of iNOS, and the serum content of TNF-α, IL-1β, and IL-6 were evaluated. Crocin treatment significantly alleviated the paw swelling of RA rats. The arthritis score in crocin treatment groups was significantly lower than that in RA model group. Additionally, the thymus index, but not the spleen index, declined remarkably in crocin treatment groups than in RA model group. Besides, crocin administration significantly reduced the iNOS production and the serum content of TNF-α, IL-1β, and IL-6. Crocin may exert potent anti-RA effects through inhibiting cytokine.

Major involvement of bacterial components in rheumatoid arthritis and its accompanying oxidative stress, systemic inflammation and hypercoagulability

We review the evidence that infectious agents, including those that become dormant within the host, have a major role to play in much of the etiology of rheumatoid arthritis and the inflammation that is its hallmark. This occurs in particular because they can produce cross-reactive (auto-)antigens, as well as potent inflammagens such as lipopolysaccharide that can themselves catalyze further inflammagenesis, including via β-amyloid formation. A series of observables coexist in many chronic, inflammatory diseases as well as rheumatoid arthritis. They include iron dysregulation, hypercoagulability, anomalous morphologies of host erythrocytes, and microparticle formation. Iron dysregulation may be responsible for the periodic regrowth and resuscitation of the dormant bacteria, with concomitant inflammagen production. The present systems biology analysis benefits from the philosophical idea of "coherence," that reflects the principle that if a series of ostensibly unrelated findings are brought together into a self-consistent narrative, that narrative is thereby strengthened. As such, we provide a coherent and testable narrative for the major involvement of (often dormant) bacteria in rheumatoid arthritis.