Red blood cells are dynamic reservoirs of cytokines

Transcriptome-based analysis reveals the toxic effects of perfluorononanoic acid by affecting the development of the cardiovascular system and lipid metabolism in zebrafish

Perfluorononanoic acid (PFNA) is a perfluoroalkyl acid containing nine carbon chains, with an additional carbon‑fluorine bond that makes it more stable and toxic. Studies have shown that PFNA can harm the reproductive, immune, and nervous systems, as well as many organs, which can increase the risk of cancer. In this study, zebrafish embryos were treated with 0 and 100 μM PFNA for 72 and 96 hpf, and their angiogenesis and haematopoiesis were observed under laser confocal microscopy using Tg (fli1:EGFP) and Tg (gata1:DsRed) transgenic zebrafish. The data showed that PFNA exposure decreased heart rate and slowed blood flow in zebrafish. PFNA was found to inhibit erythropoiesis by O-dianisidine staining. RNA-seq analysis was used to compare gene expression changes in zebrafish from control and 100 μM PFNA-exposed groups at 72 hpf. KEGG results showed significant enrichment of PPAR signaling pathway, fatty acid metabolism, steroid biosynthesis and apoptosis. The RNA-seq results were validated by real-time fluorescence quantitative PCR (RT-qPCR). Oil red O staining and Filipin staining showed increased lipid accumulation after PFNA exposure, and TUNEL staining showed that PFNA exposure led to apoptosis. In conclusion, exposure to PFNA may cause toxic effects in zebrafish by affecting cardiovascular development, causing lipid accumulation and promoting apoptosis.

Investigating the Use of Novel Blood Processing Methods to Boost the Identification of Biomarkers for Non-Small Cell Lung Cancer: A Proof of Concept

Diagnosis of non-small cell lung cancer (NSCLC) currently relies on imaging; however, these methods are not effective for detecting early stage disease. Investigating blood-based protein biomarkers aims to simplify the diagnostic process and identify disease-associated changes before they can be seen by using imaging techniques. In this study, plasma and frozen whole blood cell pellets from NSCLC patients and healthy controls were processed using both classical and novel techniques to produce a unique set of four sample types from a single blood draw. These samples were analyzed using 12 immunoassays and liquid chromatography-mass spectrometry to collectively screen 3974 proteins. Analysis of all fractions produced a set of 522 differentially expressed proteins, with conventional blood analysis (proteomic analysis of plasma) accounting for only 7 of the total. Boosted regression tree analysis of the differentially expressed proteins produced a panel of 13 proteins that were able to discriminate between controls and NSCLC patients, with an area under the ROC curve (AUC) of 0.864 for the set. Our rapid and reproducible (<10% CV for technical replicates) blood preparation and analysis methods enabled the production of high-quality data from only 30 μL of complex samples that typically require significant fractionation prior to proteomic analysis. With our methods, almost 4000 proteins were identified from a single fraction over a 62.5 min gradient by LC-MS/MS.

Red Blood Cell-Related Parameters in Rheumatoid Arthritis: Clinical Value and Immunological Significance

Rheumatoid arthritis (RA) is characterized by chronic inflammation and autoimmunity. Moreover, the disease activity, co-morbidities, and prognosis of RA are closely associated with changes in red blood cell (RBC)-related parameters. The role of these parameters in RA has therefore been extensively studied. Accordingly, this article summarizes and analyzes the close relationship of RBC-related parameters such as RBC count, hemoglobin, and RBC distribution width with disease activity, co-morbidities, and prognosis in RA by reviewing the available literature. In addition, given the immunomodulatory functions of RBCs, their surface proteins, contents, and microparticles are involved in the immunomodulatory process during RA. Overall, this review aims to assess the important clinical value and immunological significance of RBCs and their related parameters in the monitoring and management of RA, thus providing a reference for the clinical diagnosis and treatment of RA and the direction for the research on RBC-related immunity.

Erythronecroptosis: an overview of necroptosis or programmed necrosis in red blood cells

Necroptosis is considered a programmed necrosis that requires receptor-interacting protein kinase 1 (RIPK1), receptor-interacting protein kinase 3 (RIPK3), and pore-forming mixed lineage kinase domain-like protein (MLKL) to trigger a regulated cell membrane lysis. Membrane rupture in necroptosis has been shown to fuel innate immune response due to release of damage-associated molecular patterns (DAMPs). Recently published studies indicate that mature erythrocytes can undergo necroptosis as well. In this review, we provide an outline of multiple cell death modes occurring in erythrocytes, discuss possible immunological aspects of diverse erythrocyte cell deaths, summarize available evidence related to the ability of erythrocytes to undergo necroptosis, outline key involved molecular mechanisms, and discuss the potential implication of erythrocyte necroptosis in the physiology and pathophysiology. Furthermore, we aim to highlight the interplay between necroptosis and eryptosis signaling in erythrocytes, emphasizing specific characteristics of these pathways distinct from their counterparts in nucleated cells. Thus, our review provides a comprehensive summary of the current knowledge of necroptosis in erythrocytes. To reflect critical differences between necroptosis of nucleated cells and necroptosis of erythrocytes, we suggest a term erythronecroptosis for necroptosis of enucleated cells.

Red blood cells from patients with ST-elevation myocardial infarction and elevated C-reactive protein levels induce endothelial dysfunction

Endothelial dysfunction is an early consequence of vascular inflammation and a driver of coronary atherosclerotic disease leading to myocardial infarction. The red blood cells (RBCs) mediate endothelial dysfunction in patients at cardiovascular risk, but their role in patients with acute myocardial infarction is unknown. This study aimed to investigate if RBCs from patients with ST-elevation myocardial infarction (STEMI) induced endothelial dysfunction and the role of systemic inflammation in this effect. RBCs from patients with STEMI and aged-matched healthy controls were coincubated with rat aortic segments for 18 h followed by evaluation of endothelium-dependent (EDR) and endothelium-independent relaxation (EIDR). RBCs and aortic segments were also analyzed for arginase and oxidative stress. The patients were divided into groups depending on C-reactive protein (CRP) levels at admission. RBCs from patients with STEMI and CRP levels ≥2 mg/L induced impairment of EDR, but not EIDR, compared with RBCs from STEMI and CRP <2 mg/L and healthy controls. Aortic expression of arginase 1 was increased following incubation with RBCs from patients with STEMI and CRP ≥2, and arginase inhibition prevented the RBC-induced endothelial dysfunction. RBCs from patients with STEMI and CRP ≥2 had increased reactive oxygen species compared with RBCs from patients with CRP <2 and healthy controls. Vascular inhibition of NADPH oxidases and increased dismutation of superoxide improved EDR. RBCs from patients with STEMI and low-grade inflammation induce endothelial dysfunction through a mechanism involving arginase 1 as well as increased RBC and vascular superoxide by NADPH oxidases.NEW & NOTEWORTHY Red blood cells from patients with STEMI and systemic inflammation induce endothelial dysfunction ex vivo. The RBC-induced endothelial dysfunction is mediated through increased arginase 1 and a shift in the redox balance toward oxidative stress. Inhibition of arginase or free radicals attenuates the impairment of endothelial function. The study suggests that red blood cells deserve attention as a key player in systemic inflammation and STEMI.

The Association Between Perioperative Red Blood Cell Transfusions and 1-Year Mortality After Major Cancer Surgery: An International Multicenter Observational Study

BACKGROUND

Packed red blood cell (pRBC) transfusions in patients undergoing surgery for cancer are given to treat anemia or acute hemorrhage. Evidence indicates that pRBC transfusions are associated with poor perioperative and oncological outcomes. The ARCA-1 (Perioperative Care in the Cancer Patient-1) study was designed to test the association between perioperative pRBC transfusions and postoperative morbidity and mortality in patients undergoing cancer surgery. The primary hypothesis of our study was that perioperative pRBC transfusions have a negative impact on postoperative morbidity and 1-year mortality.

METHODS

ARCA-1 was an international multicenter prospective observational cohort study. Participating centers enrolled a minimum of 30 consecutive adult patients with cancer who underwent surgery with curative intent. The primary end point was all-cause mortality 1 year after major cancer surgery. Secondary end points were rates of perioperative blood product use, 1-year cancer-specific mortality, overall survival, and 30-day morbidity and mortality. We performed a propensity score matching analysis to adjust for selection bias. A multivariable logistic regression model was fitted to estimate the effects of significant covariates on 1-year mortality, cancer-related mortality, and overall survival.

RESULTS

A total of 1079 patients were included in the study. The rate of perioperative pRBC transfusions was 21.1%. Preoperative comorbidities, including anemia, American Society of Anesthesiologists (ASA) score of III to IV, a history of coronavirus disease 2019 (COVID-19), myocardial infarction, stroke, need for dialysis, history of blood transfusions, and metastatic disease were statistically significantly more frequent in transfused patients compared to nontransfused patients. The 1-year mortality rate was higher in transfused patients before (19.7% vs 6.5%; P < .0001) and after (17.4% vs 13.2%; P = .29) propensity score matching. 1-year mortality was 1.97 times higher in transfused than in no-transfused patients (odd ratio [OR], 1.97; 95% confidence interval [CI], 1.13-3.41). The odds of 1-year cancer mortality for patients who had perioperative pRBCs was 1.82 times higher (OR, 1.82; 95% CI, 0.97-3.43) compared to those who did not receive perioperative pRBC transfusion. The effect of perioperative pRBC transfusion on overall survival was also significant (hazard ratio [HR], 1.85; 95% CI, 1.15-2.99). Transfused patients also had a higher rate of 30-day postoperative mortality before (3.5% vs 0.7%; P = .0009) and after propensity score matching (4.2% vs 1.8%; P = .34).

CONCLUSIONS

This international, multicenter observational study showed that perioperative pRBC transfusion was associated with an increased mortality risk.

Divergent Metabolic Fates of Aromatic Amino Acid-Derived Isomers: Insights from Ex Vivo Metabolomics and HDX-HRMS/MS-Based Resolution of Tautomers

Tautomers are one of the many types of isomers, and differences in tautomeric structures confer altered chemical and biological properties. Using ultrahigh-performance liquid chromatography-high-resolution mass spectrometry (UHPLC-HRMS) ex vivo metabolomics, we investigate, in whole blood, the divergent metabolism of enol and keto forms of indole-3-pyruvate (IPyA), a tautomeric product of aromatic amino acid metabolism. Two new compounds resulting from IPyA metabolism were discovered, 3-(1H-indol-3-yl)-2,3-dioxopropanoic acid or "indole-3-oxopyruvic acid" and glutathionyl-indole pyruvate (GSHIPyA), which were characterized via ultraviolet photodissociation (UVPD) and higher-energy collisional dissociation (HCD). Computational calculations support the hypothesis that GSHIPyA forms specifically through the enol form of IPyA. GSHIPyA is also hypothesized to be tautomeric, and a hydrogen-deuterium exchange-high-resolution tandem mass spectrometry (HDX-HRMS/MS) approach is developed to prove the presence of an enol and keto tautomer. HDX of GSHIPyA labels the keto form with an additional deuterium, relative to the enol form. HRMS/MS of the labeled isomers is employed to leverage the relationship of resolving power scaling inversely with the square root of m/z, for Orbitrap mass analyzers. HRMS/MS yields a smaller-molecular-weight deuterated tautomeric product ion, reducing the analyte ion m/z and thus lowering the resolving power necessary to separate the deuterated keto tautomer product ion from the [13]C product ion.

Dyslipidemia and hyperglycemia induce overexpression of Syndecan-3 in erythrocytes and modulate erythrocyte adhesion

Erythrocytes are important vascular components that play vital roles in maintaining vascular homeostasis, in addition to carrying oxygen. Previously, we reported that the changes in the internal milieu (e.g. hyperglycemia or hypercholesterolemia) increase erythrocyte adhesion to various extracellular matrix components, potentially through altering glycosaminoglycans (GAGs). In this study, we have investigated the expression of syndecan (Sdc) family members that could be involved in mediating cytoadherence under conditions of dyslipidemia and hyperglycemia. Among the Sdc family members analysed, we found significant overexpression of Sdc-3 in erythrocyte membranes harvested from high-fat-fed control and diabetic animals. Animal studies revealed a positive correlation between Sdc-3 expression, blood sugar levels and erythrocyte adhesion. In the human study, diabetic cohorts with body mass index >24.9 showed significantly increased expression of Sdc-3. Interestingly, blocking the Sdc-3 moiety with an anti-Sdc-3 antibody revealed that the core protein might not be directly involved in erythrocyte adhesion to fibronectin despite the GAGs bringing about adhesion. Lastly, Nano liquid chromatography-mass spectrometry/MS verified the presence of Sdc-3 in erythrocyte membranes. In conclusion, the high-fat diet and diabetes modulated Sdc-3 expression in the erythrocyte membrane, which may alter its adhesive properties and promote vascular complications.

Utility of an Archival Dried Blood Spot (DBS) Collection from HIV-Infected Individuals with and without Cancer in a Resource-Limited Setting

The frequency of virus-associated cancers is growing worldwide, especially in resource-limited settings. One of the biggest challenges in cancer research among people living with HIV (PLWH) has been understanding how infection with both HIV and Kaposi sarcoma-associated herpesvirus (KSHV) promotes the pathogenesis of Kaposi sarcoma (KS), the most common cancer among PLWH worldwide and a significant public health problem in regions with high prevalence of HIV such as Sub-Saharan Africa (SSA). The AIDS and Cancer Specimen Resource (ACSR) provides samples for research, including dried blood spots (DBS) that were collected from large clinical epidemiology studies of KSHV and KS in PLWH conducted more than a decade ago in SSA. Here, we validated the quality of DNA derived from DBS samples from SSA studies and provided evidence of quantitative recovery of inflammatory cytokines using these DBS samples through comparison with paired frozen plasma. Significant differences in DNA, protein yields, and inflammatory biomarker levels were also observed between PLWH with/without KS. Establishing the fitness of DBS samples for studies of KS pathogenesis extends the number of projects that can be supported by these ACSR special collections and provides evidence that DBS collection for future KS research is a practical option in resource-limited settings.

Retrospective Study on the Features and Outcomes of a Tuscany COVID-19 Hospitalized Patients Cohort: Preliminary Results

Background: A few months after the COVID-19 pandemic onset, knowledge of SARS-CoV-2 infection and outcomes and treatments blew up. This paper aimed to evaluate the features of a Tuscany COVID-19 hospitalized cohort and to identify risk factors for COVID-19 severity. Methods: This retrospective observational COVID-19 cohort study (1 March 2020-1 March 2021) was conducted on patients ≥ 18 years old, admitted to Tuscany Hospital, and subjected to follow-up within 12 months after discharge. Patients were enrolled at Pisana, Senese and Careggi University Hospitals, and South East, North West, and Center Local Hospitals. Results: 2888 patients (M = 58.5%, mean age = 66.2 years) were enrolled, of whom 14.3% (N = 413) were admitted to an intensive care unit. Smokers were 25%, and overweight and obese 65%. The most used drugs were corticosteroids, antacids, antibiotics, and antithrombotics, all antiviral drugs, with slight differences between 2020 and 2021. A strong association was found between outcomes of evolution towards critical COVID-19 (non-invasive mechanical ventilation (NIV) and/or admission to intensive care) and smoking (RR = 4.91), ex-smoking (RR = 3.48), overweight (RR = 1.30), obese subjects (RR = 1.62), comorbidities (aRR = 1.38). The alteration of liver enzymes (aspartate aminotransferase, alanine aminotransferase, or gamma-glutamyl transpeptidase) was associated with NIV (aOR = 2.28). Conclusions: Our cohort, characterized by patients with a mean age of 66.2 years, showed 65% of patients were overweight and obese. Smoking/ex-smoking, overweight/obesity, and other comorbidities were associated with COVID-19 adverse outcomes. The findings also demonstrated that alterations in liver enzymes were associated with worse outcomes.

Efficacy and safety of a new heterologous fibrin biopolymer on socket bone healing after tooth extraction: An experimental pre-clinical study

AIM

To assess the efficacy of heterologous fibrin biopolymer (HFB) in promoting alveolar bone healing after tooth extraction in rats.

MATERIALS AND METHODS

The upper right incisors of 48 Wistar rats were extracted. Toothless sockets were filled with HFB (HFBG, n = 24) or blood clot (BCG, n = 24). The tooth extraction sites were subjected to micro-computed tomography (micro-CT), histological, histomorphometric and immunohistochemical (for Runt-related transcription factor 2/Runx2 and tartrate-resistant acid phosphatase/TRAP) analyses on days 0, 7, 14 and 42 after extraction.

RESULTS

Socket volume remained similar between days 0 and 14 (69 ± 5.4 mm3), except in the BCG on day 14, when it was 10% lower (p = .043). Although the number of Runx2+ osteoblasts was high and similar in both groups (34 × 102 cells/mm2), the HFBG showed lower inflammatory process and osteoclast activity than BCG at 7 days. On day 14, the number of Runx2+ osteoblasts remained high and similar to the previous period in both groups. However, osteoclast activity increased. This increase was 55% lower in the HFBG than BCG. In the BCG, the presence of an inflammatory process and larger and numerous osteoclasts on day 14 led to resorption of the alveolar bone ridge and newly formed bone. On day 42, numbers of Runx2+ osteoblast and TRAP+ osteoclasts decreased dramatically in both groups. Although the BCG exhibited a more mature cortical bone formation, it exhibited a higher socket reduction (28.3 ± 6.67%) and smaller bone volume (37 ± 5.8 mm3) compared with HFBG (socket reduction of 14.8 ± 7.14% and total bone volume of 46 ± 5.4 mm3).

CONCLUSIONS

HFB effectively suppresses osteoclast activity and reduces alveolar bone resorption compared with blood clot, thus preventing three-dimensional bone loss, particularly during the early healing period. HFB emerges as a promising biopharmaceutical material for enhancing healing processes after tooth extraction.

Portable platform for leukocyte extraction from blood using sheath-free microfluidic DLD

Leukocyte count is routinely performed for diagnostic purposes and is rapidly emerging as a significant biomarker for a wide array of diseases. Additionally, leukocytes have demonstrated considerable promise in novel cell-based immunotherapies. However, the direct retrieval of leukocytes from whole blood is a significant challenge due to their low abundance compared to erythrocytes. Here, we introduce a microfluidic-based platform that isolates and recovers leukocytes from diluted whole blood in a single step. Our platform utilizes a novel, sheathless method to initially sediment and focus blood cells into a dense stream while flowing through a tubing before entering the microfluidic device. A hexagonal-shaped structure, patterned at the device's inlet, directs all the blood cells against the channel's outer walls. The focused cells are then separated based on their size using the deterministic lateral displacement (DLD) microfluidic technique. We evaluated various parameters that could influence leukocyte separation, including different focusing structures (assessed both computationally and experimentally), the orientation of the tubing-chip interface, the effects of blood sample hematocrit (dilution), and flow rate. Our device demonstrated the ability to isolate leukocytes from diluted blood with a separation efficiency of 100%, a recovery rate of 76%, and a purity of 80%, while maintaining a cell viability of 98%. The device operates for over 30 min at a flow rate of 2 μL min-1. Furthermore, we developed a handheld pressure controller to drive fluid flow, enhancing the operability of our platform outside of central laboratories and enabling near-patient testing. Our platform can be integrated with downstream cell-based assays and analytical methods that require high leukocyte purity (80%), ranging from cell counting to diagnostics and cell culture applications.

Proteomics-The State of the Field: The Definition and Analysis of Proteomes Should Be Based in Reality, Not Convenience

With growing recognition and acknowledgement of the genuine complexity of proteomes, we are finally entering the post-proteogenomic era. Routine assessment of proteomes as inferred correlates of gene sequences (i.e., canonical 'proteins') cannot provide the necessary critical analysis of systems-level biology that is needed to understand underlying molecular mechanisms and pathways or identify the most selective biomarkers and therapeutic targets. These critical requirements demand the analysis of proteomes at the level of proteoforms/protein species, the actual active molecular players. Currently, only highly refined integrated or integrative top-down proteomics (iTDP) enables the analytical depth necessary to provide routine, comprehensive, and quantitative proteome assessments across the widest range of proteoforms inherent to native systems. Here we provide a broad perspective of the field, taking in historical and current realities, to establish a more balanced understanding of where the field has come from (in particular during the ten years since Proteomes was launched), current issues, and how things likely need to proceed if necessary deep proteome analyses are to succeed. We base this in our firm belief that the best proteomic analyses reflect, as closely as possible, the native sample at the moment of sampling. We also seek to emphasise that this and future analytical approaches are likely best based on the broad recognition and exploitation of the complementarity of currently successful approaches. This also emphasises the need to continuously evaluate and further optimize established approaches, to avoid complacency in thinking and expectations but also to promote the critical and careful development and introduction of new approaches, most notably those that address proteoforms. Above all, we wish to emphasise that a rigorous focus on analytical quality must override current thinking that largely values analytical speed; the latter would certainly be nice, if only proteoforms could thus be effectively, routinely, and quantitatively assessed. Alas, proteomes are composed of proteoforms, not molecular species that can be amplified or that directly mirror genes (i.e., 'canonical'). The problem is hard, and we must accept and address it as such, but the payoff in playing this longer game of rigorous deep proteome analyses is the promise of far more selective biomarkers, drug targets, and truly personalised or even individualised medicine.

Hypoxically stored RBC resuscitation in a rat model of traumatic brain injury and severe hemorrhagic shock

This study aims to investigate the effects of hypoxically stored Red Blood Cells (RBCs) in a rat model of traumatic brain injury followed by severe hemorrhagic shock (HS) and resuscitation. RBCs were made hypoxic using an O2 depletion system (Hemanext Inc. Lexington, MA) and stored for 3 weeks. Experimental animals underwent craniotomy and blunt brain injury followed by severe HS. Rats were resuscitated with either fresh RBCs (FRBCs), 3-week-old hypoxically stored RBCs (HRBCs), or 3-week-old conventionally stored RBCs (CRBCs). Resuscitation was provided via RBCs transfusion equivalent to 70 % of the shed blood and animals were followed for 2 h. The control group was comprised of healthy animals that were not instrumented or injured. Post-resuscitation hemodynamics and lactate levels were improved with FRBCs and HRBCs, and markers of organ injury in the liver (Aspartate aminotransferase [AST]), lung (chemokine ligand 1 [CXCL-1] and Leukocytes count), and heart (cardiac troponin, Interleukin- 6 [IL-6] and Tumor Necrosis Factor Alpha[TNF-α]) were lower with FRBCs and HRBCs resuscitation compared to CRBCs. Following reperfusion, biomarkers for oxidative stress, lipid peroxidation, and RNA/DNA injury were assessed. Superoxide dismutase [SOD] levels in the HRBCs group were similar to the FRBCs group and levels in both groups were significantly higher than CRBCs. Catalase levels were not different than control values in the FRBCs and HRBCs groups but significantly lower with CRBCs. Thiobarbituric acid reactive substances [Tbars] levels were higher for both CRBCs and HRBCs. Hypoxically stored RBCs show few differences from fresh RBCs in resuscitation from TBI + HS and decreased organ injury and oxidative stress compared to conventionally stored RBCs.

Enhanced Brain Clearance of Tau and Amyloid-β in Alzheimer's Disease Patients by Transcranial Radiofrequency Wave Treatment: A Central Role of Vascular Endothelial Growth Factor (VEGF)

Background

While drainage/removal of fluid and toxins from the brain by cerebrospinal fluid (CSF) directly into venous blood is well-known, a second drainage route has recently been (re)discovered-meningeal lymphatic vessels (mLVs)-which are responsible for up to half of total brain fluid/toxin drainage. The cytokine vascular endothelial growth factor (VEGF) increases mLV diameter and numbers to increase mLV drainage, resulting in increased mLV drainage. Alzheimer's disease (AD) is characterized by low plasma and CSF levels of VEGF.

Objective

To determine if non-invasive transcranial radiofrequency wave treatment (TRFT), through modulation of VEGF levels in blood and CSF, can affect removal of toxins tau and amyloid-β (Aβ) from the brain.

Methods

Eight mild/moderate AD subjects were given twice-daily 1-hour TRFT sessions at home by their caregivers. Blood and CSF samples were taken at baseline and following completion of 2 months of TRFT.

Results

In plasma and/or CSF, strong baseline correlations between VEGF levels and AD markers (t-tau, p-tau, Aβ1-40, Aβ1-42) were eliminated by TRFT. This effect was primarily due to TRFT-induced increases in VEGF levels in AD subjects with low or unmeasurable "baseline" VEGF levels. These increased VEGF levels were associated with increased clearance/drainage of tau and Aβ from the brain, likely through VEGF's actions on mLVs.

Conclusions

A new mechanism of TRFT is identified (facilitation of brain tau and Aβ clearance via VEGF) that is likely contributory to TRFT's reversal of cognitive impairment in AD subjects. TRFT may be particularly effective for cognitive benefit in AD subjects who have low VEGF levels.

Biomechanical characterization of a fibrinogen-blood hydrogel for human dental pulp regeneration

In dental practice, Regenerative Endodontic Treatment (RET) is applied as an alternative to classical endodontic treatments of immature necrotic teeth. This procedure, also known as dental pulp revitalization, relies on the formation of a blood clot inside the root canal leading to the formation of a reparative vascularized tissue similar to dental pulp, which would provide vitality to the affected tooth. Despite the benefit of this technique, it lacks reproducibility due to the fast degradation and poor mechanical properties of blood clots. This work presents a method for constructing a fibrinogen-blood hydrogel that mimics the viscoelastic properties of human dental pulp while preserving the biological properties of blood for application in RET. By varying the blood and fibrinogen concentrations, gels with different biomechanical and biological properties were obtained. Rheology and atomic force microscopy (AFM) were combined to study the viscoelastic properties. AFM was used to evaluate the elasticity of human dental pulp. The degradation and swelling rates were assessed by measuring weight changes. The biomimetic properties of the gels were demonstrated by studying the cell survival and proliferation of dental pulp cells (DPCs) for 14 days. The formation of an extracellular matrix (ECM) was assessed by multiphoton microscopy (MPM). The angiogenic potential was evaluated by an ex vivo aortic ring assay, in which the endothelial cells were observed by histological staining after migration. The results show that the Fbg-blood gel prepared with 9 mg ml-1 fibrinogen and 50% blood of the Fbg solution volume has similar elasticity to human dental pulp and adequate degradation and swelling rates. It also allows cell survival and ECM secretion and enhances endothelial cell migration and formation of neovessel-like structures.

Red blood cell exposure increases chondrocyte susceptibility to oxidative stress following hemarthrosis

OBJECTIVE

The detrimental effects of blood exposure on articular tissues are well characterized, but the individual contributions of specific whole blood components are yet to be fully elucidated. Better understanding of mechanisms that drive cell and tissue damage in hemophilic arthropathy will inform novel therapeutic strategies. The studies here aimed to identify the specific contributions of intact and lysed red blood cells (RBCs) on cartilage and the therapeutic potential of Ferrostatin-1 in the context of lipid changes, oxidative stress, and ferroptosis.

METHODS

Changes to biochemical and mechanical properties following intact RBC treatment were assessed in human chondrocyte-based tissue-engineered cartilage constructs and validated against human cartilage explants. Chondrocyte monolayers were assayed for changes to intracellular lipid profiles and the presence of oxidative and ferroptotic mechanisms.

RESULTS

Markers of tissue breakdown were observed in cartilage constructs without parallel losses in DNA (control: 786.3 (102.2) ng/mg; RBCINT: 751 (126.4) ng/mg; P = 0.6279), implicating nonlethal chondrocyte responses to intact RBCs. Dose-dependent loss of viability in response to intact and lysed RBCs was observed in chondrocyte monolayers, with greater toxicity observed with lysates. Intact RBCs induced changes to chondrocyte lipid profiles, upregulating highly oxidizable fatty acids (e.g., FA 18:2) and matrix disrupting ceramides. RBC lysates induced cell death via oxidative mechanisms that resemble ferroptosis.

CONCLUSIONS

Intact RBCs induce intracellular phenotypic changes to chondrocytes that increase vulnerability to tissue damage while lysed RBCs have a more direct influence on chondrocyte death by mechanisms that are representative of ferroptosis.

Hematological alterations associated with long COVID-19

Long COVID-19 is a condition characterized by persistent symptoms lasting beyond the acute phase of COVID-19. Long COVID-19 produces diverse symptomatology and can impact organs and systems, including the hematological system. Several studies have reported, in COVID-19 patients, hematological abnormalities. Most of these alterations are associated with a higher risk of severe disease and poor outcomes. This literature review identified studies reporting hematological parameters in individuals with Long COVID-19. Findings suggest that Long COVID-19 is associated with a range of sustained hematological alterations, including alterations in red blood cells, anemia, lymphopenia, and elevated levels of inflammatory markers such as ferritin, D-dimer, and IL-6. These alterations may contribute to a better understanding of the pathophysiology of Long COVID-19 and its associated symptoms. However, further research is needed to elucidate the underlying mechanisms and potential treatments for these hematological changes in individuals with Long COVID-19.

O-GlcNAcylation of RIPK1 rescues red blood cells from necroptosis

Necroptosis is a type of cell death with excessive inflammation and organ damage in various human diseases. Although abnormal necroptosis is common in patients with neurodegenerative, cardiovascular, and infectious diseases, the mechanisms by which O-GlcNAcylation contributes to the regulation of necroptotic cell death are poorly understood. In this study, we reveal that O-GlcNAcylation of RIPK1 (receptor-interacting protein kinase1) was decreased in erythrocytes of the mouse injected with lipopolysaccharide, resulting in the acceleration of erythrocyte necroptosis through increased formation of RIPK1-RIPK3 complex. Mechanistically, we discovered that O-GlcNAcylation of RIPK1 at serine 331 in human (corresponding to serine 332 in mouse) inhibits phosphorylation of RIPK1 at serine 166, which is necessary for the necroptotic activity of RIPK1 and suppresses the formation of the RIPK1-RIPK3 complex in Ripk1 ^-/- MEFs. Thus, our study demonstrates that RIPK1 O-GlcNAcylation serves as a checkpoint to suppress necroptotic signaling in erythrocytes.

Transcranial Electromagnetic Wave Treatment: A Fountain of Healthy Longevity?

Most diseases of older age have as their common denominator a dysfunctional immune system, wherein a low, chronic level of inflammation is present due to an imbalance of pro-inflammatory cytokines over anti-inflammatory cytokines that develops during aging ("inflamm-aging"). A gerotherapeutic that can restore the immune balance to that shared by young/middle-aged adults and many centenarians could reduce the risk of those age-related diseases and increase healthy longevity. In this perspectives paper, we discuss potential longevity interventions that are being evaluated and compare them to a novel gerotherapeutic currently being evaluated in humans-Transcranial Electromagnetic Wave Treatment (TEMT). TEMT is provided non-invasively and safety through a novel bioengineered medical device-the MemorEM-that allows for near complete mobility during in-home treatments. Daily TEMT to mild/moderate Alzheimer's Disease (AD) patients over a 2-month period rebalanced 11 of 12 cytokines in blood back to that of normal aged adults. A very similar TEMT-induced rebalancing of cytokines occurred in the CSF/brain for essentially all seven measurable cytokines. Overall inflammation in both blood and brain was dramatically reduced by TEMT over a 14-27 month period, as measured by C-Reactive Protein. In these same AD patients, a reversal of cognitive impairment was observed at 2 months into treatment, while cognitive decline was stopped over a 2½ year period of TEMT. Since most age-related diseases have the commonality of immune imbalance, it is reasonable to postulate that TEMT could rebalance the immune system in many age-related diseases as it appears to do in AD. We propose that TEMT has the potential to reduce the risk/severity of age-related diseases by rejuvenating the immune system to a younger age, resulting in reduced brain/body inflammation and a substantial increase in healthy longevity.

Erythrocytes: Member of the Immune System that Should Not Be Ignored

Erythrocytes are the most abundant type of cells in the blood and have a relatively simple structure when mature; they have a long life-span in the circulatory system. The primary function of erythrocytes is as oxygen carriers; however, they also play an important role in the immune system. Erythrocytes recognize and adhere to antigens and promote phagocytosis. The abnormal morphology and function of erythrocytes are also involved in the pathological processes of some diseases. Owing to the large number and immune properties of erythrocytes, their immune functions should not be ignored. Currently, research on immunity is focused on immune cells other than erythrocytes. However, research on the immune function of erythrocytes and the development of erythrocyte-mediated applications is of great significance. Therefore, we aimed to review the relevant literature and summarize the immune functions of erythrocytes.

Clinical Signs of Kawasaki Disease from the Perspective of Epithelial-to-Mesenchymal Transition Recruiting Erythrocytes: A Literature Review

Kawasaki disease (KD) is a systemic vasculitis affecting children younger than 5 years of age. Early period in life is marked by rapid somatic growth with cell proliferation and immaturity of the immunity with dominant innate immune system. Coronary complications in KD are the most common acquired heart disease in children, yet the diagnosis of KD still depends on the clinical diagnostic criteria. Glossy red lips and conjunctival injection are characteristic signs enabling pediatricians to make the initial diagnosis of KD; however, little is known why these are so characteristic. The diagnostic criteria of KD seem to be scattered in seemingly irrelevant body systems such as the eyes, lips, skin, and heart. KD is classified as a connective tissue disease. Recently, red blood cells (RBCs) have emerged as important modulators in innate immune response. RBCs are reported to participate in extracellular matrix remodeling and upregulating matrix metalloproteinase (MMP) expression in dermal fibroblasts. Also, fibroblast growth factors and microRNAs associated with fibrosis are drawing attention in KD. The cardinal signs of KD appear at the border of muco-cutaneous junction. Head and neck regions are abundant in tissues undergoing epithelial-to-mesenchymal transition (EMT). Interstitial carditis and valve insufficiency as well as coronary arterial lesions may complicate KD, and these lesions present in tissues that originated from epicardial progenitor cells by EMT. Having reviewed the recent research on KD, we presume that the signs of KD present at borders between keratinized and non-keratinized stratified squamous epithelium where the EMT is still ongoing for the rapid somatic growth where RBCs are recruited as an innate immune response and to prevent excessive fibrosis in mucosa. KD presents scarcely in adults with somatic growth and immune maturation completed. In this review, we attempted to explain the reasons for the clinical manifestations of KD and to search for a link among the diagnostic clues in the perspective of EMT during the somatic growth and immune system maturation in children with KD.

Drugs to reduce bleeding and transfusion in major open vascular or endovascular surgery: a systematic review and network meta-analysis

BACKGROUND

Vascular surgery may be followed by internal bleeding due to inadequate surgical haemostasis, abnormal clotting, or surgical complications. Bleeding ranges from minor, with no transfusion requirement, to massive, requiring multiple blood product transfusions. There are a number of drugs, given systemically or applied locally, which may reduce the need for blood transfusion.

OBJECTIVES

To assess the effectiveness and safety of anti-fibrinolytic and haemostatic drugs and agents in reducing bleeding and the need for blood transfusion in people undergoing major vascular surgery or vascular procedures with a risk of moderate or severe (> 500 mL) blood loss.

SEARCH METHODS

We searched: Cochrane Central Register of Controlled Trials; MEDLINE; Embase; CINAHL, and Transfusion Evidence Library. We also searched the WHO ICTRP and ClinicalTrials.gov trial registries for ongoing and unpublished trials. Searches used a combination of MeSH and free text terms from database inception to 31 March 2022, without restriction on language or publication status.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) in adults of drug treatments to reduce bleeding due to major vascular surgery or vascular procedures with a risk of moderate or severe blood loss, which used placebo, usual care or another drug regimen as control.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were units of red cells transfused and all-cause mortality. Our secondary outcomes included risk of receiving an allogeneic blood product, risk of reoperation or repeat procedure due to bleeding, risk of a thromboembolic event, risk of a serious adverse event and length of hospital stay. We used GRADE to assess certainty of evidence.

MAIN RESULTS

We included 22 RCTs with 3393 participants analysed, of which one RCT with 69 participants was reported only in abstract form, with no usable data. Seven RCTs evaluated systemic drug treatments (three aprotinin, two desmopressin, two tranexamic acid) and 15 RCTs evaluated topical drug treatments (drug-containing bioabsorbable dressings or glues), including fibrin, thrombin, collagen, gelatin, synthetic sealants and one investigational new agent. Most trials were conducted in high-income countries and the majority of the trials only included participants undergoing elective surgery. We also identified two ongoing RCTs. We were unable to perform the planned network meta-analysis due to the sparse reporting of outcomes relevant to this review. Systemic drug treatments We identified seven trials of three systemic drugs: aprotinin, desmopressin and tranexamic acid, all with placebo controls. The trials of aprotinin and desmopressin were small with very low-certainty evidence for all of our outcomes. Tranexamic acid versus placebo was the systemic drug comparison with the largest number of participants (2 trials; 1460 participants), both at low risk of bias. The largest of these included a total of 9535 individuals undergoing a number of different higher risk surgeries and reported limited information on the vascular subgroup (1399 participants). Neither trial reported the number of units of red cells transfused per participant up to 30 days. Three outcomes were associated with very low-certainty evidence due to the very wide confidence intervals (CIs) resulting from small study sizes and low number of events. These were: all-cause mortality up to 30 days; number of participants requiring an allogeneic blood transfusion up to 30 days; and risk of requiring a repeat procedure or operation due to bleeding. Tranexamic acid may have no effect on the risk of thromboembolic events up to 30 days (risk ratio (RR) 1.10, 95% CI 0.88 to 1.36; 1 trial, 1360 participants; low-certainty evidence due to imprecision). There is one large ongoing trial (8320 participants) comparing tranexamic acid versus placebo in people undergoing non-cardiac surgery who are at high risk of requiring a red cell transfusion. This aims to complete recruitment in April 2023. This trial has primary outcomes of proportion of participants transfused with red blood cells and incidence of venous thromboembolism (DVT or PE). Topical drug treatments Most trials of topical drug treatments were at high risk of bias due to their open-label design (compared with usual care, or liquids were compared with sponges). All of the trials were small, most were very small, and few reported clinically relevant outcomes in the postoperative period. Fibrin sealant versus usual care was the topical drug comparison with the largest number of participants (5 trials, 784 participants). The five trials that compared fibrin sealant with usual care were all at high risk of bias, due to the open-label trial design with no measures put in place to minimise reporting bias. All of the trials were funded by pharmaceutical companies. None of the five trials reported the number of red cells transfused per participant up to 30 days or the number of participants requiring an allogeneic blood transfusion up to 30 days. The other three outcomes were associated with very low-certainty evidence with wide confidence intervals due to small sample sizes and the low number of events, these were: all-cause mortality up to 30 days; risk of requiring a repeat procedure due to bleeding; and risk of thromboembolic disease up to 30 days. We identified one large trial (500 participants) comparing fibrin sealant versus usual care in participants undergoing abdominal aortic aneurysm repair, which has not yet started recruitment. This trial lists death due to arterial disease and reintervention rates as primary outcomes.

AUTHORS' CONCLUSIONS

Because of a lack of data, we are uncertain whether any systemic or topical treatments used to reduce bleeding due to major vascular surgery have an effect on: all-cause mortality up to 30 days; risk of requiring a repeat procedure or operation due to bleeding; number of red cells transfused per participant up to 30 days or the number of participants requiring an allogeneic blood transfusion up to 30 days. There may be no effect of tranexamic acid on the risk of thromboembolic events up to 30 days, this is important as there has been concern that this risk may be increased. Trials with sample size targets of thousands of participants and clinically relevant outcomes are needed, and we look forward to seeing the results of the ongoing trials in the future.

Neutrophil membrane-coated nanoparticles exhibit increased antimicrobial activities in an anti-microbial resistant K. pneumonia infection model

OBJECTIVE

To investigate the efficacy and safety of neutrophil membrane-coated nanoparticles mediated KLA peptides (KLAKLAKKLAKLAK) and gentamicin in the targeted therapy of anti-microbial resistant Klebsiella pneumoniae (K. pneumonia) lung infection.

METHODS

The characteristics of KLA-neutrophils nanoparticles (NNPs) are identified via dynamic light scattering (DLS), transmission electron microscope (TEM), SDS-PAGE, Western blot, quantitative flow cytometry (QFCM) and confocal microscopy. The safety of KLA-NNPs both in vitro and in vivo is evaluated by hemolysis test, platelet α granule membrane protein concentration, protein adsorption capacity, in vitro macrophage phagocytosis, weight change, liver function indicators, blood biochemical indicators, and pathological changes of vital organs in mice. The efficacy of KLA-NNPs is determined by time-kill assay, fluorescent label test, intracellular bacterial content, caspase-1 activity, survival rate, and HE staining both in vitro and in vivo.

RESULTS

The prepared KLA-NNPs have a typical "core-shell" structure, uniform nanometer size, and retain the membrane proteins on the neutrophil membrane that achieve functional effects. In vitro safety analysis showed that KLA-NNPs have good blood compatibility and can inhibit macrophage phagocytosis in vitro. KLA-NNPs can effectively release KLA and significantly reduce intracellular bacteria and caspase-1 activity. In vivo safety analysis and efficacy analysis revealed that KLA-NNPs have good biocompatibility and could effectively improve the survival rate of mice.

CONCLUSION

The prepared KLA-NNPs have good nano-medicine chemical and physical properties and safety. It can evade immune system clearance, achieve high-efficiency targeted aggregation and drug delivery to bacterial infection sites, and effectively inhibit the development of pneumonia induced by drug-resistant K. pneumonia.

Identification of host biomarkers from dried blood spots for monitoring treatment response in extrapulmonary tuberculosis

There is a lack of objective tools for monitoring treatment response in extrapulmonary tuberculosis (EPTB). This study aimed to explore the utility of inflammatory biomarkers from the dry blood spots (DBS) as a tool for monitoring treatment response in EPTB. In a prospective cohort study, 40 inflammatory biomarkers were investigated in DBS samples from 105 EPTB cases using a Luminex platform. The samples were taken before, and, at the end of the 2nd and 6th months of treatment. A total of 11 inflammatory host biomarkers changed significantly with treatment in all EPTB patients. CXCL9/MIG, CCL20, CCL23, CXCL10/IP-10, CXCL1, CXCL2, and CXCL8 significantly declined in our cohort of EPTB (48 TB pleuritis and 57 TB lymphadenitis) patients at both time points. A biosignature consisting of MIG, CCL23, and CXCL2, corresponded with the treatment response in 81% of patients in the 2nd month and 79% of patients at the end of treatment. MIG, CCL23, IP-10, and CXCL2 changed significantly with treatment in all patients including those showing partial clinical response at the 2nd month of treatment. The changes in the levels of inflammatory biomarkers in the DBS correspond with the treatment success and can be developed as a routine test in low-resource settings.

Oxidative stress and related metabolic alterations are induced in ex situ perfusion of donated hearts regardless of the ventricular load or leukocyte depletion

We sought to determine the role of donor blood circulating leukocytes in mediating oxidative stress and inflammation during normothermic ex situ heart perfusion (ESHP). Normothermic ESHP allows preservation of donated heart in a perfused, dynamic state, preventing ischemia. However, the cardiac function declines during ESHP, limiting the potential of this method for improvement of the outcomes of transplantation and expanding the donor pool. Extracorporeal circulation-related oxidative stress plays a critical role in the functional decline of the donor heart. Hearts from domestic pigs were perfused in working mode (WM, whole blood-based or leukocyte-depleted blood-based perfusate) or nonworking mode. Markers of oxidative stress and responsive glucose anabolic pathways were induced in the myocardium regardless of left ventricular load. Myocardial function during ESHP as well as cardioprotective mechanisms were preserved better in WM. Leukocyte-depleted perfusate did not attenuate tissue oxidative stress or perfusate proinflammatory cytokines and did not improve functional preservation. Although ESHP is associated with ongoing oxidative stress and metabolic alteration in the myocardium, preserved cardioprotective mechanisms in WM may exert beneficial effects. Leukocyte depletion of the perfusate may not attenuate inflammation and oxidative stress effectively or improve the functional preservation of the heart during ESHP.

Characterization of exercise-induced hemolysis in endurance horses

Exercise-induced hemolysis occurs as the result of intense physical exercise and is caused by metabolic and mechanical factors including repeated muscle contractions leading to capillary vessels compression, vasoconstriction of internal organs and foot strike among others. We hypothesized that exercise-induced hemolysis occurred in endurance racehorses and its severity was associated with the intensity of exercise. To provide further insight into the hemolysis of endurance horses, the aim of the study was to deployed a strategy for small molecules (metabolites) profiling, beyond standard molecular methods. The study included 47 Arabian endurance horses competing for either 80, 100, or 120 km distances. Blood plasma was collected before and after the competition and analyzed macroscopically, by ELISA and non-targeted metabolomics with liquid chromatography-mass spectrometry. A significant increase in all hemolysis parameters was observed after the race, and an association was found between the measured parameters, average speed, and distance completed. Levels of hemolysis markers were highest in horses eliminated for metabolic reasons in comparison to finishers and horses eliminated for lameness (gait abnormality), which may suggest a connection between the intensity of exercise, metabolic challenges, and hemolysis. Utilization of omics methods alongside conventional methods revealed a broader insight into the exercise-induced hemolysis process by displaying, apart from commonly measured hemoglobin and haptoglobin, levels of hemoglobin degradation metabolites. Obtained results emphasized the importance of respecting horse limitations in regard to speed and distance which, if underestimated, may lead to severe damages.

Are IL-1 family cytokines important in management of sickle cell disease in Sub-Saharan Africa patients?

Introduction

Sickle cell disease (SCD) is the most common genetic disease found in Africa and throughout the world. It is responsible for a high rate of hemolysis, systemic inflammation, and modulation of the immune system with the involvement of immunological molecules, such as cytokines. IL-1β is a major inflammatory cytokine. IL-18 and IL-33, members of IL-1 family, also exhibit characteristics of inflammation-related cytokines. Thus, in order to contribute to the evaluation of the severity and prognosis of SCD in Africa, this study aimed to estimate the cytokine response, in particular the levels of cytokines of the IL-1 family, in sickle cell patients living in a Sub-Saharan country.

Methods

Ninety patients with a diagnosis of SCD were recruited with different hemoglobin types. Samples were assessed for cytokine levels using the Human Inflammation Panel assay from BioLegend. The assay allows the simultaneous quantification of 13 human inflammatory cytokines/chemokines, i.e., IL-1β, IFN-α2, IFN-γ, TNFα, MCP-1 (CCL2), IL-6, IL-8 (CXCL8), IL-10, IL-12p70, IL-17A, IL-18, IL-23, and IL-33.

Results and discussion

the assessment of plasma cytokines in SCD patients revealed significantly increased levels of IL-1 family cytokines in crisis compared to steady state, suggesting a substantial involvement of these cytokines in clinical exacerbation. This suggests the possibility of a causal effect in the SCD pathology and can open the way to define better care, pointing toward new therapeutic avenues for sickle disease in Sub-Saharan Africa.

Modulation of growth, immune response, and immune-antioxidant related gene expression of Nile tilapia (Oreochromis niloticus) reared under biofloc system using mango peel powder

This study aimed to investigate the effects of mango peel powder (MGPP) on growth, innate immunity, and immune-antioxidant related gene expression of Nile tilapia reared under biofloc system. Three hundred Nile tilapia (average weight 14.78 ± 0.05 g) were distributed into 15 fiber tanks (300 L per tank) assigned to five treatments in triplication. Fish were fed basal diet containing different levels MGPP as follows: 0 (MGPP0: control), 6.25 (MGPP 6.25), 12.5 (MGPP 12.25), 25 (MGPP 25), and 50 (MGPP 50) g kg^-1 diet for 8 weeks. Specific growth rate (SGR), weight gain (WG), final weight (FW), feed conversion ratio (FCR), skin mucus of lysozyme (SMLA), and peroxidase activities (SMPA), serum of lysozyme (SL) and peroxidase (SP) were measured every for weeks; while immune-antioxidant-related gene expressions were determined after 8 weeks post-feeding. The results indicated that MGPP 25 diet resulted in higher SGR, WG, FW, and FCR but no significant differences among treatments were noticed. In terms of immune responses, lysozyme and peroxidase activities in mucus and serum were significantly higher in MGPP 12.5 and MGPP 25 diets against the control. Similarly, significant up-regulation of IL-1 and IL-8 gene expressions was observed in fish fed MGPP 25 against the control. However, no significant differences in LBP, GSTa, GPX, and GSR among treatments were observed. Overall, dietary inclusion of MGPP 25 significantly enhanced immune response and immune related gene expressions but not growth performance and antioxidant gene expressions. The results implied that MGPP can be potentially used as an immunostimulants in Nile tilapia culture.

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.

Chemerin Levels in Acute Coronary Syndrome: Systematic Review and Meta-Analysis

OBJECTIVE

We evaluated the relevant published studies exploring the association between chemerin concentrations and acute coronary syndromes (ACSs).

METHODS

A systematic search was performed in October 2021 using PubMed, Scopus, Embase, and Cochrane Library. We included full articles and assessed their quality using the Newcastle-Ottawa score.

RESULTS

We found 6 studies in the systematic review and 5 of these were included in our meta-analysis. Mean difference (MD) of 41.69 ng/mL (95% CI, 10.07-73.30), 132.14 ng/mL (95% CI, -102.12-366.40), and 62.10 ng/mL (95% CI, 10.31-113.89) in chemerin levels was seen in ACS patients vs control subjects, ACS patients vs stable angina pectoris patients (SAP), and type 2 diabetes mellitus (T2DM) ACS patients vs nondiabetic ACS patients, respectively.

CONCLUSION

Chemerin levels were significantly elevated in patients with ACS compared to controls, as well as in T2DM-ACS patients compared to nondiabetic ACS patients. However, no significant MD in chemerin levels was observed between SAP and ACS patients.

Hypothesis: Low Vitamin A and D Levels Worsen Clinical Outcomes When Children with Sickle Cell Disease Encounter Parvovirus B19

Human parvovirus B19 causes life-threatening anemia due to transient red cell aplasia (TRCA) in individuals with sickle cell disease (SCD). Children with SCD experiencing profound anemia during TRCA often require red blood cell transfusions and hospitalization. The prevalence of vitamin deficiencies in SCD is high and deficiencies are associated with respiratory and pain symptoms, but the effects of vitamins on acute infection with parvovirus B19 remain unclear. We performed a clinical study in which 20 SCD patients hospitalized with parvovirus B19 infections (Day 0) were monitored over a 120-day time course to query relationships between vitamins A and D and clinical outcomes. There were significant negative correlations between Day 0 vitamin levels and disease consequences (e.g., red blood cell transfusion requirements, inflammatory cytokines). There were significant positive correlations (i) between Day 0 vitamins and peak virus-specific antibodies in nasal wash, and (ii) between Day 0 virus-specific serum plus nasal wash antibodies and absolute reticulocyte counts. There was a significant negative correlation between Day 0 virus-specific serum antibodies and virus loads. To explain the results, we propose circular and complex mechanisms. Low baseline vitamin levels may weaken virus-specific immune responses to permit virus amplification and reticulocyte loss; consequent damage may further reduce vitamin levels and virus-specific immunity. While the complex benefits of vitamins are not fully understood, we propose that maintenance of replete vitamin A and D levels in children with SCD will serve as prophylaxis against parvovirus B19-induced TRCA complications.

Circulating interleukin-38 concentrations in healthy adults

Interleukin (IL)-38 is the latest discovered member of the interleukin-1 family, which has anti-inflammatory properties similar to IL-36Ra. Several studies compared circulating IL-38 concentrations in healthy and diseased populations to characterize its role in both auto-immune and inflammatory pathologies, with both higher and lower concentrations being associated with certain diseases. However, in order to use IL-38 as a biomarker, a reference range in healthy adults is needed. To establish a reference IL-38 circulating concentration, accessible data from 25 eligible studies with IL-38 concentrations in healthy adults was collected. To validate the values found in literature, we measured IL-38 concentrations by enzyme-linked immunosorbent assay (ELISA) in several cohorts from our own institute. Additionally, the effect of blood collection techniques, freeze thawing cycles, and hemolysis on IL-38 measurements was assessed. To evaluate the importance of the genetic background of individuals as confounding factor of IL-38 synthesis, we used publicly available eQTL databases with matched data on allele frequencies in individuals of different ethnicities. Mean IL-38 concentrations in the various studies were weighted by their corresponding sample size, resulting in a weighted mean, and weighted upper and lower limits were calculated by mean ± 2 SD. Differences of over 10.000-fold were found in the weighted means between studies, which could not be attributed to the blood collection method or assessment of IL-38 in plasma or serum. Although IL-38 concentrations were markedly higher in Chinese then in European population studies, we could not show an association with the genetic background. From our analysis, a reference range for circulating IL-38 in healthy adults could thus not yet be established.

Responses of human colon and breast adenocarcinoma cell lines (LoVo, MCF7) and non-tumorigenic mammary epithelial cells (MCF-10A) to the acellular fraction of packed red blood cells in the presence and absence of cisplatin

Perioperative blood transfusion in colorectal and some other cancer patients has been linked to the increased risk for recurrence, but a causal mechanism remains unclear. During the preparation and storage of packed red blood cells (PRBCs) bio-active substances accumulate in the acellular fraction (supernatant). Viability, proliferation, reactive oxygen species (ROS) levels, and DNA damage of colon (LoVo) and breast (MCF7) adenocarcinoma cells and non-tumorigenic MCF-10A cell line were determined in response to the supernatants of fresh and long-stored (day 42) PRBCs, leukoreduced (LR) or non-leukoreduced (NLR). The effect of supernatants on the cytotoxicity of cisplatin (cisPt) towards the cells was also examined. Supernatants, especially from a day 1 PRBCs, both LR and NLR, reduced the viability and inhibited proliferation of tumor cells (LoVo, MCF7), accompanying by the excessive ROS production, but these were not the case in MCF-10A. Moreover, supernatants had no effect on the cytotoxicity of cisPt against LoVo and MCF7 cells, while caused increased drug resistance in MCF-10A cells. The findings suggest the acellular fraction of PRBCs does not exhibit any pro-proliferative activity in the cancer cell lines studied. However, these are pioneering issues and require further research.

Effects of Distinct Force Magnitude of Spinal Manipulative Therapy on Blood Biomarkers of Inflammation: A Proof of Principle Study in Healthy Young Adults

OBJECTIVES

The purpose of this preliminary study was to determine the influence of thoracic spinal manipulation therapy (SMT) of different force magnitudes on blood biomarkers of inflammation in healthy adults.

METHODS

Nineteen healthy young adults (10 female, age: 25.6 ± 1.2 years) were randomized into the following 3 groups: (1) control (preload only), (2) single thoracic SMT with a total peak force of 400N, and (3) single thoracic SMT with a total peak force of 800N. SMT was performed by an experienced chiropractor, and a force-plate embedded treatment table (Force Sensing Table Technology) was used to determine the SMT force magnitudes applied. Blood samples were collected at pre intervention (baseline), immediately post intervention, and 20 minutes post intervention. A laboratory panel of 14 different inflammatory biomarkers (pro, anti, dual role, chemokine, and growth factor) was assessed by multiplex array. Change scores from baseline of each biomarker was used for statistical analysis. Two-way repeated-measures analysis of variance was used to investigate the interaction and main effects of intervention and time on cytokines, followed by Tukey's multiple comparison test (P ≤ .05).

RESULTS

A between-group (800N vs 400N) difference was observed on interferon-gamma, interleukin (IL)-5, and IL-6, while a within-group difference (800N: immediately vs 20 minutes post-intervention) was observed on IL-6 only.

CONCLUSION

In this study, we measured short-term changes in plasma cytokines in healthy young adults and found that select plasma pro-inflammatory and dual-role cytokines were elevated by higher compared to lower SMT force. Our findings aid to advance our understanding of the potential relationship between SMT force magnitude and blood cytokines and provide a healthy baseline group with which to compare similar studies in clinical populations in the future.

Pathophysiological Changes in Erythrocytes Contributing to Complications of Inflammation and Coagulation in COVID-19

Higher thrombotic burden in the acute phase of COVID-19 relies on a complex interplay between pro-inflammatory cytokine/chemokine release, increased endothelial dysfunction/damage, and potential sepsis-induced coagulopathy development in severe cases, all promoting coagulation activation. Plasma levels of cytokines and chemokines are known to be increased in COVID-19 however, are much higher in severe infections. Increased levels of IL-1β, IL-6, and IL-8 are known to play an important role in both acute and chronic inflammation, resulting in pathological clotting. However, little has been published on the effects of these interleukins on red blood cells (RBCs). Evidence shows that cytokines have a negative effect on the RBCs ultrastructure and introduce signs of eryptosis. Eryptosis can be described as a form of suicidal death of RBCs characterized by distinct findings of cell shrinkage, membrane blebbing, activation of proteases, and phosphatidylserine exposure at the outer membrane leaflet. Red blood cells from COVID-19 patients had increased levels of glycolytic intermediates, accompanied by oxidation and fragmentation of ankyrin, spectrin beta, and the N-terminal cytosolic domain of band 3 (AE1). Significantly altered lipid metabolism was also observed, in particular, short- and medium-chain saturated fatty acids, acyl-carnitines, and sphingolipids. Emerging research suggests that RBCs may contribute to a precision medicine approach to sepsis and have diagnostic value in monitoring complement dysregulation in COVID-19-sepsis and non-COVID sepsis as research indicates that complement activation products and viral antigens are present on RBCs in patients with COVID-19.

"Cells-to-cDNA on Chip": Phenotypic Assessment and Gene Expression Analysis from Live Cells in Nanoliter Volumes Using Droplet Microarrays

In vitro cell-based experiments are particularly important in fundamental biological research. Microscopy-based readouts to identify cellular changes in response to various stimuli are a popular choice, but gene expression analysis is essential to delineate the underlying molecular dynamics in cells. However, cell-based experiments often suffer from interexperimental variation, especially while using different readout methods. Therefore, establishment of platforms that allow for cell screening, along with parallel investigations of morphological features, as well as gene expression levels, is crucial. The droplet microarray (DMA) platform enables cell screening in hundreds of nanoliter droplets. In this study, a "Cells-to-cDNA on Chip" method is developed enabling on-chip mRNA isolation from live cells and conversion to cDNA in individual droplets of 200 nL. This novel method works efficiently to obtain cDNA from different cell numbers, down to single cell per droplet. This is the first established miniaturized on-chip strategy that enables the entire course of cell screening, phenotypic microscopy-based assessments along with mRNA isolation and its conversion to cDNA for gene expression analysis by real-time PCR on an open DMA platform. The principle demonstrated in this study sets a beginning for myriad of possible applications to obtain detailed information about the molecular dynamics in cultured cells.

Injection of adipose stem cells in the treatment of rotator cuff disease - a narrative review of current evidence

The purpose of this study is to summarize evidence for the use of adipose stem cell (ASC) injections in the treatment of rotator cuff tears (RCT) and identify future areas of study. A thorough literature search was performed to identify studies investigating the use of ASC injections in the treatment of RCTs. Among animal trials, it is unclear whether ASCs are of benefit for rotator cuff repair. In clinical trials, ASC injection may reduce retear rate with otherwise equivocal clinical outcomes. Although ASC injection may be safe, the literature does not provide a clear consensus as to the efficacy of ASC injections, nor does it delineate which patients would benefit most from this treatment.

Inflammation and Oxidative Stress in the Context of Extracorporeal Cardiac and Pulmonary Support

Extracorporeal circulation (ECC) systems, including cardiopulmonary bypass, and extracorporeal membrane oxygenation have been an irreplaceable part of the cardiothoracic surgeries, and treatment of critically ill patients with respiratory and/or cardiac failure for more than half a century. During the recent decades, the concept of extracorporeal circulation has been extended to isolated machine perfusion of the donor organ including thoracic organs (ex-situ organ perfusion, ESOP) as a method for dynamic, semi-physiologic preservation, and potential improvement of the donor organs. The extracorporeal life support systems (ECLS) have been lifesaving and facilitating complex cardiothoracic surgeries, and the ESOP technology has the potential to increase the number of the transplantable donor organs, and to improve the outcomes of transplantation. However, these artificial circulation systems in general have been associated with activation of the inflammatory and oxidative stress responses in patients and/or in the exposed tissues and organs. The activation of these responses can negatively affect patient outcomes in ECLS, and may as well jeopardize the reliability of the organ viability assessment, and the outcomes of thoracic organ preservation and transplantation in ESOP. Both ECLS and ESOP consist of artificial circuit materials and components, which play a key role in the induction of these responses. However, while ECLS can lead to systemic inflammatory and oxidative stress responses negatively affecting various organs/systems of the body, in ESOP, the absence of the organs that play an important role in oxidant scavenging/antioxidative replenishment of the body, such as liver, may make the perfused organ more susceptible to inflammation and oxidative stress during extracorporeal circulation. In the present manuscript, we will review the activation of the inflammatory and oxidative stress responses during ECLP and ESOP, mechanisms involved, clinical implications, and the interventions for attenuating these responses in ECC.

Erythrocytes Induce Vascular Dysfunction in COVID-19

•

Patients hospitalized for COVID-19 display marked impairment in endothelial function, which is persistent following recovery from the acute infection.

•

RBCs from patients with COVID-19 impair vascular function through mechanisms involving increased arginase 1, ROS and IFNγ, and reduced NO bioactivity.

•

These data advance our understanding in COVID-19–associated vascular injury with a clear involvement of RBCs.

•

Targeting these mechanisms might provide a novel therapeutic strategy to alleviate vascular injury in patients with COVID-19.

Current knowledge regarding mechanisms underlying cardiovascular complications in patients with COVID-19 is limited and urgently needed. We shed light on a previously unrecognized mechanism and unravel a key role of red blood cells, driving vascular dysfunction in patients with COVID-19 infection. We establish the presence of profound and persistent endothelial dysfunction in vivo in patients with COVID-19. Mechanistically, we show that targeting reactive oxygen species or arginase 1 improves vascular dysfunction mediated by red blood cells. These translational observations hold promise that restoring the redox balance in red blood cells might alleviate the clinical complications of COVID-19–associated vascular dysfunction.

Uncoupled biological and chronological aging of neutrophils in cancer promotes tumor progression

Background

Beyond their fundamental role in homeostasis and host defense, neutrophilic granulocytes (neutrophils) are increasingly recognized to contribute to the pathogenesis of malignant tumors. Recently, aging of mature neutrophils in the systemic circulation has been identified to be critical for these immune cells to properly unfold their homeostatic and anti-infectious functional properties. The role of neutrophil aging in cancer remains largely obscure.

Methods

Employing advanced in vivo microscopy techniques in different animal models of cancer as well as utilizing pulse-labeling and cell transfer approaches, various ex vivo/in vitro assays, and human data, we sought to define the functional relevance of neutrophil aging in cancer.

Results

Here, we show that signals released during early tumor growth accelerate biological aging of circulating neutrophils, hence uncoupling biological from chronological aging of these immune cells. This facilitates the accumulation of highly reactive neutrophils in malignant lesions and endows them with potent protumorigenic functions, thus promoting tumor progression. Counteracting uncoupled biological aging of circulating neutrophils by blocking the chemokine receptor CXCR2 effectively suppressed tumor growth.

Conclusions

Our data uncover a self-sustaining mechanism of malignant neoplasms in fostering protumorigenic phenotypic and functional changes in circulating neutrophils. Interference with this aberrant process might therefore provide a novel, already pharmacologically targetable strategy for cancer immunotherapy.

Exposure to lead on expression levels of brain immunoglobulins, inflammatory cytokines, and brain-derived neurotropic factor in fetal and postnatal mice with autism-like characteristics

Autism spectrum disorders (ASD) are neurodevelopmental disorders, and their incidence is increasing worldwide. Increased exposure to environmental metal lead (Pb) has been proposed as a risk factor associated with ASD. In the present study, BTBR T+ tf/J (BTBR) mice with ASD-like behavioral characteristics and control FVB mice were exposed gestationally and/or neonatally to Pb, and compared with highly social FVB mice to investigate neuroimmunological abnormalities. IgG1 and IgG2a levels in fetal brains from BTBR dams exposed to Pb (BTBR-Pb) were significantly higher than those of BTBR-controls (BTBR-C). However, this change did not occur in FVB mice exposed to Pb. The IgG1:IgG2a ratio was higher in both fetal and postnatal brains of BTBR mice compared to FVB animals regardless of Pb exposure. The IL-4:IFN-γ ratio was elevated in BTBR-Pb relative to BTBR-C mice, but this ratio was not markedly affected following Pb exposure in FVB animals. These findings suggest the potential for a Pb-driven predominant T_H2-like reactivity profile in brain microenvironment present in BTBR mice. Brain-derived neurotrophic factor was decreased in fetal and postnatal BTBR-Pb brains relative to BTBR-C brains but not in FVB-Pb relative to FVB-C mice. Taken together, data demonstrate that Pb exposure might contribute to developmental brain abnormalities associated with ASD, particularly in individuals with genetic susceptibility to ASD.

Red blood cells and their releasates compromise bone marrow-derived human mesenchymal stem/stromal cell survival in vitro

PURPOSE

The use of bone marrow aspirate (BMA) and bone marrow aspirate concentrate (BMC) in the treatment of inflammatory orthopedic conditions has become a common practice. The therapeutic effect of BMA/BMC is thought to revolve primarily around the mesenchymal stem/stromal cell (MSC) population residing within the nucleated cell fraction. MSCs have the unique ability to respond to site of injury via the secretion of immunomodulating factors, resolving inflammation in diseased joints. Recently, the importance of hematocrit (HCT) in BMC has been debated, as the potential impact on MSC function is unknown. In the present study, we investigate MSC health over a short time-course following exposure to a range of HCT and red blood cell releasate (RBC_rel) conditions.

METHODS

Bone marrow-derived human MSCs in early passage were grown under conditions of 0%, 2.5%, 5%, 10%, 20% and 40% HCT and RBC_rel conditions for 3 days. At each day, the percentage of viable, apoptotic and necrotic MSCs was determined via flow cytometry. Relative viable MSC counts in each condition was determined to account for dynamic changes in overall MSC densities over the time-course. Statistical analysis was performed using a one-way ANOVA comparing test conditions to the control followed by a Dunnett's multiple comparison test.

RESULTS

Significant reductions in viable MSCs concurrent with an increase in necrotic MSCs in high HCT and RBC_rel conditions was observed within 24 h. At each successive timepoint, the percent and relative number of viable MSCs were reduced, becoming significant in multiple HCT and RBC_rel conditions by Day 3. Necrosis appears to be the initial mode of MSC death following exposure to HCT and RBC_rel, followed by apoptosis in surviving MSC fractions.

CONCLUSION

Various levels of HCT and RBC_rel severely compromise MSC health within 3 days and HCT should be controlled in the preparation of BMC products. Further, HCT of BMCs should be routinely recorded and tracked with patient outcomes along with routine metrics (e.g. nucleated cell counts, fibroblast-colony forming units). Differences in HCT may account for the inconsistencies in the efficacy of BMC reported when treating orthopedic conditions.

The Multiple Facets of Iron Recycling

The production of around 2.5 million red blood cells (RBCs) per second in erythropoiesis is one of the most intense activities in the body. It continuously consumes large amounts of iron, approximately 80% of which is recycled from aged erythrocytes. Therefore, similar to the “making”, the “breaking” of red blood cells is also very rapid and represents one of the key processes in mammalian physiology. Under steady-state conditions, this important task is accomplished by specialized macrophages, mostly liver Kupffer cells (KCs) and splenic red pulp macrophages (RPMs). It relies to a large extent on the engulfment of red blood cells via so-called erythrophagocytosis. Surprisingly, we still understand little about the mechanistic details of the removal and processing of red blood cells by these specialized macrophages. We have only started to uncover the signaling pathways that imprint their identity, control their functions and enable their plasticity. Recent findings also identify other myeloid cell types capable of red blood cell removal and establish reciprocal cross-talk between the intensity of erythrophagocytosis and other cellular activities. Here, we aimed to review the multiple and emerging facets of iron recycling to illustrate how this exciting field of study is currently expanding.

Neutrophil Extracellular Trap-Driven Occlusive Diseases

The enlightenment of the formation of neutrophil extracellular traps (NETs) as a part of the innate immune system shed new insights into the pathologies of various diseases. The initial idea that NETs are a pivotal defense structure was gradually amended due to several deleterious effects in consecutive investigations. NETs formation is now considered a double-edged sword. The harmful effects are not limited to the induction of inflammation by NETs remnants but also include occlusions caused by aggregated NETs (aggNETs). The latter carries the risk of occluding tubular structures like vessels or ducts and appear to be associated with the pathologies of various diseases. In addition to life-threatening vascular clogging, other occlusions include painful stone formation in the biliary system, the kidneys, the prostate, and the appendix. AggNETs are also prone to occlude the ductal system of exocrine glands, as seen in ocular glands, salivary glands, and others. Last, but not least, they also clog the pancreatic ducts in a murine model of neutrophilia. In this regard, elucidating the mechanism of NETs-dependent occlusions is of crucial importance for the development of new therapeutic approaches. Therefore, the purpose of this review is to address the putative mechanisms of NETs-associated occlusions in the pathogenesis of disease, as well as prospective treatment modalities.

Interplay between LPA2 and LPA3 in LPA-mediated phosphatidylserine cell surface exposure and extracellular vesicles release by erythrocytes

Evidence is growing for the role of red blood cells (RBCs) in vascular homeostasis, including thrombogenic events and inflammation. Lysophosphatidic acid (LPA) is known to induce phosphatidylserine (PS) exposure and the release of RBC Extracellular Vesicles (REVs). Using high sensitivity flow cytometry, we examined the effects and the mechanisms by which the LPA species commonly found in human plasma could activate RBCs. We report that LPA 16:0, 18:0 and 18:1, but not LPA 20:4, induced PS exposure and the release of small PS^- and large PS⁺ REVs through LPA3 receptor signalling in RBCs. The release of large PS⁺ REVs required higher concentrations of LPA. RBCs were not activated by LPA 20:4. Interestingly, blockade of LPA2 enhanced LPA-mediated PS^- REV release in RBCs. Furthermore, LPA receptor agonists and antagonists highlighted that LPA 20:4 inhibited LPA3-dependent PS exposure and, through the LPA2 receptor, inhibited PS^- REV production. Activation of RBCs with LPA 18:1 in normal plasma stimulated the release of PS^- and PS⁺ REVs. REVs released in response to LPA were similar to those found in the plasma of systemic lupus erythematosus patients. Our results suggest that LPA species exhibit different biological activities in RBCs through targeting LPA2 and/or LPA3 receptors.