Short communication: Storage time and temperature affect plasma osmolality values in field-collected blood samples.

As climate change alters the hydric regime of many habitats, understanding the hydric physiology of animals becomes increasingly important. Plasma osmolality is a popular metric to assess an organism's hydration, but samples often need to be stored before being analyzed, under varying conditions and for different lengths of time. Previous studies on plasma storage conditions, and how they impact sample integrity, are minimal and have focused more on clinical applications than field studies. We studied the stability of osmolality values from wild rattlesnake plasma samples stored in commonly used plastic snap-cap tubes under different time (0, 2, 3, 7, 29 days) and temperature (refrigerated at 2 °C and frozen at -18 °C) treatments. We hypothesized that frozen samples would remain more stable (e.g., retain osmolality values more similar to baseline values) than refrigerated samples because freezing the plasma would reduce evaporation. We found that osmolality of samples increased over time at both temperatures, becoming significantly higher than baseline after 7 days. Contrary to our prediction, osmolality increased more in frozen samples than in refrigerated samples. We discuss possible reasons for our results, along with their implications. To obtain the most accurate plasma osmolality values, we recommend refrigerating plasma samples for as short a time as possible, 3 days or fewer, before analyzing them on an osmometer.

Interaction of carbonic anhydrase I released from red blood cells with human plasma in vitro.

Red blood cells (RBCs) constitute ∼50% of the bloodstream and represent an important target for environmental pollutants and bacterial/viral infections, which can result in their rupture. In addition, diseases such as sickle cell anaemia and paroxysmal nocturnal haemoglobinuria can also result in the rupture of RBCs, which can be potentially life-threatening. With regard to the release of cytosolic metalloproteins from RBCs into the blood-organ system, the biochemical fate of haemoglobin is rather well understood, while comparatively little is known about another highly abundant Zn-metalloprotein, carbonic anhydrase (CA I). To gain insight into the interaction of CA I with human blood plasma constituents, we have employed a metallomics tool comprised of size-exclusion chromatography (SEC) coupled online with an inductively coupled plasma atomic emission spectrometer (ICP-AES), which allows to simultaneously observe all Cu, Fe, and Zn-metalloproteins. After the addition of CA I to human blood plasma incubated at 37°C, the SEC-ICP-AES analysis using phosphate buffered saline (pH 7.4) after 5 min, 1 h, and 2 h revealed that CA I eluted after all endogenous Zn-metalloproteins in the 30 kDa range. Matrix-assisted laser desorption-time of flight mass spectrometry analysis of the collected Zn-peak confirmed that CA I eluted from the column intact. Our in vitro results suggest that CA I released from RBCs to plasma remains free and may be actively involved in health-relevant adverse processes that unfold at the bloodstream-endothelial interface, including atherosclerosis and vision loss.

Nutritional, molecular, and functional properties of a novel enzymatically hydrolyzed porcine plasma product.

In the present study, an enzymatically hydrolyzed porcine plasma (EHPP) was nutritionally and molecularly characterized. EHPP molecular characterization showed, in contrast to spray-dried plasma (SDP), many peptides with relative molecular masses (Mr) below 8,000, constituting 73% of the protein relative abundance. IIAPPER, a well-known bioactive peptide with anti-inflammatory and antioxidant properties, was identified. In vivo functionality of EHPP was tested in C. elegans and two different mouse models of intestinal inflammation. In C. elegans subjected to lipopolysaccharide exposure, EHPP displayed a substantial anti-inflammatory effect, enhancing survival and motility by 40% and 21.5%, respectively. Similarly, in mice challenged with Staphylococcus aureus enterotoxin B or Escherichia coli O42, EHPP and SDP supplementation (8%) increased body weight and average daily gain while reducing the percentage of regulatory Th lymphocytes. Furthermore, both products mitigated the increase of pro-inflammatory cytokines expression associated with these challenged mouse models. In contrast, some significant differences were observed in markers such as Il-6 and Tnf-α, suggesting that the products may present different action mechanisms. In conclusion, EHPP demonstrated similar beneficial health effects to SDP, potentially attributable to the immunomodulatory and antioxidant activity of its characteristic low Mr bioactive peptides.

Human plasma can modulate micronucleus frequency in TK6 and OE33 cells in vitro.

In this paper, we studied the potential genotoxic effects of human plasma from healthy volunteers, as well as patients with gastro-oesophageal reflux disease, Barrett's oesophagus (BO) and oesophageal adenocarcinoma (OAC) using the oesophageal adenocarcinoma cell line (OE33) and the lymphoblastoid cell line (TK6). Both TK6 and OE33 cells were treated with plasma (10 % volume, replacing foetal bovine serum (FBS) or horse serum (HS)) at different time points of 4 h (for the micronucleus (Mn) assay and the invasion assay) and 24 h (for the cell cycle studies). Plasma-induced effects on DNA damage levels, cell viability and the cell cycle were studied by the micronucleus assay, cytokinesis block proliferation index (CBPI) and flow cytometry respectively. The expression of IL-8 in supernatants of TK6 cells and IFN-ß in OE33 cells was also analysed by enzyme-linked immunosorbent assay (ELISA). Finally, we carried out an assessment of cellular invasion of OE33 cells following plasma treatment. The results of the micronucleus assay confirmed the genotoxicity of direct plasma treatment from some participants through the increase in DNA damage in TK6 cells. Conversely, some individual patient plasma samples reduced background levels of TK6 cell Mn frequency, in an anti-genotoxic fashion. In TK6 cells, (on average) plasma samples from patients with Barrett's oesophagus induced higher micronucleus levels than healthy volunteers (p= 0.0019). There was little difference in Mn induction when using plasma versus serum to treat the cells in vitro. Cell cycle results showed that direct plasma treatment had a marked impact on OE33 cells at 24 h (p=0.0182 for BO and p=0.0320 for OAC) by decreasing the proportion of cells in the S phase, while plasma exposure was less impactful on the cell cycle of TK6 cells. Invasion of OE33 cells was also seen to be non-significantly affected by plasma treatment of OE33 cells. The addition of N-acetyl cysteine NAC in a dose-dependent matter did not alter the formation of Mn in TK6 cells, suggesting that reactive oxygen species (ROS) are not the root cause of plasma's genotoxicity. The concentration of IL-8 in TK6 cells and IFN-ß in OE33 cells was significantly higher in cells treated with OAC-derived plasma than in the untreated negative control. Collectively, our results demonstrate that plasma-specific effects are detectable which helps us better understand some important aspects of the biology of blood-based biomarkers under development.

Plasma Redox Balance in Advanced-Maternal-Age Pregnant Women and Effects of Plasma on Umbilical Cord Mesenchymal Stem Cells.

Pregnancy at advanced maternal age (AMA) is a condition of potential risk for the development of maternal-fetal complications with possible repercussions even in the long term. Here, we analyzed the changes in plasma redox balance and the effects of plasma on human umbilical cord mesenchymal cells (hUMSCs) in AMA pregnant women (patients) at various timings of pregnancy. One hundred patients and twenty pregnant women younger than 40 years (controls) were recruited and evaluated at various timings during pregnancy until after delivery. Plasma samples were used to measure the thiobarbituric acid reactive substances (TBARS), glutathione and nitric oxide (NO). In addition, plasma was used to stimulate the hUMSCs, which were tested for cell viability, reactive oxygen species (ROS) and NO release. The obtained results showed that, throughout pregnancy until after delivery in patients, the levels of plasma glutathione and NO were lower than those of controls, while those of TBARS were higher. Moreover, plasma of patients reduced cell viability and NO release, and increased ROS release in hUMSCs. Our results highlighted alterations in the redox balance and the presence of potentially harmful circulating factors in plasma of patients. They could have clinical relevance for the prevention of complications related to AMA pregnancy.

Protocol to identify biomarkers in patients with post-COVID condition using multi-omics and machine learning analysis of human plasma.

Here, we present a workflow for analyzing multi-omics data of plasma samples in patients with post-COVID condition (PCC). Applicable to various diseases, we outline steps for data preprocessing and integrating diverse assay datasets. Then, we detail statistical analysis to unveil plasma profile changes and identify biomarker-clinical variable associations. The last two steps discuss machine learning techniques for unsupervised clustering of patients based on their inherent molecular similarities and feature selection to identify predictive biomarkers. For complete details on the use and execution of this protocol, please refer to Wang et al.1.

Analysis of plasma metabolomes from 11 309 subjects in five population-based cohorts.

Plasma metabolomics holds potential for precision medicine, but limited information is available to compare the performance of such methods across multiple cohorts. We compared plasma metabolite profiles after an overnight fast in 11,309 participants of five population-based Swedish cohorts (50-80 years, 52% women). Metabolite profiles were uniformly generated at a core laboratory (Metabolon Inc.) with untargeted liquid chromatography mass spectrometry and a comprehensive reference library. Analysis of a second sample obtained one year later was conducted in a subset. Of 1629 detected metabolites, 1074 (66%) were detected in all cohorts while only 10% were unique to one cohort, most of which were xenobiotics or uncharacterized. The major classes were lipids (28%), xenobiotics (22%), amino acids (14%), and uncharacterized (19%). The most abundant plasma metabolome components were the major dietary fatty acids and amino acids, glucose, lactate and creatinine. Most metabolites displayed a log-normal distribution. Temporal variability was generally similar to clinical chemistry analytes but more pronounced for xenobiotics. Extensive metabolite-metabolite correlations were observed but mainly restricted to within each class. Metabolites were broadly associated with clinical factors, particularly body mass index, sex and renal function. Collectively, our findings inform the conduct and interpretation of metabolite association and precision medicine studies.

Comparison of reversed-phase, hydrophilic interaction, and porous graphitic carbon chromatography columns for an untargeted toxicometabolomics study in pooled human liver microsomes, rat urine, and rat plasma.

INTRODUCTION: Untargeted metabolomics studies are expected to cover a wide range of compound classes with high chemical diversity and complexity. Thus, optimizing (pre-)analytical parameters such as the analytical liquid chromatography (LC) column is crucial and the selection of the column depends primarily on the study purpose. OBJECTIVES: The current investigation aimed to compare six different analytical columns. First, by comparing the chromatographic resolution of selected compounds. Second, on the outcome of an untargeted toxicometabolomics study using pooled human liver microsomes (pHLM), rat plasma, and rat urine as matrices. METHODS: Separation and analysis were performed using three different reversed-phase (Phenyl-Hexyl, BEH C18, and Gold C18), two hydrophilic interaction chromatography (HILIC) (ammonium-sulfonic acid and sulfobetaine), and one porous graphitic carbon (PGC) columns coupled to high-resolution mass spectrometry (HRMS). Their impact was evaluated based on the column performance and the size of feature count, amongst others. RESULTS: All three reversed-phase columns showed a similar performance, whereas the PGC column was superior to both HILIC columns at least for polar compounds. Comparing the size of feature count across all datasets, most features were detected using the Phenyl-Hexyl or sulfobetaine column. Considering the matrices, most significant features were detected in urine and pHLM after using the sulfobetaine and in plasma after using the ammonium-sulfonic acid column. CONCLUSION: The results underline that the outcome of this untargeted toxicometabolomic study LC-HRMS metabolomic study was highly influenced by the analytical column, with the Phenyl-Hexyl or sulfobetaine column being the most suitable. However, column selection may also depend on the investigated compounds as well as on the investigated matrix.

Exercised-enriched blood plasma rescues hippocampal impairments and cognitive deficits in an Alzheimer's disease model.

Alzheimer's disease (AD) is a progressive neurodegenerative disorder, and moderate exercise holds promise in ameliorating the ongoing neurodegeneration and cognitive decline. Here, we investigated whether exercise-enriched blood plasm could yield a beneficial therapeutic effect on AD pathologies and cognitive decline in transgenic AD (P301S) mice. In this investigation, a cohort of 2-month-old C57BL/6 mice were granted continuous access to either a running wheel or a fixed wheel for 6 weeks. After that, their plasmas were extracted and subsequently injected intravenously into 4.5-month-old P301S mice biweekly over a 6-week period. A comprehensive methodology was then employed, integrating behavioral tests, pathology assessments, and biochemical analyses to unveil the potential anti-dementia implications of exercise-enriched blood plasma in P301S mice. Upon systemic administration, the findings revealed a noteworthy attenuation of hippocampus-dependent behavioral impairments in P301S mice. Conversely, blood plasma from sedentary counterparts exhibited no discernible impact. These effects were intricately associated with the mitigation of neuroinflammation, the augmentation of hippocampal adult neurogenesis, and a reduction of synaptic impairments following the administration of exercise-enriched blood plasma. These findings advance the proposition that administering exercise-enriched blood plasma may serve as an effective prophylactic measure against AD, opening avenues for further exploration and potential therapeutic interventions.

Maximum storage time of refrigerated blood and frozen plasma samples from tambaqui, Colossoma macropomum.

Blood analysis is an important tool for monitoring the health status of fish, but the time between collection and analysis can affect the outcome of the analysis. This study sought to determine the maximum time refrigerated blood and frozen plasma samples of the tambaqui, Colossoma macropomum, can be stored without affecting analysis. Samples from 12 fish were obtained, stored under refrigeration at 4 °C and evaluated after 0, 24, 48, 72, and 96 h, while samples from 14 fish were centrifuged, and the resulting plasma was frozen at -20 °C and then evaluated after 0, 8, 12, 16 and 20 weeks. The parameters analyzed were hematocrit (Ht), hemoglobin content (Hb), total erythrocytes (RBC), total (WBC) and differential leukocytes, total thrombocytes (TC), glucose content (Glc), total protein (TP), triglyceride content (TG), total cholesterol (CoT), and the activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). For refrigerated whole blood samples, mean corpuscular hemoglobin content (MCHC) showed a transient decline in 24 h, and there were decreases in WBC, TC, Glc and TG that persisted until the 72 h sample point (for Glc and TG) or persisted until the 96 h sample point (for WBC and TC). A decrease in RBC was noted from 48 h on, while ALT was significantly higher in the 96 h sample. Significant decreases in lymphocytes, monocytes, neutrophils and eosinophils were noted from 48 h of storage on, while a significant decline in basophil counts were noted over the last two sampled timepoints. The coefficient of variation was greatest at the 96 h timepoint, indicating increased variability in measured parameters after 4 d of refrigeration. Plasma samples frozen at -20 °C showed a significant variation in ALT after 8 weeks, and increases in TP and TG after 20 weeks. Therefore, it is recommended that refrigerated tambaqui whole blood samples be analyzed within 24 h and frozen tambaqui plasma samples analyzed within 8 weeks.

Improving the mechanical and biological functions of cell sheet constructs: The interplay of human-derived periodontal ligament stem cells, endothelial cells and plasma rich in growth factors.

OBJECTIVE: The aim of this study was to produce and characterize triple-layered cell sheet constructs with varying cell compositions combined or not with the fibrin membrane scaffold obtained by the technology of Plasma Rich in Growth Factors (mPRGF). MATERIALS AND METHODS: Human primary cultures of periodontal ligament stem cells (hPDLSCs) were isolated, and their stemness nature was evaluated. Three types of triple-layered composite constructs were generated, composed solely of hPDLSCs or combined with human umbilical vein endothelial cells (HUVECs), either as a sandwiched endothelial layer or as coculture sheets of both cell phenotypes. These three triple-layered constructs were also manufactured using mPRGF as cell sheets' support. Necrosis, glucose consumption, secretion of extracellular matrix proteins and synthesis of proangiogenic factors were determined. Histological evaluations and proteomic analyses were also performed. RESULTS: The inclusion of HUVECs did not clearly improve the properties of the multilayered constructs and yet hindered their optimal conformation. The presence of mPRGF prevented the shrinkage of cell sheets, stimulated the metabolic activity and increased the matrix synthesis. At the proteome level, mPRGF conferred a dramatic advantage to the hPDLSC constructs in their ability to provide a suitable environment for tissue regeneration by inducing the expression of proteins necessary for bone morphogenesis and cellular proliferation. CONCLUSIONS: hPDLSCs' triple-layer construct onto mPRGF emerges as the optimal structure for its use in regenerative therapeutics. CLINICAL RELEVANCE: These results suggest the suitability of mPRGF as a promising tool to support cell sheet formation by improving their handling and biological functions.

Comprehensive proteomics of CSF, plasma, and urine identify DDC and other biomarkers of early Parkinson's disease.

Parkinson's disease (PD) starts at the molecular and cellular level long before motor symptoms appear, yet there are no early-stage molecular biomarkers for diagnosis, prognosis prediction, or monitoring therapeutic response. This lack of biomarkers greatly impedes patient care and translational research-L-DOPA remains the standard of care more than 50 years after its introduction. Here, we performed a large-scale, multi-tissue, and multi-platform proteomics study to identify new biomarkers for early diagnosis and disease monitoring in PD. We analyzed 4877 cerebrospinal fluid, blood plasma, and urine samples from participants across seven cohorts using three orthogonal proteomics methods: Olink proximity extension assay, SomaScan aptamer precipitation assay, and liquid chromatography-mass spectrometry proteomics. We discovered that hundreds of proteins were upregulated in the CSF, blood, or urine of PD patients, prodromal PD patients with DAT deficit and REM sleep behavior disorder or anosmia, and non-manifesting genetic carriers of LRRK2 and GBA mutations. We nominate multiple novel hits across our analyses as promising markers of early PD, including DOPA decarboxylase (DDC), also known as L-aromatic acid decarboxylase (AADC), sulfatase-modifying factor 1 (SUMF1), dipeptidyl peptidase 2/7 (DPP7), glutamyl aminopeptidase (ENPEP), WAP four-disulfide core domain 2 (WFDC2), and others. DDC, which catalyzes the final step in dopamine synthesis, particularly stands out as a novel hit with a compelling mechanistic link to PD pathogenesis. DDC is consistently upregulated in the CSF and urine of treatment-naïve PD, prodromal PD, and GBA or LRRK2 carrier participants by all three proteomics methods. We show that CSF DDC levels correlate with clinical symptom severity in treatment-naïve PD patients and can be used to accurately diagnose PD and prodromal PD. This suggests that urine and CSF DDC could be a promising diagnostic and prognostic marker with utility in both clinical care and translational research.

Sickle cell disease iPSC-derived sensory neurons exhibit increased excitability and sensitization to patient plasma.

ABSTRACT: Individuals living with sickle cell disease (SCD) experience severe recurrent acute and chronic pain. Challenges to gaining mechanistic insight into pathogenic SCD pain processes include differential gene expression and function of sensory neurons between humans and mice with SCD, and extremely limited availability of neuronal tissues from patients with SCD. Here, we used induced pluripotent stem cells (iPSCs), derived from patients with SCD, differentiated into sensory neurons (SCD iSNs) to begin to overcome these challenges. We characterize key gene expression and function of SCD iSNs to establish a model to investigate intrinsic and extrinsic factors that may contribute to SCD pain. Despite similarities in receptor gene expression, SCD iSNs show pronounced excitability using patch clamp electrophysiology. Furthermore, we find that plasma taken from patients with SCD during acute pain associated with a vaso-occlusive event increases the calcium responses to the nociceptive stimulus capsaicin in SCD iSNs compared with those treated with paired plasma from patients with SCD at steady state baseline or healthy control plasma samples. We identified high levels of the polyamine spermine in baseline and acute pain states of plasma from patients with SCD, which sensitizes SCD iSNs to subthreshold concentrations of capsaicin. Together, these data identify potential intrinsic mechanisms within SCD iSNs that may extend beyond a blood-based pathology.

Detection limitations of prion seeding activities in blood samples from patients with sporadic prion disease.

BACKGROUND: Human prion diseases (HPDs) are fatal neurodegenerative disorders characterized by abnormal prion proteins (PrPSc). However, the detection of prion seeding activity in patients with high sensitivity remains challenging. Even though real-time quaking-induced conversion (RT-QuIC) assay is suitable for detecting prion seeding activity in a variety of specimens, it shows lower accuracy when whole blood, blood plasma, and blood-contaminated tissue samples are used. In this study, we developed a novel technology for the in vitro amplification of abnormal prion proteins in HPD to the end of enabling their detection with high sensitivity known as the enhanced quaking-induced conversion (eQuIC) assay. METHODS: Three antibodies were used to develop the novel eQUIC method. Thereafter, SD50 seed activity was analyzed using brain tissue samples from patients with prion disease using the conventional RT-QUIC assay and the novel eQUIC assay. In addition, blood samples from six patients with solitary prion disease were analyzed using the novel eQuIC assay. RESULTS: The eQuIC assay, involving the use of three types of human monoclonal antibodies, showed approximately 1000-fold higher sensitivity than the original RT-QuIC assay. However, when this assay was used to analyze blood samples from six patients with sporadic human prion disease, no prion activity was detected. CONCLUSION: The detection of prion seeding activity in blood samples from patients with sporadic prion disease remains challenging. Thus, the development of alternative methods other than RT-QuIC and eQuIC will be necessary for future research.

Liquid plasma promotes angiogenesis through upregulation of endothelial nitric oxide synthase-induced extracellular matrix metabolism: potential applications of liquid plasma for vascular injuries.

BACKGROUND: Applications of nonthermal plasma have expanded beyond the biomedical field to include antibacterial, anti-inflammatory, wound healing, and tissue regeneration. Plasma enhances epithelial cell repair; however, the potential damage to deep tissues and vascular structures remains under investigation. RESULT: This study assessed whether liquid plasma (LP) increased nitric oxide (NO) production in human umbilical vein endothelial cells by modulating endothelial NO synthase (eNOS) phosphorylation and potential signaling pathways. First, we developed a liquid plasma product and confirmed the angiogenic effect of LP using the Matrigel plug assay. We found that the NO content increased in plasma-treated water. NO in plasma-treated water promoted cell migration and angiogenesis in scratch and tube formation assays via vascular endothelial growth factor mRNA expression. In addition to endothelial cell proliferation and migration, LP influenced extracellular matrix metabolism and matrix metalloproteinase activity. These effects were abolished by treatment with NG-L-monomethyl arginine, a specific inhibitor of NO synthase. Furthermore, we investigated the signaling pathways mediating the phosphorylation and activation of eNOS in LP-treated cells and the role of LKB1-adenosine monophosphate-activated protein kinase in signaling. Downregulation of adenosine monophosphate-activated protein kinase by siRNA partially inhibited LP-induced eNOS phosphorylation, angiogenesis, and migration. CONCLUSION: The present study suggests that LP treatment may be a novel strategy for promoting angiogenesis in vascular damage. Video Abstract.

SOLUBLE CD150 ISOFORM LEVEL IN PLASMA OF CHRONIC LYMPHOCYTIC LEUKEMIA PATIENTS.

BACKGROUND: SLAMF1/CD150 is an active player in B cell signaling networks in chronic lymphocytic leukemia (CLL). CD150-mediated signaling initiates through a homophilic CD150 binding, which spans the adjacent cells, or the interaction with the soluble CD150 isoform (sCD150). The expression of sCD150 isoform at the mRNA and protein levels ex vivo was confirmed. However, it is unclear whether sCD150 isoform present in the blood plasma of CLL patients is a factor in the constitutive activation of CD150+ cells. The aim of this study was to develop an ELISA assay for the specific sCD150 evaluation and assess the sCD150 levels in the blood plasma of CLL patients with different CD150 expression on B cells. MATERIALS AND METHODS: Blood plasma samples and peripheral blood mononuclear cells from 40 previously untreated CLL patients were analyzed. An ELISA method, ex vivo drug sensitivity assay, and a cell viability assay were used. RESULTS: The sCD150 isoform was found in all studied plasma samples of CLL patients at different levels regardless of the cell surface CD150 expression status of B cells and sCD150 mRNA expression. CLL cases with low levels of the cell surface CD150 expression in B cells are characterized by high levels of sCD150 in blood plasma in contrast to the CLL cases with high cell surface CD150 expression on B cells. The elevated levels of sCD150 in blood plasma are associated with a better sensitivity of malignant B cells to cyclophosphamide and bendamustine. CONCLUSIONS: The sCD150 isoform is actively secreted by CLL B cells with its accumulation in blood plasma, which may be regarded as an additional factor in the CLL clinicopathologic variability.

Comprehensive Analysis of the Role of Fibrinogen and Thrombin in Clot Formation and Structure for Plasma and Purified Fibrinogen.

Altered properties of fibrin clots have been associated with bleeding and thrombotic disorders, including hemophilia or trauma and heart attack or stroke. Clotting factors, such as thrombin and tissue factor, or blood plasma proteins, such as fibrinogen, play critical roles in fibrin network polymerization. The concentrations and combinations of these proteins affect the structure and stability of clots, which can lead to downstream complications. The present work includes clots made from plasma and purified fibrinogen and shows how varying fibrinogen and activation factor concentrations affect the fibrin properties under both conditions. We used a combination of scanning electron microscopy, confocal microscopy, and turbidimetry to analyze clot/fiber structure and polymerization. We quantified the structural and polymerization features and found similar trends with increasing/decreasing fibrinogen and thrombin concentrations for both purified fibrinogen and plasma clots. Using our compiled results, we were able to generate multiple linear regressions that predict structural and polymerization features using various fibrinogen and clotting agent concentrations. This study provides an analysis of structural and polymerization features of clots made with purified fibrinogen or plasma at various fibrinogen and clotting agent concentrations. Our results could be utilized to aid in interpreting results, designing future experiments, or developing relevant mathematical models.

Exercised blood plasma promotes hippocampal neurogenesis in the Alzheimer's disease rat brain.

BACKGROUND: Exercise training promotes brain plasticity and is associated with protection against cognitive impairment and Alzheimer's disease (AD). These beneficial effects may be partly mediated by blood-borne factors. Here we used an in vitro model of AD to investigate effects of blood plasma from exercise-trained donors on neuronal viability, and an in vivo rat model of AD to test whether such plasma impacts cognitive function, amyloid pathology, and neurogenesis. METHODS: Mouse hippocampal neuronal cells were exposed to AD-like stress using amyloid-ß and treated with plasma collected from human male donors 3 h after a single bout of high-intensity exercise. For in vivo studies, blood was collected from exercise-trained young male Wistar rats (high-intensity intervals 5 days/week for 6 weeks). Transgenic AD rats (McGill-R-Thy1-APP) were injected 5 times/fortnight for 6 weeks at 2 months or 5 months of age with either (a) plasma from the exercise-trained rats, (b) plasma from sedentary rats, or (c) saline. Cognitive function, amyloid plaque pathology, and neurogenesis were assessed. The plasma used for the treatment was analyzed for 23 cytokines. RESULTS: Plasma from exercised donors enhanced cell viability by 44.1% (p = 0.032) and reduced atrophy by 50.0% (p < 0.001) in amyloid-ß-treated cells. In vivo exercised plasma treatment did not alter cognitive function or amyloid plaque pathology but did increase hippocampal neurogenesis by ∼3 fold, regardless of pathological stage, when compared to saline-treated rats. Concentrations of 7 cytokines were significantly reduced in exercised plasma compared to sedentary plasma. CONCLUSION: Our proof-of-concept study demonstrates that plasma from exercise-trained donors can protect neuronal cells in culture and promote adult hippocampal neurogenesis in the AD rat brain. This effect may be partly due to reduced pro-inflammatory signaling molecules in exercised plasma.

Targeted ADAMTS-13 replacement therapy for thrombotic thrombocytopenic purpura.

Thrombotic thrombocytopenic purpura (TTP) is a life-threatening thrombotic disorder associated with a severe deficiency of ADAMTS-13-the protease that cleaves von Willebrand factor. Plasma therapy is the current standard of care for managing acute episodes of TTP, which involves removing patient plasma and replacing it with donor plasma to raise the level of ADAMTS-13 activity. Recently, therapies aimed at replacing ADAMTS-13 have been investigated as possible substitutes or add-ons to plasma therapy for congenital and immune-mediated TTP. Enzyme replacement therapy provides recombinant ADAMTS-13 via intravenous (i.v.) infusion to restore enzyme activity. Recombinant ADAMTS-13-loaded platelets localize to the site of thrombus formation in a more concentrated manner than enzyme replacement or plasma therapy. ADAMTS-13-encoding messenger RNA aims to induce a steady supply of secreted protein and gene therapy is a potentially curative strategy. Overall, targeted ADAMTS-13 replacement therapies may provide better outcomes than plasma therapy by achieving higher levels of ADAMTS-13 activity and a more sustained response with fewer adverse events. Herein, we describe targeted ADAMTS-13 replacement therapies for the treatment of TTP and discuss the advantages and limitations of each approach.

Comparative targeted metabolomic profiles of porcine plasma and serum.

Metabolomics has been used to characterise many biological matrices and obtain detailed pictures of biological systems based on many metabolites. Plasma and serum are two blood-derived biofluids commonly used to assess and monitor the organismal metabolism and obtain information on the physiological and health conditions of an animal. Plasma is the supernatant that is separated from the cellular components after centrifugation of the blood that is first added with an anticoagulant. Serum is obtained after centrifugation of the blood that has been coagulated. The choice of one or the other biofluid for metabolomic analyses is related to specific analytical needs and technical issues, to problems derived by the collection and preparation steps, in particular when specimens are sampled from animals involved in field studies. Thus far, most of the metabolomic studies that compared plasma and serum have been carried out in humans and very little is known on the pigs. In this study, we used a targeted metabolomic platform that can detect about 180 metabolites of five biochemical classes to compare plasma and serum profiles of samples collected from 24 pigs. To also obtain a cross-species comparative metabolomic analysis, information for human plasma and serum derived from the same platform was retrieved from previous studies. Statistical analyses included univariate and multivariate approaches aimed at identifying stable and/or differentially abundant metabolites between the two porcine biofluids. A total of 154 (∼83%) metabolites passed the initial quality control, indicating a good repeatability of the analytical platform in pigs. Discarded metabolites included aspartate and biogenic amines that were already reported to be unstable in human studies. More than 80% of the metabolites had similar profiles in both porcine biofluids (average correlation was 0.75). Concentrations were usually higher in serum than in plasma, in agreement with what was already reported in humans. The univariate analysis identified 44 metabolites that had statistically different concentrations between porcine plasma and serum, of which 28 metabolites were also confirmed by the multivariate analysis. The obtained picture described similarities and differences between these two biofluids in pigs and the related human-pig comparisons. The obtained information can be useful for the choice of one or the other matrix for the implementation of metabolomic studies in this livestock species. The results can also provide useful hints to valuing the pig as animal model, in particular when metabolite-derived physiological states are relevant.