Development, Histological, and Ultrastructural Evaluation of Sheep Hyperimmune Serum Therapy for COVID-19 / Desarrollo, Evaluación Histológica y Ultraestructural de la Terapia con Suero Hiperinmune de Oveja para COVID-19

SUMMARY: In response to the threat posed by new variants of SARS-CoV-2 and the urgent need for effective treatments in the absence of vaccines, the aim of this study was to develop a rapid and cost-effective hyperimmune serum (HS) derived from sheep and assess its efficacy. The utilization of a halal-certified, easily maintained in certain geographic regions, easy-to-handle animal such as sheep could provide a viable alternative to the expensive option of horses. Sheep were immunized with a whole inactivated SARS-CoV- 2 antigen to produce HS, which was evaluated for neutralizing potency using the PRNT50 assay. K18-hACE2 transgenic mice (n=35) were divided into three groups: control, SARS-CoV-2 exposure through inhalation, and SARS-CoV-2 exposed mice treated with HS. HS efficacy was assessed through serum proinflammatory cytokine levels, qRT-PCR analysis, histopathological examination of lungs and hearts, and transmission electron microscopy. Purified HS exhibited significant neutralizing activity (1/24,576). The SARS-CoV-2+HS group showed lower levels of TNF-α, IL-10, and IL-6 (P<0.01) and relatively lower levels of MCP-1 compared to the SARS-CoV-2 group. HS prevented death, reduced viral RNA levels in the lungs and hearts, protected against severe interstitial pneumonia, preserved lung tissue integrity, and prevented myocyte damage, while the SARS-CoV-2 group exhibited viral presence in the lungs. This study successfully developed a sheep-derived HS against the entire SARS-CoV-2 virus, resulting in a significant reduction in infection severity, inflammation, and systemic cytokine production. The findings hold promise for treating severe COVID-19 cases, including emerging viral variants, and immunocompromised patients.

En respuesta a la amenaza que suponen las nuevas variantes del SARS-CoV-2 y la urgente necesidad de tratamientos eficaces en ausencia de vacunas, el objetivo de este estudio fue desarrollar un suero hiperinmune (HS) rápido y rentable derivado de ovejas. y evaluar su eficacia. La utilización de un animal con certificación halal, de fácil mantenimiento en determinadas regiones geográficas y de fácil manejo, como las ovejas, podría proporcionar una alternativa viable a la costosa opción de los caballos. Las ovejas fueron inmunizadas con un antígeno de SARS-CoV-2 completamente inactivado para producir HS, cuya potencia neutralizante se evaluó mediante el ensayo PRNT50. Los ratones transgénicos K18-hACE2 (n = 35) se dividieron en tres grupos: control, exposición al SARS-CoV-2 mediante inhalación y ratones expuestos al SARS-CoV-2 tratados con HS. La eficacia de HS se evaluó mediante niveles de citoquinas proinflamatorias en suero, análisis qRT-PCR, examen histopatológico de pulmones y corazones y microscopía electrónica de transmisión. El HS purificado exhibió una actividad neutralizante significativa (1/24,576). El grupo SARS-CoV-2+HS mostró niveles más bajos de TNF-α, IL-10 e IL-6 (P<0,01) y niveles relativamente más bajos de MCP-1 en comparación con el grupo SARS-CoV-2. HS evitó la muerte, redujo los niveles de ARN viral en los pulmones y el corazón, protegió contra la neumonía intersticial grave, preservó la integridad del tejido pulmonar y evitó el daño de los miocitos, mientras que el grupo SARS-CoV-2 exhibió presencia viral en los pulmones. Este estudio desarrolló con éxito un HS derivado de ovejas contra todo el virus SARS-CoV-2, lo que resultó en una reducción significativa de la gravedad de la infección, la inflamación y la producción sistémica de citocinas. Los hallazgos son prometedores para el tratamiento de casos graves de COVID- 19, incluidas las variantes virales emergentes y los pacientes inmunocomprometidos.

Baricitinib protects mice from sepsis-induced cardiac dysfunction and multiple-organ failure.

Sepsis is one of the major complications of surgery resulting in high morbidity and mortality, but there are no specific therapies for sepsis-induced organ dysfunction. Data obtained under Gene Expression Omnibus accession GSE131761 were re-analyzed and showed an increased gene expression of Janus Kinase 2 (JAK2) and Signal Transducer and Activator of Transcription 3 (STAT3) in the whole blood of post-operative septic patients. Based on these results, we hypothesized that JAK/STAT activation may contribute to the pathophysiology of septic shock and, hence, investigated the effects of baricitinib (JAK1/JAK2 inhibitor) on sepsis-induced cardiac dysfunction and multiple-organ failure (MOF). In a mouse model of post-trauma sepsis induced by midline laparotomy and cecal ligation and puncture (CLP), 10-week-old male (n=32) and female (n=32) C57BL/6 mice received baricitinib (1mg/kg; i.p.) or vehicle at 1h or 3h post-surgery. Cardiac function was assessed at 24h post-CLP by echocardiography in vivo, and the degree of MOF was analyzed by determination of biomarkers in the serum. The potential mechanism underlying both the cardiac dysfunction and the effect of baricitinib was analyzed by western blot analysis in the heart. Trauma and subsequent sepsis significantly depressed the cardiac function and induced multiple-organ failure, associated with an increase in the activation of JAK2/STAT3, NLRP3 inflammasome and NF- κß pathways in the heart of both male and female animals. These pathways were inhibited by the administration of baricitinib post the onset of sepsis. Moreover, treatment with baricitinib at 1h or 3h post-CLP protected mice from sepsis-induced cardiac injury and multiple-organ failure. Thus, baricitinib may be repurposed for trauma-associated sepsis.

Protective and immunomodulatory effects of mesenchymal stem cells on multiorgan injury in male rats with heatstroke.

Heatstroke (HS) causes multiple organ dysfunction syndrome (MODS) with a mortality rate of 60% after hospitalization. Currently, there is no effective and targeted approach for the treatment of HS. Despite growing evidence that mesenchymal stem cells (MSCs) may reduce multiorgan damage and improve survival through immunomodulatory effects in several diseases, no one has tested whether MSCs have immunomodulatory effects in heatstroke. The present study focused on pathological changes and levels of the cytokines and immunoglobulins to investigate the mechanisms underlying the protective effect and the anti-inflammatory effects of MSCs. We found that MSCs treatment significantly reduced the 28-day mortality rate (P < 0.05), the levels of hepatic and renal function markers on day 1 (P < 0.01) and the pathological lesion scores of multiple organs in HS rats. The levels of IgG1, IgM, and IgA of the HS + MSC group was significantly higher than that in HS group on days 3 and 28(P < 0.05). In conclusion, MSCs contribute to protecting against multiorgan injury, reducing pro-inflammatory cytokines, stabilizing immunoglobulins, and reducing the mortality rate of HS rats.

Plantamajoside alleviates acute sepsis-induced organ dysfunction through inhibiting the TRAF6/NF-κB axis.

CONTEXT: Plantamajoside (PMS) possesses rich pharmacological characteristics that have been applied to remedy dozens of diseases. However, the understanding of PMS in sepsis remains insufficient. OBJECTIVE: Role of PMS in sepsis-regulated organ dysfunction and potential mechanisms were investigated. MATERIALS AND METHODS: Thirty C57BL/6 male mice were adaptive fed for three days and used to establish acute sepsis model by caecal ligation and perforation (CLP). These experimental mice were divided into Sham, CLP, CLP + 25 mg PMS/kg body weight (PMS/kg), CLP + 50 mg PMS/kg and CLP + 100 mg PMS/kg (n = 6). The pathological and apoptotic changes of lung, liver and heart tissues were observed via HE and TUNEL staining. The injury-related factors of lung, liver and heart were detected by corresponding kits. ELISA and qRT-PCR were applied to assess IL-6/TNF-α/IL-1ß levels. Apoptosis-related and TRAF6/NF-κB-related proteins were determined using Western blotting. RESULTS: All doses of PMS enhanced the survival rates in the sepsis-induced mouse model. PMS remitted sepsis-mediated lung, liver and heart injury through prohibiting MPO/BALF (70.4%/85.6%), AST/ALT (74.7%/62.7%) and CK-MB/CK (62.3%/68.9%) levels. Moreover, the apoptosis index (lung 61.9%, liver 50.2%, heart 55.7% reduction) and IL-6/TNF-α/IL-1ß levels were suppressed by PMS. Furthermore, PMS lowered TRAF6 and p-NF-κB p65 levels, whereas TRAF6 overexpression reversed the protective influences of PMS in organ injury, apoptosis and inflammation triggered by sepsis. DISCUSSION AND CONCLUSIONS: PMS suppressed sepsis-induced organ dysfunction by regulating the TRAF6/NF-κB axis, and PMS treatment may be considered as a novel strategy for sepsis-caused damage in future.

Inhibition of the JAK/STAT Pathway With Baricitinib Reduces the Multiple Organ Dysfunction Caused by Hemorrhagic Shock in Rats.

OBJECTIVE: The aim of this study was to investigate (a) the effects of the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway inhibitor (baricitinib) on the multiple organ dysfunction syndrome (MODS) in a rat model of hemorrhagic shock (HS) and (b) whether treatment with baricitinib attenuates the activation of JAK/STAT, NF-κB, and NLRP3 caused by HS. BACKGROUND: Posttraumatic MODS, which is in part due to excessive systemic inflammation, is associated with high morbidity and mortality. The JAK/STAT pathway is a regulator of numerous growth factor and cytokine receptors and, hence, is considered a potential master regulator of many inflammatory signaling processes. However, its role in trauma-hemorrhage is unknown. METHODS: An acute HS rat model was performed to determine the effect of baricitinib on MODS. The activation of JAK/STAT, NF-κB, and NLRP3 pathways were analyzed by western blotting in the kidney and liver. RESULTS: We demonstrate here for the first time that treatment with baricitinib (during resuscitation following severe hemorrhage) attenuates the organ injury and dysfunction and the activation of JAK/STAT, NF-κB, and NLRP3 pathways caused by HS in the rat. CONCLUSIONS: Our results point to a role of the JAK/STAT pathway in the pathophysiology of the organ injury and dysfunction caused by trauma/hemorrhage and indicate that JAK inhibitors, such as baricitinib, may be repurposed for the treatment of the MODS after trauma and/or hemorrhage.

Inhibition of Bruton's Tyrosine Kinase Activity Attenuates Hemorrhagic Shock-Induced Multiple Organ Dysfunction in Rats.

OBJECTIVE: The aim of this study was to investigate (a) the potential of the Bruton's tyrosine kinase (BTK) inhibitors acalabrutinib and fenebrutinib to reduce multiple organ dysfunction syndrome (MODS) in acute (short-term and long-term follow-up) hemorrhagic shock (HS) rat models and (b) whether treatment with either acalabrutinib or fenebrutinib attenuates BTK, NF-κB and NLRP3 activation in HS. BACKGROUND: The MODS caused by an excessive systemic inflammatory response following trauma is associated with a high morbidity and mortality. The protein BTK is known to play a role in the activation of the NLRP3 inflammasome, which is a key component of the innate inflammatory response. However, its role in trauma-hemorrhage is unknown. METHODS: Acute HS rat models were performed to determine the influence of acalabrutinib or fenebrutinib on MODS. The activation of BTK, NF-κB and NLRP3 pathways were analyzed by western blot in the kidney. RESULTS: We demonstrated that (a) HS caused organ injury and/or dysfunction and hypotension (post-resuscitation) in rats, while (b) treatment of HS-rats with either acalabrutinib or fenebrutinib attenuated the organ injury and dysfunction in acute HS models and (c) reduced the activation of BTK, NF- kB and NLRP3 pathways in the kidney. CONCLUSION: Our results point to a role of BTK in the pathophysiology of organ injury and dysfunction caused by trauma/hemorrhage and indicate that BTK inhibitors may be repurposed as a potential therapeutic approach for MODS after trauma and/or hemorrhage.

Blocking TNF signaling may save lives in COVID-19 infection.

Global vaccination effort and better understanding of treatment strategies provided a ray of hope for improvement in COVID-19 pandemic, however, in many countries, the disease continues to collect its death toll. The major pathogenic mechanism behind severe cases associated with high mortality is the burst of pro-inflammatory cytokines TNF, IL-6, IFNγ and others, resulting in multiple organ failure. Although the exact contribution of each cytokine is not clear, we provide an evidence that the central mediator of cytokine storm and its devastating consequences may be TNF. This cytokine is known to be involved in activated blood clotting, lung damage, insulin resistance, heart failure, and other conditions. A number of currently available pharmaceutical agents such as monoclonal antibodies and soluble TNF receptors can effectively prevent TNF from binding to its receptor(s). Other drugs are known to block NFkB, the major signal transducer molecule used in TNF signaling, or to block kinases involved in downstream activation cascades. Some of these medicines have already been selected for clinical trials, but more work is needed. A simple, rapid, and inexpensive method of directly monitoring TNF levels may be a valuable tool for a timely selection of COVID-19 patients for anti-TNF therapy.

Neuropeptide W Attenuates Oxidative Multi-Organ Injury in Rats Induced with Intra-Abdominal Sepsis.

Sepsis leads to systemic hypotension, disturbed perfusion, inflammation, and tissue toxicity in vital organs. Neuropeptide W (NPW) has modulatory effects in the control of blood pressure and inflammatory processes, implicating a potential beneficial effect against sepsis-induced oxidative damage. Under anesthesia, male Sprague Dawley rats underwent cecal ligation and puncture. Immediately after surgery, either saline or TNF-alpha inhibitor (etanercept; 1 mg/kg) antibiotic (ceftriaxon; 10 mg/kg) combination or NPW (0.1, 1, or 3 µg/kg) was given subcutaneously, and injections were repeated on the 12th and 24th h. The sham-operated control group was treated with saline at the same time points. All rats were euthanized on the 25th h of surgery. Sepsis resulted in oxidative damage of the brain, heart, lung, liver, and kidney. Elevations in blood urea nitrogen and alkaline phosphatase, showing renal and hepatic dysfunction, were not evident when septic rats were treated with NPW. NPW reduced serum levels of C-reactive protein, corticosterone, and interleukin-6, while histopathologically verified tissue damage in all the studied tissues was ameliorated. NPW treatment suppressed lipid peroxidation in the heart, lung, and brain, and the depleted antioxidant GSH levels of the brain and heart were replenished by NPW. Moreover, sepsis-related neutrophil recruitment to the liver and lung was also suppressed by NPW. Although the survival rate of the rats was not significantly prolonged by NPW, most of these improvements in systemic and local inflammatory events were comparable with those reached by the etanercept and antibiotic combination, suggesting the therapeutic impact of NPW during the acute period of sepsis.

Clinical implications of chemotherapeutic agent organ toxicity on perioperative care.

Cancer is the second most common cause of death in the United States and is a challenging disease to treat. The treatment options for various cancers include but are not limited to surgery, radiation, and chemotherapy. The mechanism behind chemotherapy is intended to promote cellular damage to cells that are proliferating uncontrollably. Unfortunately for the recipients, most chemotherapeutic agents cannot differentiate between malignant cells and healthy cells and tissues. Thus, chemotherapy-induced toxicities are often observed in once-healthy organs. These effects can be acute and self-limiting or chronic, appearing long after chemotherapy is completed. Cancer survivors can then present for non-cancer related surgeries later in life, due to this toxicity. Furthermore, the administration of chemotherapeutic agents can profoundly impact the anesthetic management of patients who are undergoing surgery. This review discusses how chemotherapy-induced organ toxicity can occur in multiple organ systems and what drugs should be avoided if prior toxicity exists in these organ systems.

The Role of RIPC in Preventing Organ Damage, Inflammation, and Oxidative Stress during Lower Limb DSA: A Randomised Controlled Trial.

OBJECTIVE: Diagnostic digital subtraction angiography (DSA) and DSA with percutaneous transluminal angioplasty (DSA-PTA) are common procedures for diagnosing and treating symptomatic lower extremity arterial disease (LEAD). However, organ damage following DSA and DSA-PTA is often underrecognised and hence undiagnosed. To reduce the risk induced by invasive procedures in symptomatic LEAD patients, the method of remote ischemic preconditioning (RIPC) has been suggested. The aim of the current study was to assess the effect of RIPC intervention on the organ damage markers profile, oxidative stress, and inflammation biomarkers in LEAD patients undergoing DSA and DSA-PTA procedure. METHODS: The RIPC intervention was performed by inflating a standard blood pressure cuff on the patient's upper arm to 200 mmHg for 5 minutes four times with 5-minute perfusion between each cycle. The sham intervention was performed similarly, but the cuff was inflated to 20 mmHg. Changes in the cardiac and renal damage biomarkers' profile, oxidative stress, and inflammation biomarkers were recorded before and 24 hours after DSA or DSA-PTA. RESULTS: A total of 111 (RIPC 54, sham 57) patients with symptomatic LEAD scheduled for endovascular procedure were randomised, and 102 patients (RIPC 47, sham 55) completed the study protocol. RIPC significantly limited the increase of adiponectine levels after DSA and DSA-PTA, compared to sham intervention (p = 0.020), but CK-MB levels were markedly lower in the sham group (p = 0.047) after procedure. There was no significant difference between the RIPC and the sham group in mean changes in hs-troponin-T (p = 0.25), NT-proBNP (p = 0.24), creatinine (p = 0.76), eGFR (p = 0.61), urea (p = 0.95), beta-2-microglobuline (p = 0.34), or cystatine C (p = 0.24) levels. CONCLUSION: In this controlled clinical study, RIPC failed to improve the profile of renal and cardiac biomarkers in patients with LEAD periprocedurally. RIPC significantly limits the rise in adiponectin levels and may influence the decrease of CK-MB levels 24 hours after endovascular procedure.

Therapeutic Potential of Mesenchymal Stromal Cell-Derived Extracellular Vesicles in the Prevention of Organ Injuries Induced by Traumatic Hemorrhagic Shock.

Severe trauma is the principal cause of death among young people worldwide. Hemorrhagic shock is the leading cause of death after severe trauma. Traumatic hemorrhagic shock (THS) is a complex phenomenon associating an absolute hypovolemia secondary to a sudden and significant extravascular blood loss, tissue injury, and, eventually, hypoxemia. These phenomena are responsible of secondary injuries such as coagulopathy, endotheliopathy, microcirculation failure, inflammation, and immune activation. Collectively, these dysfunctions lead to secondary organ failures and multi-organ failure (MOF). The development of MOF after severe trauma is one of the leading causes of morbidity and mortality, where immunological dysfunction plays a central role. Damage-associated molecular patterns induce an early and exaggerated activation of innate immunity and a suppression of adaptive immunity. Severe complications are associated with a prolonged and dysregulated immune-inflammatory state. The current challenge in the management of THS patients is preventing organ injury, which currently has no etiological treatment available. Modulating the immune response is a potential therapeutic strategy for preventing the complications of THS. Mesenchymal stromal cells (MSCs) are multipotent cells found in a large number of adult tissues and used in clinical practice as therapeutic agents for immunomodulation and tissue repair. There is growing evidence that their efficiency is mainly attributed to the secretion of a wide range of bioactive molecules and extracellular vesicles (EVs). Indeed, different experimental studies revealed that MSC-derived EVs (MSC-EVs) could modulate local and systemic deleterious immune response. Therefore, these new cell-free therapeutic products, easily stored and available immediately, represent a tremendous opportunity in the emergency context of shock. In this review, the pathophysiological environment of THS and, in particular, the crosstalk between the immune system and organ function are described. The potential therapeutic benefits of MSCs or their EVs in treating THS are discussed based on the current knowledge. Understanding the key mechanisms of immune deregulation leading to organ damage is a crucial element in order to optimize the preparation of EVs and potentiate their therapeutic effect.

Purinergic receptor ligands: the cytokine storm attenuators, potential therapeutic agents for the treatment of COVID-19.

The coronavirus disease-19 (COVID-19), at first, was reported in Wuhan, China, and then rapidly became pandemic throughout the world. Cytokine storm syndrome (CSS) in COVID-19 patients is associated with high levels of cytokines and chemokines that cause multiple organ failure, systemic inflammation, and hemodynamic instabilities. Acute respiratory distress syndrome (ARDS), a common complication of COVID-19, is a consequence of cytokine storm. In this regard, several drugs have been being investigated to suppress this inflammatory condition. Purinergic signaling receptors comprising of P1 adenosine and P2 purinoceptors play a critical role in inflammation. Therefore, activation or inhibition of some subtypes of these kinds of receptors is most likely to be beneficial to attenuate cytokine storm. This article summarizes suggested therapeutic drugs with potential anti-inflammatory effects through purinergic receptors.

DAMPening COVID-19 Severity by Attenuating Danger Signals.

COVID-19 might lead to multi-organ failure and, in some cases, to death. The COVID-19 severity is associated with a "cytokine storm." Danger-associated molecular patterns (DAMPs) are proinflammatory molecules that can activate pattern recognition receptors, such as toll-like receptors (TLRs). DAMPs and TLRs have not received much attention in COVID-19 but can explain some of the gender-, weight- and age-dependent effects. In females and males, TLRs are differentially expressed, likely contributing to higher COVID-19 severity in males. DAMPs and cytokines associated with COVID-19 mortality are elevated in obese and elderly individuals, which might explain the higher risk for severer COVID-19 in these groups. Adenosine signaling inhibits the TLR/NF-κB pathway and, through this, decreases inflammation and DAMPs' effects. As vaccines will not be effective in all susceptible individuals and as new vaccine-resistant SARS-CoV-2 mutants might develop, it remains mandatory to find means to dampen COVID-19 disease severity, especially in high-risk groups. We propose that the regulation of DAMPs via adenosine signaling enhancement might be an effective way to lower the severity of COVID-19 and prevent multiple organ failure in the absence of severe side effects.

Targeting HMGB1/TLR4/NF-κB signaling pathway by protocatechuic acid protects against l-arginine induced acute pancreatitis and multiple organs injury in rats.

Acute pancreatitis (AP) is a common pancreatic inflammation associated with substantial morbidity and mortality. AP may be mild or severe which can spread systemically causing multiple organs failure (MOF) and even death. In the current study, protocatechuic acid (PCA), a natural phenolic acid, was investigated for its possible protective potential against L-arginine induced AP and multiple organs injury (MOI) in rats. AP was induced by L-arginine (500 mg/100 g, ip). Two dose levels of PCA were tested (50 and 100 mg/kg, oral, 10 days before L-arginine injection). PCA successfully protected against L-arginine induced AP and MOI that was manifested by normalizing pancreatic, hepatic, pulmonary, and renal tissue architecture and restoring the normal values of pancreatic enzymes (amylase and lipase), serum total protein, liver enzymes (alanine transaminase (ALT) and aspartate transaminase (AST)) and kidney function biomarkers (blood urea nitrogen (BUN) and serum creatinine (Cr)) that were significantly elevated upon L-arginine administration. Additionally, PCA restored balanced oxidant/antioxidants status that was disrupted by L-arginine and normalized pancreatic levels of inducible nitric oxide synthase (iNOS) and nitric oxide (NO) content. Moreover, PCA significantly decreased L-arginine induced elevation in pancreatic high motility group box protein 1 (HMGB1), toll like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), nuclear factor kappa B (NF-κB), tumor necrosis factor- α (TNF-α), interleukin-1ß (IL-1ß), and interleukin-6 (IL-6) expression. PCA significantly ameliorated L-arginine-induced AP and MOI through its anti-inflammatory and antioxidant effects. HMGB1/TLR4/NF-κB was the major pathway involved in the observed protective potential.

Vagus nerve stimulation modulates arachidonic acid production in the mesenteric lymph following intestinal ischemia-reperfusion injury.

BACKGROUND: Inflammatory lipid mediators in mesenteric lymph (ML), including arachidonic acid (AA), are considered to play an important role in the pathogenesis of multiple-organ dysfunction after hemorrhagic shock. A previous study suggested that vagus nerve stimulation (VNS) could relieve shock-induced gut injury and abrogate ML toxicity, resulting in the prevention of multiple-organ dysfunction. However, the detailed mechanism of VNS in lymph toxicity remains unclear. The study aimed to investigate the relationship between VNS and inflammatory lipid mediators in ML. METHODS: Male Sprague-Dawley rats underwent laparotomy and superior mesenteric artery obstruction (SMAO) for 60 minutes to induce intestinal ischemia followed by reperfusion and observation. The ML duct was cannulated, and ML samples were obtained both before and after SMAO. The distal ileum was removed at the end of the observation period. In one group of animals, VNS was performed from 10 minutes before 10 minutes after SMAO (5 V, 0.5 Hz). Liquid chromatography-electrospray ionization-tandem mass spectrometry analysis of AA was performed for each ML sample. The biological activity of ML was examined using a monocyte nuclear factor κ-light-chain-enhancer of activated B cells activation assay. Western blotting of phospholipase A2 group IIA (PLA2-IIA) was also performed for ML and ileum samples. RESULTS: Vagus nerve stimulation relieved the SMAO-induced histological gut injury. The concentration of AA and level of nuclear factor κ-light-chain-enhancer of activated B cells activation in ML increased significantly after SMAO, whereas VNS prevented these responses. Western blotting showed PLA2-IIA expression in the ML and ileum after SMAO; however, the appearance of PLA2-IIA band was remarkably decreased in the samples from VNS-treated animals. CONCLUSION: The results suggested that VNS could relieve gut injury induced by SMAO and decrease the production of AA in ML by altering PLA2-IIA expression in the gut and ML.

Angiotensin-(1-7) treatment blocks lipopolysaccharide-induced organ damage, platelet dysfunction, and IL-6 and nitric oxide production in rats.

Sepsis can lead to shock, multiple organ failure, and even death. Platelets play an active role in the pathogenesis of sepsis-induced multiple organ failure. Angiotensin (Ang)-(1-7), a biologically active peptide, counteracts various effects of Ang II and attenuates inflammatory responses, reactive oxygen species production, and apoptosis. We evaluated the effects of Ang-(1-7) on organ injury and platelet dysfunction in rats with endotoxaemia. We treated male Wistar rats with saline or lipopolysaccharide (LPS, 10 mg, intravenously) then Ang-(1-7) (1 mg/kg, intravenous infusion for 3 h beginning 30 min after LPS administration). We analysed several haemodynamic, biochemical, and inflammatory parameters, as well as platelet counts and aggregation. Ang-(1-7) improved hypotension and organ dysfunction, and attenuated plasma interleukin-6, chemokines and nitric oxide production in rats after LPS administration. The LPS-induced reduction in platelet aggregation, but not the decreased platelet count, was restored after Ang-(1-7) treatment. The protein expression of iNOS and IκB, but not phosphorylated ERK1/2 and p38, was diminished in Ang-(1-7)-treated LPS rats. The histological changes in liver and lung were significantly attenuated in Ang-(1-7)-treated LPS rats. Our results suggest that Ang-(1-7) ameliorates endotoxaemic-induced organ injury and platelet dysfunction, likely through the inhibition of the inflammatory response and nitric oxide production.

Prognostic Value of Antithrombin Levels in COVID-19 Patients and Impact of Fresh Frozen Plasma Treatment: A Retrospective Study

Objective: The defective interplay between coagulation and inflammation may be the leading cause of intravascular coagulation and organ dysfunction in coronavirus disease-19 (COVID-19) patients. Abnormal coagulation profiles were reported to be associated with poor outcomes. In this study, we assessed the prognostic values of antithrombin (AT) activity levels and the impact of fresh frozen plasma (FFP) treatment on outcome. Materials and Methods: Conventional coagulation parameters as well as AT activity levels and outcomes of 104 consecutive critically ill acute respiratory distress syndrome (ARDS) patients with laboratory-confirmed COVID-19 disease were retrospectively analyzed. Patients with AT activity below 75% were treated with FFP. Maximum AT activity levels achieved in those patients were recorded. Results: AT activity levels at admission were significantly lower in nonsurvivors than survivors (73% vs. 81%). The cutoff level for admission AT activity was 79% and 58% was the lowest AT for survival. The outcome in those patients who had AT activity levels above 75% after FFP treatment was better than that of the nonresponding group. As well as AT, admission values of D-dimer, C-reactive protein, and procalcitonin were coagulation and inflammatory parameters among the mortality risk factors. Conclusion: AT activity could be used as a prognostic marker for survival and organ failure in COVID-19-associated ARDS patients. AT supplementation therapy with FFP in patients with COVID-19-induced hypercoagulopathy may improve thrombosis prophylaxis and thus have an impact on survival.

Mesenchymal stromal cells to fight SARS-CoV-2: Taking advantage of a pleiotropic therapy.

The devastating global impact of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has prompted scientists to develop novel strategies to fight Coronavirus Disease of 2019 (COVID-19), including the examination of pre-existing treatments for other viral infections in COVID-19 patients. This review provides a reasoned discussion of the possible use of Mesenchymal Stromal Cells (MSC) or their products as a treatment in SARS-CoV-2-infected patients. The main benefits and concerns of using this cellular therapy, guided by preclinical and clinical data obtained from similar pathologies will be reviewed. MSC represent a highly immunomodulatory cell population and their use may be safe according to clinical studies developed in other pathologies. Notably, four clinical trials and four case reports that have already been performed in COVID-19 patients obtained promising results. The clinical application of MSC in COVID-19 is very preliminary and further investigational studies are required to determine the efficacy of the MSC therapy. Nevertheless, these preliminary studies were important to understand the therapeutic potential of MSC in COVID-19. Based on these encouraging results, the United States Food and Drug Administration (FDA) authorized the compassionate use of MSC, but only in patients with Acute Respiratory Distress Syndrome (ARDS) and a poor prognosis. In fact, patients with severe SARS-CoV-2 can present infection and tissue damage in different organs, such as lung, heart, liver, kidney, gut and brain, affecting their function. MSC may have pleiotropic activities in COVID-19, with the capacity to fight inflammation and repair lesions in several organs.

Immunomodulatory and Therapeutic Effects of Mesenchymal Stem Cells on Organ Dysfunction in Sepsis.

ABSTRACT: Sepsis is a life-threatening disorder that is caused by a dysregulated inflammatory response during an infection. The disease mostly affects pregnant women, newborns, and patients in intensive care units. Sepsis treatment is a significant part of a country's health budgets. Delay in the therapy causes irreversible failure of various organs due to the lack of blood supply and reduction of oxygen in the tissues and eventually increased mortality. The involvement of four or five organs by sepsis has been attributed to an increased risk of death to over 90%. Although antibiotics are at the first line of sepsis treatment, they do not possess enough potency to control the disease and prevent subsequent organ failure. The immunomodulatory, anti-inflammatory, anti-apoptotic, and anti-microbial properties of mesenchymal stem cells (MSCs) have been reported in various studies. Therefore, the application of MSCs has been considered a potentially promising therapeutic strategy. In preclinical studies, the administration of MSCs has been associated with reduced bacterial load and decreased levels of pro-inflammatory factors as well as the improved function of the different vital organs, including heart, kidney, liver, and lungs. The current study provides a brief review of sepsis and its pathophysiology, and then highlights recent findings in the therapeutic effects of MSCs and MSC-derived secretome in improving sepsis-induced organ dysfunction. Besides, eligible sepsis candidates for MSC-therapy and the latest clinical findings in these areas have been reviewed.