Recent studies have suggested that bone marrow-derived multipotent mesenchymal stem cells (MSCs) may have therapeutic applications in multiple clinical disorders including myocardial infarction, diabetes, sepsis, and hepatic and acute renal failure. Here, we tested the therapeutic capacity of human MSCs to restore alveolar epithelial fluid transport and lung fluid balance from acute lung injury (ALI) in an ex vivo perfused human lung preparation injured by E. coli endotoxin. Intra-bronchial instillation of endotoxin into the distal airspaces resulted in pulmonary edema with the loss of alveolar epithelial fluid transport measured as alveolar fluid clearance. Treatment with allogeneic human MSCs or its conditioned medium given 1 h following endotoxin-induced lung injury reduced extravascular lung water, improved lung endothelial barrier permeability and restored alveolar fluid clearance. Using siRNA knockdown of potential paracrine soluble factors, secretion of keratinocyte growth factor was essential for the beneficial effect of MSCs on alveolar epithelial fluid transport, in part by restoring amiloride-dependent sodium transport. In summary, treatment with allogeneic human MSCs or the conditioned medium restores normal fluid balance in an ex vivo perfused human lung injured by E. coli endotoxin.

Allogeneic human mesenchymal stem cells for treatment of E. Coli endotoxin-induced acute lung injury in an ex vivo perfused human lung

In the end of 2019 COVID-19 emerged as a new threat worldwide and this disease present impaired immune system, exacerbated production of inflammatory cytokines, and coagulation disturbs. Mesenchymal stem cell (MSC) derived extracellular vesicles (EVs) have emerged as a therapeutic option due to its intrinsic properties to alleviate inflammatory responses, capable to promote the restoring of injured tissue. EVs contain heterogeneous cargo, including active microRNAs, small noncoding sequences involved in post-transcriptional gene repression or degradation and can attach in multiple targets. This study investigated whether the MSC-EVs miRNA cargo has the capacity to modulate the exacerbated cytokines, cell death and coagulation disturbs present in severe COVID-19. Through bioinformatics analysis, four datasets of miRNA, using different stem cell tissue sources (bone marrow, umbilical cord and adipose tissue), and one dataset of mRNA (bone marrow) were analyzed. 58 miRNAs overlap in the four miRNA datasets analyzed. Sequentially, those miRNAs present in at least two datasets, were analyzed using miRWalk for the 3'UTR binding target mRNA. The result predicted 258 miRNAs for exacerbated cytokines and chemokines, 266 miRNAs for cell death genes and 148 miRNAs for coagulation cascades. Some miRNAs may simultaneously attenuate inflammatory agents, inhibit cell death genes and key factors of coagulation cascade, consequently preventing tissue damage and coagulation disturbs. Therefore, the MSC-derived EVs due to their heterogeneous cargo are a potential multitarget approach able to improve the survival rates of severe COVID-19 patients.

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Mesenchymal Stem Cell-Derived Extracellular Vesicles Carrying miRNA as a Potential Multi Target Therapy to COVID-19: an In Silico Analysis.

Post-acute consequences of COVID-19, also termed long COVID, include signs and symptoms persisting for more than 12 weeks with prolonged multisystem involvement; most often, however, malnutrition is ignored. Method: The objective was to analyze persistent symptoms, nutritional status, the evolution of muscle strength and performance status (PS) at 6 months post-discharge in a cohort of COVID-19 survivors. Results: Of 549 consecutive patients hospitalized for COVID-19 between 1 March and 29 April 2020, 23.7% died and 288 patients were at home at D30 post-discharge. At this date, 136 of them (47.2%) presented persistent malnutrition, a significant decrease in muscle strength or a PS ≥ 2. These patients received dietary counseling, nutritional supplementation, adapted physical activity guidance or physiotherapy assistance, or were admitted to post-care facilities. At 6 months post-discharge, 91.0% of the 136 patients (n = 119) were evaluated and 36.0% had persistent malnutrition, 14.3% complained of a significant decrease in muscle strength and 14.9% had a performance status > 2. Obesity was more frequent in patients with impairment than in those without (52.8% vs. 31.0%; p = 0.0071), with these patients being admitted more frequently to ICUs (50.9% vs. 31.3%; p = 0.010). Among those with persistent symptoms, 10% had psychiatric co-morbidities (mood disorders, anxiety, or post-traumatic stress syndrome), 7.6% had prolonged pneumological symptoms and 4.2% had neurological symptoms. Conclusions: Obese subjects as well as patients who have stayed in intensive care have a higher risk of functional loss or undernutrition 6 months after a severe COVID infection. Malnutrition and loss of muscle strength should be considered in the clinical assessment of these patients.

Long-Term Evolution of Malnutrition and Loss of Muscle Strength after COVID-19: A Major and Neglected Component of Long COVID-19.

Abstract Most COVID-19 patients recovered with low mortality; however, some patients experienced long-term symptoms described as “long-COVID” or “Post-COVID syndrome” (PCS). Patients may have persisting symptoms for weeks after acute SARS-CoV-2 infection, including dyspnea, fatigue, myalgia, insomnia, cognitive and olfactory disorders. These symptoms may last for months in some patients. PCS may progress in association with the development of mast cell activation syndrome (MCAS), which is a distinct kind of mast cell activation disorder, characterized by hyper-activation of mast cells with inappropriate and excessive release of chemical mediators. COVID-19 survivors, mainly women, and patients with persistent severe fatigue for 10 weeks after recovery with a history of neuropsychiatric disorders are more prone to develop PCS. High D-dimer levels and blood urea nitrogen were observed to be risk factors associated with pulmonary dysfunction in COVID-19 survivors 3 months post-hospital discharge with the development of PCS. PCS has systemic manifestations that resolve with time with no further complications. However, the final outcomes of PCS are chiefly unknown. Persistence of inflammatory reactions, autoimmune mimicry, and reactivation of pathogens together with host microbiome alterations may contribute to the development of PCS. The deregulated release of inflammatory mediators in MCAS produces extraordinary symptoms in patients with PCS. The development of MCAS during the course of SARS-CoV-2 infection is correlated to COVID-19 severity and the development of PCS. Therefore, MCAS is treated by antihistamines, inhibition of synthesis of mediators, inhibition of mediator release, and inhibition of degranulation of mast cells. 

/pdf/pathophysiology-of-post-covid-syndromes-a-new-perspective-3pf1bp3t.pdf

Pathophysiology of Post-COVID syndromes: a new perspective

The number of publications studying the therapeutic use of stem cells has steadily increased since 2000. Compared to other applications, there has been little interest in the evaluation of mesenchymal stem cells (MSCs) and MSC-derived products (mostly extracellular vesicles) for the treatment of respiratory diseases. Due to the lack of efficient treatments for acute respiratory distress syndrome caused by infections with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the action of MSCs has also been studied. This review describes mode of action and use of MSCs and MSC-derived products in the treatment of lung diseases including the respective advantages and limitations of the products. Further, issues related to standardized production are addressed. Administration by inhalation of MSCs, compared to intravenous injection, could decrease cell damage by shear stress, eliminate the barrier to reach target cells in the alveoli, prevent thrombus formation in the pulmonary vasculature and retention in filter for extracorporeal membrane oxygenation. There is more feasible to deliver extracellular vesicles than MSCs with inhalers, offering the advantage of non-invasive and repeated administration by the patient. Major obstacles for comparison of results are heterogeneity of the products, differences in the treatment protocols and small study cohorts.

https://www.mdpi.com/1999-4923/13/2/232/pdf

Therapeutic Potential of Mesenchymal Stem Cells and Their Products in Lung Diseases—Intravenous Administration versus Inhalation

Therapeutic clinical and preclinical studies using cultured cells are on the rise, especially now that the World Health Organization (WHO) declared coronavirus disease 2019 (COVID-19) a "public health emergency of international concern", in January, 2020. Thus, this study aims to review the outcomes of ongoing clinical studies on stem cells in Severe Acute Respiratory Syndrome (SARS), Acute Respiratory Distress Syndrome (ARDS), and Middle East Respiratory Syndrome (MERS). The results will be associated with possible applications to COVID-19. Only three clinical trials related to stem cells are considered complete, whereby two are in Phase 1 and one is in Phase 2. Basically, the ongoing studies on coronavirus are using mesenchymal stem cells (MSCs) derived from bone marrow or the umbilical cord to demonstrate their feasibility, safety, and tolerability. The studies not related to coronavirus are all in ARDS conditions; four of them are in Phase 1 and three in Phase 2. With the COVID-19 boom, many clinical trials are being carried out using different sources with an emphasis on MSC-based therapy used to inhibit inflammation. One of the biggest challenges in the current treatment of COVID-19 is the cytokine storm, however MSCs can prevent or mitigate this cytokine storm through their immunomodulatory capacity. We look forward to the results of the ongoing clinical trials to find a treatment for the disease. Researchers around the world are joining forces to help fight COVID-19. Stem cells used in the current clinical studies are a new therapeutic promise for COVID-19 where pharmacological treatments seem insufficient.Graphical Abstract.

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Review of Trials Currently Testing Stem Cells for Treatment of Respiratory Diseases: Facts Known to Date and Possible Applications to COVID-19.

SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus-2) affects the central nervous system (CNS), which is shown in a significant number of patients with neurological events. In this study, an updated literature review was carried out regarding neurological disorders in COVID-19. Neurological symptoms are more common in patients with severe infection according to their respiratory status and divided into three categories: (1) CNS manifestations; (2) cranial and peripheral nervous system manifestations; and (3) skeletal muscle injury manifestations. Patients with pre-existing cerebrovascular disease are at a higher risk of admission to the intensive care unit (ICU) and mortality. The neurological manifestations associated with COVID-19 are of great importance, but when life-threatening abnormal vital signs occur in severely ill COVID-19 patients, neurological problems are usually not considered. It is crucial to search for new treatments for brain damage, as well as for alternative therapies that recover the damaged brain and reduce the inflammatory response and its consequences for other organs. In addition, there is a need to diagnose these manifestations as early as possible to limit long-term consequences. Therefore, much research is needed to explain the involvement of SARS-CoV-2 causing these neurological symptoms because scientists know zero about it.

Neuropsychiatric Disorders and COVID-19: What We Know So Far.

The mites Demodex folliculorum (Simon) and Demodex brevis Akbulatova are part of the regular human skin fauna, found in the pilosebaceous unit, and their infestations might cause the disease known ...

Demodex folliculorum and Demodex brevis (Acari: Demodecidae) and their association with facial and non-facial pathologies

Objetivo: Relatar a experiencia da dinâmica de selecao e funcionamento de um curso pre-vestibular popular criado e desenvolvido como projeto de extensao por alunos de medicina de uma universidade comunitaria do estado do Rio Grande do Sul. Relato de experiencia: Estudantes da graduacao estruturaram um curso pre-vestibular e desenvolveram um modelo proprio de selecao, baseado em experiencias previas com processos seletivos e nas Multiple Mini-Interviews (MMI), o qual une a avaliacao teorica (primeira etapa) com cenarios tematicos (segunda etapa). A selecao visa abranger nao somente competencias cognitivas. A avaliacao teorica evidenciou que os candidatos apresentaram dificuldades em matematica, quimica e fisica. Ja os cenarios tematicos contribuiram na identificacao de candidatos que expressassem tracos de trabalho em equipe, empatia, motivacao e interesse em participar do projeto. Apos o processo, o projeto se desenvolveu com aulas e simulados ao longo de um ano letivo. Consideracoes finais: A incorporacao dos cenarios tematicos contribuiu na reducao das desistencias ao longo do ano, a medida em que a avaliacao teorica possibilitou o conhecimento das principais dificuldades dos candidatos. Portanto, a selecao, composta pelas duas etapas, coadunaram com as particularidades do projeto de extensao e auxiliaram na aproximacao e manutencao dos alunos-academicos da realidade regional em que a universidade esta inserida.

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Relato de experiência: a construção de um curso pré-vestibular popular vinculado ao curso de medicina

Mites are among the major sources of domestic and occupational allergens worldwide, and continuous exposure to these allergens leads to chronic airway inflammation. One of the most allergenic species is the storage mite Tyrophagus putrescentiae (Schrank). Protein extracts are produced from this mite for tests that help the clinical diagnosis (via prick test), treatment, and monitoring of disease progression in patients who had positive results for allergic reactions. Therefore, the aim of the present study was to evaluate the cell viability of RAW 264.7 and L929 cells when exposed to in-house raw protein extracts of T. putrescentiae compared to a commercial product, as well as quantify TNF-α secretion by RAW 264.7. Additionally, this study quantified the effect of these extracts in IgE secretion in total blood of people affected by this mite. The study found similarity between the in-house extract and the commercial extract as they had equivalent TNF-α secretion. Additionally, viabilities of RAW 264.7 and L929 exposed to the in-house extract were compatible with viabilities of cells exposed to the commercial extract, with no cytotoxicity at the concentrations tested. Results corroborated the hypothesis that the extract produced in-house would be equivalent to the commercial extract in allergic patients when the IgE was quantified. This study is the first to show the cytotoxicity of T. putrescentiae extracts, and to provide a quantitative analysis of TNF-α and IgE. 

Lucas Vieira

Papers

Review of Trials Currently Testing Stem Cells for Treatment of Respiratory Diseases: Facts Known to Date and Possible Applications to COVID-19.

Neuropsychiatric Disorders and COVID-19: What We Know So Far.

Demodex folliculorum and Demodex brevis (Acari: Demodecidae) and their association with facial and non-facial pathologies

Relato de experiência: a construção de um curso pré-vestibular popular vinculado ao curso de medicina

Effects of in-house and commercial extracts of the allergenic mite Tyrophagus putrescentiae on murine and human cell responses