IL-17A levels increase in the infarcted region of the left ventricle in a rat model of myocardial infarction.

Th17 cells, a recently described subtype of CD4+ effector lymphocytes, have been linked to cell-mediated autoimmune and inflammatory diseases as well as to cardiovascular diseases. However, the participation of IL-17A in myocardial ischemic injury has not been clearly defined. We therefore conducted the present study to evaluate IL-17A and Th17-related cytokine levels in a rat model of myocardial infarction (MI). MI was induced in male Sprague Dawley rats by coronary artery ligation. Controls were sham-operated (Sh) or non-operated (C). Blood and samples from the left ventricle (LV) were collected at weeks 1 and 4 post-MI. At week 1, MI animals exhibited increased IL-6, IL-23 and TGF-ß mRNA levels with no apparent change in IL-17 mRNA or protein levels in whole LV. Only TGF-ß mRNA remained elevated at week 4 post-MI. However, further analysis revealed that IL-17A mRNA and protein levels as well as IL-6 and IL-23 mRNA were indeed increased in the infarcted region, though not in the remote non infarcted region of the LV, except for IL-23 mRNA. The increased expression of IL-17A and Th17-related cytokines in the infarcted region of LV, suggests that this proinflammatory pathway might play a role in early stages of post MI cardiac remodelling.

Intra-articular administration of peripheral blood stem cells with platelet-rich plasma regenerated articular cartilage and improved clinical outcomes for knee chondral lesions.

PURPOSE: To determine whether intra-articular injections of peripheral blood stem cells improved the regeneration of articular cartilage in patients with osteochondral knee injuries. METHODS: This prospective study included 20 patients with grade 3b knee osteochondral lesions who underwent knee arthroscopies. All were white, and all had performed physical activity at least five times a week. International Knee Documentation Committee (IKDC) and visual analog scale scores were recorded before surgery, six months and one year after surgery, and then yearly until five years after surgery. Magnetic resonance imaging scans were obtained six months preoperatively and then yearly and were evaluated by musculoskeletal radiologists blinded to the patient data. Tissue repair was quantified using the International Cartilage Repair Society morphologic score system. Unpaired t-tests were used for comparisons between the time points. RESULTS: The mean preoperative IKDC score was 50.5 (42-61). At the six-month follow-up, the mean values were 60.79 (P = 0.32) and 90.97. At the six-month follow-up, the mean values were 70.8 (P = 0.043). At the end of the five-year follow-up, the IKDC was 82.2 (P = 0.024). At five-year follow-up, the visual analog scale score was 1.1 (P = 0.0018). The main morphologic score system score was 3.2 preoperatively and 9.7 ±â€¯1.6 at five-year follow-up (P = 0.0021). No infection, tumors, or synovitis were reported at the end of the follow-up. CONCLUSIONS: Intra-articular peripheral blood stem cells with platelet-rich plasma regenerated articular cartilage and improved clinical outcomes for knee chondral lesions at five years of follow-up.

[Cardiac hypertrophy: molecular and cellular events]. / Hipertrofia cardiaca: eventos moleculares y celulares.

Cardiac hypertrophy is one of the main ways in which cardiomyocytes respond to mechanical and neurohormonal stimuli. It enables myocytes to increase their work output, which improves cardiac pump function. However, this compensatory mechanism can become overwhelmed by biomechanical stress, thereby resulting in heart failure, which is associated with high morbidity and mortality. The complex molecular processes that lead to cardiomyocyte growth involve membrane receptors, second messengers, and transcription factors. The common final pathway of all these intracellular substances is gene expression, whose variations are being revealed in increasing detail. The genetic response is characterized by the re-expression of fetal genes, an event which is regarded as the molecular marker of pathologic cardiac hypertrophy, and which is absent in normal physiologic cardiac growth. The possibility of stopping or reversing pathologic cardiac hypertrophy and, thereby, slowing the development of heart failure is a topic of considerable clinical interest and a large amount of relevant data has accumulated. The purpose of this review was to provide a schematic overview of current knowledge about the molecular pathogenesis of cardiomyocyte hypertrophy, with special emphasis on new research topics and investigations.

Increased IL-6 secretion by aged human mesenchymal stromal cells disrupts hematopoietic stem and progenitor cells' homeostasis.

Hematopoietic stem and progenitor cell (HSPC) homeostasis declines with age, leading to impaired hematopoiesis. Mesenchymal stromal cells (MSC) are critical components of the bone marrow niche and key regulators of the balance between HSPC proliferation and quiescence. Accrual of DNA damage, a hallmark of cellular aging, occurs in aged MSC. Whether MSC aging alters the bone marrow niche triggering HSPC dysfunction is unknown. Using a human MSC-HSPC co-culture system, we demonstrated that DNA damaged MSC have impaired capacity to maintain CD34+CD38- HSPC quiescence. Furthermore, human MSC from adult donors display some hallmarks of cellular senescence and have a decreased capacity to maintain HSPC quiescence and the most primitive CD34+CD38- subset compared to MSC from pediatric donors. IL-6 neutralization restores the MSC-HPSC crosstalk in senescent and adult MSC-HSPC co-cultures highlighting the relevance of the local microenvironment in maintaining HSPC homeostasis. These results provide new evidence implicating components of the MSC secretome in HSPC aging.

Opposing effect of mesenchymal stem cells on Th1 and Th17 cell polarization according to the state of CD4+ T cell activation.

Mesenchymal stem cells (MSCs) are multipotent progenitors with broad immunosuppressive properties. However, their therapeutic use in autoimmune disease models has shown dissimilar effects when applied at different stages of disease. We therefore investigated the effect of the addition of MSCs on the differentiation of Th1, Treg and Th17 cells in vitro, at different states of CD4(+) T cell activation. CD4(+) T lymphocytes purified by negative selection from mouse C57BL/6 splenocytes were cultured under Th1, Th17 and Treg inducing conditions with IL-12, TGF-ß+IL-6 or TGF-ß, respectively. C57BL/6 bone marrow derived MSCs were added to CD4(+) T cell cultures at day 0 or after 3 days of T cell polarizing activation. Intracellular cytokines for Th1, Th17 and Treg cells were quantitated at day 6 by flow cytometry. While early addition (day 0) of MSCs suppressed all CD4(+) T cell lineages, addition at day 3 only decreased IFN-γ production by Th1 polarized cells by 64% (p<0.05) while markedly increased IL-17 production by Th17 polarized cells by 50% (p<0.05) and left IL-10 production by Treg polarized cells unchanged. MSCs exhibit their typical suppressive phenotype when added early to cell cultures in the presence of CD4(+) T cell polarizing stimuli. However, once T cell activation has occurred, MSCs show an opposite stimulating effect on Th17 cells, while leaving Treg IL-10 producing cells unchanged. These results suggest that the therapeutic use of MSCs in vivo might exert opposing effects on disease activity, according to the time of therapeutic application and the level of effector T cell activation.

Angiotensin-(1-9) regulates cardiac hypertrophy in vivo and in vitro.

BACKGROUND: Angiotensin-(1-9) is present in human and rat plasma and its circulating levels increased early after myocardial infarction or in animals treated with angiotensin-converting enzyme inhibitor. However, the cardiovascular effects of this peptide are unknown. OBJECTIVE: To determine whether angiotensin-(1-9) is a novel anti-cardiac hypertrophy factor in vitro and in vivo and whether this peptide is involved in the pharmacological effects of cardiovascular drugs acting on the renin-angiotensin system. METHODS AND RESULTS: The administration of angiotensin-(1-9) to myocardial infarcted rats by osmotic minipumps (450 ng/kg per min, n = 6) vs. vehicle (n = 8) for 2 weeks decreased plasma angiotensin II levels, inhibited angiotensin-converting enzyme activity and also prevented cardiac myocyte hypertrophy. However, cardiac myocyte hypertrophy attenuation triggered by angiotensin-(1-9) was not modified with the simultaneous administration of the angiotensin-(1-7) receptor antagonist A779 (100 ng/kg per min, n = 6). In experiments in vitro with cultured cardiac myocytes incubated with norepinephrine (10 micromol/l) or with insulin-like growth factor-1 (10 nmol/l), angiotensin-(1-9) also prevented hypertrophy. In other experimental setting, myocardial infarcted rats (n = 37) were randomized to receive either vehicle (n = 12), enalapril (10 mg/kg per day, n = 12) or angiotensin II receptor blocker candesartan (10 mg/kg per day, n = 13) for 8 weeks. Both drugs prevented left ventricle hypertrophy and increased plasma angiotensin-(1-9) levels by several folds. Angiotensin-(1-9) levels correlated negatively with different left ventricular hypertrophy markers even after adjustment for blood pressure reduction. CONCLUSION: Angiotensin-(1-9) is an effective and a novel anti-cardiac hypertrophy agent not acting via the Mas receptor.

IL-17A levels increase in the infarcted region of the left ventricle in a rat model of myocardial infarction

Th17 cells, a recently described subtype of CD4+ effector lymphocytes, have been linked to cell-mediated autoimmune and inflammatory diseases as well as to cardiovascular diseases. However, the participation of IL-17A in myocardial ischemic injury has not been clearly defined. We therefore conducted the present study to evaluate IL-17A and Th17-related cytokine levels in a rat model of myocardial infarction (MI). MI was induced in male Sprague Dawley rats by coronary artery ligation. Controls were sham-operated (Sh) or non-operated (C). Blood and samples from the left ventricle (LV) were collected at weeks 1 and 4 post-MI. At week 1, MI animals exhibited increased IL-6, IL-23 and TGF-β mRNA levels with no apparent change in IL-17 mRNA or protein levels in whole LV. Only TGF-β mRNA remained elevated at week 4 post-MI. However, further analysis revealed that IL-17A mRNA and protein levels as well as IL-6 and IL-23 mRNA were indeed increased in the infarcted region, though not in the remote non infarcted region of the LV, except for IL-23 mRNA. The increased expression of IL-17A and Th17-related cytokines in the infarcted region of LV, suggests that this proinflammatory pathway might play a role in early stages of post MI cardiac remodelling.

La sobreexpresión del gen de enzima convertidora de angiotensina homóloga (ECA2) revierte la hipertensión arterial y el remodelado cardíaco experimental / Over expression of the homologous angiotensin converting enzyme (ACE2) gene reverts experimental hypertensión and cardiac remodeling

Antecedentes: La sobreexpresion génica de la enzima convertidora de angiotensina I homologa (ECA2) se asocia con prevención de la hipertrofia y fibrosis cardiaca dependiente de angiotensina (Ang) II. Sin embargo se desconoce si su sobreexpresion reduce la hipertensión arterial (HTA) y revierte el consecuente remodelado miocárdico (RM) dependiente de Ang II. Objetivo: Determinar si la sobreexpresion adenoviral (Ad) del gen de la ECA2 en el miocardio disminuye la HTA y RM experimental en ratas con niveles genéticamente determinados de ECA y Ang II. Métodos: Ratas homocigotas normotensas Lewis (LL) y Brown Borway (BN), con menores y mayores niveles circulantes de ECA y Ang II, respectivamente, se hicieron hipertensas por el procedimiento Goldblatt (GB). Como controles se usaron ratas seudo-operadas (sham). A la semana 5 post cirugía y con HTA establecida > 140 mmHg, las ratas se randomizaron a inyección intramiocárdica con un AdECA2 o Ad proteína fluorescente verde (GFP) como controles de infección. A la semana post infección adenoviral, los ratas se sacrificaron y se determinaron peso corporal (PC, g), masa cardiaca (MC, mg), presión arterial sistólica (RAS, mmHg), área (AC, um2) y perímetro (PERC, um) de cardiomiocitos y contenido de colágeno ( por ciento) miocárdico (CM), sub-endocárdico (CS)ytotal(CT). Resultados: La HTA aumentó significativamente la MC, MCR, AC, PERC como también el CM, CS y CT en las ratas GB vs Sham, sin diferencias en el PC ni por efecto del polimorfismo de la ECA. La sobreexpresion de ECA2 disminuyó significativamente la RAS (15 por ciento y 27 por ciento), AC (25 por ciento y 25 por ciento ) y PERC (17 por ciento y 18 por ciento) en las ratas LL y BN vs ratas hipertensas, respectivamente. Estos resultados se asociaron a una disminución significativa del CS (LL = 37 por ciento, BN = 39 por ciento), CM (LL = 54 por ciento) y CT (LL = 42 por ciento, BN = 22 por ciento) respecto a las ratas GB. Conclusión: En ratas con HTA...

Objective Background. Over expression of the gene for homologous angiotensin I converting enzyme (ACE) is associated with prevention of angiotensin II dependent cardiac hypertrophy and fibrosis. Whether this over expression is able to reduce hypertension and revert cardiac remodeling is unknown. Aim: To determine whether adenoviral ACE2 gene over expression in the myocardium decreases experimental hypertension and cardiac remodeling in rats with genetically determined levels of ACE and ANGII. Methods: Homozygous normotensive Lewis (LL) and Brown Norway (BN) rats with decreased or increased levéis of ACE and Ang II, respectively, were made hy-pertensive using the Goldblatt procedure. Sham opera-ted rats were used as control s. 5 weeks after surgery, when systolic blood pressure reached > 140 mmHg, rats were randomized to receive intramyocardial injec-tion of either AdACE2 or green fluorescent Ad protein (GFP) as infection controlling agents. One week after adenoviral infection, rats were sacrificed. Body weight (BW, Gr), relative cardiac mass (RCM, mG), systolic blood pressure (SBP, mmHg), cardiomyocite área (MA um2) and perimeter (MPER, uM), and myocardial co-llagen content, both subendocardial (SC, percent) and total (TC percent) were measured. Results: Hypertension was associated to significant in-creases in total and RCM, MA, MPER as well as SC and TC in Goldblatt vs normal rats. This was independent of BW and not affected by ACE polymorphism. ACE II over expression significantly decreased SBP (27 vs 15 percent), MA (25 vs 25 percent) and MPER (18 vs 17 percent) hy-pertensive vs normal rats, respectively. Conclusion: Over expression of ACE2 decreased hypertension, hypertrophy and fibrosis in rats with experimental hypertension and different levels of ACE and Ang II. (Fondecyt 1070662).

Hipertrofia cardiaca: eventos moleculares y celulares / Cardiac hypertrophy: molecular and cellular events

La hipertrofia cardiaca constituye una de las principales formas de respuesta del cardiomiocito a estímulos mecánicos y neurohormonales y permite al miocito generar mayor trabajo, con aumento de la función de la bomba cardiaca. Esta acción compensadora, sin embargo, se ve en algún momento sobrepasada por el estrés biomecánico, lo que da lugar al cuadro de insuficiencia cardiaca, que causa una gran morbilidad y mortalidad. En los complejos procesos moleculares que llevan al crecimiento del miocito cardiaco intervienen receptores de membrana, segundos mensajeros y factores de transcripción. La vía final común en que convergen estos agentes intracelulares es la expresión génica, cuyos cambios están siendo caracterizados cada vez con más detalle. Esta modificación génica se caracteriza por la reexpresión de genes fetales, evento considerado como el marcador molecular de hipertrofia patológica, ausente en condiciones de crecimiento ventricular fisiológico. La posibilidad de detener o revertir la hipertrofia patológica y, así, detener la evolución hacia insuficiencia cardiaca, ha generado un considerable interés y mucha información al respecto. El objetivo de la presente revisión es mostrar esquemáticamente el conocimiento actual de la patogenia molecular de la hipertrofia patológica del cardiomiocito, con énfasis en los nuevos interrogantes y líneas de investigación (AU)

Cardiac hypertrophy is one of the main ways in which cardiomyocytes respond to mechanical and neurohormonal stimuli. It enables myocytes to increase their work output, which improves cardiac pump function. However, this compensatory mechanism can become overwhelmed by biomechanical stress, thereby resulting in heart failure, which is associated with high morbidity and mortality. The complex molecular processes that lead to cardiomyocyte growth involve membrane receptors, second messengers, and transcription factors. The common final pathway of all these intracellular substances is gene expression, whose variations are being revealed in increasing detail. The genetic response is characterized by the re-expression of fetal genes, an event which is regarded as the molecular marker of pathologic cardiac hypertrophy, and which is absent in normal physiologic cardiac growth. The possibility of stopping or reversing pathologic cardiac hypertrophy and, thereby, slowing the development of heart failure is a topic of considerable clinical interest and a large amount of relevant data has accumulated. The purpose of this review was to provide a schematic overview of current knowledge about the molecular pathogenesis of cardiomyocyte hypertrophy, with special emphasis on new research topics and investigations (AU)

Valor pronóstico de la proteína C reactiva en pacientes sometidos a ventilación mecánica / Predictive value of C-reactive protein in patients receiving mechanical ventilation

La Proteína C Reactiva (PCR) es una de las proteínas de fase aguda más utilizadas en clínica, como marcador de infección y de intensidad de la respuesta inflamatoria. En el presente estudio evaluamos la utilidad clínica de la PCR en pacientes críticos sometidos a ventilación mecánica (VM). De 214 pacientes admitidos a la UCI Quirúrgica desde junio de 1999 a diciembre del 2000 y que fueron ventilados por más de 24 horas, 160 (75 por ciento) tenían medición de PCR. El 73 por ciento de ellos ingresó por problemas infecciosos, mientras el 27 por ciento lo hizo por problemas neurológicos. No hubo diferencia entre la PCR de ingreso o PCR máxima de los pacientes que sobrevivieron y los que fallecieron. Tampoco hubo correlación entre el valor de la PCR y los días de UCI, días de VM y días libres de VM. La mortalidad de 131 pacientes que alcanzaron la PCR máxima antes de las primeras 72 horas de admisión a la UCI fue inferior a aquellos que la presentaron después de las 72 horas (17,6 por ciento vs 44,8 por ciento, p<0,05). En el presente estudio, la PCR como valor aislado no mostró gran valor pronóstico en cuanto a la sobrevida de los pacientes, ni a los días en UCI o en VM. Sin embargo, su evolución en el tiempo aporta información clínica que puede ser relevante en el manejo de los pacientes ventilados.

El índice de oxigenación es un mejor indicador del intercambio gaseoso que la relación PaO2: FiO2 en pacientes adultos sometidos a ventilación mecánica / Oxygenation index is a better indicator of gaseous interchange than PaO2/FiO2 ratio in adult patients receiving mechanical ventilation

Oxygenation Index (Oxlx = MAP x 100 / Pa/FiO2) has been widely used to assess gas exchange in pediatric patients. We evaluated Oxlx and PaO2:FiO2 ratio (Pa/FiO2) in adults patients under Mechanical Ventilation (MV). Seventy-two patients (39 M, 33 F, 53 ± 21 yo, APACHE II 17 ± 7) required MV for 4 ± 3 days (1-18), of which 17 died (24 per cent). Arterial blood gases along FiO2, PEEP and mean airway pressure (MAP), to calculate Pa/FiO2 and Oxlx, and static toraco-pulmonar Compliance (Cst) were measured on a daily basis. Compliance had a good correlation with Oxlx (r = -0.7, p = 0.0001) and Pa/FiO2 (r = 0.5, p = 0.0001). Correlation between Cst and Oxlx improved (r = 0.8, p = 0.0001) when considering only Acute Respiratory Failure patients (ARF, n = 37). Mortality in ARF patients was related to a greater MAP, lower Cst and a worst Oxlx but not Pa/FiO2. Patients who fulfilled ARDS criteria had the worst Pa/FiO2, Oxlx and Cst values. In contrast, no relationship could be observed between Cst and gas exchange markers in neurologic patients (n = 22), or between these parameters and mortality. Oxygenation Index seems to be a better marker of gas exchange than Pa/FiO2 in adults patients under MV. It had a better relationship with the impairment in pulmonary function and mortality in ARF patients.

Ventilación con presión positiva no invasiva, VPPNI, en pacientes con insuficiencia respiratoria aguda hipoxémica / Noninvasive ventilation with positive pressure in patients with acute hypoxemic respiratory failure

Quisimos evaluar la aplicabilidad y eficacia de la ventilación con presión positiva no invasiva (VPPNI) en pacientes con insuficiencia respiratoria aguda (IRA) hipoxémica y aumento del trabajo respiratorio. En un periodo de 10 meses evaluamos a 64 pacientes que ingresaron a nuestro servicio con el diagnóstico de IRA y signos de fatiga muscular, en ausencia de patología crónica. Fueron considerados no aptos para VPPNI quienes tuvieran compromiso de conciencia importante, inestabilidad hemodinámica o más de dos órganos en falla, cirugía reciente de esófago, estómago o duodeno, hemorragia digestiva alta activa, distensión abdominal importante o dificultad en el manejo de secreciones. Luego de aplicar los criterios de exclusión, 14 (23 por ciento) pacientes fueron sometidos a VPPNI por un periodo de 1 a 9 días. La Pa/FiO2, sin cambios significativos en la PaCO2 y frecuencia respiratoria. En 5 pacientes (36 por ciento) fracasó el método, de los cuales 2 fallecieron. Un paciente presentó una escara nasal. Por su mínima invasividad y fácil aplicación, la VPPNI debe ser considerada precozmente en todo paciente con IRA hipoxémica con buen nivel de conciencia y que preserve su ventilación espontánea