First detection of Leishmania DNA in Lutzomyia longipalpis sensu lato (Diptera: Phlebotominae) in southem Mexico.

Background & objectives: Lutzomyia longipalpis sensu lato is an important vector of Leishmania infantum, the causative agent of visceral leishmaniasis (VL) in Latin America. In Mexico, this species has been recorded in endemic areas of leishmaniasis transmission, but it has never been detected as infected with Leishmania sp. This study aimed to explore the presence of Leishmania DNA in Lutzomyia longipalpis s.l. from samples collected with a human baited trap from an endemic region of leishmaniasis in southeastern Mexico. Methods: This is a prospective study where a total of 45 specimens of Lu. longipalpis s.l. collected in two sites of Yucatan state with records of leishmaniasis were tested. The nuclear ribosomal Internal Transcribed Spacer was amplified for the detection of Leishmania DNA. Results: Two females were positive for Leishmania DNA. None of the specimens positive for parasite DNA were found fed or gravid. Our finding represents the first record of infection by Leishmania in Lu. longipalpis s.l. for the country. Interpretation & conclusion: More studies are necessary to understand the potential role of this vector species in the transmission cycle of the causative agent of leishmaniasis in the southeastern and other regions of Mexico.

Vesicle-associated Membrane Protein 3 (VAMP3) Mediates Constitutive Trafficking of the Renal Co-transporter NKCC2 in Thick Ascending Limbs: ROLE IN RENAL FUNCTION AND BLOOD PRESSURE.

Renal cells of the thick ascending limb (TAL) reabsorb NaCl via the apical Na+/K+/2Cl- co-transporter NKCC2. Trafficking of NKCC2 to the apical surface regulates NKCC2-mediated NaCl absorption and blood pressure. The molecular mechanisms by which NKCC2 reaches the apical surface and their role in renal function and maintenance of blood pressure are poorly characterized. Here we report that NKCC2 interacts with the vesicle fusion protein VAMP3, and they co-localize at the TAL apical surface. We observed that silencing VAMP3 in vivo blocks constitutive NKCC2 exocytic delivery, decreasing the amount of NKCC2 at the TAL apical surface. VAMP3 is not required for cAMP-stimulated NKCC2 exocytic delivery. Additionally, genetic deletion of VAMP3 in mice decreased total expression of NKCC2 in the TAL and lowered blood pressure. Consistent with these results, urinary excretion of water and electrolytes was higher in VAMP3 knock-out mice, which produced more diluted urine. We conclude that VAMP3 interacts with NKCC2 and mediates its constitutive exocytic delivery to the apical surface. Additionally, VAMP3 is required for normal NKCC2 expression, renal function, and blood pressure.

Vesicle-associated membrane protein 2 (VAMP2) but Not VAMP3 mediates cAMP-stimulated trafficking of the renal Na+-K+-2Cl- co-transporter NKCC2 in thick ascending limbs.

In the kidney, epithelial cells of the thick ascending limb (TAL) reabsorb NaCl via the apical Na(+)/K(+)/2Cl(-) co-transporter NKCC2. Steady-state surface NKCC2 levels in the apical membrane are maintained by a balance between exocytic delivery, endocytosis, and recycling. cAMP is the second messenger of hormones that enhance NaCl absorption. cAMP stimulates NKCC2 exocytic delivery via protein kinase A (PKA), increasing steady-state surface NKCC2. However, the molecular mechanism involved has not been studied. We found that several members of the SNARE family of membrane fusion proteins are expressed in TALs. Here we report that NKCC2 co-immunoprecipitates with VAMP2 in rat TALs, and they co-localize in discrete domains at the apical surface. cAMP stimulation enhanced VAMP2 exocytic delivery to the plasma membrane of renal cells, and stimulation of PKA enhanced VAMP2-NKCC2 co-immunoprecipitation in TALs. In vivo silencing of VAMP2 but not VAMP3 in TALs blunted cAMP-stimulated steady-state surface NKCC2 expression and completely blocked cAMP-stimulated NKCC2 exocytic delivery. VAMP2 was not involved in constitutive NKCC2 delivery. We concluded that VAMP2 but not VAMP3 selectively mediates cAMP-stimulated NKCC2 exocytic delivery and surface expression in TALs. We also demonstrated that cAMP stimulation enhances VAMP2 exocytosis and promotes VAMP2 interaction with NKCC2.

Renin release: role of SNAREs.

Little is known about the molecular mechanism mediating renin granule exocytosis and the identity of proteins involved. We previously showed that soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNAREs), a family of proteins required for exocytosis, mediate the stimulated release of renin from juxtaglomerular cells. This minireview focuses on the current knowledge of the proteins that facilitate renin-granule exocytosis. We discuss the identity of potential candidates that mediate the signaling and final steps of exocytosis of the renin granule.

Role of the SNARE protein SNAP23 on cAMP-stimulated renin release in mouse juxtaglomerular cells.

Renin, the rate-limiting enzyme in the formation of angiotensin II, is synthesized and stored in granules in juxtaglomerular (JG) cells. Therefore, the controlled mechanism involved in renin release is essential for the regulation of blood pressure. Exocytosis of renin-containing granules is likely involved in renin release; a process stimulated by cAMP. We found that the "soluble NSF (N-ethylmaleimide-sensitive factor) attachment protein receptor" (SNARE) protein VAMP2 mediates cAMP-stimulated renin release and exocytosis in JG cells. To mediate exocytosis, VAMP2 must interact with a synaptosome-associated protein (SNAP). In the renal cortex, the isoform SNAP23 is abundantly expressed. We hypothesized that SNAP23 mediates cAMP-stimulated renin release from primary cultures of mouse JG cells. We found that SNAP23 protein is expressed and colocalized with renin-containing granules in primary cultures of mouse JG cell lysates. Thus, we then tested the involvement of SNAP23 in cAMP-stimulated renin release by transducing JG cells with a dominant-negative SNAP23 construct. In control JG cells transduced with a scrambled sequence, increasing cAMP stimulated renin release from 1.3 ± 0.3 to 5.3 ± 1.2% of renin content. In cells transduced with dominant-negative SNAP23, cAMP increased renin from 1.0 ± 0.1 to 3.0 ± 0.6% of renin content, a 50% blockade. Botulinum toxin E, which cleaves and inactivates SNAP23, reduced cAMP-stimulated renin release by 42 ± 17%. Finally, adenovirus-mediated silencing of SNAP23 significantly blocked cAMP-stimulated renin release by 50 ± 13%. We concluded that the SNARE protein SNAP23 mediates cAMP-stimulated renin release. These data show that renin release is a SNARE-dependent process.

Juxtaglomerular cell CaSR stimulation decreases renin release via activation of the PLC/IP(3) pathway and the ryanodine receptor.

The calcium-sensing receptor (CaSR) is a G-coupled protein expressed in renal juxtaglomerular (JG) cells. Its activation stimulates calcium-mediated decreases in cAMP content and inhibits renin release. The postreceptor pathway for the CaSR in JG cells is unknown. In parathyroids, CaSR acts through G(q) and/or G(i). Activation of G(q) stimulates phospholipase C (PLC), and inositol 1,4,5-trisphosphate (IP(3)), releasing calcium from intracellular stores. G(i) stimulation inhibits cAMP formation. In afferent arterioles, the ryanodine receptor (RyR) enhances release of stored calcium. We hypothesized JG cell CaSR activation inhibits renin via the PLC/IP(3) and also RyR activation, increasing intracellular calcium, suppressing cAMP formation, and inhibiting renin release. Renin release from primary cultures of isolated mouse JG cells (n = 10) was measured. The CaSR agonist cinacalcet decreased renin release 56 ± 7% of control (P < 0.001), while the PLC inhibitor U73122 reversed cinacalcet inhibition of renin (104 ± 11% of control). The IP(3) inhibitor 2-APB also reversed inhibition of renin from 56 ± 6 to 104 ± 11% of control (P < 0.001). JG cells were positively labeled for RyR, and blocking RyR reversed CaSR-mediated inhibition of renin from 61 ± 8 to 118 ± 22% of control (P < 0.01). Combining inhibition of IP(3) and RyR was not additive. G(i) inhibition with pertussis toxin plus cinacalcet did not reverse renin inhibition (65 ± 12 to 41 ± 8% of control, P < 0.001). We conclude stimulating JG cell CaSR activates G(q), initiating the PLC/IP(3) pathway, activating RyR, increasing intracellular calcium, and resulting in calcium-mediated renin inhibition.

Vesicle-associated membrane protein-2 (VAMP2) mediates cAMP-stimulated renin release in mouse juxtaglomerular cells.

Renin is essential for blood pressure control. Renin is stored in granules in juxtaglomerular (JG) cells, located in the pole of the renal afferent arterioles. The second messenger cAMP stimulates renin release. However, it is unclear whether fusion and exocytosis of renin-containing granules is involved. In addition, the role of the fusion proteins, SNAREs (soluble N-ethylmaleimide-sensitive factor attachment proteins), in renin release from JG cells has not been studied. The vesicle SNARE proteins VAMP2 (vesicle associated membrane protein 2) and VAMP3 mediate cAMP-stimulated exocytosis in other endocrine cells. Thus, we hypothesized that VAMP2 and/or -3 mediate cAMP-stimulated renin release from JG cells. By fluorescence-activated cell sorting, we isolated JG cells expressing green fluorescent protein and compared the relative abundance of VAMP2/3 in JG cells versus total mouse kidney mRNA by quantitative PCR. We found that VAMP2 and VAMP3 mRNA are expressed and enriched in JG cells. Confocal imaging of primary cultures of JG cells showed that VAMP2 (but not VAMP3) co-localized with renin-containing granules. Cleavage of VAMP2 and VAMP3 with tetanus toxin blocked cAMP-stimulated renin release from JG cells by ~50% and impaired cAMP-stimulated exocytosis by ~50%, as monitored with FM1-43. Then we specifically knocked down VAMP2 or VAMP3 by adenoviral-mediated delivery of short hairpin silencing RNA. We found that silencing VAMP2 blocked cAMP-induced renin release by ~50%. In contrast, silencing VAMP3 had no effect on basal or cAMP-stimulated renin release. We conclude that VAMP2 and VAMP3 are expressed in JG cells, but only VAMP2 is targeted to renin-containing granules and mediates the stimulatory effect of cAMP on renin exocytosis.

Intrarenal Renin Angiotensin System Imbalance During Postnatal Life Is Associated With Increased Microvascular Density in the Mature Kidney.

Environmental stress during early life is an important factor that affects the postnatal renal development. We have previously shown that male rats exposed to maternal separation (MatSep), a model of early life stress, are normotensive but display a sex-specific reduced renal function and exacerbated angiotensin II (AngII)-mediated vascular responses as adults. Since optimal AngII levels during postnatal life are required for normal maturation of the kidney, this study was designed to investigate both short- and long-term effect of MatSep on (1) the renal vascular architecture and function, (2) the intrarenal renin-angiotensin system (RAS) components status, and (3) the genome-wide expression of genes in isolated renal vasculature. Renal tissue and plasma were collected from male rats at different postnatal days (P) for intrarenal RAS components mRNA and protein expression measurements at P2, 6, 10, 14, 21, and 90 and microCT analysis at P21 and 90. Although with similar body weight and renal mass trajectories from P2 to P90, MatSep rats displayed decreased renal filtration capacity at P90, while increased microvascular density at both P21 and P90 (p < 0.05). MatSep increased renal expression of renin, and angiotensin type 1 (AT1) and type 2 (AT2) receptors (p < 0.05), but reduced ACE2 mRNA expression and activity from P2-14 compared to controls. However, intrarenal levels of AngII peptide were reduced (p < 0.05) possible due to the increased degradation to AngIII by aminopeptidase A. In isolated renal vasculature from neonates, Enriched Biological Pathways functional clusters (EBPfc) from genes changed by MatSep reported to modulate extracellular structure organization, inflammation, and pro-angiogenic transcription factors. Our data suggest that male neonates exposed to MatSep could display permanent changes in the renal microvascular architecture in response to intrarenal RAS imbalance in the context of the atypical upregulation of angiogenic factors.

Corrigendum: Intrarenal Renin Angiotensin System Imbalance During Postnatal Life Is Associated With Increased Microvascular Density in the Mature Kidney.

[This corrects the article DOI: 10.3389/fphys.2020.01046.].

Role of Alström syndrome 1 in the regulation of blood pressure and renal function.

Elevated blood pressure (BP) and renal dysfunction are complex traits representing major global health problems. Single nucleotide polymorphisms identified by genome-wide association studies have identified the Alström syndrome 1 (ALMS1) gene locus to render susceptibility for renal dysfunction, hypertension, and chronic kidney disease (CKD). Mutations in the ALMS1 gene in humans causes Alström syndrome, characterized by progressive metabolic alterations including hypertension and CKD. Despite compelling genetic evidence, the underlying biological mechanism by which mutations in the ALMS1 gene lead to the above-mentioned pathophysiology is not understood. We modeled this effect in a KO rat model and showed that ALMS1 genetic deletion leads to hypertension. We demonstrate that the link between ALMS1 and hypertension involves the activation of the renal Na+/K+/2Cl- cotransporter NKCC2, mediated by regulation of its endocytosis. Our findings establish a link between the genetic susceptibility to hypertension, CKD, and the expression of ALMS1 through its role in a salt-reabsorbing tubular segment of the kidney. These data point to ALMS1 as a potentially novel gene involved in BP and renal function regulation.

La prevención en salud: posibilidad y realidad / The prevention in health: possibility and reality

INTRODUCCIÓN: Estudios previos evidencian que la prevención de enfermedades aun no está a la altura de las expectativas, sobre todo en lo referente a las acciones de orientación psicológica desarrolladas por profesionales de la salud. OBJETIVO: Reflexionar sobre la necesidad de perfeccionar el quehacer preventivo de los profesionales de la salud. MÉTODOS: Análisis y síntesis de la bibliografía consultada a la luz de investigaciones previas sobre el tema. CONCLUSIONES: Existe una actitud favorable hacia la prevención de enfermedades en los profesionales de la salud, pero requieren de una mayor y mejor preparación en los aportes de las ciencias sociales a las ciencias médicas y de la salud. RECOMENDACIONES: Redefinir el concepto de prevención de enfermedades a la luz de los conocimientos acumulados y las experiencias desarrolladas en las ciencias sociales.

INTRODUCTION: Prior studies demonstrate that disease prevention yet it is not to be worthy of the expectancies, mainly concerning actions of psychological guidances developed by health professionals. OBJECTIVE: To think about the necessity of perfecting the preventive chore of the health professionals. METHODS: To reflect on the need of improve the preventive tasks of health professionals. CONCLUSIONS: In health professionals there is a favorable attitude to diseases prevention, but it is necessary a greater and better training in the social sciences contributions to medical and health sciences. RECOMMENDATIONS: To redefine the concept of prevention of illnesses in the light of the accumulated knowledge and the experiences developed in the Social Sciences.

PGE2-induced hypertrophy of cardiac myocytes involves EP4 receptor-dependent activation of p42/44 MAPK and EGFR transactivation.

Upon induction of cyclooxygenase-2 (COX-2), neonatal ventricular myocytes (VMs) mainly synthesize prostaglandin E2 (PGE2). The biological effects of PGE2 are mediated through four different G protein-coupled receptor (GPCR) subtypes (EP(1-4)). We have previously shown that PGE2 stimulates cAMP production and induces hypertrophy of VMs. Because the EP4 receptor is coupled to adenylate cyclase and increases in cAMP, we hypothesized that PGE2 induces hypertrophic growth of cardiac myocytes through a signaling cascade that involves EP4-cAMP and activation of protein kinase A (PKA). To test this, we used primary cultures of VMs and measured [3H]leucine incorporation into total protein. An EP4 antagonist was able to partially block PGE2 induction of protein synthesis and prevent PGE2-dependent increases in cell surface area and activity of the atrial natriuretic factor promoter, which are two other indicators of hypertrophic growth. Surprisingly, a PKA inhibitor had no effect. In other cell types, G protein-coupled receptor activation has been shown to transactivate the epidermal growth factor receptor (EGFR) and result in p42/44 mitogen-activated protein kinase (MAPK) activation and cell growth. Immunoprecipitation of myocyte lysates demonstrated that the EGFR was rapidly phosphorylated by PGE2 in VMs, and the EP4 antagonist blocked this. In addition, the selective EGFR inhibitor AG-1478 completely blocked PGE2-induced protein synthesis. We also found that PGE2 rapidly phosphorylated p42/44 MAPK, which was inhibited by the EP4 antagonist and by AG-1478. Finally, the p42/44 MAPK inhibitor PD-98053 (25 micromol/l) blocked PGE2-induced protein synthesis. Altogether, we believe these are the first data to suggest that PGE2 induces protein synthesis in cardiac myocytes in part via activation of the EP4 receptor and subsequent activation of p42/44 MAPK. Activation of p42/44 MAPK is independent of the common cAMP-PKA pathway and involves EP4-dependent transactivation of EGFR.

Regulation of the membrane-localized prostaglandin E synthases mPGES-1 and mPGES-2 in cardiac myocytes and fibroblasts.

The proinflammatory mediator cyclooxygenase (COX)-2 and its product PGE(2) are induced in the ischemic heart, contributing to inflammatory cell infiltration, fibroblast proliferation, and cardiac hypertrophy. PGE(2) synthesis coupled to COX-2 involves two membrane-localized PGE synthases, mPGES-1 and mPGES-2; however, it is not clear how these synthases are regulated in cardiac myocytes and fibroblasts. To study this, we used primary cultures of neonatal ventricular myocytes (VM) and fibroblasts (VF) treated with IL-1beta for 24 h. To test for involvement of MAPKs in IL-1beta regulation of mPGES-1 and-2, cells were pretreated with the pharmacological inhibitors of p42/44 MAPK, p38 MAPK, and c-Jun kinase (JNK). mRNA was analyzed by RT-PCR. Protein was analyzed by densitometry of Western blots. mPGES-1 was undetectable in untreated VF but induced by IL-1beta; inhibition of either p42/44 MAPK or JNK, but not p38 MAPK, was almost completely inhibitory. In VM, inhibition of the three MAPKs reduced IL-1beta-stimulated mPGES-1 protein by 70-90%. mPGES-2 was constitutively synthesized in both VM and VF and was not regulated by IL-1beta or MAPKs. Confocal microscopy revealed colocalization of both mPGES-1 and mPGES-2 with COX-2 in the perinuclear area of both VF and VM. Finally, PGE(2) production was higher in VM than VF. Our data show that 1) mPGES-1 is induced in both VF and VM, 2) regulation of mPGES-1 by MAPK family members is different in the two cell types, 3) mPGES-2 is constitutively synthesized in both VM and VF and is not regulated, and 4) mPGES-1 and mPGES-2 are colocalized with COX-2 in both cells. Thus differences in activity of mPGES-1 and COX-2 or coupling of COX-2 with mPGES-1 may contribute to differences in PGE(2) production by myocytes and fibroblasts.

Representación social de la prevención de enfermedades en la atención primaria de salud / Social consideration related to diseases prevention in health primary care

INTRODUCCIÓN: el plan del Médico de Familia está instaurado hace más de 20 años para prevenir enfermedades y promover salud; sin embargo, los resultados no se corresponden aún con lo esperado. La forma en que los profesionales de la Atención Primaria de la Salud se representan y practican la prevención pudiera condicionar tal problema. OBJETIVO: explorar la relación de las representaciones sociales del profesional de la salud en la Atención Primaria de la Salud con sus prácticas preventivas cotidianas. MÉTODOS: cualitativos, aplicando las técnicas de entrevista, observación y análisis de contenido a la Revista Cubana de Medicina General Integral. RESULTADOS: los profesionales de la Atención Primaria de la Salud se representan la prevención de enfermedades esencialmente como la ejecución de acciones orientadas por programas e informar a la población sobre las pautas de conducta a seguir. Aunque se manifestó una actitud favorable hacia la prevención en sí, se quejan de sobrecarga laboral y las condiciones de trabajo en este nivel de atención. CONCLUSIONES: las representaciones de la prevención de enfermedades y las prácticas preventivas en Atención Primaria de la Salud son complementarias, puesto que la práctica preventiva en este nivel de atención se caracteriza por realizar lo exigido por los programas, sobre todo, si son priorizados, así como por informar sobre las pautas de conductas preventivas...

INTRODUCTION: family Physician program was established twenty years ago to prevent diseases and to promote the health; however, results are not as expected. How the Health Primary Care professionals consider and practice the prevention could fit such problem. AIM: to explore the relation of social consideration of health professional in Health Primary Care with their daily preventive practices. METHODS: qualitative types applying the interview, observation, and content analysis techniques to Cuban Journal of General Integral Medicine. RESULTS: health primary care professionals consider the disease prevention essentially as the execution of actions directed by programs and the information to population on behavior guidelines to be followed. Although there was a favorable attitude toward the prevention per se, there are complaints of work overload and the work condition at this care level. CONCLUSIONS: considerations of disease prevention and the preventive practices in Health Primary Care are complementary, since the preventive practice at this care level is characterized by that demanded by programs, mainly, if they are priority, as well as to inform on preventive behavior guidelines...

Trophic effects of the cyclooxygenase-2 product prostaglandin E(2) in cardiac myocytes.

Interleukin-1beta (IL-1beta), a proinflammatory cytokine, induces cyclooxygenase-2 (COX-2) in cultured neonatal ventricular myocytes (NVMs), resulting in the preferential production of prostaglandin E(2) (PGE(2)). To explain the preferential PGE(2) release by myocytes, we studied whether its specific synthase, PGE(2) synthase (PGES), is also induced by IL-1beta. Because COX-2 has been extensively associated with cell growth, we questioned whether PGE(2) plays a role in cardiac cell growth. IL-1beta--treated myocytes showed induction of PGES protein and mRNA by Western blot and reverse transcription--polymerase chain reaction, respectively. Immunofluorescence studies revealed perinuclear localization of COX-2 and PGES in IL-1beta--treated myocytes. Exogenous PGE(2) increased protein synthesis in NVMs, as indicated by a 1.6-fold increase in [(3)H]leucine incorporation, comparable to the known hypertrophic factor phenylephrine (1.6-fold). Because PGE(2) exerts different effects through 4 receptor subtypes (EP(1), EP(2), EP(3), and EP(4)), we investigated whether these receptors are functional in myocytes. Treatment of NVMs with the selective EP(1)/EP(3) agonist sulprostone significantly increased protein synthesis (1.7-fold), whereas the EP(1)/EP(2) antagonist AH6809 blocked this effect by 43%. In contrast, AH6809 had no effect on PGE(2)-induced protein synthesis. Regarding second messengers, sulprostone had no effect on cAMP, whereas PGE(2) increased it. We concluded that (1) PGE(2) production requires the induction of its specific synthase; (2) in myocytes, the inducible enzymes COX-2 and PGES are perinuclear; and (3) PGE(2) and sulprostone induce cardiac myocyte growth but seem to activate a different subset of EP receptors.

PPARgamma inhibition of cyclooxygenase-2, PGE2 synthase, and inducible nitric oxide synthase in cardiac myocytes.

Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors belonging to the nuclear receptor superfamily. They regulate lipid metabolism, glucose homeostasis, cell proliferation, and differentiation and modulate inflammatory responses. We examined whether PPARgamma is functional in cultured neonatal ventricular myocytes and studied its role in inflammation. Western blots revealed PPARgamma in myocytes. When myocytes were transfected with a PPAR response element reporter plasmid (PPRE-TK-luciferase), the PPARgamma activator 15-deoxy-Delta12,14-prostaglandin J2 (15dPGJ2) increased promoter activity, whereas cotransfection of a dominant negative PPARgamma inhibited it. To determine the role of 15dPGJ2 in expression of proinflammatory genes, we tested its effect on interleukin-1beta induction of cyclooxygenase-2 (COX-2). 15dPGJ2 decreased interleukin-1beta stimulation of COX-2 by 40% and PGE2 production by 73%. We next questioned whether 15dPGJ2 was modulating the expression of inducible prostaglandin E2 synthase (PGES) and found that it completely blocked interleukin-1beta induction of PGES. Use of a second PPARgamma agonist, troglitazone, and the selective PPARgamma antagonist GW9662 demonstrated that the effects seen were PPARgamma-dependent. In addition, we found that 15dPGJ2 blocked interleukin-1beta stimulation of inducible nitric oxide synthase (iNOS). We concluded that 15dPGJ2 may play an anti-inflammatory role in a PPARgamma-dependent manner, decreasing COX-2, PGES, and PGE2 production, as well as iNOS expression.

Regulation of the human brain natriuretic peptide gene by GATA-4.

Brain natriuretic peptide (BNP) is a cardiac hormone constitutively expressed in the adult heart. We previously showed that the human BNP (hBNP) proximal promoter region from -127 to -40 confers myocyte-specific expression. The proximal hBNP promoter contains several putative cis elements. Here we tested whether the proximal GATA element plays a role in basal and inducible regulation of the hBNP promoter. The hBNP promoter was coupled to a luciferase reporter gene (1818hBNPLuc) and transferred into neonatal ventricular myocytes (NVM), and luciferase activity was measured as an index of hBNP promoter activity. Mutation of the putative GATA element at -85 of the hBNP promoter [1818(mGATA)hBNPLuc] reduced activity by 97%. To study transactivation of the hBNP promoter, we co-transfected 1818hBNPLuc with the GATA-4 expression vector. GATA-4 activated 1818hBNPLuc, and this effect was eliminated by mutation of the proximal GATA element. Electrophoretic mobility shift assay showed that an oligonucleotide containing the hBNP GATA motif bound to cardiomyocyte nuclear protein, which was competed for by a consensus GATA oligonucleotide but not a mutated hBNP GATA element. The beta-adrenergic agonist isoproterenol and its second messenger cAMP stimulated hBNP promoter activity and binding of nuclear protein to the proximal GATA element. Thus the GATA element in the proximal hBNP promoter is involved in both basal and inducible transcriptional regulation in cardiac myocytes.

Inhibition of cyclooxygenase-2 improves cardiac function after myocardial infarction in the mouse.

Cyclooxygenase (COX)-2 is expressed in the heart in animal models of ischemic injury. Recent studies have suggested that COX-2 products are involved in inflammatory cell infiltration and fibroblast proliferation in the heart. Using a mouse model, we questioned whether 1). myocardial infarction (MI) in vivo induces COX-2 expression chronically, and 2). COX-2 inhibition reduces collagen content and improves cardiac function in mice with MI. MI was produced by ligation of the left anterior descending coronary artery in mice. Two days later, mice were treated with 3 mg/kg NS-398, a selective COX-2 inhibitor, or vehicle in drinking water for 2 wk. After the treatment period, mice were subjected to two-dimensional M-mode echocardiography to determine cardiac function. Hearts were then analyzed for determination of infarct size, interstitial collagen content, brain natriuretic peptide (BNP) mRNA, myocyte cross-sectional area, and immunohistochemical staining for transforming growth factor (TGF)-beta and COX-2. COX-2 protein, detected by immunohistochemistry, was increased in MI versus sham hearts. MI resulted in increased left ventricular systolic and diastolic dimension and decreased ejection fraction, fractional shortening, and cardiac output. NS-398 treatment partly reversed these detrimental changes. Myocyte cross-sectional area, a measure of hypertrophy, was decreased by 30% in the NS-398 versus vehicle group, but there was no effect on BNP mRNA. The interstitial collagen fraction increased from 5.4 +/- 0.4% in sham hearts to 10.4 +/- 0.9% in MI hearts and was decreased to 7.9 +/- 0.6% in NS-398-treated hearts. A second COX-2 inhibitor, rofecoxib (MK-0966), also decreased myocyte cross-sectional area and interstitial collagen fraction. TGF-beta, a key regulator of collagen synthesis, was increased in MI hearts. NS-398 treatment reduced TGF-beta immunostaining by 40%. NS-398 treatment had no effect on infarct size. These results suggest that COX-2 products contribute to cardiac remodeling and functional deficits after MI. Thus selected inhibition of COX-2 may be a therapeutic target for reducing myocyte damage after MI.

Lesiones no intencionales en adolescentes de 15 a 19 años / Unintentional injuries in adolescents aged 15-19

Las lesiones no intencionales constituyen importantes causas de mortalidad y morbilidad en Cuba y en el resto del mundo. Con el objetivo de caracterizar estas lesiones en los adolescentes, se realizó un estudio descriptivo en 1 397 estudiantes de Ciudad de La Habana, en el 2005. El cuestionario incluía variables de conocimiento, percepción, actitudes de riesgo y antecedentes de estas lesiones. Se calcularon porcentajes y sus intervalos de confianza al 95 por ciento. La mayoría aceptó que dichas lesiones se podían prevenir, pero solo 13,4 por ciento respondieron correctamente cómo hacerlo. Las vías de información más frecuentes fueron los padres (81,4 por ciento) y la televisión (56,1 por ciento). La mayoría de los adolescentes plantearon que las actitudes de riesgo eran adoptadas por diversión y desconocimiento del peligro; 35,4 por ciento tuvieron antecedentes de estas lesiones. Se concluyó que el conocimiento y la percepción de riesgo insuficientes, junto a las características psicológicas de la edad, favorecieron las prácticas de riesgo.

Unintentional injuries are important causes of mortality and morbidity in Cuba and in the rest of the world. To characterize these injuries in adolescents, a descriptive study was conducted in 1 397 students of Havana City in 2005. The questionnaire included variables of knowledge, perception, risk attitudes, and antecedents of these injuries. Percentages and their confidence intervals at 95 percent were calculated. Most of them accepted that such injuries could be prevented, but only 3,4 percent answered correctly how to do it. The most frequent ways of getting information were parents (81,4 percent) and television (56,1 percent). Most of the adolescents expressed that risk attitudes were adopted as entertainment and due to the lack of knowledge about danger. 35,4 percent had had these injuries. It was concluded that an inadequate knowledge and perception of risk, together with the psychological characteristics of age, favored the risk practices.