ABSTRACT
OBJECTIVES: Telomeres are a terminal "DNA cap" that prevent chromosomal fusion and degradation. However, aging is inherent to life, and so is the loss of terminal sequences. Telomerase is a specialized reverse transcriptase encoded by self-splicing introns that counteract chromosome erosion. Telomerase activity is observed during early embryonic development, but after the blastocyst stage, the expression of telomerase reduces. The consequences of either insufficient or unrestrained telomerase activity underscore the importance of ongoing studies aimed at elucidating the regulation of telomerase activity in humans. In the present study, we aimed to standardize a simplified telomerase repeat-amplification protocol (TRAP) assay to detect telomerase activity in unstimulated and PHA-stimulated mononuclear cells. METHODS and RESULTS: Our optimized qPCR-based can efficiently evaluate telomerase activity. Quantification of protein and DNA between unstimulated and PHA-stimulated peripheral blood mononuclear cells revealed cellular activation and cell-cycle entry. The assay also showed that relative telomerase activity is significantly different between these two conditions, supporting the applicability of the assay. Furthermore, our findings corroborated that telomerase activity decreases with age. CONCLUSIONS: Telomeres and telomerase are implicated in aging and development of chronic diseases and cancer; however, difficulty in accessing commercial kits to investigate these aspects is a critical constraint in health surveillance studies. Our optimized assay was successfully used to differentiate telomerase activity between unstimulated and stimulated cells, clearly showing the reactivation of telomerase upon cell activation. This assay is affordable, reproducible, and can be executed in resource-limited settings.
Subject(s)
Humans , Female , Pregnancy , Telomerase/genetics , Telomerase/metabolism , Neoplasms , Aging , Leukocytes, Mononuclear/metabolism , Chronic Disease , Cost-Benefit AnalysisABSTRACT
In humans, the right coronary artery is dominant. However, we did not find any citations in the literature concerning anatomical indicators of dominance among dogs. We used 30 hearts from mongrels of both sexes, fixed in 10 percent formalin. The branches of the coronary arteries were dissected with special attention to the levels that were considered to be reference points. In 96.7 percent, the circumflex branch of the left coronary artery reached or went beyond the crux cordis. The subsinuosus interventricular artery, ended before reaching the apex in 21 cases, at the apex in five cases and after the apex in four cases. The paraconal interventricular artery, ended before reaching the apex in two cases, at the apex in 11 cases and after the apex in 17 cases. The region of the heart apex was irrigated by branches of the left coronary artery, through the paraconal interventricular branch or through both of the interventricular branches. The mean length and number of ventricular branches of the left coronary artery were greater than those of the right coronary artery. The subsinuosus interventricular branch is a branch of the circumflex branch of the left coronary artery. In the hearts of dogs, the left coronary artery is dominant. The dominance pattern in dogs is different from the dominance pattern in human that is mentioned in the specialized literature.
En los corazones humanos la dominancia coronaria es derecha. Sin embargo, no encontramos referencias en la literatura sobre los indicadores de esta dominancia en perros. Utilizamos 30 corazones de perros de ambos sexos y raza mixta, fijados en formaldeído al 10 por ciento. Las ramas de las arterias coronarias fueron disecadas con especial atención a los niveles considerados como referencias. En 96,7 por ciento de los corazones, la rama circunfleja de la arteria coronaria izquierda excedió o llegó a la crux cordis. La arteria interventricular subsinuosa, terminó antes de llegar al ápice en 21 casos, en el ápice en 5 casos y después del ápice en 4 casos. La arteria interventricular paraconal, terminó antes de llegar al ápice en 2 casos, en el ápice en 11 casos y después del ápice en 17 casos. La región del ápice del corazón estaba irrigada por ramas de la arteria coronaria izquierda a través de la rama interventricular paraconal o a través de los dos ramas interventriculares. La longitud media y el número de ramas ventriculares de la arteria coronaria izquierda son más grandes que las ramas de la arteria coronaria derecha. La rama interventricular subsinuosa es una rama de la rama circunfleja de la arteria coronaria izquierda. En los corazones de los perros, sin embargo, la dominancia es izquierda. La norma de dominancia en los perros es diferente de la norma de dominancia en humanos encontrada en la literatura.