RESUMEN
There has been a global increase in the older population in recent decades and, as age advances, complex metabolic and epigenetic changes occur in the organism, and these may trigger some health complications commonly found among this population. Additionally, several changes occur in older people that can reduce the dietary intake or the process of nutrient absorption. In this way, tissues with high nutrient requirements are more affected. Hematopoiesis is the process of formation, development, and maturation of blood cells and is a process with a high turnover. This high demand makes the integrity of the hematopoietic process susceptible to various factors that impair physiological function, such as aging and micronutrient bioavailability. Among these micronutrients, Zinc is considered an important micronutrient, playing diverse roles across various tissues and cell types. Some of the alterations in hematopoiesis that appear as a consequence of aging and due to insufficient micronutrient intake are well described in the literature; however, not much is known about how zinc deficiency contributes towards the development of diseases seen in aging. Considering the importance of zinc to act on several biological processes, this narrative review discusses several studies related to the physiological requirements, deficiency, or excess of zinc, including studies in experimental models and humans, and aimed to shed light on the relationship between zinc and the regulation of hematopoietic tissue, exploring possible links between this mineral with common disorders that appear during aging.
RESUMEN
O envelhecimento é um processo fisiológico que traz consigo uma série de alterações no organismo que se estendem até o nível molecular. Diante disto, este é um processo complexo que afeta diversos tecidos, sendo um deles o hematopoético, local onde, através de interações da Célula Tronco Hematopoética (CTH) com o ambiente ao seu redor, incluindo a Célula Tronco Mesenquimal (CTM), ocorre a hematopoese. Embora já sejam descritas na literatura algumas alterações na medula óssea consequentes do envelhecimento, os mecanismos por trás de tais mudanças permanecem elusivas, principalmente no âmbito das interações celulares ocorrentes na medula óssea. Portanto, este trabalho buscou investigar como o envelhecimento afeta a regulação hematopoética no contexto de sua relação com as CTM medulares. Para esta pesquisa, foram utilizados camundongos machos isogênicos da linhagem C57BL/6, dividindoos em grupos conforme sua idade: jovens (3 5 meses) e idosos (18 19 meses). Foi realizada a caracterização do modelo através de aspectos físicos como consumo proteico, variação de peso, entre outros, seguido de avaliação bioquímica e hematológica. Adicionalmente, foram coletadas células medulares e, posteriormente, realizado o isolamento das CTMs. Para estudar a relação destas células com a hematopoese, foram realizados ensaios in vitro utilizando a linhagem celular leucêmica C1498 (TIB-49™, ATCC®) mantidas em contato com o sobrenadante das CTMs isoladas. Quanto aos parâmetros bioquímicos, os animais idosos apresentaram menores níveis de albumina, aspartato alanina transferase (ALT) e de triglicerídeos quando comparados aos animais jovens. Contrariamente, os animais idosos apresentaram um maior nível de colesterol. Na avaliação hematológica, foi constatado pelo hemograma que os animais idosos apresentaram valores comparáveis aos animais jovens, todavia, o mielograma mostrou menor celularidade geral, seguido de menor número de células da linhagem eritroide e maior número de precursores granulocíticos. Através da imunofenotipagem, foi revelado um maior número de CTHs e de precursores grânulosmonocíticos na medula de animais idosos quando comparado aos jovens, e uma menor frequência de progenitores linfoides. Na imunofenotipagem de sangue periférico de animais idosos houve uma redução no número de linfócitos B e de eritrócitos, e aumento na população de células natural killers. Na imunofenotipagem de CTMs, o marcador CD73 apresentou menor expressão nos animais idosos. Avaliando o secretoma destas células estromais, foram encontrados no sobrenadante de CTMs de animais idosos aumentos significativos nas concentrações de CXCL12 e SCF e redução de IL-11. No âmbito molecular, as CTMs de animais idosos apresentaram aumento na expressão de Akt1, Nos e Ppar-γ, e redução na expressão de Csf3 e Cdh2. Adicionalmente, quando comparado a ação das CTMs de animais idosos em relação as CTMs de animais jovens, observou-se que CTMs de animais idosos foram capazes de aumentar a expressão de Sox2, Pou5f1 e Nanog e diminuir a expressão de Cdkn1a de células da linhagem C1498. O sobrenadante de CTMs de animais idosos também resultou na maior proliferação e migração de células da linhagem C1498. Portanto, levando em consideração a importância das CTMs sobre a regulação do sistema hematopoético, pode-se concluir que, no envelhecimento, as CTMs criam um ambiente propício para a proliferação celular no qual a manutenção da pluripotência é estimulada, o que pode acarretar em uma desregulação do sítio hematopoético quando habitado por células malignas
Aging is a physiological process in which occurs a series of alterations in an organism that extend to a molecular level. It is a complex process that affects various tissues, one of them being the bone marrow, wherethrough the interactions of the hematopoietic stem cell (CTH) with its surrounding environment, including with the mesenchymal stem cell (CTM), hematopoiesis takes place. Although some aging-associated alterations in the bone marrow can be found described in the literature, the mechanisms behind said changes remain elusive, especially when regarding the cellular interactions present inside the bone marrow. Therefore, this research aimed to investigate how aging affects the regulation of hematopoiesis in the context of its interactions with bone marrow-derived CTMs. For this investigation, male isogenic C57BL/6 mice were used as animal models. These were separated in two groups according to their age: young (3 5 months) and aged (18 19 months). The animal models were characterized by their physical properties such as protein intake and weight variation, followed by biochemical and hematological evaluation. Bone marrow cells were obtained and identified through immunophenotyping, thus isolating different cell populations, including the CTMs. To study the relationship between these cells and hematopoiesis, in vitro assays were conducted utilizing the leukemic cell lineage C1498 (TIB-49™, ATCC®) maintained in contact with the supernatant of isolated CTMs. By their biochemical profile, aged mice showed lower levels of albumin, alanine-aspartate transferase (ALT) and triglycerides compared to the young group. In contrast, aged mice had a higher cholesterol level. Hematological evaluation by total blood count showed similar results between the two groups, however, the myelogram revealed that the aged animals had lower cellularity, with less frequent cells from the erythroid lineage, with an increase in granulocytic precursors. Through immunophenotyping, it was also revealed that aged mice have higher numbers of hematopoietic stem cells, while also being noted a reduced population of lymphoid progenitors. An increase in the granulomonocytic progenitors was also found. Immunophenotyping peripheral blood cells of aged mice revealed reduced numbers of B lymphocytes and erythrocytes, and an increased natural killer cell population. Additionally, the cell surface marker CD73 was found to be less expressed in aged mice CTMs. The secretome of these stromal cells obtained from aged mice showed higher levels of CXCL12 and SCF, and lower levels of IL-11when compared to the young counterparts. At a molecular level, CTMs obtained from aged mice expressed more Akt1, Nos and Ppar-γ, while the expression of Csf3 and Cdh2 was reduced. Additionally, when comparing the effects of aged mice CTMs with young mice CTMs, it was observed that the first expressed were capable of increasing the expression of Sox2, Pou5f1 and Nanog, while decreasing Cdkn1a expression in the C1498 cell lineage. The supernatant obtained from aged mice also favored the proliferation and cell migration of the C1498 cell line. Thus, considering the importance that CTMs have over the hematopoietic system, we can conclude that, in aging, CTMs create a special environment which favors cell proliferation and maintenance of pluripotency, which can result in a dysregulation of the hematopoietic tissue when malignant cells are present
Asunto(s)
Animales , Masculino , Ratones , Envejecimiento/metabolismo , Células Madre Mesenquimatosas/clasificación , Hematopoyesis/genética , Células Madre Hematopoyéticas/clasificación , Sistema Hematopoyético/anomalíasRESUMEN
Objetivo: Este estudo buscou analisar a presença de anemia, definida como a redução nos níveis de hemoglobina, e relacioná-la com a deficiência de ferritina sérica entre pacientes com idade igual ou superior a 15 anos, identificando possíveis casos de anemia ferropriva. Métodos: Foi realizada a coleta de resultados laboratoriais de pacientes que realizaram o exame de hemograma completo acompanhado da dosagem de ferritina no Laboratório de Análises Clínicas do CESUPA durante o período de agosto de 2018 a junho de 2019. Pacientes que realizaram ambos os exames e revelaram baixos níveis de hemoglobina foram inclusos, obtendo-se assim uma amostra de 177 pacientes anêmicos. Resultados: Nos pacientes incluídos no estudo, constatou-se que a faixa etária com maior prevalência de anemia foi a de pacientes com idade entre 61 a 70 anos de idade, representando 27,1% da amostra total. Classificando-se os tipos de anemia presente com base em seus índices hematimétricos, notou-se maior frequência daquelas com perfil de normocitose e normocromia (55,4%), seguida de microcitose e hipocromia (31,6%) e de macrocitose com normocromia (2,3%). Entre os pacientes com perfil de microcitose e hipocromia, 91,1% apresentaram anisocitose. Dos 177 pacientes anêmicos, apenas 19 (10,7%) apresentaram valores baixos de ferritina, enquanto que os pacientes com níveis normais de ferritina foram os mais frequentes (59,9%). Conclusão: O perfil hematimétrico compatível com quadros de anemia ferropriva foi o segundo mais frequente neste estudo, sendo o de normocitose e normocromia o mais frequente, assim corroborando com maior parte das faixas etárias identificadas.
Objective: This study aimed to analyze the presence of anemia, being evaluated by the reduced hemoglobin levels, and associate it with serum ferritin deficiency among patients at 15 years old or greater, identifying possible cases of iron-deficiency anemia. Methods: Exam results from patients who did the complete blood count exam and the dosage of ferritin levels at the Laboratory of Clinical Analyzes from CESUPA during the interval of august 2018 to june 2019 were collected. Patients who performed both tests and revealed low hemoglobin levels were included, creating a sample of 177 anemic patients. Results: In the patients included in this study, it was found that anemia was most prevalent among patients with an age within the range of 61 to 70 years old, representing 27,1% of the total sample. Classifying the types of anemia present by use of the hematimetric paramaters, it was noted that those with the profile of normocytic and normochromic were the most frequent (55,4%), followed by the profile of microcytic and hypocromic anemia patients with microcytosis and hypochromia, 91,1% also had the presence of anisocytosis. Of the 177 patients with anemia, only 19 (10,7%) showed low ferritin levels, while those with normal ferritin levels were the most frequent (59,9%). Conclusion: The hematimetric profile compatible with iron-deficiency anemia was the second most frequent in this study, while the profile of microcytosis and hypochromia was the most frequent one, thus corroborating with most of the identified age groups.