RESUMEN
Describing temporal relations between perceptual and emotional elements underlying responses to infant crying is important to our understanding of sensitive parenting. Prior research on adults' responses to infant crying has mostly relied on playback and snapshot approaches to obtaining recall of responses following exposure to relatively short cry stimuli. This study documented continuous temporal relations in the perception of the infant's distress and affect-related processes in response to a 4-min-long bout of crying. Three visual-analog slider scales were used to collect 90 participants' real-time responses on perceived aversiveness of the cry, empathic concern for the infant, and personal distress elicited by the cry, respectively. The results highlighted a moderating role of empathic concern at certain second in the relation between personal distress and empathic concern at the following second. In addition, personal distress moderated the relation between concurrent perceived aversiveness and empathic concern. The findings carry potentially important implications for cognitive and emotional regulation in adaptive parenting.
Asunto(s)
Cuidadores/psicología , Llanto/psicología , Empatía , Responsabilidad Parental/psicología , Adulto , Femenino , Humanos , Lactante , Conducta del Lactante/fisiología , Masculino , Conducta Materna/psicología , Percepción , Adulto JovenRESUMEN
Hyperplasia is a major contributor to the increase in adipose tissue mass that is characteristic of obesity. However, the identity and characteristics of cells that can be committed into adipocyte lineage remain unclear. Stem cell antigen 1 (Sca-1) has been used recently as a candidate marker in the search for tissue-resident stem cells. In our quest for biomarkers of cells that can become adipocytes, we analyzed ear mesenchymal stem cells (EMSC), which can differentiate into adipocytes, osteocytes, chondrocytes, and myocytes. Our previous studies have demonstrated that EMSC abundantly expressed Sca-1. In the present study, we have analyzed the expression of adipogenic transcription factors and adipocyte-specific genes in Sca-1-enriched and Sca-1-depleted EMSC fractions. Sca-1-enriched EMSC accumulated more lipid droplets during adipogenic differentiation than Sca-1-depleted. Similarly, EMSC isolated from Sca-1(-/-) mice displayed reduced lipid accumulation relative to EMSC from wild-type controls (p < .01). Comparative analysis of the adipogenic differentiation process between Sca-1-enriched and Sca-1-depleted populations of EMSC revealed substantial differences in the gene expression. Preadipocyte factor 1, CCAAT enhancer-binding protein (C/EBP) beta, C/EBPalpha, peroxisome proliferator-activated receptor gamma2, lipoprotein lipase, and adipocyte fatty acid binding protein were expressed at significantly higher levels in the Sca-1-enriched EMSC fraction. However, the most striking observation was that leptin was detected only in the conditioned medium of Sca-1-enriched EMSC. In addition, we performed loss-of-function (Sca-1 morpholino oligonucleotide) experiments. The data presented here suggest that Sca-1 is a biomarker for EMSC with the potential to become functionally active adipocytes. Disclosure of potential conflicts of interest is found at the end of this article.
Asunto(s)
Adipogénesis , Antígenos Ly/metabolismo , Oído , Proteínas de la Membrana/metabolismo , Células Madre Mesenquimatosas/citología , Adipocitos/citología , Adipocitos/metabolismo , Adipogénesis/efectos de los fármacos , Animales , Antígenos Ly/genética , Regulación hacia Abajo/efectos de los fármacos , Técnicas de Silenciamiento del Gen , Proteínas de la Membrana/genética , Células Madre Mesenquimatosas/efectos de los fármacos , Células Madre Mesenquimatosas/metabolismo , Ratones , Ratones Endogámicos C57BL , ARN sin Sentido/farmacología , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
We have previously shown that cells isolated from the outer ears of adult mice are a source of mesenchymal stem cells that can be induced to differentiate into adipo-, osteo-, and chondrocytes. In this study, we demonstrate that ear mesenchymal stem cells (EMSC) express stromal cell-associated markers (CD44, CD73) and stem cell marker Sca-1 and can be differentiated into spontaneously contracting muscle cells. Treatment of cells with epidermal growth factor (EGF) change their morphology from fibroblast shapes into stick-like structures that show repeated spontaneous contractions. Under conditions that promote myogenic differentiation, EMSC expressed mRNA for myoD and ventricular specific myosin light chain (MLC-2v) and protein for connexin 43, sarcomeric alpha-actinin, myocyte enhancer factor 2c (MEF2c), myosin heavy chain (MyHC), myogenin, and sarco-endoplasmic reticulum Ca(2+)ATPase (SERCA) 1. However, the cells were negative for Nkx2.5, GATA4, and ANP. Intracellular Ca(2+) transients in spontaneously beating EMSC, visualized by Fluo-3AM, showed a frequency of Ca(2+) oscillations ranging over 28-59/min (mean 41.17 +/- SEM 1.54). We also demonstrated that small pieces of ear tissues (ear punches) collected from live mice provide sufficient numbers of EMSC to isolate, culture and differentiate them into myocytes. Due to the ease of acquiring an expanding repertoire of differentiated EMSC cell types by a noninvasive surgical procedure, we conclude that the ear may prove to be a potential source of autologous cells for regenerative medicine, as supported by the fact that ears are one of the best sources of cells for somatic cell nuclear transfer (SCNT).
Asunto(s)
Oído Externo/citología , Células Madre Mesenquimatosas/citología , Células Musculares/citología , Animales , Antígenos CD/metabolismo , Biomarcadores/metabolismo , Calcio/metabolismo , Diferenciación Celular , Células Cultivadas , Expresión Génica , Inmunofenotipificación , Células Madre Mesenquimatosas/metabolismo , Ratones , Ratones Endogámicos C57BL , Células Musculares/metabolismo , Células Musculares/fisiología , Contracción Muscular , Proteínas Musculares/genética , Proteínas Musculares/metabolismoRESUMEN
Cutaneous wound healing is associated with migratory and remodeling events that require the action of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs). Differences in their expressions were observed during scar-forming and scar-free skin wound healing. We previously found that athymic nude mice are exceptional among mature mammals in their ability to heal injured skin scarlessly. The present study was undertaken to determine whether the modulation of MMP-2 and MMP-9 expression during scarless healing in nude mice was different from scar-forming animals. Full thickness skin wounds were made into the back of nude, wild-type controls (C57BL/6J), immunodeficient SCID and Rag, thymectomized neonates and adults, and cyclosporin A treated mice. Post-injured skin tissues were harvested at Day 7 and 24 after injury. Quantitative RT-PCR, Western blot, gelatin zymography and immunohistochemical assays were performed. Our results show that MMP-2 protein was high but similarly expressed in all post-injured animals on Day 7 after injury. Late phase (Day 24) of wound repair was characterized by a decrease in mRNA and protein expression and a decrease in gelatinolytic activity of MMP-2 in all post-injured samples. On the contrary, high (p < 0.001) levels of mRNA expression, prominent pro-and active forms of MMP-9 and cells immunopositive for MMP-9 were present exclusively in the post-injured tissues from nude mice on Day 24 after wounding. This data suggest that MMP-9 expression in the remodeling phase of wound healing in nude mice could be a major component of their ability for scar-free healing.
Asunto(s)
Cicatriz , Regulación de la Expresión Génica , Metaloproteinasa 9 de la Matriz/biosíntesis , Regulación hacia Arriba , Cicatrización de Heridas , Animales , Inmunohistoquímica , Metaloproteinasa 2 de la Matriz/biosíntesis , Ratones , Ratones Endogámicos C57BL , Ratones Desnudos , Regeneración , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Piel/metabolismoRESUMEN
Scarring, the end result of the wound healing process in adult mammals, is a problem of significant clinical importance. We observed that athymic nude-nu mice, similar to mammalian fetuses, are able to restore the structure and integrity of injured skin through a process resembling regeneration, where scar formation is absent. Among the postinjured skin tissues collected from athymic nude-nu, wild-type controls (C57BL/6J), severe-combined immunodeficient, Rag (lack of B and T cells), athymic (thymectomized neonates and adult C57BL/6J), and mice treated with an immunosuppressant (cyclosporin A), only athymic nude-nu mice showed: a lack of scar by histological examination (hematoxylin & eosin and Masson's trichrome staining), low levels of collagen (as determined by hydroxyproline content), high levels of hyaluronic acid, a statistically significant increase in elastic modulus for injured samples over unwounded (biomechanical testing) and low levels of the pro-scarring cytokines platelet-derived growth factor-B and transforming growth factor beta1. Additionally, immunohistochemical and Western blot analyses of postinjured tissues as well as flow cytometry analysis of blood samples showed the presence of CD8-positive cells in all studied animals except nude-nu mice. We conclude that scarless skin healing in athymic nude-nu mice provides a new model to study the influence of the immune system on tissue regeneration.