The use of adipose tissue-derived stem cells within a dermal substitute improves skin regeneration by increasing neoangiogenesis and collagen synthesis

BACKGROUND: Surgical treatment of injuries with loss of skin tissue has improved significantly with the advent of regenerative medicine and tissue bioengineering, and the use of stem cells and dermal substitutes. The success of tissue regeneration depends on optimal local vascularization and the successful integration of the artificial skin. The present study combines the use of autologous adipose-derived stem cells with a commercially available dermal substitute (Integra) for skin regeneration. METHODS: Adipose-derived stem cells were isolated from the inguinal region of eight Sprague-Dawley adult rats, seeded onto a piece of dermal substitute for 48 hours, and then implanted into the same rat, followed by comparison of the evolution with a contralateral implant without adipose-derived stem cells. After 1, 2, and 3 weeks of regeneration in vivo, implants were removed for histologic evaluation. RESULTS: Adipose-derived stem cells adhere properly to the dermal matrix, and autologous ti

G2 checkpoint-dependent DNA repair and its response to catalase in Down syndrome and control lymphocyte cultures

The amount of DNA lesions repaired in G2 and also G2 timing are controlled by the DNA damage-dependent checkpoint. Down syndrome (DS) lymphocytes showed twice as much constitutive DNA damage in G2 than control ones, when recording it as chromosomal aberrations in metaphase, after caffeine-induced checkpoint abrogation. During G2, DS lymphocytes repaired 1.5 times more DNA lesions than control ones. However the DS cells displayed a decreased threshold for checkpoint adaptation, as the spontaneous override of the G2 to mitosis transition block induced by the checkpoint took place in the DS cells when they had three times more DNA lesions than controls. Catalase addition to cultures scavenges hydrogen peroxide diffused from cells, resulting in subsequent intracellular depletion (Antunes and Cadenas, 2000). The intracellular H2O2 level seemed to regulate the G2 checkpoint. Thus, in controls, H2O2 depletion (induced by 3.2-50 μg/mL catalase) prevented its functioning: chromosomal damage in

Chromosomal Instability in Mouse Embryonic Fibroblasts Null for the Transcriptional Co-Repressor Ski

Artículo de publicación ISISki is a transcriptional regulator that has been considered an oncoprotein given its ability to induce oncogenic transformation in avian model systems. However, studies in mouse and in some human tumor cells have also indicated a tumor suppressor activity for this protein. We found that Ski-/- mouse embryo fibroblasts exhibit high levels of genome instability, namely aneuploidy, consistent with a tumor suppressor function for Ski. Time-lapse microscopy revealed lagging chromosomes and chromatin/chromosome bridges as the major cause of micronuclei (MN) formation and the subsequent aneuploidy. Although these cells arrested in mitosis after treatment with spindle disrupting drugs and exhibited a delayed metaphase/anaphase transition, spindle assembly checkpoint (SAC) was not sufficient to prevent chromosome missegregation, consistent with a weakened SAC. Our in vivo analysis also showed dynamic metaphase plate rearrangements with switches in polarity in cells arrested in metaphase. Importantly, after ectopic expression of Ski the cells that displayed this metaphase arrest died directly during metaphase or after aberrant cell division, relating SAC activation and mitotic cell death. This increased susceptibility to undergo mitosis-associated cell death reduced the number of MN-containing cells. The presented data support a new role for Ski in the mitotic process and in maintenance of genetic stability, providing insights into the mechanism of tumor suppression mediated by this protein.US Public Health Service, National Cancer Institute CA42573 T32-CA009176 Vicerrectoria de Investigacion y Desarrollo (VID) from Universidad de Chile 107/11-2 Fondo de Financiamiento de Centros de Excelencia en Investigacion (FONDAP) 1501000

Effect of vitamin E (DL α-tocopherol) on chromosomal damage in lymphocytes from patients with ataxia telangiectasia Efecto de la vitamina E (DL α-tocoferol) sobre el daño cromosómico en linfocitos de pacientes con ataxia telangiectasia

Background: In ataxia telangiectasia (A-T), the lack of a functional ATM kinase is associated with disturbances in the processing of DNA damage and a chronic oxidative stress. These disturbances may be responsible for an increment of chromosomal damage in A-T cells. Aim: To study the in vitro effect of vitamin E (DL-α-tocopherol) on the frequency of chromosomal damage of lymphocytes from patients with A-T. Patients and methods: Seven patients with A-T and age-sex matched controls were studied. Chromosomal damage in mitosis was evaluated in lymphocytes cultures both under basal conditions and when G 2 repair was prevented by 5 mM caffeine. Results: In cells from patients with A-T, vitamin E induced a 57.1 and 47.9% decrease in chromosomal damage under basal and inhibited G 2 repair conditions, respectively. However, there was a non significant improvement in their repair activity. Vitamin E effects on chromosomal damage was not significant in control subjects. Conclusions: Vitamin E re

TRPM4 enhances cell proliferation through up-regulation of the β-catenin signaling pathway

Altered expression of some members of the TRP ion channel superfamily has been associated with the development of pathologies like cancer. In particular, TRPM4 levels are reportedly elevated in diffuse large B-cell non-Hodgkin lymphoma, prostate, and cervical cancer. However, whether such changes in TRPM4 expression may be relevant to genesis or progression of cancer remains unknown. Here we show that reducing TRPM4 expression decreases proliferation of HeLa cells, a cervical cancer-derived cell line. In this cell line, constitutive TRPM4 silencing promoted GSK-3β-dependent degradation of β-catenin and reduced β-catenin/Tcf/Lef-dependent transcription. Conversely, overexpression of TRPM4 in T-REx 293 cells (a HEK293-derived cell line) increased cell proliferation and β-catenin levels. Our results identify TRPM4 as an important, unanticipated regulator of the β-catenin pathway, where aberrant signaling is frequently associated with cancer. © 2010 Wiley-Liss, Inc

Angiotensin receptor II is present in dopaminergic cell line of rat substantia nigra and it is down regulated by aminochrome

Angiotensin receptor II mRNA was found to be expressed in dopaminergic neuronal cell line RCSN3 of rat substantia nigra using RT-PCR reaction. Aminochrome (150 μM), a metabolite of the dopamine oxidative pathway, was found to down regulate the expression of angiotensin receptor mRNA in RCSN3 cells by 83% (p < 0.05)

Parity history determines a systemic inflammatory response to spread of ovarian cancer in naturally aged mice

Aging intersects with reproductive senescence in women by promoting a systemic low-grade chronic inflammation that predisposes women to several diseases including ovarian cancer (OC). OC risk at menopause is significantly modified by parity records during prior fertile life. To date, the combined effects of age and parity on the systemic inflammation markers that are particularly relevant to OC initiation and progression at menopause remain largely unknown. Herein, we profiled a panel of circulating cytokines in multiparous versus virgin C57BL/6 female mice at peri-estropausal age and investigated how cytokine levels were modulated by intraperitoneal tumor induction in a syngeneic immunocompetent OC mouse model. Serum FSH, LH and TSH levels increased with age in both groups while prolactin (PRL) was lower in multiparous respect to virgin mice, a finding previously observed in parous women. Serum CCL2, IL-10, IL-5, IL-4, TNF-alpha, IL1-beta and IL-12p70 levels increased with age irrespective of parity status, but were specifically reduced following OC tumor induction only in multiparous mice. Animals developed hemorrhagic ascites and tumor implants in the omental fat band and other intraperitoneal organs by 12 weeks after induction, with multiparous mice showing a significantly extended survival. We conclude that previous parity history counteracts aging-associated systemic inflammation possibly by reducing the immunosuppression that typically allows tumor spread. Results suggest a partial impairment of the M2 shift in tumor-associated macrophages as well as decreased stimulation of regulatory B-cells in aged mice. This long term, tumor-concurrent effect of parity on inflammation markers at menopause would be a contributing factor leading to decreased OC risk.Fondecyt grant, from the Ministry of Education, Chile 113029

Inhibition of the 3-Hydroxy-3-Methyl-Glutaryl-CoA Reductase Induces Orofacial Defects in Zebrafish

Background: Orofacial clefts (OFCs) are common birth defects, which include a range of disorders with a complex etiology affecting formation of craniofacial structures. Some forms of syndromic OFCs are produced by defects in the cholesterol pathway. The principal enzyme of the cholesterol pathway is the 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMGCR). Our aim is to study whether defects of HMGCR function would produce orofacial malformation similar to those found in disorders of cholesterol synthesis. Methods: We used zebrafish hmgcrb mutants and HMGCR inhibition assay using atorvastatin during early and late stages of orofacial morphogenesis in zebrafish. To describe craniofacial phenotypes, we stained cartilage and bone and performed in situ hybridization using known craniofacial markers. Also, we visualized neural crest cell migration in a transgenic fish. Results: Our results showed that mutants displayed loss of cartilage and diminished orofacial outgrowth, and in some cases palatal cleft. Late treatments with statin show a similar phenotype. Affected-siblings displayed a moderate phenotype, whereas early-treated embryos had a minor cleft. We found reduced expression of the downstream component of Sonic Hedgehog-signaling gli1 in ventral brain, oral ectoderm, and pharyngeal endoderm in mutants and in late atorvastatin-treated embryos. Conclusion: Our results suggest that HMGCR loss-of-function primarily affects postmigratory cranial neural crest cells through abnormal Sonic Hedgehog signaling, probably induced by reduction in metabolites of the cholesterol pathway. Malformation severity correlates with the grade of HMGCR inhibition, developmental stage of its disruption, and probably with availability of maternal lipids. Together, our results might help to understand the spectrum of orofacial phenotypes found in cholesterol synthesis disorder

TRPM4 channel is involved in regulating epithelial to mesenchymal transition, migration, and invasion of prostate cancer cell lines

© 2018 Wiley Periodicals, Inc. Transient Receptor Potential Melastatin 4 (TRPM4) is a Ca2+-activated and voltage-dependent monovalent cation channel, which depolarizes the plasma cell membrane, thereby modulating Ca2+ influx across Ca2+-permeable pathways. TRPM4 is involved in different physiological processes such as T cell activation and the migration of endothelial and certain immune cells. Overexpression of this channel has been reported in various types of tumors including prostate cancer. In this study, a significant overexpression of TRPM4 was found only in samples from cancer with a Gleason score higher than 7, which are more likely to spread. To evaluate whether TRPM4 overexpression was related to the spreading capability of tumors, TRPM4 was knockdown by using shRNAs in PC3 prostate cancer cells and the effect on cellular migration and invasion was analyzed. PC3 cells with reduced levels of TRPM4 (shTRPM4) display a decrease of the migration/invasion capability. A reduction