RESUMO
Genes encoding Toll-like receptors (TLRs) are expressed by germ cells in the mouse testis. Nevertheless, the expression of TLRs by germ cells has only been demonstrated for TLR-3, TLR-9, and TLR-11. Furthermore, the expression of each TLR in relation to the stage of spermatogenesis remains uncertain. We aimed in the present study to examine the expression pattern of all TLRs in germ cells throughout the cycle of seminiferous epithelium in the adult mouse testis. Immunohistochemistry was used to evaluate the expression of TLRs. Results of the present study reveal the expression of TLRs by specific populations of germ cells. Expression of TLRs, except for TLR-7, at endosomal compartments, acrosomes, and/or residual bodies was another interesting and novel finding of the present study. We further demonstrate that the expression of TLR-1, -2, -3, -4, -5, -7, -11, -12, and -13 follows a distinct spatiotemporal pattern throughout the cycle of seminiferous epithelium. While TLR-1, -3, -5, -11, and -12 are expressed in all stages, TLR-4 is expressed only in early and middle stages of spermatogenic cycle. On the other hand, TLR-2, -7, and -13 are expressed only in early stage of spermatogenic cycle. Evidence demonstrating the expression of TLRs in a stage specific manner throughout spermatogenesis strengthen the hypothesis that the expression of various TLRs by germ cells is a developmentally regulated process. However, if TLRs play a role in the regulation of proliferation, growth, maturation, and differentiation of germ cells throughout the cycle of the seminiferous epithelium warrants further investigations.
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Mouse fetuses generated by in vitro embryo culture and embryo transfer exhibit impaired lung development, altered composition of pulmonary epithelial cells associated with downregulation of several genes involved in lung development and toll-like receptor (TLR) signaling pathway. The aims of the present study were to determine the expression of all TLRs and to examine if the expression of TLRs, along with genes involved in TLR signaling pathway, is altered in the lung tissue of mouse fetuses generated through embryo culture and embryo transfer. Two experimental (EGs) and one control (CG) group were included in the study. Embryos cultured at 5% CO2-95% air for 95 h or less than 24 h were transferred to pseudo-pregnant females to obtain fetuses comprising EGin vitro (n = 18) and EGin vivo (n = 18), respectively. Fetuses obtained from naturally ovulating females on day 18 of pregnancy served as the CG (n = 18). Western blot and immunohistochemistry were used to determine the expression of TLR proteins. The expression of transcripts encoding TLRs, and the genes involved in TLR signaling pathway (Lbp, Pik3r1, Pik3cb, Nfkbia, and Fos), was determined using qRT-PCR. While all TLRs were expressed by cells lining the bronchial/bronchiolar epithelium of lung tissues in all groups, some of the TLRs were expressed in a specific pattern. When compared to CG, the expression of transcripts encoding TLR-2, -3, -4, -5, -7, -8, -9, -12, -13, Lbp, Pik3r1, Pik3cb, Nfkbia, and Fos was significantly downregulated in both EGs. It appears that stress imposed on embryos at preimplantation stages of development is associated with downregulation of TLRs, along with some of the genes involved in TLR signaling pathway, in the lung tissue during the perinatal period. It remains to be determined if downregulation of TLRs, along with the genes involved in TLR signaling pathway, has any functional consequences in the adult lung tissue.
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In vitro culture under atmospheric oxygen puts embryos under oxidative stress and impairs preimplantation development. However, to what extent this process alters the redox balance in the perinatal period remains largely unknown. The aim of the present study was to examine if the redox balance is altered in the lung tissue of fetuses generated through transfer of mouse embryos exposed to atmospheric oxygen at different stages of development and to determine if this has any effect on lung morphogenesis and gene expression. Two experimental groups (EGs) were generated by transferring in vitro- and in vivo-derived blastocysts to pseudo-pregnant females. In vivo-developed fetuses served as control. Enzymatic/nonenzymatic antioxidants, malondialdehyde (MDA) levels, total antioxidant capacity, stage of lung development and gene expression were evaluated on day 18 of pregnancy. Weight of fetuses was significantly less in both experimental cohorts (ANOVA, P < 0.001 versus control), associated with delayed lung development, higher amounts of MDA (ANOVA, P < 0.001 versus control) and altered expression of several genes in oxidative stress/damage pathways. Evidence gathered in the present study indicates that pre-implantation stress caused by culture under atmospheric oxygen, even for a short period of time, leads to fetal growth restriction, impaired lung development and redox balance along with dysregulation of several genes in oxidative stress response. Absence of an EG in which in vitro embryo culture was performed at 5% oxygen and the use of genetically heterogeneous F2 fetuses are the limitations of the study. In any case, the long-term impact of such dramatic changes in the developmental programming of resulting fetuses warrants further investigations.
Assuntos
Blastocisto/metabolismo , Desenvolvimento Embrionário/fisiologia , Retardo do Crescimento Fetal/etiologia , Pulmão/crescimento & desenvolvimento , Oxigênio/metabolismo , Animais , Técnicas de Cultura Embrionária , Feminino , Fertilização in vitro/efeitos adversos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Organogênese/fisiologia , Oxirredução , Estresse Oxidativo/fisiologia , GravidezRESUMO
The aim of the present study was to investigate changes occurring in the number of beta cells, as well as the expressions of Ngn-3, nestin and Pdx-1 of pancreatic progenitor cells in the pancreas of experimentally-induced adult diabetic rats and to determine the effect of orally-administered lycopene on these changes. Following the administration of 50 mg/kg streptozotocin to rats, four groups of animals were established: control + corn oil, control + lycopene, diabetic + corn oil and diabetic + lycopene. The animals in the control + lycopene and diabetic + lycopene groups received 4 mg/kg lycopene for a period of four weeks. The expressions of insulin, Ngn-3, nestin, and Pdx-1 were determined through immunohistochemistry in sections taken from pancreas tissue samples at the end of the experiment. The number of insulin-positive cells was found to be significantly low in the diabetic groups compared to the control groups. In addition, the presence of Ngn-3 and nestin-positive cells within the exocrine pancreas surrounding the islands was noted in the diabetic groups. Lycopene, in general did not have any effect in any of the parameters analyzed in the present study. It is suggested that these cells would function as stem cells to replace the lost beta-cell population. It is also suggested that it is possible to demonstrate the antioxidant effects of lycopene in the pancreas of diabetic rats by increasing the dose and duration of lycopene administration. Anat Rec, 300:2200-2207, 2017. © 2017 Wiley Periodicals, Inc.
Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/biossíntese , Carotenoides/farmacologia , Diabetes Mellitus Experimental/metabolismo , Proteínas de Homeodomínio/biossíntese , Proteínas do Tecido Nervoso/biossíntese , Nestina/biossíntese , Pâncreas/metabolismo , Transativadores/biossíntese , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Carotenoides/uso terapêutico , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/genética , Feminino , Proteínas de Homeodomínio/genética , Licopeno , Proteínas do Tecido Nervoso/genética , Nestina/genética , Pâncreas/efeitos dos fármacos , Ratos , Ratos Wistar , Transativadores/genéticaRESUMO
This study aimed to investigate the changes occurring in estrogen receptor (ER) α-positive cells, proliferating cells, apoptotic cells and malondialdehyde (MDA) expression in the pancreas of experimentally induced adult diabetic rats and to determine the effect of orally administered lycopene on these changes. Experimental diabetes was induced using a single dose of 50 mg/kg streptozotocin (STZ). Following the administration of STZ, four groups of animals were established: Control + corn oil, control + lycopene, diabetic + corn oil and diabetic + lycopene. The expressions of ER α, Ki-67, and MDA were determined through immunohistochemistry in sections taken from pancreas tissue samples at the end of the experiment. Apoptotic cells were determined through the TUNEL method. In the diabetic groups, the densities of ER α expression in islets and ER α-positive cells in exocrine parts increased. Whereas the number of proliferating Ki-67 positive cells was higher in the diabetic groups, no significant difference was observed in terms of apoptotic cell number between the control and diabetic groups. Lycopene in general did not have any effect on any of the parameters analyzed in the study. The presence of ER α-positive cells around the islets was demonstrated for the first time in diabetic groups. Based on these observations, demonstrating the antioxidant effects of lycopene in the pancreas of diabetic rats may be possible by increasing the dose and/or the duration of lycopene. Anat Rec, 2017. © 2017 Wiley Periodicals, Inc. Anat Rec, 300:2000-2007, 2017. © 2017 Wiley Periodicals, Inc.
Assuntos
Antioxidantes/farmacologia , Carotenoides/farmacologia , Diabetes Mellitus Experimental/patologia , Receptor alfa de Estrogênio/metabolismo , Células Secretoras de Insulina/patologia , Animais , Antioxidantes/uso terapêutico , Apoptose/efeitos dos fármacos , Glicemia/metabolismo , Carotenoides/uso terapêutico , Proliferação de Células/efeitos dos fármacos , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/metabolismo , Feminino , Células Secretoras de Insulina/efeitos dos fármacos , Antígeno Ki-67/metabolismo , Licopeno , Malondialdeído/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Pâncreas/citologia , Pâncreas/efeitos dos fármacos , Pâncreas/patologia , Ratos , Ratos Wistar , Estreptozocina/toxicidade , Fatores de TempoRESUMO
Free radicals increase in the presence of diabetes. Lycopene is a powerful antioxidant. The goal of the present study was to determine the effect of diabetes on rat ovaries and the protective role of lycopene in that context. Experimental diabetes was induced with 50 mg÷kg streptozotocin. Rats were randomly separated into four groups, as follows: control + corn oil, control + lycopene, diabetes + corn oil and diabetes + lycopene. The histological and histometric evaluations were performed using Crossman's triple staining method. The immunohistochemical connexin-43 expression was identified and the apoptotic cell density was determined using the terminal deoxynucleotidyl transferase dUTP nick-end labeling method, while the malondialdehyde levels were measured using the enzyme-linked immunosorbent assay technique in the ovaries. Vacuolization of the corpus luteum, hydropic degeneration in the interstitial regions, and the number of corpora lutea increased in the ovary as effects of diabetes while the diameter of the corpora lutea decreased. The intensity of connexin-43 expression decreased in the primordial and atretic follicles, interstitial cells and luteal cells of the corpora lutea in the diabetes + corn oil group. The ovarian malondialdehyde levels and the number of apoptotic cells in the granulose layers of the large antral follicles increased in the presence of diabetes. Lycopene increased the expression of connexin-43 in the primordial, secondary and large antral follicles in the ovaries of diabetic animals. The changes caused by diabetes in the ovaries and the protective role of lycopene in some but not all parameters was revealed.
Assuntos
Carotenoides/uso terapêutico , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/patologia , Ovário/patologia , Animais , Apoptose/efeitos dos fármacos , Glicemia/metabolismo , Peso Corporal/efeitos dos fármacos , Carotenoides/farmacologia , Contagem de Células , Conexina 43/metabolismo , Corpo Lúteo/efeitos dos fármacos , Corpo Lúteo/patologia , Diabetes Mellitus Experimental/sangue , Ciclo Estral/efeitos dos fármacos , Jejum/sangue , Feminino , Imuno-Histoquímica , Licopeno , Malondialdeído/metabolismo , Folículo Ovariano/efeitos dos fármacos , Folículo Ovariano/patologia , Ovário/efeitos dos fármacos , Ratos WistarRESUMO
The current study has two main objectives: first, to determine if cells derived from the area pellucida are able to populate extraembryonic membranes, and second, to determine if donor cells have the potential to differentiate to endothelial (EC) and hematopoietic cells (HC) in the yolk sac and allantois, the two extraembryonic membranes functioning as hematopoietic organs in the avian embryo. To this end, quail chick chimeras were constructed by transferring dissociated cells from the areae pellucidae of the stage X-XII (EG&K) quail embryo into the subgerminal cavity of the unincubated chick blastoderm. The distribution of quail cells in the allantois, yolk sac, amnion, and chorion of resulting putative chimeras was examined using quail cell-specific antibody against a perinuclear antigen (QCPN) after 6 days of incubation. The presence of EC, HC, and smooth muscle cells among the QCPN(+) donor cells was examined using QH-1, a quail-specific marker identifying HC and EC and an anti-α-smooth muscle actin antibody. Evidence gathered in the present study demonstrates that quail cells derived from the areae pellucidae are able to populate all of the extraembryonic membranes of resulting heterospecific quail chick chimeras and, most importantly, give rise to HC, EC, and smooth muscle cells, all of the three main mesodermal lineages derived from the posterior mesoderm both in the yolk sac and allantois.
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Blastoderma/citologia , Codorniz/embriologia , Animais , Técnicas de Cultura de Células , Diferenciação Celular/fisiologia , Linhagem da Célula , Quimera , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Morfolinas/metabolismo , Osteoblastos/citologia , Osteoblastos/metabolismo , Purinas/metabolismoRESUMO
The objective of the current study was to determine the tissue distribution of cells derived from the area opaca in heterospecific quail-chick blastodermal chimeras. Quail-chick chimeras were constructed by transferring dissociated cells from the area opaca of the stage X-XII (EG&K) quail embryo into the subgerminal cavity of the unincubated chick blastoderm. The distribution of quail cells in embryonic as well as extra-embryonic tissues of the recipient embryo were examined using the QCPN monoclonal antibody after 6 days of incubation in serial sections taken at 100-mum intervals. Data gathered in the present study demonstrated that, when introduced into the subgerminal cavity of a recipient embryo, cells of the area opaca are able to populate not only extra-embryonic structures such as the amnion and the yolk sac, but also various embryonic tissues derived from the ectoderm and less frequently the mesoderm. Ectodermal chimerism was confined mainly to the head region and was observed in tissues derived from the neural ectoderm and the surface ectoderm, including the optic cup, diencephalon and lens. Although the possibility of random incorporation of transplanted cells into these embryonic structures cannot be excluded, these results would suggest that area opaca, a peripheral ring of cells in the avian embryo destined to form the extra-embryonic ectoderm and endoderm of the yolk sac, might harbor cells that have the potential to give rise to various cell types in the recipient chick embryo, including those derived from the surface ectoderm and neural ectoderm.