RESUMO
Germline stem cells in the Drosophila ovary are maintained by a somatic niche. The niche is structurally and functionally complex and contains four cell types, the escort, cap, and terminal filament cells and the newly identified transition cell. We find that the large Maf transcription factor Traffic jam (Tj) is essential for determining niche cell fates and architecture, enabling each niche in the ovary to support a normal complement of 2-3 germline stem cells. In particular, we focused on the question of how cap cells form. Cap cells express Tj and are considered the key component of a mature germline stem cell niche. We conclude that Tj controls the specification of cap cells, as the complete loss of Tj function caused the development of additional terminal filament cells at the expense of cap cells, and terminal filament cells developed cap cell characteristics when induced to express Tj. Further, we propose that Tj controls the morphogenetic behavior of cap cells as they adopted the shape and spatial organization of terminal filament cells but otherwise appeared to retain their fate when Tj expression was only partially reduced. Our data indicate that Tj contributes to the establishment of germline stem cells by promoting the cap cell fate, and controls the stem cell-carrying capacity of the niche by regulating niche architecture. Analysis of the interactions between Tj and the Notch (N) pathway indicates that Tj and N have distinct functions in the cap cell specification program. We propose that formation of cap cells depends on the combined activities of Tj and the N pathway, with Tj promoting the cap cell fate by blocking the terminal filament cell fate, and N supporting cap cells by preventing the escort cell fate and/or controlling the number of cap cell precursors.
Assuntos
Proteínas de Drosophila/genética , Fatores de Transcrição Maf Maior/genética , Ovário/citologia , Proteínas Proto-Oncogênicas/genética , Nicho de Células-Tronco , Animais , Drosophila/citologia , Drosophila/genética , Proteínas de Drosophila/metabolismo , Feminino , Fatores de Transcrição Maf Maior/metabolismo , Oogônios/citologia , Oogônios/metabolismo , Ovário/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Receptores Notch/genética , Receptores Notch/metabolismoRESUMO
The commercial sexual exploitation of children (CSEC) is considered normative and expected among some Indian castes. Focusing on the Bedia specifically, we sought to identify factors responsible for the intergenerational continuation of CSEC as well as opportunities for prevention. To this end, three questions were posed, including: (a) What structural factors perpetuate CSEC among the Bedia? (b) What are the mechanisms by which Bedia children enter the commercial sex industry (CSI)? and (c) To what extent do Bedia women have personal agency in exiting the CSI and in keeping their children from entering? Guided by structural vulnerability theory and a phenomenological approach, in-depth interviews were conducted with 31 Bedia women engaged in (or exited from) the CSI. Results indicate that girls as young as 12 are "selected" to enter the CSI; once involved, they carry the burden of familial financial sustainability and exit only comes when they are no longer able to attract paying clients and younger female kin able to assume the primary breadwinner role. Ability to keep female children from entry is minimal. Implications for future research, practice, and policy are discussed.
Assuntos
Tráfico de Pessoas , Trabalho Sexual , Classe Social , Criança , Humanos , Índia , População RuralRESUMO
Violence against women is a complex phenomenon that is deeply embedded in Indian society. In this mixed methods article, court records data (2005-2010) from two sites in Maharashtra, India along with in-depth interviews with stakeholders were analyzed to examine the implementation of the Protection of Women from Domestic Violence Act, 2005 (PWDVA). Out of 77.28% married women who filed a case under the PWDVA, 60.28% of them reported dowry-related harassment. Maharashtra has the social infrastructure in place to implement the law, although optimal use needs to be ensured for speedy delivery of justice.
Assuntos
Violência Doméstica , Feminino , Humanos , Índia , CasamentoRESUMO
Thousands of Indian women and girls enter the commercial sex industry (CSI) annually based solely on membership in particular castes (e.g., Bedia, Nat). CSI-involved females bear the burden of sustaining entire family units on money earned in the sex trade; it is a life-long responsibility with negligible social status or personal indemnity. Based on the life-course developmental theory (Elder, Jr. 1994, 1998) this investigation was intended to examine trafficked women's experiences within the commercial sex industry across time. Beyond the CSI, we were equally interested in experiences with factors that could promote well-being (i.e., social support) and normative developmental transitions including education attainment and motherhood. To that end, three questions were posed. First, to what extent do factors surrounding CSI entry and continued involvement differ through time among CSI-involved Bedia? Second, how do CSI-involved Bedia describe social network composition and perceived support through time? Finally, are differences detectable, through time, in CSI-involved Bedia women's experiences with normative developmental transitions including education attainment and motherhood? Interview data were collected from 31 Bedia females (age range 17 - 65 years) residing in rural Madhya Pradesh, India. To examine change through time, participants were divided into cohorts based on age and time involved in the commercial sex industry. Data were then analyzed within and across cohorts with particular attention to cohort-related experiential differences. Policy implications and suggestions for continued research are presented.
Assuntos
Tráfico de Pessoas , Trabalho Sexual , Feminino , Humanos , Idoso , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Classe Social , Escolaridade , Comportamento SocialRESUMO
Largely characterized as an urban issue, empirical studies of minor sex trafficking in rural communities-including India, a global hotspot for child sex trafficking-are exceptionally uncommon. Yet, the commercial sexual exploitation of children thrives in many rural Indian villages, fueled by caste discrimination, family tradition, and poverty. In response, this study aimed to investigate minor sex trafficking among a particular culturally unique and geographically isolated population, in relation to the dominant human trafficking literature. In-depth interviews were conducted with 31 female members of the Bedia caste-a unique population whose primary form of income is derived from participation in the rural sex trade. Framed by the social theory of intersectionality, we sought to (1) identify vulnerabilities for commercial sex industry entry among Bedia youth and (2) examine the cultural context of the commercial sex industry among the Bedia, with particular attention to the dominant victim/perpetrator paradigms. Implications for continued research, practice, and policy are included.
Assuntos
Tráfico de Pessoas , Criança , Adolescente , Feminino , Humanos , Trabalho Sexual , Comportamento Sexual , Índia , Classe SocialRESUMO
Host cell and bacterial factors determine severity and duration of infections. To allow for bacteria pathogenicity and persistence, bacteria have developed mechanisms that modify expression of host genes involved in cell cycle progression, apoptosis, differentiation and the immune response. Recently, Helicobacter pylori infection of the stomach has been correlated with epigenetic changes in the host genome. To identify epigenetic changes during Escherichia coli induced urinary tract infection (UTI), we developed an in vitro model of persistent infection of human uroepithelial cells with uropathogenic E. coli (UPEC), resulting in intracellular bacteria colonies. Cells inoculated with FimH-negative E. coli (N-UPEC) that are not internalized and non-inoculated cells were used as controls. UPEC infection significantly induced de novo methyltransferase (DNMT) activity (12.5-fold P=0.002 UPEC vs non-inoculated and 250-fold P=0.001 UPEC vs N-UPEC inoculated cells) and Dnmt1 RNA expression (6-fold P=0.04 UPEC vs non-inoculated cells) compared with controls. DNMT1 protein levels were significantly increased in three uroepithelial cell lines (5637, J82, HT-1197) in response to UPEC infection as demonstrated by confocal analysis. Real-time PCR analysis of candidate genes previously associated with bacteria infection and/or innate immunity, revealed UPEC-induced downregulation of the tumor suppressor gene CDKN2A (3.3-fold P=0.007 UPEC vs non-inoculated and 3.3-fold P=0.001 UPEC vs N-UPEC) and the DNA repair gene MGMT (9-fold P=0.03 UPEC vs non-inoculated). Expression of CDH1, MLH1, DAPK1 and TLR4 was not affected. Pyrosequencing of CDKN2A and MGMT CpG islands revealed increased methylation in CDKN2A exon 1 (3.8-fold P=0.04 UPEC vs N-UPEC and UPEC vs non-inoculated). Methylation of MGMT was not affected. UPEC-induced methylation of CDKN2A exon 1 may increase bladder cancer and presage UTI risk, and be useful as a biological marker for UTI susceptibility or recurrence.
Assuntos
Regulação para Baixo/fisiologia , Epigênese Genética/fisiologia , Infecções por Escherichia coli/fisiopatologia , Infecções Urinárias/microbiologia , Escherichia coli Uropatogênica , Genes p16/fisiologia , Humanos , Técnicas In Vitro , Metiltransferases/metabolismo , Microscopia ConfocalRESUMO
Maladaptive bladder muscle overgrowth and de-differentiation in human bladder obstructive conditions is instigated by coordinate responses to three stimuli: mechanical strain, tissue hypoxia, and extracellular matrix remodeling.( 1,2) Pathway analysis of genes induced by obstructive models of injury in bladder smooth muscle cells (BSMCs) identified a mammalian target of rapamycin (mTOR)-specific inhibitor as a potential pharmacological inhibitor. Strain-induced mTOR-specific S6K activation segregated differently from ERK1/2 activation in intact bladder ex vivo. Though rapamycin's antiproliferative effects in vascular smooth muscle cells are well known, its effects on BSMCs were previously unknown. Rapamycin significantly inhibited proliferation of BSMCs in response to mechanical strain, hypoxia, and denatured collagen. Rapamycin inhibited S6K at mTOR-sensitive phosphorylation sites in response to strain and hypoxia. Rapamycin also supported smooth muscle actin expression in response to strain or hypoxia-induced de-differentiation. Importantly, strain plus hypoxia synergistically augmented mTOR-dependent S6K activation, Mmp7 expression and proliferation. Forced expression of wild-type and constitutively active S6K resulted in loss of smooth muscle actin expression. Decreased smooth muscle actin, increased Mmp7 levels and mTOR pathway activation during in vivo partial bladder obstruction paralleled our in vitro studies. These results point to a coordinate role for mTOR in BSMCs responses to the three stimuli and a potential new therapeutic target for myopathic bladder disease.
Assuntos
Desdiferenciação Celular , Matriz Extracelular/patologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Miócitos de Músculo Liso/enzimologia , Miócitos de Músculo Liso/patologia , Proteínas Serina-Treonina Quinases/metabolismo , Estresse Mecânico , Bexiga Urinária/patologia , Actinas/metabolismo , Animais , Bovinos , Desdiferenciação Celular/efeitos dos fármacos , Hipóxia Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Ativação Enzimática/efeitos dos fármacos , Matriz Extracelular/efeitos dos fármacos , Matriz Extracelular/metabolismo , Metaloproteinase 7 da Matriz/metabolismo , Mitógenos/farmacologia , Modelos Biológicos , Miócitos de Músculo Liso/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Proteínas Quinases S6 Ribossômicas/metabolismo , Transdução de Sinais/efeitos dos fármacos , Sirolimo/farmacologia , Serina-Treonina Quinases TOR , Bexiga Urinária/efeitos dos fármacosRESUMO
Extracellular matrix changes are often crucial inciting events for fibroproliferative disease. Epigenetic changes, specifically DNA methylation, are critical factors underlying differentiated phenotypes. We examined the dependency of matrix-induced fibroproliferation and SMC phenotype on DNA methyltransferases. The cooperativity of matrix with growth factors, cell density and hypoxia was also examined. Primary rat visceral SMC of early passage (0-2) were plated on native collagen or damaged/heat-denatured collagen. Hypoxia was induced with 3% O2 (balanced 5% CO2 and 95% N2) over 48 hours. Inhibitors were applied 2-3 hours after cells were plated on matrix, or immediately before hypoxia. Cells were fixed and stained for DNMT3A and smooth muscle actin (SMA) or smooth muscle myosin heavy chain. Illumina 450 K array of CpG sites was performed on bisulfite-converted DNA from smooth muscle cells on damaged matrix vs native collagen. Matrix exquisitely regulates DNMT3A localization and expression, and influences differentiation in SMCs exposed to denatured matrix +/- hypoxia. Analysis of DNA methylation signatures showed that Matrix caused significant DNA methylation alterations in a discrete number of CpG sites proximal to genes related to SMC differentiation. Matrix has a profound effect on the regulation of SMC phenotype, which is associated with altered expression, localization of DNMTs and discrete changes DNA methylation.