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1.
Rural Remote Health ; 22(1): 6855, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-35051341

RESUMO

INTRODUCTION: This study aimed to investigate awareness of type 2 diabetes and how sociodemographic factors influence diabetes knowledge in a rural population of Tamil Nadu, India. Previous research has identified poor awareness of diabetes in several low and middle-income countries, which can lead to a high prevalence of undiagnosed diabetes. India having the second highest prevalence of diabetes globally, it is increasingly important to assess how diabetes can be addressed in rural Indian populations. METHODS: Systematic random sampling was used to gather study participants in 17 villages within the Krishnagiri district of Tamil Nadu, India. Data on diabetes knowledge was collected using a validated questionnaire. Knowledge score range was 0-8; a score of zero was designated as 'low knowledge', scores 1-4 as 'moderate knowledge', and scores 5-8 as 'good knowledge'. Associations between sociodemographic factors and composite diabetes knowledge score were assessed using a multinomial logistic GLLAMM model in Stata. RESULTS: A total of 753 individuals participated in the study. The average age of participants was 47 years and 55% were women. Overall awareness of diabetes was low, with 66% of individuals having no knowledge of diabetes. Only 16% and 17% achieved a moderate and a good knowledge score, respectively. Achieving a moderate knowledge score was significantly positively associated with education, wealth, participation in the Mahatma Gandhi National Rural Employment Guarantee Act (MGNREGA), and business ownership as a source of income. Achieving a good knowledge score was significantly positively associated with education, wealth, rurality, participation in MGNREGA, business ownership as a source of income, and frequency of healthcare utilization. Rurality was significantly negatively associated (relative risk ratio (95% confidence interval)) with both moderate knowledge score (0.34 (0.19-0.59)), and good knowledge score (0.43 (0.24-0.74)). The strongest predictor of having a good knowledge score was having a high-school graduate or post-secondary education (11.07 (4.44-27.61)). Enrolment in MGNREGA employment was the strongest predictor for having a moderate knowledge score (3.27 (1.93-5.54)), as well as strongly associated with having a good knowledge score (2.39 (1.31-4.36)). CONCLUSION: The low awareness of diabetes among participants of this study raises serious concerns for public health in India. Public health efforts must prioritize health equity to lessen the impacts of diabetes in rural populations, where individuals face systemic barriers to receiving prevention and treatment for conditions such as diabetes.


Assuntos
Diabetes Mellitus Tipo 2 , População Rural , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/epidemiologia , Escolaridade , Feminino , Humanos , Índia/epidemiologia , Pessoa de Meia-Idade , Fatores Sociodemográficos
2.
Qual Health Res ; 31(14): 2602-2616, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34605697

RESUMO

In this article, we present a case study of sewing as a strategy for arts-based inquiry in health research, situated within a broader project that highlighted Nunavut Inuit women's childbirth experiences. Five focus groups were hosted as sewing sessions with pregnant women (N = 19) in Iqaluit, Nunavut (2017-2018). Women's reflections on the sessions, and the significance of sewing to Inuit, were integrated with researchers' critical reflections to examine the value of sewing as a strategy for arts-based inquiry within a focus group method: results related to the flexibility of the sessions; how collective sewing created space for voicing, sharing, and relating; sewing as a tactile and place-specific practice tied to Inuit knowledge and tradition; and lessons learned. Our results underscore the possibilities of arts-based approaches, such as sewing, to enhance data gathering within a focus group method and to contribute to more locally appropriate, place-based methods for Indigenous health research.


Assuntos
Inuíte , Pesquisa , Feminino , Grupos Focais , Humanos , Nunavut , Gravidez
3.
Plants (Basel) ; 9(9)2020 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-32961677

RESUMO

Common bean (Phaseolus vulgaris L.) provides critical nutrition and a livelihood for millions of smallholder farmers worldwide. Beans engage in symbiotic nitrogen fixation (SNF) with Rhizobia. Honduran hillside farmers farm marginal land and utilize few production inputs; therefore, bean varieties with high SNF capacity and environmental resiliency would be of benefit to them. We explored the diversity for SNF, agronomic traits, and water use efficiency (WUE) among 70 Honduran landrace, participatory bred (PPB), and conventionally bred bean varieties (HON panel) and 6 North American check varieties in 3 low-N field trials in Ontario, Canada and Honduras. Genetic diversity was measured with a 6K single nucleotide polymorphism (SNP) array, and phenotyping for agronomic, SNF, and WUE traits was carried out. STRUCTURE analysis revealed two subpopulations with admixture between the subpopulations. Nucleotide diversity was greater in the landraces than the PPB varieties across the genome, and multiple genomic regions were identified where population genetic differentiation between the landraces and PPB varieties was evident. Significant differences were found between varieties and breeding categories for agronomic traits, SNF, and WUE. Landraces had above average SNF capacity, conventional varieties showed higher yields, and PPB varieties performed well for WUE. Varieties with the best SNF capacity could be used in further participatory breeding efforts.

4.
Soc Sci Med ; 262: 113206, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32823215

RESUMO

Nunavut's maternal healthcare system is characterized by rapid transition from community-based birth to a practice of obstetric evacuation and institutionalized birth. Given calls for Inuit self-determination in research, maternal health research - which informs healthcare practices and policies - may need to be conducted differently, using different research methodologies, to include Inuit women's voices and lived experiences. In light of these calls, this article systematically synthesized the published maternal health literature in Nunavut and critically examined reported research methods. This systematic search and critical review involved a comprehensive database search and multi-level eligibility screening conducted by two independent reviewers. Data on the temporal, geographic, methodological, and topical range of studies were extracted, then descriptive statistics were calculated to summarize these data. A hybrid inductive and deductive qualitative analysis of the full-text articles was conducted to critically analyze research methodology. The initial search yielded 2656 distinct articles and twenty-eight articles met the inclusion criteria. These articles were published from 1975 to 2016, mostly used quantitative research methodology (71.4%), were written from clinical perspectives (57.1%), and focused on maternity care (53.6%). Emergent themes related to both the contributions and areas for growth of research methodology in the conceptualization, initiation, implementation, reporting, and knowledge mobilization stages of the research process. This review revealed opportunities for maternal health researchers to: redress the ongoing impacts of colonization; further include Inuit definitions of health and perspectives on birth in study designs; explore new methodologies that resonate with Inuit ways of knowing; continue (re)aligning research with community priorities; and move from consultation and collaborative partnership in research to Inuit leadership and data ownership. Indeed, this review illustrates that at each step of the research process, opportunity exists for Inuit perspectives and active involvement to shape and define maternal health research in Nunavut.


Assuntos
Serviços de Saúde Materna , Saúde Materna , Atenção à Saúde , Feminino , Humanos , Liderança , Nunavut , Gravidez
5.
BMC Public Health ; 20(1): 675, 2020 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-32404080

RESUMO

BACKGROUND: The double burden of malnutrition is the co-occurrence of undernutrition (e.g. underweight, stunting, and micronutrient deficiencies) and over-nutrition (e.g. obesity, type 2 diabetes, and cardiovascular disease) at the population, household, or individual level. The objectives of this study were to determine the extent and determinants of individual-level co-morbid anemia and overweight and co-morbid anemia and diabetes in a population in rural Tamil Nadu, South India. METHODS: We undertook a cross-sectional study of adults (n = 753) in a rural region of Tamil Nadu, South India. A survey assessed socio-demographic factors, physical activity levels, and dietary intake. Clinical measurements included body-mass index, an oral glucose tolerance test, and blood hemoglobin assessments. Multivariable logistic regression analyses were used to determine associations between risk factors and two co-morbid double burden pairings: (1) anemia and overweight, and (2) anemia and diabetes. RESULTS: Prevalence of co-morbid anemia and overweight was 23.1% among women and 13.1% among men. Prevalence of co-morbid anemia and diabetes was 6.2% among women and 6.3% among men. The following variables were associated with co-morbid anemia and overweight in multivariable models [odds ratio (95% confidence interval)]: female sex [2.3 (1.4, 3.85)], high caste [3.2 (1.34, 7.49)], wealth index [1.1 (1.00, 1.12)], rurality (0.7 [0.56, 0.85]), tobacco consumption [0.6 (0.32, 0.96)], livestock ownership [0.5 (0.29, 0.89)], and energy-adjusted meat intake [1.8 (0.61, 0.94)]. The following variables were associated with co-morbid anemia and diabetes in multivariable models: age [1.1 (1.05, 1.11)], rurality [0.8 (0.57, 0.98)], and family history of diabetes [4.9 (1.86, 12.70). CONCLUSION: This study determined the prevalence and factors associated with individual-level double burden of malnutrition. Women in rural regions of India may be particularly vulnerable to individual-level double burden of malnutrition and should be a target population for any nutrition interventions to address simultaneous over- and undernutrition.


Assuntos
Anemia/epidemiologia , Diabetes Mellitus Tipo 2/epidemiologia , Desnutrição/epidemiologia , Estado Nutricional , Sobrepeso/epidemiologia , Adulto , Idoso , Índice de Massa Corporal , Estudos Transversais , Feminino , Hemoglobinas , Humanos , Índia/epidemiologia , Masculino , Pessoa de Meia-Idade , Razão de Chances , Prevalência , Fatores de Risco , População Rural/estatística & dados numéricos , Fatores Socioeconômicos , Adulto Jovem
6.
Artigo em Inglês | MEDLINE | ID: mdl-31978999

RESUMO

In the context of climate change, a nutritional transition, and increased pressures to migrate internally and internationally, this study examined the relationship between seasonal food insecurity and demographic, socioeconomic, and agricultural production factors among small-scale subsistence farmers in rural northern Honduras. Anchored by a partnership with the Fundación para la Investigación Participativa con Agricultores de Honduras (FIPAH) and the Yorito Municipal Health Centre, a cross-sectional household survey was administered in Yorito, Honduras, in July 2014. The study population included 1263 individuals from 248 households across 22 rural communities. A multivariate mixed effects negative binomial regression model was built to investigate the relationship between the self-reported number of months without food availability and access from subsistence agriculture in the previous year (August 2013-July 2014) and demographic, socioeconomic, and agricultural production variables. This study found a lengthier 'lean season' among surveyed household than previously documented in Honduras. Overall, 62.2% (95% confidence interval (CI): [59.52, 64.87]) of individuals experienced at least four months of insufficient food in the previous year. Individuals from poorer and larger households were more likely to experience insufficient food compared to individuals from wealthier and smaller households. Additionally, individuals from households that produced both maize and beans were less likely to have insufficient food compared to individuals from households that did not grow these staple crops (prevalence ratio (PR) = 0.83; 95% CI: [0.69, 0.99]). Receiving remittances from a migrant family member did not significantly reduce the prevalence of having insufficient food. As unpredictable crop yields linked to climate change and extreme weather events are projected to negatively influence the food security and nutrition outcomes of rural populations, it is important to understand how demographic, socioeconomic, and agricultural production factors may modify the ability of individuals and households engaged in small-scale subsistence agriculture to respond to adverse shocks.


Assuntos
Agricultura , Abastecimento de Alimentos , População Rural , Estudos Transversais , Feminino , Honduras , Humanos , Masculino , Estações do Ano , Classe Social , Fatores Socioeconômicos
7.
Anemia ; 2018: 7123976, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30112198

RESUMO

BACKGROUND/OBJECTIVES: To determine the prevalence and determinants of blood haemoglobin level and mild, moderate, and severe anemia in a sample of adults from rural Tamil Nadu, India. SUBJECTS/METHODS: We recruited a sample of men and nonpregnant women aged 20 years and older. Clinical health measures included blood haemoglobin concentration and body mass index. We assessed associations between anemia outcomes and sociodemographic and dietary factors using linear and logistic regression modeling. RESULTS: A total of 753 individuals (412 women and 341 men) participated in this study. The prevalence of anemia was 57.2% among women and 39.3% among men (P<0.001). Prevalence of anemia increased with age among men (P<0.001) but not women (P>0.05). Iron intake was low; 11.7% women and 24.1% of men reported iron intakes above recommended dietary allowances (P<0.001). Factors (OR (95% CI)) associated with mild or moderate anemia among women included television ownership (0.27 (0.13, 0.58)), livestock ownership (0.46 (0.28, 0.75)), refined grain consumption (1.32 (1.02, 1.72)), meat consumption (0.84 (0.71, 0.99)), and commercial agriculture production (mild: 4.6 (1.1, 18.8); moderate: 6.8 (1.98, 23.1)). Factors associated with mild, moderate, or severe anemia among men included rurality (0.50 (0.25, 0.99)), sugar consumption (1.04 (1.01, 1.06)), egg consumption (0.80 (0.65, 0.99)), and high caste (7.3 (1.02, 52.3)). CONCLUSION: Both women and men in this region may be particularly vulnerable to anemia, and future research must expand beyond dietary risk factors to examine the impacts of sociodemographic and environmental factors.

8.
BMC Int Health Hum Rights ; 17(1): 23, 2017 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-28899374

RESUMO

BACKGROUND: Internal labour migration is an important and necessary livelihood strategy for millions of individuals and households in India. However, the precarious position of migrant workers within Indian society may have consequences for the health of these individuals. Previous research on the connections between health and labour mobility within India have primarily focused on the negative health outcomes associated with this practice. Thus, there is a need to better identify the determinants of internal migrant health and how these determinants shape migrant health outcomes. METHODS: An exploratory mixed methods study was conducted in 26 villages in the Krishnagiri district of Tamil Nadu. Sixty-six semi-structured interviews were completed using snowball sampling, followed by 300 household surveys using multi-stage random sampling. For qualitative data, an analysis of themes and content was completed. For quantitative data, information on current participation in internal labour migration, in addition to self-reported morbidity and determinants of internal migrant health, was collected. Morbidity categories were compared between migrant and non-migrant adults (age 14-65 years) using a Fisher's exact test. RESULTS: Of the 300 households surveyed, 137 households (45.7%) had at least one current migrant member, with 205 migrant and 1012 non-migrant adults (age 14-65 years) included in this study. The health profile of migrant and non-migrants was similar in this setting, with 53 migrants (25.9%) currently suffering from a health problem compared to 273 non-migrants (27.0%). Migrant households identified both occupational and livelihood factors that contributed to changes in the health of their migrant members. These determinants of internal migrant health were corroborated and further expanded on through the semi-structured interviews. CONCLUSIONS: Internal labour migration in and of itself is not a determinant of health, as participation in labour mobility can contribute to an improvement in health, a decline in health, or no change in health among migrant workers. Targeted public health interventions should focus on addressing the determinants of internal migrant health to enhance the contributions these individuals can make to their households and villages of origin.


Assuntos
Nível de Saúde , Saúde Pública , Migrantes , Adulto , Idoso , Emprego , Feminino , Humanos , Índia , Masculino , Pessoa de Meia-Idade , Ocupações , Inquéritos e Questionários , Adulto Jovem
9.
Med Anthropol ; 36(2): 96-110, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-27644458

RESUMO

Type 2 diabetes mellitus is an escalating public health problem in India, associated with genetic susceptibility, dietary shift, and rapid lifestyle changes. Historically a disease of the urban elite, quantitative studies have recently confirmed rising prevalence rates among marginalized populations in rural India. To analyze the role of cultural and sociopolitical factors in diabetes onset and management, we employed in-depth interviews and focus groups within a rural community of Tamil Nadu. The objectives of the study were to understand sources and extent of health knowledge, diabetes explanatory models, and the impact of illness on individual, social, and familial roles. Several cultural, socioeconomic, and political factors appear to contribute to diabetes in rural regions of India, highlighting the need to address structural inequities and empower individuals to pursue health and well-being on their own terms.


Assuntos
Diabetes Mellitus Tipo 2/etnologia , Diabetes Mellitus Tipo 2/epidemiologia , Epidemias/estatística & dados numéricos , Conhecimentos, Atitudes e Prática em Saúde/etnologia , Adulto , Antropologia Médica , Feminino , Humanos , Índia , Masculino , Pessoa de Meia-Idade , População Rural , Fatores Socioeconômicos
10.
Soc Sci Med ; 161: 118-25, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27285663

RESUMO

In Tamil Nadu, India, improvements have been made toward developing a high-quality, universally accessible healthcare system. However, some rural residents continue to confront significant barriers to obtaining healthcare. The primary objective of this study was to investigate self-reported morbidity, health literacy, and healthcare preferences, utilization, and experiences in order to identify priority areas for government health policies and programs. Drawing on 66 semi-structured interviews and 300 household surveys (including 1693 individuals), administered in 26 rural villages in Tamil Nadu's Krishnagiri district, we found that the prevalence of self-reported major health conditions was 22.3%. There was a large burden of non-communicable and chronic diseases, and the most common major morbidities were: connective tissue problems (7.6%), nervous system and sense organ diseases (5.0%), and circulatory and respiratory diseases (2.5%). Increased age and decreased education level were associated with higher odds of reporting most diseases. Low health literacy levels resulted in individuals seeking care only once pain interfered with daily activities. As such, individuals' health-seeking behaviour depended on which strategy was believed to result in the fastest return to work using the fewest resources. Although government facilities were the most common healthcare access point, they were mistrusted; 48.8% and 19.2% of respondents perceived inappropriate treatment protocols and corruption, respectively, at public facilities. Conversely, 93.3% of respondents reported high treatment cost as the main barrier to accessing private facilities. Our results highlight that addressing the chronic and non-communicable disease burdens amongst rural populations in this context will require health policies and village-level programs that address the low health literacy and the issues of rural healthcare accessibility and acceptability.


Assuntos
Acessibilidade aos Serviços de Saúde/normas , Serviços de Saúde/estatística & dados numéricos , Morbidade/tendências , População Rural/tendências , Autorrelato , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Distribuição de Qui-Quadrado , Criança , Pré-Escolar , Feminino , Acessibilidade aos Serviços de Saúde/estatística & dados numéricos , Hinduísmo/psicologia , Humanos , Índia , Lactente , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Pesquisa Qualitativa , População Rural/estatística & dados numéricos
11.
Diabetol Metab Syndr ; 8: 21, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26958082

RESUMO

BACKGROUND: India's national rural prevalence of type 2 diabetes has quadrupled in the past 25 years. Despite the growing rural burden, few studies have examined putative risk factors and their relationship with glucose intolerance and diabetes in rural areas. We undertook a cross-sectional study to determine the prevalence of impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and type 2 diabetes in a rural area of south India. In addition, we determined which factors were associated with type 2 diabetes. METHODS: We sampled 2 % of the adult population from 17 villages using a randomized household-level sampling technique. Each participant undertook a questionnaire that included basic descriptive information and an assessment of socioeconomic status, physical activity, and dietary intake. Height, weight, waist and hip circumference, and blood pressure measurements were taken. An oral glucose tolerance test was used to determine diabetes status. We used stepwise logistic model building techniques to determine associations between several putative factors and type 2 diabetes. RESULTS: 753 participants were included in the study. The age- and sex-standardized prevalence of IFG was 3.9 %, IGT was 5.6 %, and type 2 diabetes was 10.8 %. Factors associated with type 2 diabetes after adjusting for confounders included physical activity [OR 0.81], rurality [OR 0.76], polyunsaturated fat intake [OR 0.94], body mass index [OR 1.85], waist to hip ratio [OR 1.62], and tobacco consumption [OR 2.82]. CONCLUSION: Our study contributes to the growing body of research suggesting that diabetes is a significant concern in rural south India. Associated risk factors should be considered as potential targets for reducing health burdens in India.

12.
BMC Obes ; 3: 12, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26904203

RESUMO

BACKGROUND: Overweight, obesity, and related chronic diseases are becoming serious public health concerns in rural areas of India. Compounded with the existing issue of underweight, such concerns expose the double burden of disease and may put stress on rural healthcare. The purpose of this article was to present the prevalence and factors associated with underweight, overweight, and obesity in an area of rural south India. METHODS: During 2013 and 2014, a random sample of adults aged 20-80 years were selected for participation in a cross-sectional study that collected information on diet (using a food frequency questionnaire), physical activity (using the Global Physical Activity Questionnaire), socioeconomic position (using a wealth index), rurality (using the MSU rurality index), education, and a variety of descriptive factors. BMI was measured using standard techniques. Using a multivariate linear regression analysis and multivariate logistic regression analyses, we examined associations between BMI, overweight, obesity, and underweight, and all potential risk factors included in the survey. RESULTS: Age and sex-adjusted prevalence of overweight, obesity class I, and obesity class II were 14.9, 16.1, and 3.3 % respectively. Prevalence of underweight was 22.7 %. The following variables were associated with higher BMI and/or increased odds of overweight, obesity class I, and/or obesity class II: Low physical activity, high wealth index, no livestock, low animal fat consumption, high n-6 polyunsaturated fat consumption, television ownership, time spent watching television, low rurality index, and high caste. The following variables were associated with increased odds of underweight: low wealth index, high rurality index, and low intake of n-6 PUFAs. CONCLUSION: Underweight, overweight, and obesity are prevalent in rural regions of southern India, indicating a village-level dual burden. A variety of variables are associated with these conditions, including physical activity, socioeconomic position, rurality, television use, and diet. To address the both underweight and obesity, policymakers must simultaneously focus on encouraging positive behaviour through education and addressing society-level risk factors that inhibit individuals from achieving optimal health.

13.
Proc Natl Acad Sci U S A ; 110(49): E4743-52, 2013 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-24248360

RESUMO

Collagen fibrils can exceed thousands of microns in length and are therefore the longest, largest, and most size-pleomorphic protein polymers in vertebrates; thus, knowing how cells transport collagen fibrils is essential for a more complete understanding of protein transport and its role in tissue morphogenesis. Here, we identified newly formed collagen fibrils being transported at the surface of embryonic tendon cells in vivo by using serial block face-scanning electron microscopy of the cell-matrix interface. Newly formed fibrils ranged in length from ~1 to ~30 µm. The shortest (1-10 µm) occurred in intracellular fibricarriers; the longest (~30 µm) occurred in plasma membrane fibripositors. Fibrils and fibripositors were reduced in numbers when collagen secretion was blocked. ImmunoEM showed the absence of lysosomal-associated membrane protein 2 on fibricarriers and fibripositors and there was no effect of leupeptin on fibricarrier or fibripositor number and size, suggesting that fibricarriers and fibripositors are not part of a fibril degradation pathway. Blebbistatin decreased fibricarrier number and increased fibripositor length; thus, nonmuscle myosin II (NMII) powers the transport of these compartments. Inhibition of dynamin-dependent endocytosis with dynasore blocked fibricarrier formation and caused accumulation of fibrils in fibripositors. Data from fluid-phase HRP electron tomography showed that fibricarriers could originate at the plasma membrane. We propose that NMII-powered transport of newly formed collagen fibrils at the plasma membrane is fundamental to the development of collagen fibril-rich tissues. A NMII-dependent cell-force model is presented as the basis for the creation and dynamics of fibripositor structures.


Assuntos
Membrana Celular/metabolismo , Colágeno/metabolismo , Miosina Tipo II/metabolismo , Actomiosina/metabolismo , Aminoácidos Dicarboxílicos , Animais , Transporte Biológico , Embrião de Galinha , Colágeno/biossíntese , Colágeno/fisiologia , Colágeno/ultraestrutura , Matriz Extracelular/metabolismo , Microscopia Eletrônica de Varredura , Microscopia Imunoeletrônica , Inibidores de Prolil-Hidrolase/farmacologia
14.
J Biol Chem ; 283(18): 12129-35, 2008 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-18285337

RESUMO

It is established fact that type I collagen spontaneously self-assembles in vitro in the absence of cells or other macromolecules. Whether or not this is the situation in vivo was unknown. Recent evidence shows that intracellular cleavage of procollagen (the soluble precursor of collagen) to collagen can occur in embryonic tendon cells in vivo, and when this occurs, intracellular collagen fibrils are observed. A cause-and-effect relationship between intracellular collagen and intracellular fibrils was not established. Here we show that intracellular cleavage of procollagen to collagen occurs in postnatal murine tendon cells in situ. Pulse-chase analyses showed cleavage of procollagen to collagen via its two propeptide-retained intermediates. Furthermore, immunoelectron microscopy, using an antibody that recognizes the triple helical domain of collagen, shows collagen molecules in large-diameter transport compartments close to the plasma membrane. However, neither intracellular fibrils nor fibripositors (collagen fibril-containing plasma membrane protrusions) were observed. The results show that intracellular collagen occurs in murine tendon in the absence of intracellular fibrillogenesis and fibripositor formation. Furthermore, the results show that murine postnatal tendon cells have a high capacity to prevent intracellular collagen fibrillogenesis.


Assuntos
Colágeno Tipo I/metabolismo , Colágenos Fibrilares/metabolismo , Fibroblastos/metabolismo , Espaço Intracelular/metabolismo , Peptídeos/metabolismo , Precursores de Proteínas/metabolismo , Tendões/metabolismo , Animais , Animais Recém-Nascidos , Matriz Extracelular/efeitos dos fármacos , Matriz Extracelular/metabolismo , Proteínas da Matriz Extracelular/isolamento & purificação , Proteínas da Matriz Extracelular/metabolismo , Fibroblastos/efeitos dos fármacos , Fibroblastos/ultraestrutura , Espaço Intracelular/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Octoxinol , Polietilenoglicóis/farmacologia , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Especificidade da Espécie , Cauda/efeitos dos fármacos , Cauda/ultraestrutura , Tendões/efeitos dos fármacos , Tendões/ultraestrutura , Tripsina/metabolismo
15.
Mol Cell Biol ; 27(17): 6218-28, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17562872

RESUMO

The ability of tendon to transmit forces from muscle to bone is directly attributable to an extracellular matrix (ECM) containing parallel bundles of collagen fibrils. Although the biosynthesis of collagen is well characterized, how cells deposit the fibrils in regular parallel arrays is not understood. Here we show that cells in the tendon mesenchyme are nearly cylindrical and are aligned side by side and end to end along the proximal-distal axis of the limb. Using three-dimensional reconstruction electron microscopy, we show that the cells have deep channels in their plasma membranes and contain bundles of parallel fibrils that are contiguous from one cell to another along the tendon axis. A combination of electron microscopy, microarray analysis, and immunofluorescence suggested that the cells are held together by cadherin-11-containing cell-cell junctions. Using a combination of RNA interference and electron microscopy, we showed that knockdown of cadherin-11 resulted in cell separation, loss of plasma membrane channels, and misalignment of the collagen fibrils in the ECM. Our results show that tendon formation in the developing limb requires precise regulation of cell shape via cadherin-11-mediated cell-cell junctions and coaxial alignment of plasma membrane channels in longitudinally stacked cells.


Assuntos
Caderinas/metabolismo , Forma Celular , Junções Intercelulares/metabolismo , Tendões/crescimento & desenvolvimento , Animais , Caderinas/genética , Membrana Celular/metabolismo , Membrana Celular/ultraestrutura , Embrião de Galinha , Matriz Extracelular/metabolismo , Matriz Extracelular/ultraestrutura , Junções Intercelulares/ultraestrutura , Camundongos , Modelos Anatômicos , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Tendões/citologia , Tendões/ultraestrutura
16.
J Biol Chem ; 281(50): 38592-8, 2006 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-17020878

RESUMO

Cells in tendon deposit parallel arrays of collagen fibrils to form a functional tissue, but how this is achieved is unknown. The cellular mechanism is thought to involve the formation of intracellular collagen fibrils within Golgi to plasma membrane carriers. This is facilitated by the intracellular processing of procollagen to collagen by members of the tolloid and ADAMTS families of enzymes. The carriers subsequently connect to the extracellular matrix via finger-like projections of the plasma membrane, known as fibripositors. In this study we have shown, using three-dimensional electron microscopy, the alignment of fibripositors with intracellular fibrils as well as an orientated cable of actin filaments lining the cytosolic face of a fibripositor. To demonstrate a specific role for the cytoskeleton in coordinating extracellular matrix assembly, cytochalasin was used to disassemble actin filaments and nocodazole or colchicine were used to disrupt microtubules. Microtubule disruption delayed procollagen transport through the secretory pathway, but fibripositor numbers were unaffected. Actin filament disassembly resulted in rapid loss of fibripositors and a subsequent disappearance of intracellular fibrils. Procollagen secretion or processing was not affected by cytochalasin treatment, but the parallelism of extracellular collagen fibrils was altered. In this case a significant proportion of collagen fibrils were found to no longer be orientated with the long axis of the tendon. The results suggest an important role for the actin cytoskeleton in the alignment and organization of the collagenous extracellular matrix in embryonic tendon.


Assuntos
Actinas/metabolismo , Colágeno/metabolismo , Tendões/metabolismo , Animais , Embrião de Galinha , Fibroblastos/metabolismo , Microscopia Eletrônica de Transmissão , Tendões/citologia , Tendões/embriologia , Tendões/enzimologia
17.
Stem Cells ; 24(1): 186-98, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16100003

RESUMO

We used serial analysis of gene expression to catalog the transcriptome of murine mesenchymal stem cells (MSCs) enriched from bone marrow by immunodepletion. Interrogation of this database, results of which are delineated in the appended databases, revealed that immunodepleted murine MSCs (IDmMSCs) highly express transcripts encoding connective tissue proteins and factors modulating T-cell proliferation, inflammation, and bone turnover. Categorizing the transcriptome based on gene ontologies revealed the cells also expressed mRNAs encoding proteins that regulate mesoderm development or that are characteristic of determined mesenchymal cell lineages, thereby reflecting both their stem cell nature and differentiation potential. Additionally, IDmMSCs also expressed transcripts encoding proteins regulating angiogenesis, cell motility and communication, hematopoiesis, immunity and defense as well as neural activities. Immunostaining and fluorescence-activated cell sorting analysis revealed that expression of various regulatory proteins was restricted to distinct subpopulations of IDmMSCs. Moreover, in some cases, these proteins were absent or expressed at reduced levels in other murine MSC preparations or cell lines. Lastly, by comparing their transcriptome to that of 17 other murine cell types, we also identified 43 IDmMSC-specific transcripts, the nature of which reflects their varied functions in bone and marrow. Collectively, these results demonstrate that IDmMSC express a diverse repertoire of regulatory proteins, which likely accounts for their demonstrated efficacy in treating a wide variety of diseases. The restricted expression pattern of these proteins within populations suggests that the cellular composition of marrow stroma and its associated functions are more complex than previously envisioned.


Assuntos
Genômica/métodos , Células-Tronco Mesenquimais/fisiologia , Animais , Diferenciação Celular , Linhagem da Célula , Células Cultivadas , Impressões Digitais de DNA , Expressão Gênica , Regulação da Expressão Gênica , Biblioteca Gênica , Células-Tronco Mesenquimais/imunologia , Camundongos , Reprodutibilidade dos Testes , Transcrição Gênica
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