ST2 regulates bone loss in a site-dependent and estrogen-dependent manner.

Interleukin-33 (IL-33) and its receptor, ST2, are implicated in bone remodeling. The lack of estrogen after menopause results in an accelerated bone loss. Here we investigated the role of ST2 in the bone loss induced by estrogen deficiency. ST2-deficient mice (ST2-/- ) and their littermates (wildtype [WT]) were ovariectomized (OVX), while ovary-intact mice were used as controls. Bone sites were analyzed by microcomputed tomography, histomorphometry, and quantitative real-time polymerase chain reaction (qPCR). Deletion of IL-33 or ST2 resulted in a similar bone loss in the femur and maxilla. Ovariectomy in WT mice caused bone loss in the same areas. The lack of ST2 in OVX mice did not alter bone remodeling in the femur but prevented bone loss in the maxilla. Consistently, ovariectomy increased the IL-33 messenger RNA (mRNA) levels in the maxilla but not in the femur. Under mechanical stimulation, ovariectomy and ST2 deletion independently increased bone remodeling induced by orthodontic tooth movement, which was also associated with a greater number of osteoclasts and a reduced number of osteoblasts in the maxillary bone. ST2-/- OVX mice, however, displayed twice as many osteoblasts as that of WT OVX mice. Ovariectomy and ST2 deletion differently altered the cytokine mRNA levels in the maxilla. Remarkably, interleukin-10 expression was decreased in both WT OVX and ST2-/- mice, and this reduction was completely restored in ST2-/- OVX mice. The results demonstrate that estrogen and IL33/ST2 independently protect against bone loss. However, the ovariectomy-induced bone loss is IL-33/ST2-dependent in the maxilla but not in the femur, indicating a bimodal and site-specific role of ST2 in bone remodeling.

Perinatal and early life factors associated with symptoms of depression in Brazilian children.

BACKGROUND: Few studies have been conducted on the association between perinatal and early life factors with childhood depression and results are conflicting. Our aim was to estimate the prevalence and perinatal and early life factors associated with symptoms of depression in children aged 7 to 11 years from two Brazilian birth cohorts. METHODS: The study was conducted on 1444 children whose data were collected at birth and at school age, in 1994 and 2004/2005 in Ribeirao Preto, where they were aged 10-11 years and in 1997/98 and 2005/06 in São Luís, where children were aged 7-9 years. Depressive symptoms were investigated with the Child Depression Inventory(CDI), categorized as yes (score ≥ 20) and no (score < 20). Adjusted and non-adjusted prevalence ratios (PR) were estimated by Poisson regression with robust estimation of the standard errors. RESULTS: The prevalence of depressive symptoms was 3.9% (95%CI = 2.5-5.4) in Ribeirão Preto and 13.7% (95%CI = 11.0-16.4) in São Luís. In the adjusted analysis, in Ribeirão Preto, low birth weight (PR = 3.98; 95%CI = 1.72-9.23), skilled and semi-skilled manual occupation (PR = 5.30; 95%CI = 1.14-24.76) and unskilled manual occupation and unemployment (PR = 6.65; 95%CI = 1.16-38.03) of the household head were risk factors for depressive symptoms. In São Luís, maternal schooling of 0-4 years (PR = 2.39; 95%CI = 1.31-4.34) and of 5 to 8 years (PR = 1.80; 95%CI = 1.08-3.01), and paternal age <20 years (PR = 1.92; 95%CI = 1.02-3.61), were independent risk factors for depressive symptoms. CONCLUSIONS: The prevalence of depressive symptoms was much higher in the less developed city, São Luís, than in the more developed city, Ribeirão Preto, and than those reported in several international studies. Low socioeconomic level was associated with depressive symptoms in both cohorts. Low paternal age was a risk factor for depressive symptoms in the less developed city, São Luís, whereas low birth weight was a risk factor for depressive symptoms in the more developed city, Ribeirão Preto.

Prevalence of non-communicable diseases in Brazilian children: follow-up at school age of two Brazilian birth cohorts of the 1990's.

BACKGROUND: Few cohort studies have been conducted in low and middle-income countries to investigate non-communicable diseases among school-aged children. This article aims to describe the methodology of two birth cohorts, started in 1994 in Ribeirão Preto (RP), a more developed city, and in 1997/98 in São Luís (SL), a less developed town. METHODS: Prevalences of some non-communicable diseases during the first follow-up of these cohorts were estimated and compared. Data on singleton live births were obtained at birth (2858 in RP and 2443 in SL). The follow-up at school age was conducted in RP in 2004/05, when the children were 9-11 years old and in SL in 2005/06, when the children were 7-9 years old. Follow-up rates were 68.7% in RP (790 included) and 72.7% in SL (673 participants). The groups of low (<2500 g) and high (≥ 4250 g) birthweight were oversampled and estimates were corrected by weighting. RESULTS: In the more developed city there was a higher percentage of non-nutritive sucking habits (69.1% vs 47.9%), lifetime bottle use (89.6% vs 68.3%), higher prevalence of primary headache in the last 15 days (27.9% vs 13.0%), higher positive skin tests for allergens (44.3% vs 25.3%) and higher prevalence of overweight (18.2% vs 3.6%), obesity (9.5% vs 1.8%) and hypertension (10.9% vs 4.6%). In the less developed city there was a larger percentage of children with below average cognitive function (28.9% vs 12.2%), mental health problems (47.4% vs 38.4%), depression (21.6% vs 6.0%) and underweight (5.8% vs 3.6%). There was no difference in the prevalence of bruxism, recurrent abdominal pain, asthma and bronchial hyperresponsiveness between cities. CONCLUSIONS: Some non-communicable diseases were highly prevalent, especially in the more developed city. Some high rates suggest that the burden of non-communicable diseases will be high in the future, especially mental health problems.