ABSTRACT
Objective: to compare the gene expression levels of collagen type I alpha 2 (COL1A2) in children with and without dental fluorosis. methods: cross-sectional study involving 92 children between 5 and 12 years of age. socio-demographic characteristics, the presence of dental fluorosis by means of the Thylstrup-Fejerskov index, and gene expression analysis of COL1A2 in peripheral blood samples by reverse transcription polymerase chain reaction (RT-PCR) assays, were described. for the descriptive analysis, measures of central tendency, dispersion and proportions were used. differences between the groups (p<0.05) were established by the student t-test. results: mean age was 8.6 (SD=1.9) years, 51.1 percent were female; 54 children were diagnosed with fluorosis and 38 without fluorosis; prevalence of dental fluorosis was 58.7 percent (95 percent CI: 48.4 percent -68.9 percent). gene expression of COL1A2 was statistically significantly lower (p<0.05) in the participants with dental fluorosis. conclusion: there are differences in the expression levels of the COL1A2 gene among the population under study. therefore, COL1A2 may be potentially involved in the development of dental fluorosis.
Subject(s)
Humans , Male , Female , Child, Preschool , Child , Collagen Type I/physiology , Fluorosis, Dental/etiology , Gene Expression , Gene Expression Regulation/physiology , Cross-Sectional Studies , Colombia/epidemiologyABSTRACT
OBJECTIVE: Literature review of new genes related to osteogenesis imperfecta (OI) and update of its classification. SOURCES: Literature review in the PubMed and OMIM databases, followed by selection of relevant references. SUMMARY OF THE FINDINGS: In 1979, Sillence et al. developed a classification of OI subtypes based on clinical features and disease severity: OI type I, mild, common, with blue sclera; OI type II, perinatal lethal form; OI type III, severe and progressively deforming, with normal sclera; and OI type IV, moderate severity with normal sclera. Approximately 90% of individuals with OI are heterozygous for mutations in the COL1A1 and COL1A2 genes, with dominant pattern of inheritance or sporadic mutations. After 2006, mutations were identified in the CRTAP, FKBP10, LEPRE1, PLOD2, PPIB, SERPINF1, SERPINH1, SP7, WNT1, BMP1, and TMEM38B genes, associated with recessive OI and mutation in the IFITM5 gene associated with dominant OI. Mutations in PLS3 were recently identified in families with osteoporosis and fractures, with X-linked inheritance pattern. In addition to the genetic complexity of the molecular basis of OI, extensive phenotypic variability resulting from individual loci has also been documented. CONCLUSIONS: Considering the discovery of new genes and limited genotype-phenotype correlation, the use of next-generation sequencing tools has become useful in molecular studies of OI cases. The recommendation of the Nosology Group of the International Society of Skeletal Dysplasias is to maintain the classification of Sillence as the prototypical form, universally accepted to classify the degree of severity in OI, while maintaining it free from direct molecular reference. .
OBJETIVO: Revisão da literatura sobre novos genes relacionados à osteogênese imperfeita (OI) e atualização da sua classificação. FONTE DOS DADOS : Revisão nas bases de dados do PUBMED e OMIM com seleção de referências relevantes. SÍNTESE DOS DADOS: Sillence et al., em 1979, desenvolveram uma classificação dos subtipos de OI baseada em características clínicas e gravidade da doença: OI tipo I, forma leve, comum, com escleras azuladas; OI tipo II, forma perinatal letal; OI tipo III, forma grave e progressivamente deformante com esclera normal; e OI tipo IV, forma de gravidade moderada com esclera normal. Cerca de 90% dos indivíduos com OI são heterozigotos para mutações em COL1A1 e COL1A2, com padrão de herança dominante ou esporádico. A partir de 2006 foram identificadas mutações nos genes CRTAP, FKBP10, LEPRE1, PLOD2, PPIB, SERPINF1, SERPINH1, SP7, WNT1, BMP1 e TMEM38B associadas à OI recessiva e mutação em IFITM5 associada à OI dominante. Mutações em PLS3 foram identificadas recentemente em famílias com osteoporose e fraturas, com padrão de herança ligado ao X. Além da complexidade genética das bases moleculares das OI, extensa variabilidade fenotípica resultante de loci individuais também tem sido documentada. CONCLUSÕES: Face à descoberta de novos genes e à correlação genótipo-fenótipo limitada, o uso de ferramentas de sequenciamento de nova geração torna-se útil no estudo molecular de casos de OI. A recomendação do Grupo de Nosologia da Sociedade Internacional de Displasias Esqueléticas é manter a classificação de Sillence como a forma prototípica e universalmente aceita para classificar o grau de gravidade na OI, e libertá-la de referência ...
Subject(s)
Humans , Osteogenesis Imperfecta/classification , Osteogenesis Imperfecta/genetics , Collagen Type I/physiology , Mutation/geneticsABSTRACT
After axotomy, regeneration can be enhanced by bridging the transected nerve with a biocompatible tube, and the effect of trophic substances or molecules from the extracellular matrix can be investigated by filling the prosthesis. In this study, we assessed the importance of the molecular organization and aggregational state of collagen type I in axonal regeneration and guidance. Two types of collagen were used, namely, a collagen gel derived from bovine tendon that displays supraorganization after extrusion, and collagen from rat tail which does not self-organize under such conditions. Adult male Wistar rats were divided into four groups. In the first group (n=3), the polyethylene tube was filled with bovine collagen, while in the second (n=3), the prosthesis was filled with rat-derived collagen. In the third group (n=3), the tube was left empty, and the fourth group (n=3), consisted of unoperated rats. Six weeks after tubulization, the number of axons was significantly higher with bovine collagen than with rat collagen (7,661 ± 1,018 versus 4,110 ± 1,027, p<0.05), as was the degree of implant absorption. These results support the hypothesis that the use of extracellular matrix substances that self-assembly in an organized pattern can enhance nerve regeneration.