The aim of the present study was to evaluate the behavioral patterns associated with autism and the prevalence of these behaviors in males and females, to verify whether our model of lipopolysaccharide (LPS) administration represents an experimental model of autism. For this, we prenatally exposed Wistar rats to LPS (100 μg/kg, intraperitoneally, on gestational day 9.5), which mimics infection by gram-negative bacteria. Furthermore, because the exact mechanisms by which autism develops are still unknown, we investigated the neurological mechanisms that might underlie the behavioral alterations that were observed. Because we previously had demonstrated that prenatal LPS decreases striatal dopamine (DA) and metabolite levels, the striatal dopaminergic system (tyrosine hydroxylase [TH] and DA receptors D1a and D2) and glial cells (astrocytes and microglia) were analyzed by using immunohistochemistry, immunoblotting, and real-time PCR. Our results show that prenatal LPS exposure impaired communication (ultrasonic vocalizations) in male pups and learning and memory (T-maze spontaneous alternation) in male adults, as well as inducing repetitive/restricted behavior, but did not change social interactions in either infancy (play behavior) or adulthood in females. Moreover, although the expression of DA receptors was unchanged, the experimental animals exhibited reduced striatal TH levels, indicating that reduced DA synthesis impaired the striatal dopaminergic system. The expression of glial cell markers was not increased, which suggests that prenatal LPS did not induce permanent neuroinflammation in the striatum. Together with our previous finding of social impairments in males, the present findings demonstrate that prenatal LPS induced autism-like effects and also a hypoactivation of the dopaminergic system.

Background Cellular channels composed of connexin 43 are known to act as key players in the life cycle of the skin and consequently to underlie skin repair. Objective This study was specifically set up to investigate the suite of molecular mechanisms driven by connexin 43-based channels on wound healing. Methods To this end, a battery of parameters, including re-epithelialization, neovascularization, collagen deposition and extracellular matrix remodeling, was monitored over time during experimentally induced skin repair in heterozygous connexin 43 knockout mice. Results It was found that connexin 43 deficiency accelerates re-epithelialization and wound closure, increases proliferation and activation of dermal fibroblasts, and enhances the expression of extracellular matrix remodeling mediators. Conclusion These data substantiate the notion that connexin 43 may represent an interesting therapeutic target in dermal wound healing.

Gap junction channels, formed by connexins (Cx), are involved in the maintenance of tissue homeostasis, cell growth, differentiation, and development. Several studies have shown that Cx43 is involved in the control of wound healing in dermal tissue. However, it remains unknown whether Cx43 plays a role in the control of liver fibrogenesis. Our study investigated the roles of Cx43 heterologous deletion on carbon tetrachloride (CCl(4))-induced hepatic fibrosis in mice. We administered CCl(4) to both Cx43-deficient (Cx43(+/-)) and wild-type mice and examined hepatocellular injury and collagen deposition by histological and ultrastructural analyses. Serum biochemical analysis was performed to quantify liver injury. Hepatocyte proliferation was analyzed immunohistochemically. Protein and messenger RNA (mRNA) expression of liver connexins were evaluated using immunohistochemistry as well as immunoblotting analysis and quantitative real-time PCR. We demonstrated that Cx43(+/-) mice developed excessive liver fibrosis compared with wild-type mice after CCl(4) -induced chronic hepatic injury, with thick and irregular collagen fibers. Histopathological evaluation showed that Cx43(+/-) mice present less necroinflammatory lesions in liver parenchyma and consequent reduction of serum aminotransferase activity. Hepatocyte cell proliferation was reduced in Cx43(+/-) mice. There was no difference in Cx32 and Cx26 protein or mRNA expression in fibrotic mice. Protein expression of Cx43 increased in CCl(4)-treated mice, although with aberrant protein location on cytoplasm of perisinusoidal cells. Our results demonstrate that Cx43 plays an important role in the control and regulation of hepatic fibrogenesis.

ABSTRACT. Transgenic animals are used extensively in the study of in vivo gene function, as models for human diseases and in the production of biopharmaceuticals. The technology behind obtaining these animals involves molecular biology techniques, cell culture and embryo manipulation; the mouse is the species most widely used as an experimental model. In scientific research, diverse models are available as tools for the elucidation of gene function, such as transgenic animals, knockout and conditional knockout animals, knock-in animals, humanized animals, and knockdown animals. We examined the evolution of the science for the development of these animals, as well as the techniques currently used in obtaining these animal models. We review the phenotypic techniques used for elucidation of alterations caused by genetic modification. We also investigated the role of genetically modified animals in the biotechnology industry, where they promise a revolution in obtaining heterologous proteins through natural secretions, such as milk, increas- ing the scale of production and facilitating purification, thereby lowering the cost of production of hormones, growth factors and enzymes.

GJA1 gene (Connexin43, also known as Cx43) is the most abundant gap junction protein isoform in animal cells and is associated with bone development in embryos. The objective of the present work was to evaluate in vivo osteal development in GJA1-deficient fetal mice through determination of the histological and molecular alterations induced by partial or total deletion of the GJA1 gene. Heterozygous C57BL/6 mice (HT) harboring a null mutation of the GJA1 gene were mated, and pregnant females were submitted to euthanasia and Caesarean section from 12.5 to 19.5 days post coitum (dpc). HT (GJA1 þ/-) and homozygous (GJA1 -/-) knockout (KO) mutants and wild-type (WT) fetuses were identified by polymerase chain reaction (PCR), and development curves were constructed on the basis of fetus weight and crown-rump length. Histopathological, histochemical, and realtime PCR analyses were performed in order to assess the expression of markers associated with bone development, namely, osteocalcin, osteopontin, alkaline phosphatase, RUNX2, GJA1, GJC1 (Cx45), and GJA3 (Cx46). HT and KO fetuses exhibited delays in the differentiation of osteoblasts and, consequently, in bone development in comparison with the WT group. Additionally, less deposition of mineralized and osteoid matrix was observed in GJA1-deficient fetuses. Bone development in KO fetuses was delayed through the moment of birth, but in HT animals the delay only extended until 17.5 dpc, following which development was normalized. The expression of genes coding for osteocalcin, osteopontin, alkaline phosphatise, and RUNX2 were also delayed in GJA1-deficient fetuses. Animals that exhibited a lower expression of GJA1 presented delayed expression of the GJC1 and GJA3 genes and their corresponding protein products in the bone tissue. The results of the present study contribute to our understanding of the function of GJA1 during bone development and suggest that GJC1 could play a role in restoring intercellular communication in GJA1-deficient mice.