Transforming growth factor-beta (TGF-beta) is a multifunctional growth modulator that inhibits the proliferation of many epithelial cells while stimulating the proliferation of most fibroblasts. To examine the role of TGF-beta in mouse lung chemically induced tumorigenesis, expression of the TGF-beta 1, -beta 2, and -beta 3 proteins was examined in A/J mice treated with the carcinogen urethane to induce lung adenomas using immunohistochemical staining analysis. Immunostaining for the TGF-beta ligands was detected in the epithelium of the bronchioles of untreated A/J mice with immunostaining being more intense for TGF-beta 1 than for TGF-beta 2 and TGF-beta 3; immunostaining for each TGF-beta ligand was also detected in the bronchiolar epithelium of urethane-treated A/J mice at levels similar to untreated mice. Immunostaining for the TGF-beta ligands was also detected in adenomas by 2 months; staining for TGF-beta 1, -beta 2, and -beta 3 in adenomas was detected at levels comparable with bronchioles. Following treatment with urethane for 8 months, immunostaining for TGF-beta s 1, 2, and 3 in bronchioles persisted at levels comparable to that in normal bronchioles and also persisted in adenomas, with staining for the TGF-beta ligands being very prominent on the edge of the tumor. Expression of TGF-beta 1 mRNA was examined in urethane-treated mouse lung tissue using Northern blot hybridization; here, expression of TGF-beta 1 mRNA increased 2-fold in 3-month urethane-treated lung tissue and an additional 2.5-fold by 8 months following urethane administration. Expression of TGF-beta 1 mRNA was also examined in nontumorigenic and tumorigenic mouse lung cells; in these cells, expression of TGF-beta 1 mRNA was higher in the tumorigenic cells than in the nontumorigenic cell line. These data show that there is an increase in expression of TGF-beta 1 during tumorigenesis and suggest that TGF-beta may play an important role in mouse lung carcinogenesis induced by urethane.
Adrenomedullin (AM) is a hypotensive polypeptide that has been shown to stimulate cyclic AMP and intracellular free Ca2+ agents that are known to induce expression of proto-oncogenes, in various cell types. Transforming growth factor-beta 1 (TGF-beta1) is a multifunctional polypeptide that regulates proliferation, differentiation and cell cycle progression in both normal and malignant epithelial cells. The diverse biological actions of AM and TGF-beta1 may be related to their capacities to initiate different genomic programs in target cells via the induction of expression of multiple genes including early response genes and proto-oncogenes. AM, TGF-beta1 and phorbol-12-myristate-13-acetate (PMA) exert both positive and negative effects on mitogenesis. The effects of AM, TGF-beta1 and PMA were examined in human non-small cell lung cancer (NSCLC) cells. AM caused an increase in its mRNA transcript that peaked by 6 hours and persisted to 24 hours. While expression of TGF-beta1 mRNA was not affected by AM in these cells, the mRNAs for TGF-beta1 and TGF-beta3 decreased by 3 hours. In contrast, TGF-beta1 had no effect on expression of AM mRNA. Interestingly, PMA caused an increase in AM and TGF-beta1 mRNAs in NSCLC cells. While both TGF-beta1 and PMA caused a transient increase in expression of the mRNAs for early response genes including c-fos, c-jun and egr-1 that peaked by 1 hour following treatment, the increase in expression of these mRNAs following treatment with AM peaked only after 3-6 hours. Western blotting analysis showed increases in the levels of c-jun protein following treatment with AM, TGF-beta1 and PMA. The increase in c-jun protein from treatment with AM occurred 10 hours after that from TGF-beta1 and PMA. Activator protein 1 (AP-1) DNA binding activity was also demonstrated to increase following treatment with AM, TGF-beta1 and PMA, with the increase in AP-1 DNA binding activity following AM treatment occurring 10 hours later than that from TGF-beta1 and PMA treatment. These data show that AM can regulate expression of its mRNA transcript in NSCLC cells. Our study suggests that NSCLC cells are important targets of AM and TGF-beta1 and that AM and TGF-beta1 may regulate activities in these malignant lung cells through differential induction of various early response genes.
Objective: The objectives of this systematic review are to verify the effects of strength training on muscular strength and functional capacity in adults with stroke sequelae. Method: Systematic review study, carried out with published articles on strength training, applied to adults with sequelae of acute or chronic stroke, indexed in the PubMed, SciELO, PEDro and LILACS databases. Descriptors in Portuguese and English were used (Stroke and Strength Training; Stroke and Exercise; Stroke and Physical Fitness; Stroke and Exercise), published between January/2014 and January/2023. Results: 11 clinical trials were included. The studies used different strength training methods. The studies observed an increase in maximum dynamic and isometric strength and in functional capacity tests in all groups that performed strength training. Conclusion: Strength exercise can contribute to increasing muscle strength and improving the functional capacity of people with stroke sequelae, but studies with a larger number of participants are necessary.
The transforming growth factor-betas (TGF-betas) are multifunctional regulatory polypeptides that play a crucial role in many cell processes and function through a set of cell surface protein receptors that includes TGF-beta type I (RI) and type II (RII). The present study reports a comprehensive comparison of the patterns of expression of TGF-beta RI and RII proteins and mRNAs in the developing mouse embryo using immunohistochemical and in situ hybridization analyses. Although widespread expression of both TGF-beta receptors was detected throughout the embryonic development period so that many similarities occur in localization of the TGF-beta receptors, TGF-beta RI was expressed in a well-defined, non-uniform pattern that was different in many respects from that of TGF-beta RII. Whereas higher levels of TGF-beta RI compared to TGF-beta RII were detected in some tissues of the embryo at the beginning of organogenesis, the level of TGF-beta RII increased more dramatically than that of TGF-beta RI during late organogenesis; this was especially true in many neural structures where TGF-beta RI and RII were comparable by day 16. The lung, kidney and intestine, in which epithelial-mesenchymal interactions occur, showed a complex pattern of TGF-beta RI and Rll expression. Additionally, northern blot hybridization and reverse transcription-polymerase chain reaction (RT-PCR) amplification showed non-uniform expression of the transcripts for TGF-beta RI and RII in embryonic and adult mouse and rat tissues. These data show that regulation of TGF-beta1 RI and RII occurs concurrently, but distinctly, in a spatial and temporal manner in rodent embryogenesis which may allow control of signal transduction of TGF-beta during development.
