Lmpt regulates the function of Drosophila muscle by acting as a repressor of Wnt signaling.

BACKGROUND: LIM domain is considered to be important in mediating protein-protein interactions, and members of the LIM protein family can co-regulate tissue-specific gene expression by interacting with different transcription factors. However, its exact function in vivo remains unclear. Our study demonstrates that the LIM protein family member Lmpt may act as a cofactor that interacts with other transcription factors to regulate cellular functions. METHODS: In this study, we generated Lmpt knockdown Drosophila (Lmpt-KD) using the UAS-Gal4 system. We assessed the lifespan and motility of Lmpt-KD Drosophila and analyzed the expression of muscle-related and metabolism-related genes using qRT-PCR. Additionally, we utilized Western blot and Top-Flash luciferase reporter assay to evaluate the level of the Wnt signaling pathway. RESULTS: Our study revealed that knockdown of the Lmpt gene in Drosophila resulted in a shortened lifespan and reduced motility. We also observed a significant increase in oxidative free radicals in the fly gut. Furthermore, qRT-PCR analysis indicated that knockdown of Lmpt led to decreased expression of muscle-related and metabolism-related genes in Drosophila, suggesting that Lmpt plays a crucial role in maintaining muscle and metabolic functions. Finally, we found that reduction of Lmpt significantly upregulated the expression of Wnt signaling pathway proteins. CONCLUSION: Our results demonstrate that Lmpt is essential for motility and survival in Drosophila and acts as a repressor in Wnt signaling.

The roles of FHL2 in cancer.

LIM domain protein 2, also known as LIM protein FHL2, is a member of the LIM-only family. Due to its LIM domain protein characteristics, FHL2 is capable of interacting with various proteins and plays a crucial role in regulating gene expression, cell growth, and signal transduction in muscle and cardiac tissue. In recent years, mounting evidence has indicated that the FHLs protein family is closely associated with the development and occurrence of human tumors. On the one hand, FHL2 acts as a tumor suppressor by down-regulating in tumor tissue and effectively inhibiting tumor development by limiting cell proliferation. On the other hand, FHL2 serves as an oncoprotein by up-regulating in tumor tissue and binding to multiple transcription factors to suppress cell apoptosis, stimulate cell proliferation and migration, and promote tumor progression. Therefore, FHL2 is considered a double-edged sword in tumors with independent and complex functions. This article reviews the role of FHL2 in tumor occurrence and development, discusses FHL2 interaction with other proteins and transcription factors, and its involvement in multiple cell signaling pathways. Finally, the clinical significance of FHL2 as a potential target in tumor therapy is examined.

The Roles of the LIM Domain Proteins in Drosophila Cardiac and Hematopoietic Morphogenesis.

Drosophila melanogaster has been used as a model organism for study on development and pathophysiology of the heart. LIM domain proteins act as adaptors or scaffolds to promote the assembly of multimeric protein complexes. We found a total of 75 proteins encoded by 36 genes have LIM domain in Drosophila melanogaster by the tools of SMART, FLY-FISH, and FlyExpress, and around 41.7% proteins with LIM domain locate in lymph glands, muscles system, and circulatory system. Furthermore, we summarized functions of different LIM domain proteins in the development and physiology of fly heart and hematopoietic systems. It would be attractive to determine whether it exists a probable "LIM code" for the cycle of different cell fates in cardiac and hematopoietic tissues. Next, we aspired to propose a new research direction that the LIM domain proteins may play an important role in fly cardiac and hematopoietic morphogenesis.

[p53-dependent antiproliferation and apoptosis of H22 cell induced by melatonin].

BACKGROUND & OBJECTIVE: It has been shown that melatonin has a direct inhibitory effect on the proliferation of H22 mouse hepatoma cells in our research. This study was designed to investigate its molecular mechanism. METHODS: (1) Animal models were established by transplanting H22 cells and treated with melatonin, and then the p53 and cyclin E of the tumor tissue were determined by immunohistochemical analysis. (2) After treatment of H22 cells with melatonin in vitro, the percentage of cells in each cell cycle phase and apoptosis rate were analyzed by flow cytometry. p53 and cyclin E were determined again by immunohistochemical analysis. The level of Fas mRNA was examined by real time polymerase chain reaction (RT-PCR). RESULTS: (1) After treated with melatonin (1 x 10(-6) mol/L), the number of the H22 cells in phase G(0)/G(1) were elevated from 75.24% to 85.46%, while which in phase S almost decreased from 10.32% to 0, and at the same time, the number of apoptotic cells increased from 5.07% to 12.77%. (2) Compared with the control, the level of p53 elevated 42.5% (in vitro) and 19.5% (in vivo), however, the level of cyclin E decreased 31.7% (in vitro) and 39.9% (in vivo). (3) Fas mRNA increased about 44.2% after melatonin treatment (P< 0.01). CONCLUSION: Melatonin inhibits the proliferation of H22 cells by arrest and apoptosis, and the mechanism perhaps interferes with increasing p53 that results in down-regulation of cyclin E indirectly and stimulates the expression of Fas gene.