👤 Birol Ay

Dysregulated actions of the bone-derived phosphaturic hormone, fibroblast growth factor-23 (FGF23), underlie the pathophysiology of several diseases. FGF23 is synthesized primarily in osteocytes in response to various endogenous molecules; however, the mechanisms governing FGF23 production are incompletely understood. Glycerol-3-phosphate (G3P), a glycolytic by-product originating from the kidney, critically controls skeletal FGF23 synthesis via its conversion in bone to lysophosphatidic acid (LPA), which stimulates osteocyte FGF23 production. The bioactive vitamin D, 1,25-dihydroxyvitamin D (1,25D), also promotes FGF23 production in osteocytes. We herein demonstrated that LPA requires 1,25D action to raise FGF23 levels in mouse bone explants and mice. RNA sequencing of osteocyte-like Ocy454 cells identified differentially expressed genes (DEGs) uniquely induced by LPA/1,25D co-treatment. These unique DEGs were enriched for the ribosome biogenesis pathway. DEGs concurrently induced by individual LPA and 1,25D treatments were enriched for MAPK signaling, and inhibiting this pathway obliterated LPA/1,25D-induced FGF23 production. DEGs following LPA/1,25D co-treatment were enriched for the cytokine-cytokine receptor interaction pathway. Moreover, LPA/1,25D co-treatment, but not individual LPA and 1,25D treatments, rapidly induced the expression of Il12a, the gene encoding the pro-inflammatory cytokine interleukin-12 alpha-subunit, which responded solely to 1,25D at later times and required MAPK-ERK1/2 signaling. Inhibiting cytokine signaling or knocking down Il12a inhibited, while overexpressing Il12a enhanced LPA/1,25D-induced FGF23 production. However, challenging Ocy454 cells with recombinant bioactive interleukin-12 failed to enhance FGF23 production, suggesting that Il12a plays a noncanonical role. Our results reveal a mechanism of skeletal FGF23 synthesis involving synergistic actions of LPA and 1,25D, advancing our understanding of FGF23 regulation. Show less

This study was conducted to examine the effect of hope and psychological well-being on quality of life in elderly cancer patients using latent profile analysis (LPA). The study was conducted with 398 elderly cancer patients in Ataturk University Research in Turkey between September 2024 and January 2025. R programming language 4.1.3, G*Power 3.1 and SPSS-22 program were used in the analysis of the study. In our study, in the first stage of LPA analysis, BIC values were obtained by iterating each model and each class for 4 models and 9 classes. Since the lowest BIC value was found in the EEE model, the EEE model was considered as the appropriate model in the study and the class analysis was performed over this model. It is concluded that the best fitting class is the 2-class solution. As a result of LPA, class 1 has the lowest arithmetic mean in all indicators. According to the latent classes of the individuals in our study; it was found that the quality of life of individuals with Low Psychological Status was significantly lower than individuals with High Psychological Status (p < 0.05). In our study, two classes were found as a result of LPA. According to the classes, it was found that the quality of life of individuals with low psychological status was lower than individuals with high psychological status. Increased hope and psychological well-being were found to improve quality of life in elderly cancer patients. Longitudinal studies on quality of life in elderly cancer patients are recommended. Show less

FLRG (follistatin-related gene) is a secreted glycoprotein which is very similar to follistatin. As observed for follistatin, FLRG is involved in the regulation of various biological processes through its binding to members of the TGFbeta (transforming growth factor beta) superfamily, activin, BMPs (bone morphogenetic proteins) and myostatin. Unlike follistatin, FLRG has been found to be both secreted and localized within the nucleus of many FLRG-producing cells, suggesting the existence of specific intracellular functions of the protein. In order to analyse the function of the nuclear form of FLRG, we performed a yeast two-hybrid screen, in which we identified AF10 [ALL1 (acute lymphoblastic leukaemia) fused gene from chromosome 10], a translocation partner of the MLL (mixed-lineage leukaemia) oncogene in human leukaemia, as a FLRG-interacting protein. This interaction was confirmed by far-Western-blot analysis and co-immunoprecipitation with transfected COS-7 cells. The N-terminal region of AF10, including the PHD (plant homeodomain), is sufficient to mediate this interaction, and has been shown to be involved in AF10 homo-oligomerization. By immunoprecipitation experiments, we showed that FLRG enhances the homo-oligomerization of AF10. Functional studies demonstrated that FLRG enhances the transactivation properties of the AF10 protein fused to Gal4 DNA-binding domains in transient transfection assays. Our present study provides novel insights into the function of the nuclear form of the FLRG protein, which is revealed as a novel regulator of transcription. The nuclear isoform of FLRG lacks an intrinsic transactivation domain, but enhances AF10-mediated transcription, probably through promoting the homo-oligomerization of AF10, thus facilitating the recruitment of co-activators. Show less