Beyond Glycemic Control: GLP-1 Receptor Agonists and Their Impact on Calcium Homeostasis in Real-World Patients.

Background/Objectives: The effect of glucagon-like peptide-1 receptor (GLP-1R) agonists on calcium homeostasis is poorly understood. This study aimed to investigate the association between GLP-1R agonist use and the risk of hypocalcemia and/or hypercalcemia, as well as other clinical outcomes. Methods: A retrospective cohort study used de-identified patient data from the TriNetX Global Collaborative Network, including 15,655 adult patients prescribed GLP-1R agonists and 15,655 propensity-matched controls. Outcomes included hypocalcemia, hypercalcemia, emergency visits, hospitalizations, cardiovascular events, and all-cause mortality. Results: GLP-1R agonist use was associated with a reduced risk of hypocalcemia (2.7% vs. 5.5%, RR 0.49, 95% CI: 0.44-0.55) but an increased risk of hypercalcemia (2.3% vs. 1.1%, RR 2.02, 95% CI: 1.69-2.42). The effect on hypocalcemia was most pronounced during the first six months of treatment. Among individual agents, tirzepatide showed the most pronounced effect, reducing hypocalcemia risk by 63% while increasing hypercalcemia risk by 85%. Semaglutide demonstrated similar effects, while dulaglutide and liraglutide showed modest effects. Furthermore, GLP-1R agonist use was associated with reduced risks of emergency visits (RR 0.57, 95% CI: 0.54-0.60), hospitalizations (RR 0.40, 95% CI: 0.36-0.44), cardiovascular events, and all-cause mortality (HR 0.27, 95% CI: 0.21-0.36). Conclusions: GLP-1R agonists exhibit a complex influence on calcium homeostasis, reducing hypocalcemia risk while increasing hypercalcemia risk. Beyond calcium regulation, these medications significantly reduce healthcare utilization, improve cardiovascular outcomes, and decrease mortality. Further research is needed to elucidate the mechanisms behind the differential effects of individual GLP-1R agonists, particularly tirzepatide, to optimize personalized treatment approaches and long-term safety.

Experimental treatment efficacy of dmrFABP5 on prostate cancer singly or in combination with drugs in use.

Enzalutamide is a drug used to treat prostate cancer (PC) and docetaxel is a drug for chemotherapeutic treatment of diverse cancer types, including PC. The effectiveness of these drugs in treating castration-resistant prostate cancer (CRPC) is poor and therefore CRPC is still largely incurable. However, the bio-inhibitor of fatty acid-binding protein 5 (FABP5), dmrFABP5, which is a mutant form of FABP5 incapable of binding to fatty acids, has been shown recently to be able to suppress the tumorigenicity and metastasis of cultured CRPC cells. The present study investigated the possible synergistic effect of dmrFABP5 combined with either enzalutamide or docetaxel on suppressing the tumorigenic properties of PC cells, including cell viability, migration, invasion and colony proliferation in soft agar. A highly significant synergistic inhibitory effect on these properties was observed when dmrFABP5 was used in combination with enzalutamide on androgen-responsive PC 22RV1 cells. Moreover, a highly significant synergistic inhibitory effect was also observed when dmrFABP5 was combined with docetaxel, and added to 22RV1 cells and to the highly malignant, androgen-receptor (AR)-negative Du145 cells. DmrFABP5 alone failed to produce any suppressive effect when added to the FABP5-negative cell line LNCaP, although enzalutamide could significantly suppress LNCaP cells when used as a single agent. These synergistic inhibitory effects of dmrFABP5 were produced by interrupting the FABP5-related signal transduction pathway in PC cells. Thus, dmrFABP5 appears to be not only a potential single therapeutic agent, but it may also be used in combination with existing drugs to suppress both AR-positive and AR-negative PC.

FABP5 can substitute for androgen receptor in malignant progression of prostate cancer cells.

Fatty acid­binding protein 5 (FABP5) and androgen receptor (AR) are critical promoters of prostate cancer. In the present study, the effects of knocking out the FABP5 or AR genes on malignant characteristics of prostate cancer cells were investigated, and changes in the expression of certain key proteins in the FABP5 (or AR)­peroxisome proliferator activated receptor­Î³ (PPARγ)­vascular endothelial growth factor (VEGF) signaling pathway were monitored. The results obtained showed that FABP5­ or AR­knockout (KO) led to a marked suppression of the malignant characteristics of the cells, in part, through disrupting this signaling pathway. Moreover, FABP5 and AR are able to interact with each other to regulate this pathway, with FABP5 controlling the dominant AR splicing variant 7 (ARV7), and AR, in return, regulates the expression of FABP5. Comparisons of the RNA profiles revealed the existence of numerous differentially expressed genes (DEGs) comparing between the parental and the FABP5­ or AR­KO cells. The six most abundant changes in DEGs were found to be attributable to the transition from androgen­responsive to androgen­unresponsive, castration­resistant prostate cancer (CRPC) cells. These findings have provided novel insights into the complex molecular pathogenesis of CRPC cells, and have demonstrated that interactions between FABP5 and AR contribute to the transition of prostate cancer cells to an androgen­independent state. Moreover, gene enrichment analysis revealed that the most highly enriched biological processes associated with the DEGs included those responsive to fatty acids, cholesterol and sterol biosynthesis, as well as to lipid and fatty acid transportation. Since these pathways regulated by FABP5 or AR may be crucial in terms of transducing signals for cancer cell progression, targeting FABP5, AR and their associated pathways, rather than AR alone, may provide a new avenue for the development of therapeutic strategies geared towards suppressing the malignant progression to CRPC cells.

Molecular mechanisms on how FABP5 inhibitors promote apoptosis-induction sensitivity of prostate cancer cells.

Previous work showed that FABP5 inhibitors suppressed the malignant progression of prostate cancer cells, and this suppression might be achieved partially by promoting apoptosis. But the mechanisms involved were not known. Here, we investigated the effect of inhibitors on apoptosis and studied the relevant mechanisms. WtrFABP5 significantly reduced apoptotic cells in 22Rv1 and PC3 by 18% and 42%, respectively. In contrast, the chemical inhibitor SB-FI-26 produced significant increases in percentages of apoptotic cells in 22Rv1 and PC3 by 18.8% (±4.1) and 4.6% (±1.1), respectively. The bio- inhibitor dmrFABP5 also did so by 23.1% (±2.4) and 15.8% (±3.0), respectively, in these cell lines. Both FABP5 inhibitors significantly reduced the levels of the phosphorylated nuclear fatty acid receptor PPARγ, indicating that these inhibitors promoted apoptosis-induction sensitivity of the cancer cells by suppressing the biological activity of PPARγ. Thus, the phosphorylated PPARγ levels were reduced by FABP5 inhibitors, the levels of the phosphorylated AKT and activated nuclear factor kapper B (NFκB) were coordinately altered by additions of the inhibitors. These changes eventually led to the increased levels of cleaved caspase-9 and cleaved caspase-3; and thus, increase in the percentage of cells undergoing apoptosis. In untreated prostate cancer cells, increased FABP5 suppressed the apoptosis by increasing the biological activity of PPARγ, which, in turn, led to a reduced apoptosis by interfering with the AKT or NFκB signaling pathway. Our results suggested that the FABP5 inhibitors enhanced the apoptosis-induction of prostate cancer cells by reversing the biological effect of FABP5 and its related pathway.

Corneal biomechanical properties following corneal cross-linking: Does age have an effect?

PURPOSE: To explore the effect of age on corneal biomechanical properties following corneal cross-linking (CXL). METHODS: A total of 12 pairs of human eye-banked corneas (24 corneas, from 14 females and 10 males) were used in the study. The mean donor age was 48.5 years (ranging from 26 to 71 years). Corneas were divided into three age groups: A (26-41 years), B (42-57 years) and C (58-71 years), with four pairs in each group. For each pair, the right corneas were cross-linked using accelerated CXL with UVA (10 mW/cm2) and riboflavin, while the left corneas served as controls and were not exposed to either UVA irradiation or riboflavin. The corneal elastic modulus of the anterior, mid and posterior corneal stroma was measured using nanoindentation. RESULTS: The difference in the corneal elastic modulus following CXL was significant in the anterior (p = 0.00002) and mid stroma (p = 0.001); however, the difference was not significant in the posterior stroma (p = 0.27) when compared to control corneas. The corneal elastic modulus of the anterior stroma increased by 178.44% in Group A, 119.7% in Group B and 50.73% in Group C compared to control corneas. For the mid stroma, the elastic modulus increased by 47.35% in Group A, 25% in Group B and 24.56% in Group C. No differences were observed in the posterior stroma between age groups. CONCLUSIONS: Corneal elasticity showed a greater response to CXL in the younger group compared to older groups. CXL treatment showed effectiveness in enhancing stromal strength, and the effect was concentrated in the anterior and mid stroma with minimal impact on the posterior stroma in all age groups.