Essential Role Of High Glucose-Induced Overexpression Of PKCβ And PKCδ In GLP-1 Resistance In Rodent Cardiomyocytes

Effect of 460 nm blue light PBM on human MeWo melanoma cells

Photobiomodulation (PBM) using 460 nm blue light has been shown to have an inhibitory effect on skin cancer cells. In this study, we used a continuous LED light source with a wavelength of 460 nm and designed various combinations of power density (ranging from 6.4 to 25.6 mW) and dose (ranging from 0.96 to 30.72 J/cm2) to conduct treatment experiments on MeWo cells to investigate the effects of blue light on MeWo melanoma cells. We are focusing on cell viability, cytotoxicity, mitochondrial function, oxidative stress, and apoptosis. We found that blue light inhibits these melanoma cells through oxidative stress and DNA damage, and this inhibition intensifies at higher irradiance levels. Although the cells initially attempt to resist the stress induced by the treatment, they eventually undergo apoptosis over time. These findings contribute to understanding melanoma's molecular response to blue light PBM, lay the groundwork for future clinical applications.

Blue light photobiomodulation induced apoptosis by increasing ROS level and regulating SOCS3 and PTEN/PI3K/AKT pathway in osteosarcoma cells

Blue light photobiomodulation (PBM) has attracted great attention in diminishing proliferation and inducing death of cancer cells recently. Osteosarcoma (OS) primarily occurring in children and adolescents, the limitations of drug resistance and limb salvage make it urgent to develop and identify new adjuvant therapeutic strategies. In this work, we attempted to research the anticancer effects and biological mechanisms of blue light PBM in human OS MG63 cells. The effects of various blue light parameters on MG63 cells indicated that suppressed cell proliferation and cell migration, induced cell apoptosis which are experimentally assessed using multiple assays including CCK, LDH, wound healing assay and Hoechst staining. Concurrently, the increases of ROS level and the inhibition of PI3K and AKT expression were identified under high-dose blue light PBM in MG63 cells. Meanwhile, SOCS3 is a major inducible anti-tumor molecule, we also found that blue light LED substantially promoted its expression. Thus, this study proposed that bule light PBM may be a hopeful therapeutic approach in OS clinical treatment in the future.

Control of human pancreatic beta cell kinome by glucagon-like peptide-1 receptor biased agonism

AIM

To determine the kinase activity profiles of human pancreatic beta cells downstream of glucagon-like peptide-1 receptor (GLP-1R) balanced versus biased agonist stimulations.

MATERIALS AND METHODS

This study analysed the kinomic profiles of human EndoC-βh1 cells following vehicle and GLP-1R stimulation with the pharmacological agonist exendin-4, as well as exendin-4-based biased derivatives exendin-phe1 and exendin-asp3 for acute (10-minute) versus sustained (120-minute) responses, using PamChip protein tyrosine kinase and serine/threonine kinase assays. The raw data were filtered and normalized using BioNavigator. The kinase analyses were conducted with R, mainly including kinase-substrate mapping and Kyoto Encyclopedia of Genes and Genomes pathway analysis.

RESULTS

The present analysis reveals that kinomic responses are distinct for acute versus sustained GLP-1R agonist exposure, with individual responses associated with agonists presenting specific bias profiles. According to pathway analysis, several kinases, including JNKs, PKCs, INSR and LKB1, are important GLP-1R signalling mediators, constituting potential targets for further research on biased GLP-1R downstream signalling.

CONCLUSION

The results from this study suggest that differentially biased exendin-phe1 and exendin-asp3 can modulate distinct kinase interaction networks. Further understanding of these mechanisms will have important implications for the selection of appropriate anti-type 2 diabetes therapies with optimized downstream kinomic profiles.

High Glucose Attenuates Cardioprotective Effects of Glucagon-Like Peptide-1 Through Induction of Mitochondria Dysfunction via Inhibition of β-Arrestin-Signaling

An increased vulnerability has been detected after ischemia/reperfusion injury in cardiomyocytes in diabetic patients. Glucagon-like peptide-1 (GLP-1) has been proven to have a notable cardioprotective effect in cardiomyocytes. However, in diabetic patients, the cardioprotective effects of GLP-1 are compromised, which is called GLP-1 resistance. β-arrestin is one of the two main downstream effectors of GLP-1 and β-arrestin signaling pathway exerts cardioprotective effects upon activation of GLP-1R. Our hypothesis is that the increased vulnerability of cardiomyocytes in diabetic patients is partly due to disruption of the β-arrestin signaling pathway. To test this, we analyzed cardiomyocyte viability and survival in high glucose and normal glucose condition after hypoxia/reoxygenation injury in vitro, additional GLP-1 was used to determine whether β-arrestin signaling pathway was involved. We also investigated the role of mitochondrial dysfunction in GLP-1 resistance. Our results showed that cardioprotective effects of GLP-1 were reduced in high glucose cultured H9C2 cells compared to normal glucose cultured H9C2, verifying the existence of GLP-1 resistance in high glucose cultured H9C2 cells. Further study suggested that β-arrestin plays a key role in GLP-1 resistance: β-arrestin expression is notably downregulated in high glucose condition and cardioprotective effects of GLP-1 can be diminished by downregulation of β-arrestin in normal glucose condition while upregulation of β-arrestin can restore cardioprotective effects of GLP-1 in high glucose condition. Then we explore how β-arrestin affects the cardioprotective effects of GLP-1 and found that β-arrestin exerts cardioprotective effects by improving mitochondria quality control via the PI3K/Akt signaling pathway. Thus, our study found out a new mechanism of GLP-1 resistance of cardiomyocytes in high glucose conditions that impaired β-arrestin expression, caused mitochondria dysfunction and eventually cell death. Our study provided a new perspective in treating myocardial ischemia/reperfusion injury in diabetic patients.

The Role of Non-coding RNAs in Diabetic Nephropathy-Related Oxidative Stress

Diabetic nephropathy (DN) is one of the main complications of diabetes and the main cause of diabetic end-stage renal disease, which is often fatal. DN is usually characterized by progressive renal interstitial fibrosis, which is closely related to the excessive accumulation of extracellular matrix and oxidative stress. Non-coding RNAs (ncRNAs) are RNA molecules expressed in eukaryotic cells that are not translated into proteins. They are widely involved in the regulation of biological processes, such as, chromatin remodeling, transcription, post-transcriptional modification, and signal transduction. Recent studies have shown that ncRNAs play an important role in the occurrence and development of DN and participate in the regulation of oxidative stress in DN. This review clarifies the functions and mechanisms of ncRNAs in DN-related oxidative stress, providing valuable insights into the prevention, early diagnosis, and molecular therapeutic targets of DN.

Comparative transcriptome analysis of gene expression patterns on B16F10 melanoma cells under Photobiomodulation of different light modes

Cutaneous melanoma is one of the aggressive cancers. Recent studies have shown that Photobiomodulation (PBM) can inhibit the proliferation of melanoma cells. However, it is not clear that the effect of PBM light mode on the inhibition of melanoma cells. Herein, we investigated the difference of influence between continuous wave (CW) and Pulse PBM on B16F10 melanoma cells. Our results suggested that Pulse mode had a more significant inhibition on the viability of B16F10 melanoma cells than CW mode under the PBM light parameter of wavelength, dose, and average irradiance at 457 nm, 1.14 J/cm2, and 0.19 mW/cm2. Besides, we revealed the differentially expressed genes of B16F10 melanoma cells under the various treatments of PBM light mode (not PBM treatment, CW mode, and Pulse mode) by RNA sequencing. Together, our data suggested that Pulse-PBM can improve the effect of PBM on cells significantly and there may be different molecular mechanisms between Pulse and CW mode including anti-proliferative and cell necrosis. The study shed new light on investigating the molecular mechanisms of various PBM light modes on B16F10 melanoma cells.