Osteocalcin-expressing endothelial progenitor cells and serum osteocalcin forms are independent biomarkers of coronary atherosclerotic disease severity in male and female patients

New insights into vitamin K biology with relevance to cancer

Phylloquinone (vitamin K1) and menaquinones (vitamin K2 family) are essential for post-translational γ-carboxylation of a small number of proteins, including clotting factors. These modified proteins have now been implicated in diverse physiological and pathological processes including cancer. Vitamin K intake has been inversely associated with cancer incidence and mortality in observational studies. Newly discovered functions of vitamin K in cancer cells include activation of the steroid and xenobiotic receptor (SXR) and regulation of oxidative stress, apoptosis, and autophagy. We provide an update of vitamin K biology, non-canonical mechanisms of vitamin K actions, the potential functions of vitamin K-dependent proteins in cancer, and observational trials on vitamin K intake and cancer.

RS 2247911 polymorphism of GPRC6A gene and serum undercarboxylated-osteocalcin are associated with testis function

PURPOSE

Undercarboxylated-Osteocalcin (ucOCN), acting on its putative receptor GPRC6A, was shown to stimulate testosterone (T) production by Leydig cells in rodents, in parallel with the hypothalamus-pituitary-gonadal axis (HPG) mediated by luteinizing hormone (LH). The aim of this cross-sectional study was to evaluate the association among serum ucOCN, rs2247911 polymorphism of GPRC6A gene and the endocrine/semen pattern in a cohort of infertile males, possibly identifying an involvement of the ucOCN-GPRC6A axis on testis function.

METHODS

190 males, including 74 oligozoospermic subjects, 58 azoosperminc patients and 58 normozoospermic controls, were prospectively recruited at the Orient Hospital for Infertility, Assisted Reproduction and Genetics in Syria (Study N. 18FP), from July 2018 to June 2020. Outpatient evaluation included the clinical history, anthropometrics and a fasting blood sampling for hormonals, serum OCN (both carboxylated and undercarboxylated), glycemic and lipid profile and screening for rs2247911 GPRC6A gene polymorphism.

RESULTS

Higher serum ucOCN associated with higher T and HDL-cholesterol (respectively: r = 0.309, P < 0.001 and r = 0.248, P = 0.001), and with lower FSH (r =  - 0.327, P < 0.001) and LDL-cholesterol (r =  - 0.171; P = 0.018). Patients bearing the GG genotype of rs2247911 had higher sperm count compared to GA genotype (P = 0.043) and, compared to both AG and AA genotypes, had higher serum T (P = 0.004, P = 0.001) and lower triglycerides levels (P = 0.002, P < 0.001). Upon normalization for LH levels and body mass index, rs2274911 and ucOCN were significantly associated with higher serum T at linear stepwise regression analysis (P = 0.013, P = 0.007).

CONCLUSIONS

Our data suggest the involvement of ucOCN-GPRC6A axis in the regulation of T production by the testis, subsidiary to HPG.

Endothelial Progenitor Cells as Biomarkers of Cardiovascular Pathologies: A Narrative Review

Endothelial progenitor cells (EPC) may influence the integrity and stability of the vascular endothelium. The association of an altered total EPC number and function with cardiovascular diseases (CVD) and risk factors (CVF) was discussed; however, their role and applicability as biomarkers for clinical purposes have not yet been defined. Endothelial dysfunction is one of the key mechanisms in CVD. The assessment of endothelial dysfunction in vivo remains a major challenge, especially for a clinical evaluation of the need for therapeutic interventions or for primary prevention of CVD. One of the main challenges is the heterogeneity of this particular cell population. Endothelial cells (EC) can become senescent, and the majority of circulating endothelial cells (CEC) show evidence of apoptosis or necrosis. There are a few viable CECs that have properties similar to those of an endothelial progenitor cell. To use EPC levels as a biomarker for vascular function and cumulative cardiovascular risk, a correct definition of their phenotype, as well as an update on the clinical application and practicability of current isolation methods, are an urgent priority.