Maternal Gut Microbiome Decelerates Fetal Endochondral Bone Formation by Inducing Inflammatory Reaction.

To investigate the effect of the maternal gut microbiome on fetal endochondral bone formation, fetuses at embryonic day 18 were obtained from germ-free (GF) and specific-pathogen-free (SPF) pregnant mothers. Skeletal preparation of the fetuses' whole bodies did not show significant morphological alterations; however, micro-CT analysis of the tibiae showed a lower bone volume fraction in the SPF tibia. Primary cultured chondrocytes from fetal SPF rib cages showed a lower cell proliferation and lower accumulation of the extracellular matrix.

CCN3 (NOV) Drives Degradative Changes in Aging Articular Cartilage.

Aging is a major risk factor of osteoarthritis, which is characterized by the degeneration of articular cartilage. CCN3, a member of the CCN family, is expressed in cartilage and has various physiological functions during chondrocyte development, differentiation, and regeneration. Here, we examine the role of CCN3 in cartilage maintenance.

Circadian production of melatonin in cartilage modifies rhythmic gene expression.

Endochondral ossification, including bone growth and other metabolic events, is regulated by circadian rhythms. Herein, we provide evidence that melatonin has a direct effect on the circadian rhythm of chondrocytes. We detected mRNA expression of the genes which encode the melatonin-synthesizing enzymes AANAT (arylalkylamine N-acetyltransferase) and HIOMT (hydroxyindole O-methyltransferase), as well as the melatonin receptors MT1 and MT2 in mouse primary chondrocytes and cartilage.

TNF-alpha stimulation increases dental pulp stem cell migration in vitro through integrin alpha-6 subunit upregulation.

Objective: The dissemination of stem cells into tissues requiring inflammatory and reparative response is fundamentally dependent upon their chemotactic migration. Expression of TNF-α is up regulated in inflamed pulps. Dental pulp cells are also known to express integrin α6 subunit.