[Decreased stimulation of glycosaminoglycan synthesis in cultured human skin fibroblasts within the scope of in vitro aging caused by interleukin 1]

Inhibition of P-glycoprotein facilitated glycosaminoglycan accumulation during chondrogenesis of human bone marrow mesenchymal stem cells

AIM

P-glycoprotein (P-gp) is an adenosine-5-triphosphate Binding Cassettes B 1 (ABCB1) transporter that exports various substrates on cellular membrane. Surface expression of P-gp was decreased during chondrogenesis of human bone marrow mesenchymal stem cells (BM-MSCs). We examined the role of P-gp in extracellular matrix deposition during chondrogenesis of human BM-MSCs.

METHOD

BM-MSCs were isolated from 16 volunteers after informed consent and incubated for 28 days using three-dimensional culture methods in chondrogenic medium with and without P-gp inhibitor (verapamil, 10 μmol/L).

RESULTS

Hematoxylin and eosin staining revealed a cartilaginous structure with chondrogenic cells in the lacunae after 2 weeks of culture. Total glycosaminoglycan (GAG) content was increased and rose during pellet culture. Hyaluronan (HA) content of the culture medium decreased with P-gp inhibitor. Type II collagen deposition decreased with P-gp inhibitor.

CONCLUSION

Inhibition of P-gp facilitated GAG accumulation via HA export inhibition during chondrogenic differentiation of human BM-MSCs. Modulation of P-gp expression during chondrogenesis would be a possible therapeutic approach for articular cartilage regeneration.

Heart disease and vascular risk factors in the cognitively impaired elderly: implications for Alzheimer's dementia

The term "cardiogenic dementia" was introduced a few decades ago to indicate an alteration of consciousness and cognition due to heart disease. Although this term is now disused, the relationship between cardiovascular disease and cognitive impairment is currently of great interest, not only for its potential therapeutic implications. but also for the recently recognized important role that vascular factors appear to play in Alzheimer's disease. The aims of this review are therefore 1) to show data supporting the role of cardiac disease--namely congestive heart failure, myocardial infarction and atrial fibrillation--and other vascular risk factors--i.e., hypertension and diabetes--in the development or worsening of cognitive impairment; 2) to highlight recent observations on the relationship between presence and severity of congestive heart failure/ myocardial infarction/atrial fibrillation and Alzheimer's disease: and 3) to uncover the type of studies needed in this field in order to facilitate a more precise algorithm of dementia prevention as well as intervention in demented patients with cardiovascular disease.