Cellular aging in vitro

The accumulation of versican in the nodules of benign prostatic hyperplasia

BACKGROUND

Proteoglycans, a complex group of extracellular matrix (ECM) molecules, are elevated in benign prostatic hyperplasia (BPH). Versican is a stromal proteoglycan present in prostate tissue. Versican expression is elevated in tissues with increased proliferation. Based on these observations, we determined the extent and distribution of versican expression in prostates with BPH.

METHODS

The involvement of versican in BPH nodules was compared with levels in non-nodular transition (TZ) and peripheral zone (PZ) tissues from 18 human prostate glands using immunohistochemistry, Northern blots and/or QRTPCR to localize versican and quantify versican mRNA transcript levels, and Western blots to assess gene product levels.

RESULTS

Increased versican immunoreactivity was observed in the stroma of BPH nodules. Higher steady state levels of versican variants V0, V1, and V3 mRNA transcript and gene product were detected in the nodular tissues than in the non-nodular TZ or PZ parenchyma.

CONCLUSIONS

These results suggest that versican may play a role in nodule formation in BPH.

Activation of innate immunity system during aging: NF-kB signaling is the molecular culprit of inflamm-aging

Innate and adaptive immunity are the major defence mechanisms of higher organisms against inherent and environmental threats. Innate immunity is present already in unicellular organisms but evolution has added novel adaptive immune mechanisms to the defence armament. Interestingly, during aging, adaptive immunity significantly declines, a phenomenon called immunosenescence, whereas innate immunity seems to be activated which induces a characteristic pro-inflammatory profile. This process is called inflamm-aging. The recognition and signaling mechanisms involved in innate immunity have been conserved during evolution. The master regulator of the innate immunity is the NF-kB system, an ancient signaling pathway found in both insects and vertebrates. The NF-kB system is in the nodal point linking together the pathogenic assault signals and cellular danger signals and then organizing the cellular resistance. Recent studies have revealed that SIRT1 (Sir2 homolog) and FoxO (DAF-16), the key regulators of aging in budding yeast and Caenorhabditis elegans models, regulate the efficiency of NF-kB signaling and the level of inflammatory responses. We will review the role of innate immunity signaling in the aging process and examine the function of NF-kB system in the organization of defence mechanisms and in addition, its interactions with the protein products of several gerontogenes. Our conclusion is that NF-kB signaling seems to be the culprit of inflamm-aging, since this signaling system integrates the intracellular regulation of immune responses in both aging and age-related diseases.