Herpes simplex virus (HSV) 1 disaggregates the nuclear domain 10 (ND10) nuclear structures and disperses its organizing promyelocytic leukemia protein (PML). An earlier report showed that ectopic overexpression of PML precludes the disaggregation of ND10 but has no effect on viral replication. PML has been reported to mediate the effects of interferon (

No abstract

Earlier studies have shown that the d120 mutant of herpes simplex virus 1, which lacks both copies of the ␣4 gene, induces caspase-3-dependent apoptosis in HEp-2 cells. Apoptosis was also induced by the ␣4

Because miR-146a expression in articular chondrocytes is associated with osteoarthritis (OA), we assessed whether miR-146a is linked to cartilage degeneration in the spine. Monolayer cultures of nucleus pulposus (NP) cells from the intervertebral discs (IVD) of bovine tails were transfected with a miR-146a mimic. To provoke inflammatory responses and catabolic extracellular matrix (ECM) degradation, cells were co-treated with interleukin-1 (IL-1). Transfection of miR-146a decreases IL-1 induced mRNA levels of inflammatory genes and catabolic proteases in NP cells based on quantitative real-time reverse transcriptase PCR (qRT-PCR) analysis. Similarly, miR146a suppresses IL-1 induced protein levels of matrix metalloproteinases and aggrecanases as revealed by immunoblotting. Disc segments from wild type (WT) and miR-146a knockout (KO) mice were cultured ex vivo in the presence or absence of IL-1 for 3 days. Histological and immunohistochemical (IHC) analyses of disc organ cultures revealed that IL-1 mediates changes in proteoglycan (PG) content and in-situ levels of catabolic proteins (MMP-13 and ADAMTS-5) in the nucleus pulposus of the disc. However, these IL-1 effects are more pronounced in miR-146a KO discs compared to WT discs. For example, absence of miR-146a increases the percentage of MMP-13 and ADAMTS-5 positive cells after treatment with IL-1. Thus, miR-146a appears to protect against IL-1 induced IVD degeneration and inflammation. Stimulation of endogenous miR-146a expression or exogenous delivery of miRNA-146a are viable therapeutic strategies that may decelerate disc degeneration and regain a normal homeostatic balance in extracellular matrix production and turn-over.

Objective To examine the link between cytokines in intervertebral disc (IVD) tissues and axial back pain. Design In vitro study with human IVD cells cultured from cadaveric donors and annulus fibrosus (AF) tissues from patients. Results Cultured nucleus pulposus (NP) and AF cells were stimulated with interleukin (IL)-1β. IL-8 and IL-7 gene expression was analyzed using real-time PCR. IL-8 protein was quantified by ELISA. Following IL-1β stimulation, IL-8 gene expression increased 26,541 fold in NP cells and 22,429 fold in AF cells, while protein released by the NP and AF cells increased 2,389 and 1,784 fold, respectively. IL-7 gene expression increased 3.3 fold in NP cells (p<0.05). Cytokine profiles in AF tissues collected from patients undergoing surgery for back pain (painful group) or scoliosis (controls) were compared by cytokine array. IL-8 protein in the AF tissues from patients with back pain was 1.81 fold of that in controls. IL-7 and IL-10 in AF tissues from the painful group were, respectively, 6.87 and 4.63 times greater than the corresponding values in controls (p<0.05). Conclusion Inflammatory mediators found in AF tissues from patients with discogenic back pain are likely produced by IVD cells, and may play a key role in back pain.