Loss of Pinch Proteins Causes Severe Degenerative Disc Disease-Like Lesions in Mice

Degenerative disc disease (DDD) is one of the most common skeletal disorders affecting aged populations. DDD is the leading cause of low back/neck pain, resulting in disability and huge socioeconomic burdens. However, the molecular mechanisms underlying DDD initiation and progression remain poorly understood. Pinch1 and Pinch2 are LIM-domain-containing proteins with crucial functions in mediating multiple fundamental biological processes, such as focal adhesion, cytoskeletal organization, cell proliferation, migration, and survival. In this study, we found that Pinch1 and Pinch2 were both highly expressed in healthy intervertebral discs (IVDs) and dramatically downregulated in degenerative IVDs in mice. Deleting Pinch1 in aggrecan-expressing cells and Pinch2 globally (AggrecanCreERT2; Pinch1fl/fl; Pinch2-/-) caused striking spontaneous DDD-like lesions in lumbar IVDs in mice. Pinch loss inhibited cell proliferation and promoted extracellular matrix (ECM) degradation and apoptosis in lumbar IVDs. Pinch loss markedly enhanced the production of pro-inflammatory cytokines, especially TNFα, in lumbar IVDs and exacerbated instability-induced DDD defects in mice. Pharmacological inhibition of TNFα signaling mitigated the DDD-like lesions caused by Pinch loss. In human degenerative NP samples, reduced expression of Pinch proteins was correlated with severe DDD progression and a markedly upregulated expression of TNFα. Collectively, we demonstrate the crucial role of Pinch proteins in maintaining IVD homeostasis and define a potential therapeutic target for DDD.

Anti-TNFα therapy for chronic inflammatory disease in kidney transplant recipients: Clinical outcomes

Anti-tumor necrosis factor-α (TNFα) therapy has improved the prognosis of many chronic inflammatory diseases. It appears to be well-tolerated by liver-transplant patients. However, their use and their safety in kidney-transplant patients have yet to be determined.In this retrospective study, we identified 16 adult kidney-transplant patients aged 46.5 years (34-51.8) who received anti-TNFα therapy from 7 kidney transplantation centers. The indications for this treatment included: chronic inflammatory bowel disease (n = 8), inflammatory arthritis (n = 5), AA amyloidosis (n = 1), psoriasis (n = 1), and microscopic polyangiitis (n = 1).Anti-TNFα therapies resulted in a clinical response in 13/16 patients (81%). Estimated glomerular filtration rates (MDRD-4) were similar on day 0 and at 24 months (M24) after anti-TNFα treatment had been initiated (41 [12-55] and 40 [21-53] mL/min/1.73 m, respectively). Two allograft losses were observed. The 1st case was due to antibody-mediated rejection (M18), while the 2nd was the result of AA amyloidosis recurrence (M20). There were several complications: 8 patients (50%) developed 23 serious infections (18 bacterial, 4 viral, and 1 fungal) and 4 developed cancer. Five patients died (infection n = 2, cardiac AA amyloidosis n = 1, intraalveolar hemorrhage following microscopic polyangiitis n = 1, and acute respiratory distress syndrome n = 1). On univariate analysis, recipient age associated with death (P = 0.009) and infection development (P = 0.06).Using anti-TNFα therapies, remission can be achieved in chronic inflammatory diseases in kidney-transplant patients. However, concommitant anti-TNFα and immunosuppresive therapies must be used with caution due to the high risk of infection, particularly after the age of 50.