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Pathologic diabetic wound healing is caused by sequential and progressive deterioration of hemostasis, inflammation, proliferation, and resolution/remodeling. Cellular senescence promotes wound healing; however, diabetic wounds exhibit low levels of senescent factors and accumulate senescent cells, which impair the healing process. Here we show that the number of p15(INK4B) + PDGFR alpha + senescent mesenchymal cells in adipose tissue increases transiently during early phases of wound healing in both non-diabetic mice and humans. Transplantation of adipose tissue from diabetic mice into non-diabetic mice results in impaired wound healing and an altered cellular senescence-associated secretory phenotype (SASP), suggesting that insufficient induction of adipose tissue senescence after injury is a pathological mechanism of diabetic wound healing. These results provide insight into how regulation of senescence in adipose tissue contributes to wound healing and could constitute a basis for developing therapeutic treatment for wound healing impairment in diabetes. Type-2 diabetic adipose tissue impairs transient senescence during wound healing with expression of different components of the senescence-associated secretory phenotype (SASP), and this is associated with deteriorated wound healing.

Up to 60% of patients with systemic lupus erythematosus (SLE) experience autonomic symptom. Sympathetic nervous system damage can cause dysfunction of the bone marrow that activates inflammatory cells, potentially causing multiple organ damage. We hypothesized that sympathetic nervous system damage would induce bone marrow dysfunction with multiple organ damage in SLE, and that multiple organ damage could be improved by therapy targeting the nervous system. Here, we showed that damage to autonomic nerves and Schwann cells occurred in the bone marrow and central nervous system of SLE model mice. A neurotoxic drug increased mortality and induced severe neuropathy and multiple organ damage, while a neuroprotective drug prevented multiple organ damage. The administration of bone marrow-derived mesenchymal stromal cells (BMSCs) cultured on a 3-dimensional fiber scaffold improved bone marrow neuropathy, skin lesions, kidney function, and mortality. Our results reveal that bone marrow neuropathy influence multiple organ damage associated with SLE, and improvement of bone marrow neuropathy by intrathecal injection of BMSC may be a target for SLE multiple-organ damage.

Systemic lupus erythematosus (SLE) is a chronic autoimmune inflammatory disease characterized by the involvement of multiple organs. Lupus nephritis (LN) is a major risk factor for overall morbidity and mortality in SLE patients. Hence, designing effective drugs is pivotal for treating individuals with LN. Fisetin plays a senolytic role by specifically eliminating senescent cells, inhibiting cell proliferation, and exerting anti-inflammatory, anti-oxidant, and anti-tumorigenic effects. However, limited research has been conducted on the utility and therapeutic mechanisms of fisetin in chronic inflammation. Similarly, whether the effects of fisetin depend on cell type remains unclear. In this study, we found that LN-prone MRL/lpr mice demonstrated accumulation of Ki-67-positive myofibroblasts and p15(INK4B)-positive senescent tubular epithelial cells (TECs) that highly expressed transforming growth factor beta (TGF-beta). TGF-beta stimulation induced senescence of NRK-52E renal TECs and proliferation of NRK-49F renal fibroblasts, suggesting that TGF-beta promotes senescence and proliferation in a cell type-dependent manner, which is inhibited by fisetin treatment in vitro. Furthermore, fisetin treatment in vivo reduced the number of senescent TECs and myofibroblasts, which attenuated kidney fibrosis, reduced senescence-associated secretory phenotype (SASP) expression, and increased TEC proliferation. These data suggest that the effects of fisetin vary depending on the cell type and may have therapeutic effects in complex and diverse LN pathologies.

Up to 60% of patients with systemic lupus erythematosus (SLE) experience autonomic symptom. Sympathetic nervous system damage can cause dysfunction of the bone marrow that activates inflammatory cells, potentially causing multiple organ damage. We hypothesized that sympathetic nervous system damage would induce bone marrow dysfunction with multiple organ damage in SLE, and that multiple organ damage could be improved by therapy targeting the nervous system. Here, we showed that damage to autonomic nerves and Schwann cells occurred in the bone marrow and central nervous system of SLE model mice. A neurotoxic drug increased mortality and induced severe neuropathy and multiple organ damage, while a neuroprotective drug prevented multiple organ damage. The administration of bone marrow-derived mesenchymal stromal cells (BMSCs) cultured on a 3-dimensional fiber scaffold improved bone marrow neuropathy, skin lesions, kidney function, and mortality. Our results reveal that bone marrow neuropathy influence multiple organ damage associated with SLE, and improvement of bone marrow neuropathy by intrathecal injection of BMSC may be a target for SLE multiple-organ damage.

Neuropsychiatric manifestations targeting the central, peripheral, and autonomic nervous system are common in systemic lupus erythematosus (SLE); collectively, these symptoms are termed neuropsychiatric SLE (NPSLE). Among a wide variety of neuropsychiatric symptoms, depression is observed in about 24-39% of SLE patients. Several cytokines and chemokines have been identified as biomarkers or therapeutic targets of NPSLE; in particular, the levels of type 1 interferons, TNFs, and IL-6 are elevated in SLE patient's cerebrospinal fluid (CSF), and these factors contribute to the pathology of depression. Here, we show that senescent neural cells accumulate in the hippocampal cornu ammonis 3 (CA3) region in MRL/lpr SLE model mice with depressive behavior. Furthermore, oral administration of fisetin, a senolytic drug, reduced the number of senescent neural cells and reduced depressive behavior in the MRL/lpr mice. In addition, transcription of several senescence and senescence-associated secretory phenotype (SASP) factors in the hippocampal region also decreased after fisetin treatment in the MRL/lpr mice. These results indicate that the accumulation of senescent neural cells in the hippocampus plays a role in NPSLE pathogenesis, and therapies targeting senescent cells may represent a candidate approach to treat NPSLE.

Neuropsychiatric manifestations targeting the central, peripheral, and autonomic nervous system are common in systemic lupus erythematosus (SLE); collectively, these symptoms are termed neuropsychiatric SLE (NPSLE). Among a wide variety of neuropsychiatric symptoms, depression is observed in about 24-39% of SLE patients. Several cytokines and chemokines have been identified as biomarkers or therapeutic targets of NPSLE; in particular, the levels of type 1 interferons, TNFs, and IL-6 are elevated in SLE patient's cerebrospinal fluid (CSF), and these factors contribute to the pathology of depression. Here, we show that senescent neural cells accumulate in the hippocampal cornu ammonis 3 (CA3) region in MRL/lpr SLE model mice with depressive behavior. Furthermore, oral administration of fisetin, a senolytic drug, reduced the number of senescent neural cells and reduced depressive behavior in the MRL/lpr mice. In addition, transcription of several senescence and senescence-associated secretory phenotype (SASP) factors in the hippocampal region also decreased after fisetin treatment in the MRL/lpr mice. These results indicate that the accumulation of senescent neural cells in the hippocampus plays a role in NPSLE pathogenesis, and therapies targeting senescent cells may represent a candidate approach to treat NPSLE.

Idiopathic inflammatory myopathies cause progressive muscle weakness and degeneration. Since high-dose glucocorticoids might not lead to full recovery of muscle function, physical exercise is also an important intervention, but some exercises exacerbate chronic inflammation and muscle fibrosis. It is unknown how physical exercise can have both beneficial and detrimental effects in chronic myopathy. Here we show that senescence of fibro-adipogenic progenitors (FAPs) in response to exercise-induced muscle damage is needed to establish a state of regenerative inflammation that induces muscle regeneration. In chronic inflammatory myopathy model mice, exercise does not promote FAP senescence or resistance against tumor necrosis factor-mediated apoptosis. Pro-senescent intervention combining exercise and pharmacological AMPK activation reverses FAP apoptosis resistance and improves muscle function and regeneration. Our results demonstrate that the absence of FAP senescence after exercise leads to muscle degeneration with FAP accumulation. FAP-targeted pro-senescent interventions with exercise and pharmacological AMPK activation may constitute a therapeutic strategy for chronic inflammatory myopathy.