Myxoid pleomorphic liposarcoma is characterized by pathological features of both pleomorphic liposarcoma and myxoid liposarcoma, as the name suggests. In this case, a myxoid pleomorphic liposarcoma was observed in a 5-year-old male African pygmy hedgehog. It consisted of ~60% of the myxoid substance area with proliferating round cells and ~30% of pleomorphic neoplastic cells. The subject presented with extrapulmonary metastasis, but a good prognosis during 6 months of follow-up, which is similar to the characteristics of myxoid liposarcoma. The histopathological features of myxoid pleomorphic liposarcoma may reflect the features of either myxoid liposarcoma or pleomorphic liposarcoma depending on the proportion of each histopathological feature. The proportion of the pleomorphic area and the myxoid area may offer information on the prognosis and metastasis of myxoid pleomorphic liposarcoma, which will be helpful for setting up a treatment plan. Thus, analyzing the proportion of pleomorphic area and myxoid area could be suggested as one of the ways to predict clinical outcomes. In addition to the fact that this is the first case of a myxoid pleomorphic liposarcoma in hedgehogs, this case is meaningful, considering the unique histopathological characteristics and rare incidence of myxoid pleomorphic liposarcoma that could be important in humans as well.
Heterogeneous nuclear ribonucleoprotein U (hnRNPU) is known to play multiple biological roles by regulating transcriptional expression, RNA splicing, RNA stability, and chromatin structure in a tissue-dependent manner. The role of hnRNPU in skeletal muscle development and maintenance has not been previously evaluated. In this study, skeletal muscle specific hnRNPU knock out mice is utilized and evaluated skeletal muscle mass and immune cell infiltration through development. By 4 weeks, muscle-specific hnRNPU knockout mice revealed Ly6C+ monocyte infiltration into skeletal muscle, which preceded muscle atrophy. Canonical NF-kB signaling is activated in a myofiber-autonomous manner with hnRNPU repression. Inducible hnRNPU skeletal muscle knockout mice further demonstrated that deletion of hnRNPU in adulthood is sufficient to cause muscle atrophy, suggesting that hnRNPU's role in muscle maintenance is not during development alone. Treatment with salirasib, to inhibit proliferation of immune cells, prevents muscle atrophy in muscle-specific hnRNPU knock out mice, indicating that immune cell infiltration plays causal role in muscle atrophy of hnRNPU knock out mice. Overall, the findings suggest that loss of hnRNPU triggers muscle inflammation and activates NF-κB signaling in a cell-autonomous manner, culminating in muscle atrophy.
Although there are growing demands for stem cell-based therapy for companion animals in various diseases, a few clinical trials have been reported. Moreover, most of them are the results from only one or a few times of stem cell injection.The aim of this study is to describe a long-term treatment with allogeneic adipose-derived stem cells (ASCs) in a dog with rheumatoid arthritis (RA), which is a rare canine disease.The dog with RA received intravascular injection of allogeneic ASCs derived from two healthy donors once a month for 11 months. To assess therapeutic effects of ASCs, orthopedic examination and clinical evaluation was performed. Cytokines of tumor necrosis factor-α and interleukin-6 in the plasma were measured using ELISA analysis.Despite this repeated and long-term administration of allogeneic ASCs, there were no side effects such as immunorejection responses or cell toxicity. The orthopedic examination score for the dog decreased after ASCs treatment, and the clinical condition of the dog and owner's satisfaction were very good.Although ASCs has been suggested as one of the options for RA treatment because of its anti-inflammatory and immunosuppressive functions, it has never been used to treat RA in dogs. The present report describes a case of canine RA treated with allogeneic ASCs for long-term in which the dog showed clinical improvement without adverse effects.