Peripheral nerve injuries can lead to lasting functional impairments, impacting movement and quality of life. FK-506, a widely used immunosuppressant, has demonstrated potential in promoting nerve regeneration in addition to its immunosuppressive effects. This study investigates the use of a local reservoir flap to deliver FK-506 directly to the nerve injury site, aiming to enhance nerve regeneration while minimizing systemic immunosuppression.
Sciatic nerve injuries were surgically induced in 24 rats, which were divided into control, 0.5 mg/kg FK-506 (Exp 1), and 2.0 mg/kg FK-506 (Exp 2) groups. A superficial inferior epigastric artery flap served as a reservoir for FK-506, allowing direct delivery to the injury site. FK-506 was administered intermittently over a 4-week period. Outcomes included the Sciatic Functional Index (SFI), muscle recovery (width and weight), nerve morphology, expression of neurogenic markers such as GDNF, immune cell counts, and body weight.
Exp 1 (0.5 mg/kg) demonstrated significant improvements in SFI, GDNF expression, and muscle width compared to the control and high-dose groups. These findings suggest that FK-506 administration via a reservoir flap, particularly at a lower dose, supports effective nerve regeneration. Additionally, FK-506 treatment did not result in significant changes in immune cell profiles or body weight, indicating minimal systemic effects.
Localized FK-506 administration via a reservoir flap effectively enhances peripheral nerve regeneration and minimizes systemic immunosuppression, making it a promising approach for clinical application in treating peripheral nerve injuries.
© Copyright: Yonsei University College of Medicine 2024.

Multiple sclerosis (MS) is a chronic autoimmune disease in the central nervous system. Forskolin (FSK) is a plant-derived diterpene with excellent immunomodulatory properties and has not been systematically reported for treating MS. This study investigated the therapeutic effects of FSK on cellular and animal MS models and preliminarily explored related mechanisms. The results showed that FSK suppressed the inflammatory response, reduced the expression of STEAP4, and relieved iron deposition in BV-2 cells pretreated by LPS at the cellular level. Meanwhile, at the animal level, FSK treatment halted the progression of experimental autoimmune encephalomyelitis (EAE), alleviated the damage at the lesion sites, reduced the concentration of proinflammatory factors in peripheral blood, and inhibited the immune response of peripheral immune organs in EAE mice. Besides, FSK treatment decreased the expression of STEAP4 in the spinal cord and effectively restored the iron balance in the brain, spinal cord, and serum of EAE mice. Further investigation showed that FSK can reduce IL-17 expression, prevent the differentiation of TH17 cells, and inhibit the calcium signaling pathway. Thus, these results demonstrate that FSK may have the potential to treat MS clinically.
© 2024 The Authors. Published by Elsevier Ltd.

Dual-specificity phosphatase 6 (DUSP6) serves a specific and conserved function on the dephosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2). We previously identified Dusp6 as a regenerative repressor during zebrafish heart regeneration, therefore we propose to investigate the role of this repressor in mammalian cardiac repair. Utilizing a rat strain harboring Dusp6 nonsense mutation, rat neutrophil-cardiomyocyte co-culture, bone marrow transplanted rats and neutrophil-specific Dusp6 knockout mice, we find that Dusp6 deficiency improves cardiac outcomes by predominantly attenuating neutrophil-mediated myocardial damage in acute inflammatory phase after myocardial infarction. Mechanistically, Dusp6 is transcriptionally activated by p38-C/EBPβ signaling and acts as an effector for maintaining p-p38 activity by down-regulating pERK and p38-targeting phosphatases DUSP1/DUSP16. Our findings provide robust animal models and novel insights for neutrophil-mediated cardiac damage and demonstrate the potential of DUSP6 as a therapeutic target for post-MI cardiac remodeling and other relevant inflammatory diseases.
© 2022. The Author(s).

Glioblastoma (GBM) is the most common intracranial tumor with characteristic of malignancy. Resveratrol, a natural originated polyphenolic compound, has been reported to act as a potential radiosensitizer in cancer therapy. Magnetic resonance imaging (MRI) is the first choice for the diagnosis, pathological grading, and efficacy evaluation of GBM. In this study, MRI was applied to observe whether resveratrol could intensify the anti-GBM tumor effect by enhancing antitumor immunity during radiotherapy. We established an intracranial C6 GBM model in SD rats, treated with radiation and resveratrol. The increased body weight, the inhibition on mortality, and tumor volume in radiated- GBM rats were further enhanced by resveratrol addition, while the pathological damage of brain was alleviated. The modulation of radiation on inflammation, cell cycle, and apoptosis was strengthened by resveratrol; and Ki-67, PD-L1, and cell cycle- and apoptosis-related protein expressions were also improved by cotreatment. Besides, cotreatment attenuated DNA damage and induced G0/G1-phase cell arrest of GBM rats, accompanied with the changed expression of ATM-AKT-STAT3 pathway-related proteins. Moreover, the percentages of CD3+CD8+T cells and IFN-γ +CD8+T cells were enhanced, while (CD4+CD25+Foxp3)/CD4+T cells were decreased by radiation or resveratrol, which was strengthened by cotreatment. The modulation effect of cotreatment on CD3, Foxp3, and IFN-γ levels was also stronger than radiation or resveratrol alone. To conclude, resveratrol enhanced the effect of radiotherapy by inducing DNA damage and antitumor immunity in the intracranial C6 GBM.
Copyright © 2022 Liping Qian et al.

Ovarian cancer is a highly fatal malignancy characterized by early chemotherapy responsiveness but the eventual development of resistance. Immune targeting therapies are changing treatment paradigms for numerous cancer types but have had minimal success in ovarian cancer. Through retrospective patient sample analysis, we have determined that high human epididymis protein 4 (HE4) production correlates with multiple markers of immune suppression in ovarian cancer, including lower CD8+ T cell infiltration, higher PD-L1 expression, and an increase in the peripheral monocyte to lymphocyte ratio. To further understand the impact that HE4 has on the immune microenvironment in ovarian cancer, we injected rats with syngeneic HE4 high- and low-expressing cancer cells and analyzed the differences in their tumor and ascites immune milieu. We found that high tumoral HE4 expression promotes an ascites cytokine profile that is rich in myeloid-recruiting and differentiation factors, with an influx of M2 macrophages and increased arginase 1 production. Additionally, CTL activation is significantly reduced in the ascites fluid, and there is a trend toward lower CTL infiltration of the tumor, whereas NK cell recruitment to the ascites and tumor is also reduced. PD-L1 expression by tumor cells and macrophages is increased by HE4 through a novel posttranscriptional mechanism. Our data have identified HE4 as a mediator of tumor-immune suppression in ovarian cancer, highlighting this molecule as a potential therapeutic target for the treatment of this devastating disease.
Copyright © 2021 by The American Association of Immunologists, Inc.