Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with no effective therapy, causing progressive loss of motor neurons in the spinal cord, brainstem, and motor cortex. Regardless of its genetic or sporadic origin, there is currently no cure for ALS or therapy that can reverse or control its progression. In the present study, taking advantage of a human superoxide dismutase-1 mutant (hSOD1-G93A) mouse that recapitulates key pathological features of human ALS, we investigated the possible role of voltage-gated potassium channel Kv1.3 in disease progression. We found that chronic administration of the brain-penetrant Kv1.3 inhibitor, PAP-1 (40 mg/Kg), in early symptomatic mice (i) improves motor deficits and prolongs survival of diseased mice (ii) reduces astrocyte reactivity, microglial Kv1.3 expression, and serum pro-inflammatory soluble factors (iii) improves structural mitochondrial deficits in motor neuron mitochondria (iv) restores mitochondrial respiratory dysfunction. Taken together, these findings underscore the potential significance of Kv1.3 activity as a contributing factor to the metabolic disturbances observed in ALS. Consequently, targeting Kv1.3 presents a promising avenue for modulating disease progression, shedding new light on potential therapeutic strategies for ALS.
Copyright © 2024 Ratano, Cocozza, Pinchera, Busdraghi, Cantando, Martinello, Scioli, Rosito, Bezzi, Fucile, Wulff, Limatola and D’Alessandro.

Type I IFN is produced upon infection and tissue damage and induces the expression of many IFN-stimulated genes (ISGs) that encode host-protective proteins. ISG15 is a ubiquitin-like molecule that can be conjugated to proteins but is also released from cells in a free form. Free, extracellular ISG15 is suggested to have an immune-regulatory role, based on disease phenotypes of ISG15-deficient humans and mice. However, the underlying mechanisms by which free ISG15 would act as a "cytokine" are unclear and much debated. We, in this study, demonstrate in a clinically relevant mouse model of therapeutic vaccination that free ISG15 is an alarmin that induces tissue alert, characterized by extracellular matrix remodeling, myeloid cell infiltration, and inflammation. Moreover, free ISG15 is a potent adjuvant for the CTL response. ISG15 produced at the vaccination site promoted the vaccine-specific CTL response by enhancing expansion, short-lived effector and effector/memory differentiation of CD8+ T cells. The function of free ISG15 as an extracellular ligand was demonstrated, because the equivalents in murine ISG15 of 2 aa recently implicated in binding of human ISG15 to LFA-1 in vitro were required for its adjuvant effect in vivo. Moreover, in further agreement with the in vitro findings on human cells, free ISG15 boosted the CTL response in vivo via NK cells in the absence of CD4+ T cell help. Thus, free ISG15 is part of a newly recognized innate route to promote the CTL response.
Copyright © 2020 by The American Association of Immunologists, Inc.

Mesenchymal stromal cells (MSCs) have been shown to reverse radiation damage to marrow stem cells. We have evaluated the capacity of MSC-derived extracellular vesicles (MSC-EVs) to mitigate radiation injury to marrow stem cells at 4 h to 7 days after irradiation. Significant restoration of marrow stem cell engraftment at 4, 24 and 168 h post irradiation by exposure to MSC-EVs was observed at 3 weeks to 9 months after transplant and further confirmed by secondary engraftment. Intravenous injection of MSC-EVs to 500cGy exposed mice led to partial recovery of peripheral blood counts and restoration of the engraftment of marrow. The murine hematopoietic cell line, FDC-P1 exposed to 500cGy, showed reversal of growth inhibition, DNA damage and apoptosis on exposure to murine or human MSC-EVs. Both murine and human MSC-EVs reverse radiation damage to murine marrow cells and stimulate normal murine marrow stem cell/progenitors to proliferate. A preparation with both exosomes and microvesicles was found to be superior to either microvesicles or exosomes alone. Biologic activity was seen in freshly isolated vesicles and in vesicles stored for up to 6 months in 10% dimethyl sulfoxide at -80 °C. These studies indicate that MSC-EVs can reverse radiation damage to bone marrow stem cells.

Intrauterine growth restriction (IUGR) affects up to 10% of pregnancies in Western societies. IUGR is a strong predictor of reduced short-term neonatal survival and impairs long-term health in children. Placental insufficiency is often associated with IUGR; however, the molecular mechanisms involved in the pathogenesis of placental insufficiency and IUGR are largely unknown. Here, we developed a mouse model of fetal-growth restriction and placental insufficiency that is induced by a midgestational stress challenge. Compared with control animals, pregnant dams subjected to gestational stress exhibited reduced progesterone levels and placental heme oxygenase 1 (Hmox1) expression and increased methylation at distinct regions of the placental Hmox1 promoter. These stress-triggered changes were accompanied by an altered CD8+ T cell response, as evidenced by a reduction of tolerogenic CD8+CD122+ T cells and an increase of cytotoxic CD8+ T cells. Using progesterone receptor- or Hmox1-deficient mice, we identified progesterone as an upstream modulator of placental Hmox1 expression. Supplementation of progesterone or depletion of CD8+ T cells revealed that progesterone suppresses CD8+ T cell cytotoxicity, whereas the generation of CD8+CD122+ T cells is supported by Hmox1 and ameliorates fetal-growth restriction in Hmox1 deficiency. These observations in mice could promote the identification of pregnancies at risk for IUGR and the generation of clinical interventional strategies.

Transforming growth factor-beta (TGF-beta) is a pleiotropic growth factor; its overexpression has been implicated in many diseases, making it a desirable target for therapeutic neutralization. In initial safety studies, mice were chronically treated (three times per week) with high doses (50 mg/kg) of a murine, pan-neutralizing, anti-TGF-beta antibody. Nine weeks after the initiation of treatment, a subset of mice exhibited weight loss that was concurrent with decreased food intake. Histopathology revealed a unique, nonneoplastic cystic epithelial hyperplasia and tongue inflammation, as well as dental dysplasia and epithelial hyperplasia and inflammation of both the gingiva and esophagus. In an effort to determine the cause of this site-specific pathology, we examined TGF-beta expression in these tissues and saliva under normal conditions. By immunostaining, we found higher expression levels of active TGF-beta1 and TGF-beta3 in normal tongue and esophageal submucosa compared with gut mucosal tissues, as well as detectable TGF-beta1 in normal saliva by Western blot analysis. Interestingly, mast cells within the tongue, esophagus, and skin co-localized predominantly with the TGF-beta1 expressed in these tissues. Our findings demonstrate a novel and restricted pathology in oral and esophageal tissues of mice chronically treated with anti-TGF-beta that is associated with basal TGF-beta expression in saliva and by mast cells within these tissues. These studies illustrate a previously unappreciated biological role of TGF-beta in maintaining homeostasis within both oral and esophageal tissues.