Inhibitory effects of superoxide dismutase 3 on IgE production in B cells.

Immunoglobulin E (IgE) functions as a first-line defense against parasitic infections. However, aberrant production of IgE is known to be associated with various life-threatening allergic diseases. Superoxide dismutase 3 (SOD3) has been found to suppress IgE in various allergic diseases such as allergic conjunctivitis, ovalbumin-induced allergic asthma, and dust mite-induced atopic dermatitis-like skin inflammation. However, the role of SOD3 in the regulation of IgE production in B cells remains elusive. In this study, we investigated the effect of SOD3 on LPS/IL-4 and anti-CD40/IL-4-mediated secretion of IgE in murine B cells. Our data showed that SOD3 can suppress both LPS/IL-4 and antiCD40/IL-7-induced IgE secretion in B cells isolated from both wild-type (SOD3 +/+ ) and SOD3 knock-out (SOD3 -/- ) mice. Interestingly, B cells isolated from SOD3 -/- mice showed higher secretion of IgE, whereas, the use of DETCA, a known inhibitor of SOD3 activity, reversed the inhibitory effect of SOD3 on IgE production. Similarly, SOD3 was found to reduce the proliferation, IgE isotype switch, ROS level, and CCL17 and CCL22 productions in B cells. Furthermore, SOD3 was found to suppress both LPS/IL-4 and anti-CD40/IL-4-mediated activation of downstream signaling such as JAK1/JAK3, STAT6, NF-κB, p38, and JNK in B cells. Taken together, our data showed that SOD3 can be used as an alternative therapy to restrict IgE-mediated allergic diseases.

Superoxide Dismutase 3-Transduced Mesenchymal Stem Cells Preserve Epithelial Tight Junction Barrier in Murine Colitis and Attenuate Inflammatory Damage in Epithelial Organoids.

Superoxide dismutase 3 (SOD3), also known as extracellular superoxide dismutase, is an enzyme that scavenges reactive oxygen species (ROS). It has been reported that SOD3 exerts anti-inflammatory abilities in several immune disorders. However, the effect of SOD3 and the underlying mechanism in inflammatory bowel disease (IBD) have not been uncovered. Therefore, in the present study, we investigated whether SOD3 can protect intestinal cells or organoids from inflammation-mediated epithelial damage. Cells or mice were treated with SOD3 protein or SOD3-transduced mesenchymal stem cells (MSCs). Caco-2 cells or intestinal organoids stimulated with pro-inflammatory cytokines were used to evaluate the protective effect of SOD3 on epithelial junctional integrity. Dextran sulfate sodium (DSS)-induced colitis mice received SOD3 or SOD3-transduced MSCs (SOD3-MSCs), and were assessed for severity of disease and junctional protein expression. The activation of the mitogen-activated protein kinase (MAPK) pathway and elevated expression of cytokine-encoding genes decreased in TNF-α-treated Caco-2 cells or DSS-induced colitis mice when treated with SOD3 or SOD3-MSCs. Moreover, the SOD3 supply preserved the expression of tight junction (ZO-1, occludin) or adherence junction (E-cadherin) proteins when inflammation was induced. SOD3 also exerted a protective effect against cytokine- or ROS-mediated damage to intestinal organoids. These results indicate that SOD3 can effectively alleviate enteritis symptoms by maintaining the integrity of epithelial junctions and regulating inflammatory- and oxidative stress.

Extracellular Superoxide Dismutase Prevents Skin Aging by Promoting Collagen Production through the Activation of AMPK and Nrf2/HO-1 Cascades.

With aging, the skin becomes thin and drastically loses collagen. Extracellular superoxide dismutase (EC-SOD), also known as superoxide dismutase (SOD) 3, is the major SOD in the extracellular matrix of the tissues and is well-known to maintain the reduction‒oxidation homeostasis and matrix components of such tissues. However, the role of EC-SOD in aging-associated reductions of skin thickness and collagen production is not well-studied. In this study, we compared the histological differences in the dorsal skin of EC-SOD‒overexpressing transgenic mice (Sod3+/+) of different age groups with that in wild-type mice and also determined the underlying signaling mechanism. Our data showed that the skin thickness in Sod3+/+ mice significantly increased with aging compared with that in wild-type male mice. Furthermore, Sod3+/+ mice had promoted collagen production through the activation of adenosine monophosphate-activated protein kinase and Nrf2/HO-1 pathways in aged mice. Interestingly, subcutaneous injection of adeno-associated virus‒overexpressing EC-SOD exhibited increased skin thickness and collagen expression. Furthermore, combined recombinant EC-SOD and dihydrotestosterone treatment synergistically elevated collagen production through the activation of TGFß in human dermal fibroblasts. Altogether, these results showed that EC-SOD prevents skin aging by promoting collagen production in vivo and in vitro. Therefore, we propose that EC-SOD may be a potential therapeutic target for antiaging in the skin.

Superoxide Dismutase 3 Controls the Activation and Differentiation of CD4+T Cells.

Superoxide dismutase 3 (SOD3), a well-known antioxidant has been shown to possess immunomodulatory properties through inhibition of T cell differentiation. However, the underlying inhibitory mechanism of SOD3 on T cell differentiation is not well understood. In this study, we investigated the effect of SOD3 on anti-CD3/CD28- or phorbol myristate acetate (PMA) and ionomycin (ION)-mediated activation of mouse naive CD4+ T cells. Our data showed that SOD3 suppressed the expression of activation-induced surface receptor proteins such as CD25, and CD69, and cytokines production. Similarly, SOD3 was found to reduce CD4+T cells proliferation and suppress the activation of downstream pathways such as ERK, p38, and NF-κB. Moreover, naïve CD4+T cells isolated from global SOD3 knock-out mice showed higher expression of CD25, CD69, and CD71, IL-2 production, proliferation, and downstream signals compared to wild-type CD4+T cells. Whereas, the use of DETCA, a known inhibitor of SOD3 activity, found to nullify the inhibitory effect of SOD3 on CD4+T cell activation of both SOD3 KO and wild-type mice. Furthermore, the expression of surface receptor proteins, IL-2 production, and downstream signals were also reduced in Th2 and Th17 differentiated cells upon SOD3 treatment. Overall, our data showed that SOD3 can attenuate CD4+T cell activation through modulation of the downstream signalings and restrict CD4+T cell differentiation. Therefore, SOD3 can be a promising therapeutic for T cell-mediated disorders.

Low-Temperature Argon Plasma Regulates Skin Moisturizing and Melanogenesis-Regulating Markers through Yes-Associated Protein.

Extensive water loss and melanin hyperproduction can cause various skin disorders. Low-temperature argon plasma (LTAP) has shown the possibility of being used for the treatment of various skin diseases, such as atopic dermatitis and skin cancer. However, the role of LTAP in regulating skin moisturizing and melanogenesis has not been investigated. In this study, we aimed to determine the effect of LTAP on yes-associated protein (YAP), a major transcriptional coactivator in the Hippo signaling pathway that is involved in skin moisturizing and melanogenesis-regulating markers. In normal human epidermal keratinocytes (NHEKs), the human epidermal keratinocyte line HaCaT, and human dermal fibroblasts (HDFs), we found that LTAP exhibited increased expression levels of YAP protein. In addition, the expression levels of filaggrin (FLG), which is involved in natural moisturizing factors (NMFs), and hyaluronic acid synthase (HAS), transglutaminase (TGM), and involucrin (IVL), which regulate skin barrier and moisturizing, were also increased after exposure to LTAP. Furthermore, collagen type I alpha 1 and type III alpha 1 (COL1A1, COL3A1) were increased after LTAP exposure, but the expression level of matrix metalloproteinase-3 (MMP-3) was reduced. Moreover, LTAP was found to suppress alpha-melanocyte stimulating hormone (α-MSH)-induced melanogenesis in murine melanoma B16F10 cells and normal human melanocytes (NHEMs). LTAP regulates melanogenesis of the melanocytes through decreased YAP pathway activation in a melanocortin 1 receptor (MC1R)-dependent manner. Taken together, our data show that LTAP regulates skin moisturizing and melanogenesis through modulation of the YAP pathway, and the effect of LTAP on the expression level of YAP varies from cell to cell. Thus, LTAP might be developed as a treatment method to improve the skin barrier, moisture content, and wrinkle formation, and to reduce melanin generation.

Treatment with phosphodiester CpG-ODN ameliorates atopic dermatitis by enhancing TGF-ß signaling.

Synthetic oligodeoxynucleotides (ODNs) containing unmethylated CpG phosphorothioate (PS CpG-ODN) are known to decrease IgE synthesis in Th2 allergy responses. Nonetheless, the therapeutic role of PS CpG-ODN is limited due to cytotoxicity. Therefore, we developed a phosphodiester (PO) form of CpG-ODN (46O) with reduced toxicity but effective against allergies. In this study, we first compared the toxicity of 46O with CpG-ODNs containing a PS backbone (1826S). We also investigated the therapeutic efficacy and mechanism of 46O injected intravenously in a mouse model of ovalbumin (OVA)-induced atopic dermatitis (AD). To elucidate the mechanism of 46O underlying the inhibition of IgE production, IgE- and TGF-ô€…-associated molecules were evaluated in CD40/IL-4- or LPS/IL-4-stimulated B cells. Our data showed that the treatment with 46O was associated with a lower hematological toxicity compared with 1826S. In addition, injection with 46O reduced erythema, epidermal thickness, and suppressed IgE and IL-4 synthesis in mice with OVA-induced AD. Additionally, 46O induced TGF-ß production in LPS/IL-4-stimulated B cells via inhibition of Smad7, which suppressed IgE synthesis via interaction between Id2 and E2A. These findings suggest that enhanced TGF-ß signaling is an effective treatment for IgE-mediated allergic conditions, and 46O may be safe and effective for treating allergic diseases such as AD and asthma. [BMB Reports 2021; 54(2): 142-147].

Insights into superoxide dismutase 3 in regulating biological and functional properties of mesenchymal stem cells.

Mesenchymal stem cells (MSCs) have been extensively studied and implicated for the cell-based therapy in several diseases due to theirs immunomodulatory properties. Embryonic stem cells and induced-pluripotent stem cells have either ethical issues or concerns regarding the formation of teratomas, introduction of mutations into genome during prolonged culture, respectively which limit their uses in clinical settings. On the other hand, MSCs also encounter certain limitation of circumscribed survival and reduced immunomodulatory potential during transplantation. Plethora of research is undergoing to improve the efficacy of MSCs during therapy. Several compounds and novel techniques have been employed to increase the therapeutic potency of MSCs. MSCs secreted superoxide dismutase 3 (SOD3) may be the mechanism for exhibiting direct antioxidant activities by MSCs. SOD3 is a well known antioxidant enzyme and recently known to possess immunomodulatory properties. Along with superoxide scavenging property, SOD3 also displays anti-angiogenic, anti-chemotactic and anti-inflammatory functions in both enzymatic and non-enzymatic manners. In this review, we summarize the emerging role of SOD3 secreted from MSCs and SOD3's effects during cell-based therapy.

Pathologic properties of SOD3 variant R213G in the cardiovascular system through the altered neutrophils function.

The SOD3 variant, SOD3R213G, results from substitution of arginine to glycine at amino acid 213 (R213G) in its heparin binding domain (HBD) and is a common genetic variant, reported to be associated with ischemic heart disease. However, little is understood about the role of SOD3R213G in innate immune function, and how it leads to dysfunction of the cardiovascular system. We observed pathologic changes in SOD3R213G transgenic (Tg) mice, including cystic medial degeneration of the aorta, heart inflammation, and increased circulating and organ infiltrating neutrophils. Interestingly, SOD3R213G altered the profile of SOD3 interacting proteins in neutrophils in response to G-CSF. Unexpectedly, we found that G-CSF mediated tyrosine phosphatase, SH-PTP1 was down-regulated in the neutrophils of SOD3R213G overexpressing mice. These effects were recovered by reconstitution with Wt SOD3 expressing bone marrow cells. Overall, our study reveals that SOD3R213G plays a crucial role in the function of the cardiovascular system by controlling innate immune response and signaling. These results suggest that reconstitution with SOD3 expressing bone marrow cells may be a therapeutic strategy to treat SOD3R213G mediated diseases.

Superoxide Dismutase 3 Inhibits LL-37/KLK-5-Mediated Skin Inflammation through Modulation of EGFR and Associated Inflammatory Cascades.

The expressions of LL-37 and KLK-5 were found to be altered in various dermatoses, including atopic dermatitis, psoriasis, and rosacea. However, the downstream inflammatory effect of LL-37 and KLK-5 is not as well studied. In addition, there is little high-quality evidence for the treatment of LL-37- and KLK-5-mediated inflammation. In this study, we investigated the effect of superoxide dismutase 3 (SOD3) on LL-37- or KLK-5-induced skin inflammation in vitro and in vivo and its underlying anti-inflammatory mechanisms. Our data showed that SOD3 significantly reduced both LL-37- and KLK-5-induced expression of pro-inflammatory mediators and suppressed the activation of EGFR, protease-activated receptor 2, nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3, and p38/extracellular signal-regulated kinase signaling pathways in human keratinocytes. Moreover, SOD3 suppressed LL-37-induced expression of inflammatory mediators, reactive oxygen species production, and p38/extracellular signal-regulated kinase activation in mast cells. In addition, subcutaneous injection of KLK-5 in SOD3 knockout mice exhibited erythema with increased epidermal thickness, mast cell and neutrophil infiltration, expression of inflammatory mediators, and activation of EGFR, protease-activated receptor 2, nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3, and downstream mitogen-activated protein kinase pathways. However, treatment with SOD3 in SOD3 knockout mice rescued KLK-5-induced inflammatory cascades. Similarly, KLK-5-induced inflammation in wild-type mice was also ameliorated when treated with SOD3. Taken together, our data suggest that SOD3 is a potentially effective therapy for both LL-37-and KLK-5-induced skin inflammation.

Enhanced therapeutic effects of human mesenchymal stem cells transduced with superoxide dismutase 3 in a murine atopic dermatitis-like skin inflammation model.

BACKGROUND: The use of mesenchymal stem cells (MSCs) has been proposed to treat various autoimmune diseases. However, effective strategies for treating atopic dermatitis (AD) are still lacking, and the mechanisms underlying stem cell therapy remain largely unknown. In this study, we sought to explore potential clinical application of superoxide dismutase 3-transduced MSCs (SOD3-MSCs) to experimental AD-like skin inflammation in in vitro and in vivo and its underlying anti-inflammatory mechanisms. METHODS: SOD3-MSCs were administered subcutaneously to mice with AD, and associated symptoms and biologic changes were evaluated. Human keratinocytes, mast cells, and murine T helper (Th) 2 cells were cocultured in vitro with SOD3-MSCs to investigate potential therapeutic effects of SOD3-MSCs. RESULTS: In mice with AD, SOD3-MSCs ameliorated AD pathology and enhanced the efficacy of MSC therapy by controlling activated immune cells, by reducing expression levels of proinflammatory mediators in the skin, and by inhibiting the histamine H4 receptor (H4R)-mediated inflammatory cascade and activation of Janus kinase signal transducer and activator of transcription pathways. Similarly, coculture of SOD3-MSCs with mast cells, keratinocytes, and Th2 cells effectively dampened H4R-dependent persistent inflammatory responses by multiple mechanisms. Moreover, we also showed that SOD3 interacts with H4R and IL-4 receptor α. The functional significance of this interaction could be a markedly reduced inflammatory response in keratinocytes and overall AD pathogenesis, representing a novel mechanism for SOD3's anti-inflammatory effects. CONCLUSION: SOD3-MSCs can be potentially used as an effective and clinically relevant therapy for AD and other autoimmune disorders.

Superoxide dismutase 3 protects mesenchymal stem cells through enhanced autophagy and regulation of FoxO3a trafficking.

Therapeutic applications of mesenchymal stem cells (MSCs) are limited due to their early death within the first few days of transplantation. Therefore, to improve the efficacy of cellbased therapies, it is necessary to manipulate MSCs so that they can resist various stresses imposed by the microenvironment. Moreover, the role of superoxide dismutase 3 (SOD3) in regulating such survival under different stress conditions remain elusive. In this study, we overexpressed SOD3 in MSCs (SOD3-MSCs) and evaluated its effect under serum starvation conditions. Nutritional limitation can decrease the survival rate of transplanted MSCs and thus can reduce their efficacy during therapy. Interestingly, we found that SOD3-MSCs exhibited reduced reactive oxygen species levels and greater survival rates than normal MSCs under serum-deprived conditions. In addition, overexpression of SOD3 attenuated starvationinduced apoptosis with increased autophagy in MSCs. Moreover, we have demonstrated that SOD3 protects MSCs against the negative effects of serum deprivation via modulation of AMP-activated protein kinase/sirtulin 1, extracellular signalregulated kinase activation, and promoted Forkhead box O3a trafficking to the nucleus. Taken together, these results demonstrate that SOD3 promotes MSCs survival and add further evidence to the concept that SOD3-MSCs may be a potential therapeutic agent with better outcomes than normal MSCs for various diseases involving oxidative stress and compromised MSCs survival during therapy. [BMB Reports 2018; 51(7): 344-349].