Bacillus-Derived Manganese Superoxide Dismutase Relieves Ocular-Surface Inflammation and Damage by Reducing Oxidative Stress and Apoptosis in Dry Eye.

Purpose: We hypothesized that antioxidative enzymes supplementation could be a treatment option for dry eye. We investigated the efficacy of oral administration of Bacillus-derived superoxide dismutase (Bd-SOD) in a murine experimental dry eye (EDE). Methods: In part I, mice were randomly assigned to normal control, EDE, and mice groups that were treated with oral Bd-SOD after induction of EDE (EDE + Bd-SOD group; four mice in each group). Expression of SOD2, a major antioxidant enzyme with manganese as a cofactor, was assessed by immunofluorescence staining. In part II, mice were divided into seven groups (six mice in each group): normal control, EDE, vehicle-treated, topical 0.05% cyclosporin A (CsA)-treated, and oral Bd-SOD-treated (2.5, 5.0, and 10.0 mg/kg Bd-SOD) groups. Tear volume, tear-film break-up time (TBUT), and corneal fluorescein-staining scores (CFS) were measured at zero, five, and 10 days after treatment. Ten days after treatment, 2',7'-dichlorodihydrofluorescein diacetate for reactive oxygen species (ROS), enzyme-linked immunosorbent for malondialdehyde, and TUNEL assays for corneal apoptosis, flow cytometry inflammatory T cells, and histological assessment were performed. Results: Compared to the normal control group in part I, the EDE group showed significantly decreased SOD2 expression by immunofluorescence staining. However, the EDE + Bd-SOD group recovered similar to the normal control group. In part II, ROS, malondialdehyde, and corneal apoptosis were decreased in CsA and all Bd-SOD-treated groups. Corneal and conjunctival inflammatory T cells decreased, and conjunctival goblet cell density increased in CsA-treated and Bd-SOD-treated groups. Compared to the CsA-treated group, the 2.5 mg/kg Bd-SOD-treated group showed increased TBUT and decreased inflammatory T cells, and the 5.0 mg/kg Bd-SOD-treated group showed decreased CFS and increased conjunctival goblet cells. Conclusions: Oral Bd-SOD administration might increase autogenous SOD2 expression in ocular surface tissue in EDE and could be developed as a complementary treatment for DE in the future.

Differential role of lipoteichoic acids isolated from Staphylococcus aureus and Lactobacillus plantarum on the aggravation and alleviation of atopic dermatitis.

Lipoteichoic acid (LTA), a cell wall component of gram-positive bacteria, up-regulates inflammatory cytokine production through the toll-like receptor 2 (TLR2) signaling pathway, and also contributes to anti-inflammatory responses against immune cells stimulated by lipopolysaccharides. In the current study, we examined the effects of LTAs isolated from Staphylococcus aureus (aLTA) and Lactobacillus plantarum (pLTA) on the aggravation and alleviation of atopic dermatitis (AD). aLTA strongly induced CCL2 production in THP-1 cells. CCL2 was regulated by the TLR2 pathway including the activation of IRAK2, NF-κB and JNK. CCL2 induced Th2 polarization of CD4+T cells through induction of interleukin (IL)-2, -4, and -5 and inhibition of interferon-gamma (IFN-γ). CCL2 levels and immunoglobulin E (IgE) production were increased in aLTA-injected mice. On the other hand, pLTA moderately affected CCL2 production and it inhibited aLTA-mediated CCL2 production. The serum levels of CCL2 and IgE were inhibited by pLTA pre-injection followed by aLTA reinjection, which resulted in the alleviation of irritant contact dermatitis (ICD) symptoms. Our results suggest that S. aureus infection causes an increase in CCL2 production, and may exacerbate atopic dermatitis (AD)-like symptoms through the excessive IgE production. Alternatively, pLTA alleviated AD-like symptoms by inhibiting aLTA-induced CCL2 and IgE production.

Combination treatment with lipoteichoic acids isolated from Lactobacillus plantarum and Staphylococcus aureus alleviates atopic dermatitis via upregulation of CD55 and CD59.

The innate immune complement system helps clear invading pathogens by forming membrane attack complexes (MACs) on their surface. Abnormal activation of the complement system may aggravate atopic dermatitis (AD) symptoms in AD patients. Here, we investigated the anti-AD effects of LTAs isolated from Lactobacillus plantarum (pLTA) and Staphylococcus aureus (aLTA) by examination of complement regulatory proteins (CRPs). Combination treatment with pLTA and aLTA increased CD55 and CD59 production in HaCaT cells. The regulation of CD55 and CD59 was mediated by p38 mitogen-activated protein kinase (p38) signaling pathways in pLTA- and aLTA-treated cells. Complement-dependent cytotoxicity (CDC) and bactericidal assays revealed that combination treatment with pLTA and aLTA down-regulated the complement system. In experiments using an irritant contact dermatitis (ICD)-induced mouse model, the levels of MAC and C3 convertase (C3C) were lower in serum collected from pLTA- and aLTA-injected mice than in serum from mice who were untreated or received pLTA or aLTA alone. Combination treatment also inhibited IgE and CCL2 levels in ICD mice. On the other hand, IFN-γ level was significantly increased, indicating that combination treatment switches the Th2 response to a Th1 response. Our results suggest that combination treatment with LTAs could be a good therapeutic approach to alleviate AD by reducing formation of MACs and inducing a Th1 response.

Bee Venom Alleviates Atopic Dermatitis Symptoms through the Upregulation of Decay-Accelerating Factor (DAF/CD55).

Bee venom (BV)-a complex mixture of peptides and toxic proteins including phospholipase A2 and melittin-promotes blood clotting. In this study, we investigated the anti-atopic properties of BV and the mechanism associated with its regulation of the complement system. BV treatment upregulated the mRNA and protein levels of CD55 in THP-1 cells. Further experiments revealed that the phosphorylation of ERK was associated with upregulation of CD55. A complement-dependent cytotoxicity assay and a bacteria-killing assay showed that BV inactivated the complement system through the induction of CD55. The serum levels of C3 convertase (C3C) and Membrane attack complex (MAC) increased, while CD55 decreased in mice with AD-like lesions from DNCB treatment. However, the levels were inverted when the AD-like mice were treated with BV using subcutaneous injection, and we observed that the AD symptoms were alleviated. BV is often used to treat AD but its mechanism has not been elucidated. Here, we suggest that BV alleviates AD through the inactivation of the complement system, especially by the induction of CD55.