Background and PurposeAtopic dermatitis (AD) is a multifactorial skin condition with complex interactions of innate and adaptive immune responses. There are several existing therapies for AD, including topical glucocorticosteroids, emollients, phototherapies, calcineurin inhibitors and immunosuppressants, such as cyclosporine A. Although these therapies reduce inflammation, they also cause serious side effects. Therefore, it is necessary to develop new therapeutic approaches for AD treatment without side effects. There are several studies on natural materials or toxins, such as herbs, ginseng extract and snake venom, for AD treatment. However, treatment of AD with bee venom and its major component, melittin has rarely been studied.Experimental ApproachEffects of bee venom and melittin were studied in a model of AD in vivo induced by 1‐chloro‐2,4‐dinitrobenzene (DNCB) in female Balb/c mice and in cultures of human keratinocytes, stimulated by TNF‐α/IFN‐γ. The potential pharmacological effects of bee venom and melittin on these in vivo and in vitro AD‐like skin disease models were studied.Key ResultsBee venom and melittin exhibited potent anti‐atopic activities, shown by decreased AD‐like skin lesions, induced by DNCB in mice. In vitro studies using TNF‐α/IFN‐γ‐stimulated human keratinocytes showed that bee venom and melittin inhibited the increased expression of chemokines, such as CCL17 and CCL22, and pro‐inflammatory cytokines, including IL‐1β, IL‐6 and IFN‐γ, through the blockade of the NF‐κB and STAT signalling pathways.Conclusions and ImplicationsOur results suggest that bee venom and melittin would be suitable for epicutaneous application, as topical administration is often appropriate for the treatment of AD.

These results suggest that apamin has therapeutic effect on AD through improvement of inflammatory condition.

Liver fibrosis is characterized by changes in tissue architecture and extracellular matrix composition. Liver fibrosis affects not only hepatocytes but also the non-parenchymal cells such as hepatic stellate cells (HSCs), which are essential for maintaining an intact liver structure and function. Transforming growth factor β1 (TGF-β1) is a multifunctional cytokine that induces liver fibrosis through activation of Smad signaling pathways. To improve a new therapeutic approach, synthetic TGF-β1/Smad oligodeoxynucleotide (ODN) was used to suppress both TGF-β1 expression and Smad transcription factor using a combination of antisense ODN and decoy ODN. The aims of this study are to investigate the anti-fibrotic effects of TGF-β1/Smad ODN on simultaneous suppressions of both Smad transcription factor and TGF-β1 mRNA expression in the hepatic fibrosis model in vitro and in vivo. Synthetic TGF-β1/Smad ODN effectively inhibits Smad binding activity and TGF-β1 expression. TGF-β1/Smad ODN attenuated the epithelial mesenchymal transition (EMT) and activation of HSCs in TGF-β1-induced AML12 and HSC-T6 cells. TGF-β1/Smad ODN prevented the fibrogenesis and deposition of collagen in CCl4-treated mouse model. Synthetic TGF-β1/Smad ODN demonstrates anti-fibrotic effects that are mediated by the suppression of fibrogenic protein and inflammatory cytokines. Therefore, synthetic TGF-β1/Smad ODN has substantial therapeutic feasibility for the treatment of liver fibrotic diseases.

Cholestatic liver disease is characterized by the progressive destruction of biliary epithelial cells (BECs) followed by fibrosis, cirrhosis and liver failure. Activated hepatic stellate cells (HSCs) and portal fibroblasts are the major cellular effectors of enhanced collagen deposition in biliary fibrosis. Apamin, an 18 amino acid peptide neurotoxin found in apitoxin (bee venom), is known to block Ca2+-activated K+ channels and prevent carbon tetrachloride-induced liver fibrosis. In the present study, we aimed to ascertain whether apamin inhibits biliary fibrosis and the proliferation of HSCs. Cholestatic liver fibrosis was established in mouse models with 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) feeding. Cellular assays were performed on HSC-T6 cells (rat immortalized HSCs). DDC feeding led to increased hepatic damage and proinflammtory cytokine levels. Notably, apamin treatment resulted in decreased liver injury and proinflammatory cytokine levels. Moreover, apamin suppressed the deposition of collagen, proliferation of BECs and expression of fibrogenic genes in the DDC-fed mice. In HSCs, apamin suppressed activation of HSCs by inhibiting the Smad signaling pathway. These data suggest that apamin may be a potential therapeutic target in cholestatic liver disease.

Kidney fibrosis is a common process of various kidney diseases leading to end-stage renal failure irrespective of etiology. Myofibroblasts are crucial mediators in kidney fibrosis through production of extracellular matrix (ECM), but their origin has not been clearly identified. Many study proposed that epithelial and endothelial cells become myofibroblasts by epithelial dedifferentiation and endothelial-mesenchymal transition (EndoMT). TGF-β1/Smad signaling plays a crucial role in partly epithelial-mensencymal transition (EMT) and EndoMT. Thus, we designed the TGF-β1/ Smad oligodeoxynucleotide (ODN), a synthetic short DNA containing complementary sequence for Smad transcription factor and TGF-β1 mRNA. Therefore, this study investigated the anti-fibrotic effect of synthetic TGF-β1/Smad ODN on UUO-induced kidney fibrosis in vivo model and TGF-β1-induced in vitro model.To examine the effect of TGF-β1/Smad ODN, we performed various experiments to evaluate kidney fibrosis. The results showed that UUO induced inflammation, ECM accumulation, epithelial dedifferentiation and EndoMT processes, and tubular atrophy. However, synthetic TGF-β1/Smad ODN significantly suppressed UUOinduced fibrosis. Furthermore, synthetic ODN attenuated TGF-β1-induced epithelial dedifferentiation and EndoMT program via blocking TGF-β1/Smad signaling. In conclusion, this study demonstrated that administration of synthetic TGF-β1/Smad ODN attenuates kidney fibrosis, epithelial dedifferentiation, and EndoMT processes.The findings propose the possibility of synthetic ODN as a new effective therapeutic tool for kidney fibrosis. K E Y W O R D SEndoMT, epithelial dedifferentiation, kidney fibrosis, TGF-β1/Smad oligodeoxynucleotide, UUO 334 | GWON et al. | MATERIALS AND METHODS | Synthesis of oligodeoxynucleotidesTarget site of TGF-β1 was selected using S-Fold program. Synthetic ODNs were synthesized on Macrogen (Seoul, Korea). TGF-β1/Smad ODN and scrambled (Scr) ODN 340 | GWON et al. F I G U R E 3 TGF-β1/Smad ODN attenuated kidney fibrosis and ECM accumulation in UUO-injured mice. A, Pathological stain withhematoxylin and eosin (H&E) and B, Masson's trichrome performed using kidney sections. Trichrome stain showed that TGF-β1/Smad ODN attenuated interstitial fibrosis. C, The quantitative analysis of blue-stained collagen in trichrome staining (n = 3). D, Collagen Ⅰ was detected by RT-PCR. This result demonstrated the effect of synthetic ODN on ECM accumulation. The graphs summarize the analysis of the Collagen Ⅰ mRNA expressions (n = 4). E, Immunohistochemistry stain showed that the expression of fibronectin was inhibited by TGF-β1/Smad ODN administration in UUO-injured mice. F, The quantitative graph of fibronectin expression. G, Representative Western blot data revealed that TGF-β1/Smad ODN diminished expression of fibronectin. β-actin was used to confirm equal volume protein sample loading (n = 3). Scale bar = 50 μm; +: treated; −: un-treated; *P < .05 compared to the normal control group; †P < .05 compared to the UUO group