Evaluating Novel SP-B and SP-C Synthetic Analogues for Pulmonary Surfactant Efficacy.

Pulmonary surfactants, a complex assembly of phospholipids and surfactant proteins such as SP-B and SP-C, are critical for maintaining respiratory system functionality by lowering surface tension (ST) and preventing alveolar collapse. Our study introduced five synthetic SP-B peptides and one SP-C peptide, leading to the synthesis of CHAsurf candidates (CHAsurf-1 to CHAsurf-5) for evaluation. We utilized a modified Wilhelmy balance test to assess the surface tension properties of the surfactants, measuring spreading rate, surface adsorption, and ST-area diagrams to comprehensively evaluate their performance. Animal experiments were performed on New Zealand white rabbits to test the efficacy of CHAsurf-4B, a variant chosen for its economic viability and promising ST reduction properties, comparable to Curosurf®. The study confirmed that higher doses of SP-B in CHAsurf-4 are associated with improved ST reduction. However, due to cost constraints, CHAsurf-4B was selected for in vivo assessment. The animal model revealed that CHAsurf-4B could restore alveolar structure and improve lung elasticity, akin to Curosurf®. Our research highlights the significance of cysteine residues and disulfide bonds in the structural integrity and function of synthetic SP-B analogues, offering a foundation for future surfactant therapy in respiratory disorders. This study's findings support the potential of CHAsurf-4B as a therapeutic agent, meriting further investigation to solidify its role in clinical applications.

Cyclic pentapeptide cRGDfK enhances the inhibitory effect of sunitinib on TGF-ß1-induced epithelial-to-mesenchymal transition in human non-small cell lung cancer cells.

In human lung cancer progression, the EMT process is characterized by the transformation of cancer cells into invasive forms that migrate to other organs. Targeting to EMT-related molecules is emerging as a novel therapeutic approach for the prevention of lung cancer cell migration and invasion. Traf2- and Nck-interacting kinase (TNIK) has recently been considered as an anti-proliferative target molecule to regulate the Wnt signaling pathway in several types of cancer cells. In the present study, we evaluated the inhibitory effect of a tyrosine kinase inhibitor sunitinib and the integrin-αⅤß3 targeted cyclic peptide (cRGDfK) on EMT in human lung cancer cells. Sunitinib strongly inhibited the TGF-ß1-activated EMT through suppression of Wnt signaling, Smad and non-Smad signaling pathways. In addition, the cRGDfK also inhibited the expression of TGFß1-induced mesenchymal marker genes and proteins. The anti-EMT effect of sunitinib was enhanced when cRGDfK was treated together. When sunitinib was treated with cRGDfK, the mRNA and protein expression levels of mesenchymal markers were decreased compared to the treatment with sunitinib alone. Co-treatment of cRGDfK has shown the potential to improve the efficacy of anticancer agents in combination with therapeutic agents that may be toxic at high concentrations. These results provide new and improved therapies for treating and preventing EMT-related disorders, such as lung fibrosis and cancer metastasis, and relapse.

Synthesis and Biological Evaluation of the Anti-Melanogenesis Effect of Coumaric and Caffeic Acid-Conjugated Peptides in Human Melanocytes.

Excessive pigmentation and reduced elasticity are the major skin problems that dermatologists and cosmetologists address. Compounds that inhibit melanin production might contribute to improving skin problems. In this study, we investigated whether coumaric acid- and caffeic acid-conjugated peptides might affect alpha-melanocyte stimulating hormone-induced melanin production, tyrosinase activity, and melanin synthesis-related gene expression in SK-MEL-2 human melanoma cells. Coumaric acid and caffeic acid showed no significant cytotoxicity, and they inhibited melanin production. In addition, coumaric acid- and caffeic acid-conjugated peptides suppressed tyrosinase activity more than arbutin, a known tyrosinase inhibitor. Quantitative real-time PCR (qRT-PCR) results also showed that both peptides inhibited the expression of melanin synthesis-related genes, TYR, TYRP1, TYRP2, and MITF. In particular, among the nine conjugated peptides tested, caffeic acid linked to a Gly-Gly-Gly linker and conjugated to the tripeptide, ARP, showed the greatest inhibition of gene expression in the qRT-PCR analysis. These results suggested that the inhibition of melanin exerted by coumaric acid- and caffeic acid-conjugated peptides might provide important information for the development of pigmentation-related skin diseases and cosmetic products.

Anti-Wrinkle Benefits of Peptides Complex Stimulating Skin Basement Membrane Proteins Expression.

The dermal-epidermal junction (DEJ) provides a physical and biological interface between the epidermis and the dermis. In addition to providing a structural integrity, the DEJ also acts as a passageway for molecular transport. Based on the recently reported importance of the DEJ in skin aging, novel peptide derivatives have been tested for their effects on basement membrane (BM) protein expressions in cultured human epidermal keratinocytes. As a result, protein expressions of collagen XVII, laminin and nidogen were stimulated by the test peptide and peptides complex. Further ex vivo evaluation using excised human skin, confirmed that the topical application of the peptides complex significantly increased dermal collagen expression, as well as expressions of collagen XVII and laminin. Interestingly, while the origin of the laminin protein is epidermal keratinocytes, the immunohistochemical staining of skin showed that laminin was only detected in the uppermost layer of the dermis, which suggests a tight assembly of laminin protein onto the dermal side of the DEJ. These results suggest that a peptide complex could improve the structural properties of the DEJ through its ability to stimulate BM proteins. In order to evaluate the anti-wrinkle benefits of the peptide complex in vivo, a clinical study was performed on 22 healthy Asian female volunteers older than 40 years. As a result, significant improvements in skin wrinkles for all of the five sites were observed after two weeks, as assessed by skin topographic measurements. Collectively, these results demonstrate the anti-aging efficacy of the peptides complex.

In vitro combinatorial anti-proliferative and immunosuppressive effects of Brucea javanica extract with CX-4945 and imatinib in human T-cell acute lymphoblastic leukemia cells.

Since 1970, the isolated and identified components of Brucea javanica (L.) Merr. have been known to contain anticancer effects, particularly antileukemic effect. In this study, the inhibitory effect of Brucea javanica (BJ) on cell growth and inflammation was confirmed in human T-cell acute lymphocytic leukemia (T-ALL) cells, and its efficacy as an antileukemic agent was verified. Our results showed that BJ extract induced caspase-dependent apoptosis of T-ALL Jurkat cells through inhibition of the CK2-mediated signaling pathway, while exerting no significant cytotoxicity in normal peripheral blood mononuclear cells. Moreover, BJ extract suppressed the NF-κB signaling pathway, thus, inhibiting the interleukin (IL)-2 expression induced by phorbol 12-myristate 13-acetate (PMA) and phytohemagglutinin (PHA). Notably, combined treatment with BJ extract plus CX-4945 or imatinib exerted enhanced inhibitory effects on T-ALL cell growth and IL-2 production. Overall, these results suggest that BJ extract can be a potent therapeutic herbal agent for T-ALL treatment and prevention of IL-2 mediated inflammatory immune responses.

Vitamin C-linker-conjugated tripeptide AHK stimulates BMP-2-induced osteogenic differentiation of mouse myoblast C2C12 cells.

Vitamin C-linker-conjugated Ala-His-Lys tripeptide (Vit C-AHK) is a derivative of Vitamin C-conjugated tripeptides, which were originally developed as a component of a product for collagen synthesis enhancement or human dermal fibroblast growth. Here, we investigated the effect of Vit C-AHK on bone morphogenetic protein (BMP)-2-induced osteoblast differentiation in a cell culture model. Vit C-AHK enhanced proliferation of C2C12 cells and induction of BMP-2-induced alkaline phosphatase, a typical marker of osteoblast differentiation. Vit C-AHK also stimulated the phosphorylation and translocation of Smad1/5/8 to the nucleus and phosphorylation of mitogen-activated protein kinases (MAPKs) including ERK1/2 and p38. In addition, Vit C-AHK enhanced the BMP-2-induced mRNA expression of osteoblast differentiation-related genes such as ALP, BMP-2, Osteocalcin, and Runx2. Our results suggest that Vit C-AHK exerts an enhancing effect on osteoblast proliferation and differentiation through activation of Smad1/5/8 and MAPK ERK1/2 and p38 signaling and without significant cytotoxicity. These results provide important data for the development of peptide-based bone-regenerative agents and treatment of bone-related disorders.

Synergistic therapeutic effect of diethylstilbestrol and CX-4945 in human acute T-lymphocytic leukemia cells.

Human acute T-lymphocytic leukemia (T-ALL) is one of the most commonly diagnosed hematological disorders, and is characterized by poor prognosis and survival rate. Despite the development of new therapeutic approaches, leukemia treatment options remain limited. In this study, we investigated the immunosuppressive and anti-proliferative effects of the synthetic estrogen diethylstilbestrol (DES), both alone and combined with the casein kinase 2 (CK2) inhibitor CX-4945. Our results indicated that DES induced caspase-dependent apoptosis in a human T-ALL cell line (Jurkat cells), while exerting no significant cytotoxicity in normal peripheral blood mononuclear cells (PBMCs). Phytohaemagglutinin and phorbol 12-myristate 13-acetate induced interleukin (IL)-2 production and activation of NF-κB signaling pathways, which were both inhibited by DES. Moreover, DES exerted synergistic effects with CX-4945 on proliferation and IL-2 production in Jurkat cells. Our results demonstrated that DES exerts anti-proliferative and immunosuppressive effects through inhibition of CK2 and the NF-κB signaling pathway in human T-ALL Jurkat cells.

Synergistic inhibition effect of TNIK inhibitor KY-05009 and receptor tyrosine kinase inhibitor dovitinib on IL-6-induced proliferation and Wnt signaling pathway in human multiple myeloma cells.

Multiple myeloma is a fetal form of plasma cell malignancy characterized by abnormal clonal proliferation of plasma cells. Especially, the canonical Wnt signaling pathway mediated by ß-catenin is activated in multiple myeloma cells, stimulating their proliferation. Here, we investigated the relationship between interleukin-6-induced proliferation of multiple myeloma cells and Traf2- and Nck-interacting kinase (TNIK) expression in Wnt signaling. Interleukin-6 increased the proliferation of multiple myeloma cells and TNIK mRNA and protein expression. In addition, we examined the effect on TNIK of TNIK inhibitor KY-05009 and receptor tyrosine kinase inhibitor dovitinib and whether inhibition of TNIK suppresses the interleukin-6-induced proliferation of multiple myeloma cells. KY-05009 and dovitinib synergistically inhibited interleukin-6-stimulated proliferation and induced apoptosis through the inhibition of Wnt signaling in MM cells. Our results provide crucial information that TNIK is involved in the interleukin-6-dependent proliferation of multiple myeloma cells and inhibition of Wnt signaling involving TNIK could be a therapeutic strategy for the treatment of interleukin-6-dependent multiple myeloma.