[Advances of Claudin6-targeting drugs in cancer therapy].

CLDN6 is a member of the CLDNs family that is specifically and highly expressed in cancers such as ovarian, testicular, endocervical, liver and lung adenocarcinoma, but hardly expressed in adult normal tissues. CLDN6 is able to activate multiple signaling pathways, which take part in the development and progression of cancer, including promoting tumor growth, migration and invasion, and promoting chemoresistance in cancer. In recent years, CLDN6 has received much attention as a novel target for cancer therapeutics. Many types of anticancer drugs targeting CLDN6 have been developed, including antibody-conjugated drugs (ADC), monoclonal antibodies, bispecific antibodies, and chimeric antigen receptor T-cell immunotherapy (CAR-T). This paper briefly summarizes the structure, expression and function of CLDN6 in tumors, and reviews the current status and ideas of developing targeted CLDN6 anticancer drugs.

Distributions and impacts of plutonium in the environment originating from the Fukushima Daiichi Nuclear Power Plant accident: An overview of a decade of studies.

This paper reviews the current knowledge on plutonium (Pu) isotopic composition (the atom or activity ratios) and activity concentrations of 238Pu, 239Pu, 240Pu, and 241Pu resulting from the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident in 2011. In this critical review, we document the characteristic values of Pu atom or activity ratios (fingerprints) and present their spatial distributions around the FDNPP site. Based on multiple Pu fingerprints (238Pu/239+240Pu activity ratio, 240Pu/239Pu atom ratio, and 241Pu/239Pu atom ratio), we clarify that Pu contamination from the FDNPP accident occurred in a restricted terrestrial area, while Pu in the Northwest Pacific Ocean is still predominately sourced from the Pacific Proving Grounds (PPG) and global fallout. Using a simple two end-member mixing model, we calculate average contributions of Pu from the FDNPP accident of 13 ± 20% (n = 180) in soil samples, 55 ± 32% (n = 38) in leaf litter samples, and 67 ± 26% (n = 129) in air dust/black substances. In the marine environment, the PPG source average contributions are 45 ± 15% (n = 76) in seawater and 42 ± 12% (n = 48) in sediments. The spatial distributions of Pu atom or activity ratios based on existing studies suggest that: 1) in the terrestrial region investigated 80 km northwest of the FDNPP site, the Pu contamination is mainly observed in an area within a 50 km distance, and 2) in the terrestrial region investigated 60 km southwest of the FDNPP site, the Pu contamination is mainly observed in an area within a 30 km distance. Studies of Cs-bearing radioactive particles indicate that Pu occurs as Pu oxide, and the fuel fragments containing Pu that were released from the reactors to the surrounding environment are associated with micron-scale Cs-bearing radioactive particles. We note that the fractionation between Pu and other radionuclides occurred after release. These new findings about the Pu fingerprints around the FDNPP site will help researchers to establish a reference background database for future environmental risk assessment and geochemical study there.

SiamMixer: A Lightweight and Hardware-Friendly Visual Object-Tracking Network.

Siamese networks have been extensively studied in recent years. Most of the previous research focuses on improving accuracy, while merely a few recognize the necessity of reducing parameter redundancy and computation load. Even less work has been done to optimize the runtime memory cost when designing networks, making the Siamese-network-based tracker difficult to deploy on edge devices. In this paper, we present SiamMixer, a lightweight and hardware-friendly visual object-tracking network. It uses patch-by-patch inference to reduce memory use in shallow layers, where each small image region is processed individually. It merges and globally encodes feature maps in deep layers to enhance accuracy. Benefiting from these techniques, SiamMixer demonstrates a comparable accuracy to other large trackers with only 286 kB parameters and 196 kB extra memory use for feature maps. Additionally, we verify the impact of various activation functions and replace all activation functions with ReLU in SiamMixer. This reduces the cost when deploying on mobile devices.

Comparative research on the metabolism of metoprolol by four CYP2D6 allelic variants in vitro with LC-MS/MS.

Specific study about the effect of cytochrome P450 2D6 (CYP2D6) polymorphisms on the metabolism of clinic drugs is of great significance for drug safety investigation. Here, the interaction between CYP2D6 variants (*1, *2, *10, *39) and metoprolol (MET) was intensively researched in vitro from the aspect of drug-enzyme kinetic study. To obtain quantitative data, α-hydroxymetoprolol (main metabolite of MET) was selected as an ideal analyte and an LC-MS/MS method was adopted for sample determination. Firstly, by selecting suitable internal standard and optimizing separation condition, the LC-MS/MS method was established and validated. Then, the drug-enzyme incubation system was optimized by two parameters: incubation time and amount of enzyme. Lastly, the interaction between CYP2D6 allelic variants and MET was characterized by Km, Vmax and CLint. As a result, four CYP2D6 enzymes displayed diverse Km or Vmax towards MET and the values of CLint showed a wide range from 8.91 to 100%. Relative to CYP2D6*1 (CLint*1 = 100%), CYP2D6*2 demonstrated the second high catalytic activity (CLint*2/*1 = 74.87%) while CYP2D6*39 (CLint*39/*1 = 29.65%) and CYP2D6*10 (CLint*10/*1 = 8.91%) showed minimal catalytic activity. This comprehensive in vitro data suggested the prominent influence of CYP2D6 polymorphisms on the metabolism of MET, which could offer valuable information for personalized administration of MET in clinic.

Fragment-Based Lead Generation of 5-Phenyl-1H-pyrazole-3-carboxamide Derivatives as Leads for Potent Factor Xia Inhibitors.

FXIa is suggested as a major target for anticoagulant drug discovery because of reduced risk of bleeding. In this paper, we defined 5-phenyl-1H-pyrazole-3-carboxylic acid derivatives as privileged fragments for FXIa inhibitors' lead discovery. After replacing the (E)-3-(5-chloro-2-(1H-tetrazol-1-yl)phenyl)acrylamide moiety in compound 3 with 5-(3-chlorophenyl)-1H-pyrazole-3-carboxamide, we traveled from FXIa inhibitor 3 to a scaffold that fused the privileged fragments into a pharmacophore for FXIa inhibitors. Subsequently, we synthesized and assessed the FXIa inhibitory potency of a series of 5-phenyl-1H-pyrazole-3-carboxamide derivatives with different P1, P1' and P2'moiety. Finally, the SAR of them was systematically investigated to afford the lead compound 7za (FXIa Ki = 90.37 nM, 1.5× aPTT in rabbit plasma = 43.33 µM) which exhibited good in vitro inhibitory potency against FXIa and excellent in vitro coagulation activities. Furthermore, the binding mode of 7za with FXIa was studied and the results suggest that the 2-methylcyclopropanecarboxamide group of 7za makes 2 direct hydrogen bonds with Tyr58B and Thr35 in the FXIa backbone, making 7za binds to FXIa in a highly efficient manner.

Synthesis of a Novel Series of Amino Acid Prodrugs Based on Thienopyridine Scaffolds and Evaluation of Their Antiplatelet Activity.

The thienopyridines class of drugs used as P2Y12 receptor antagonists plays a vital role in antiplatelet therapy. To further optimized this compound class, we designed and synthesized a series of amino acid prodrugs of 2-hydroxytetrahydrothienopyridine. All compounds were then evaluated for their inhibitory effect on ADP-induced platelet aggregation in rats and then ED50 and bleeding time of the most potent compounds were compared with commercial drugs. The results showed compound 5c could be a potent and safe candidate for further research.

Glycyrrhetic Acid Derivative TY501 Protects Against Lithocholic Acid-Induced Cholestasis.

The aim of the study is to investigate the protective effects of TY501 against LCA-induced cholestasis in mice and to explore the potential mechanisms. It was demonstrated that TY501(5, 15 or 45 mg/kg, i.g.) can markedly reduced the level of ALT, AST and ALP which increased by LCA treatment. Meanwhile, TY501 also lowered total bile acids, total bilirubin and total cholesterol levels in serum. Furthermore, TY501 can protect HepG2 cell cultures from LCA-induced cytotoxicity. RT-PCR and Western Blot analysis showed that TY501 recovered the expression of BSEP, MRP2 and NTCP which were down-regulated by LCA. Moreover, mRNA and protein of FXR was also observed in TY501 treated mice significantly accumulation in nucleus. Taken together, It can be concluded that TY501 exerted beneficial effects on LCA-induced cholestasis, possibly via activation of FXR mediated upregulation of BSEP, MRP2 and NTCP.

Myricetin: a potent approach for the treatment of type 2 diabetes as a natural class B GPCR agonist.

The physiologic properties of glucagon-like peptide 1 (GLP-1) make it a potent candidate drug target in the treatment of type 2 diabetes mellitus (T2DM). GLP-1 is capable of regulating the blood glucose level by insulin secretion after administration of oral glucose. The advantages of GLP-1 for the avoidance of hypoglycemia and the control of body weight are attractive despite its poor stability. The clinical efficacies of long-acting GLP-1 derivatives strongly support discovery pursuits aimed at identifying and developing orally active, small-molecule GLP-1 receptor (GLP-1R) agonists. The purpose of this study was to identify and characterize a novel oral agonist of GLP-1R (i.e., myricetin). The insulinotropic characterization of myricetin was performed in isolated islets and in Wistar rats. Long-term oral administration of myricetin demonstrated glucoregulatory activity. The data in this study suggest that myricetin might be a potential drug candidate for the treatment of T2DM as a GLP-1R agonist. Further structural modifications on myricetin might improve its pharmacology and pharmacokinetics.-Li, Y., Zheng, X., Yi, X., Liu, C., Kong, D., Zhang, J., Gong, M. Myricetin: a potent approach for the treatment of type 2 diabetes as a natural class B GPCR agonist.

Role of the PEBP4 protein in the development and metastasis of gastric cancer.

Phosphatidylethanolamine-binding protein 4 (PEBP4) has previously been reported to be upregulated in various cancers. However, the physiological functions of PEBP4 in gastric cancer are still unknown. Aiming to clarify the properties and role of PEBP4 in the development and invasion of gastric cancer, we performed several biological assays and a knockdown assay. The expression level of PEBP4 was shown to be significantly upregulated in gastric cancer tissue samples, and knockdown of the expression of PEBP4 induced significant inhibitory effects on cell proliferation, migration and invasiveness. In addition, it was demonstrated that PEBP4 was associated with the development and invasion of gastric cancer cells through activation of the PI3K/Akt signaling pathway. Our findings supported the hypothesis that PEBP4 might be a novel potential drug target for the treatment of gastric cancer.

Delivery of a peptide-drug conjugate targeting the blood brain barrier improved the efficacy of paclitaxel against glioma.

The challenge of effectively delivering therapeutic agents to the brain has created an entire field of active research devoted to overcoming the blood brain barrier (BBB) and efficiently delivering drugs to the brain. Angiopep-2 can trigger transcytosis and traverse the BBB by recognizing low-density lipoprotein related protein-1 (LRP-1) expressed on the brain capillary endothelial cells. Here, we designed a novel strategy for the delivery of drugs to the brain. The novel drug delivery system was a combination of a receptor-targeting ligand, such as low-density lipoprotein related protein 1, and a cell-penetrating peptide (CPP). It was hypothesized that this conjugate will enhance the delivery of associated therapeutic cargo across the BBB and increase the permeability of a solid tumor. Our findings indicate that the combination of these two agents in a delivery vehicle significantly improved translocation of small molecules (paclitaxel) into the brain compared to the vehicle treatment, which contained only receptor-targeting ligand. The application of this strategy could potentially expand the horizons for the treatment of central nervous system disorders.

Myricetin, a potent natural agent for treatment of diabetic skin damage by modulating TIMP/MMPs balance and oxidative stress.

Foot ulceration is a major cause of morbidity in patients with diabetes, and abnormal peripheral neuropathy often results in hospitalization. Up-regulation of matrix metalloproteinases and down-regulation of tissue inhibitor of metalloproteinase 1 are noted to be distinctive biological functions of diabetic dermal fibroblasts. The aim of this study was to evaluate the biological effects of modified retinoids on diabetic fibroblasts. Myricetin, a natural compound, balances the TIMP1/MMP ratio and oxidative stress in diabetic fibroblasts. Our results indicate that myricetin significantly ameliorates the effects of diabetes on dermal fibroblasts. In addition, we found that the oxidative stress imbalance induced by a high glucose concentration plays an important role in the changes to dermal fibroblasts that occur in diabetes. Our findings support the hypothesis that myricetin has the potential to repair faulty skin function arising from diabetes.

Variant fatty acid-like molecules Conjugation, novel approaches for extending the stability of therapeutic peptides.

The multiple physiological properties of glucagon-like peptide-1 (GLP-1) make it a promising drug candidate for the treatment of type 2 diabetes. However, the in vivo half-life of GLP-1 is short due to rapid degradation by dipeptidyl peptidase-IV (DPP-IV) and renal clearance. The poor stability of GLP-1 has significantly limited its clinical utility; however, many studies are focused on extending its stability. Fatty acid conjugation is a traditional approach for extending the stability of therapeutic peptides because of the high binding affinity of human serum albumin for fatty acids. However, the conjugate requires a complex synthetic approach, usually involving Lys and occasionally involving a linker. In the current study, we conjugated the GLP-1 molecule with fatty acid derivatives to simplify the synthesis steps. Human serum albumin binding assays indicated that the retained carboxyl groups of the fatty acids helped maintain a tight affinity to HSA. The conjugation of fatty acid-like molecules improved the stability and increased the binding affinity of GLP-1 to HSA. The use of fatty acid-like molecules as conjugating components allowed variant conjugation positions and freed carboxyl groups for other potential uses. This may be a novel, long-acting strategy for the development of therapeutic peptides.

Potent tumor targeting drug release system comprising MMP-2 specific peptide fragment with self-assembling characteristics.

Self-assembling peptides are capable of forming a complex containing a cavity where cytotoxic agents can be wrapped in a self-assembling manner. These complexes are beneficial for improving the pharmacological properties and pharmacokinetics of cytotoxic agents, such as doxorubicin and paclitaxel. In the present study, this self-assembling feature was successfully integrated into a hexapeptide with matrix metalloproteinase (MMP)-2 specific targeting activity, producing a supramolecule possessing controlled drug release characteristics. The MMP-2 specific substrate fragment, PVGLIG, makes this supramolecule disassociate in the presence of MMP-2, and this system is considered to be a powerful tool for the treatment of tumors with high expression of MMP-2 or tumor metastasis. Our findings show that this modified self-assembling peptide with the PVGLIG fragment was able to significantly enhance specificity against HT1080 cells, a tumor cell line with high expression of MMP-2. In addition, residence time of the complex in blood was prolonged since paclitaxel was wrapped into the supramolecule. Our results suggest that the modified MMP-2 specific substrate, SAMTA7, could act as a controlled and sustained drug carrier for treatment of tumors with high expression of MMP-2 and for tumor metastasis.

Long-acting GLP-1 analogue in V-shaped conformation by terminal polylysine modifications.

Glucagon-like peptide-1 (GLP-1) possesses multiple physiological functions, which make it a potential drug candidate for the treatment of type 2 diabetes. However, its clinical application was limited severely by its short half-life in vivo. Therefore, stabilization of GLP-1 is critical for the use of this peptide in drug development. In this study, a novel GLP-1 derivative, VGLP1K6, processed a significantly prolonged half-life in vivo. Structural analysis using molecular dynamics simulations demonstrated that VGLP1K6 has a rigid V-shaped conformation resulting from the intrapeptide disulfide bond. The C-terminal polylysine residues of VGLP1K6 caused the vulnerable N-terminus of GLP-1 (HA-fragment) to reside within the pocket-like cavity of the peptide due to the intrahydrogen bonds. The structural analysis suggested that this structural alteration contributed to the remarkable prolonged half-life of VGLP1K6, which was approximately 70 h. In addition, VGLP1K6 induced better long-acting glucose tolerance and greater HbA1c reductions than GLP-1 in rodents. Our findings suggest that the GLP-1 derivative VGLP1K6 might be a possible potent antidiabetic drug for the treatment of type 2 diabetes mellitus.

Self-assembling peptides improve the stability of glucagon-like peptide-1 by forming a stable and sustained complex.

The multiple physiological characterizations of glucagon-like peptide-1 (GLP-1) make it a promising drug candidate for the treatment of T2DM. However, the short half-life of GLP-1 limits its clinical utility. Self-assembling peptides are presumed to wrap GLP-1 peptide, and this helps to prolong the stability of GLP-1 consequently. The aim of this study was to investigate whether self-assembling peptides could be applied to prolong the half-life of GLP-1 as sustained release preparations. In this study, five different self-assembling peptides were employed. The formation of the complexes was monitored using gel filtration and mass spectrometry and was simulated by Molecular Dynamics. Stabilization, insulin secretion stimulation, and glucose tolerance tests were performed to investigate the physiological characteristics retained by GLP-1 following complex formation with self-assembling peptides. Our findings revealed that, among the five different self-assembling peptides tested, complex of Pep-1 and GLP-1 exhibited a remarkable extension in the half-life of GLP-1. In addition, the experimental animals treated with a GLP-1/Pep-1 complex exhibited better blood glucose clearance activity over a greater duration of time than the animals treated with GLP-1 alone. Based on our results, an adjustment of the Pep-1 and GLP-1 ratios is presumed to be able to control the half-life of GLP-1 (e.g., medium-acting and long-acting). Collectively, the findings in this study suggest that the self-assembling peptide Pep-1 could serve as a powerful drug preparation tool to extend the short half-life of therapeutic peptides.

[Effect of modified sijunzi decoction on the bone metabolism of adriamycin induced nephropathy rats].

OBJECTIVE: To explore the effect of Modified Sijunzi Decoction (MSD) on the bone metabolism of prednisone intervened adriamycin-induced nephropathy rats. METHODS: The adriamycin-induced nephropathy rat model was prepared. Totally 50 SD rats were randomly divide into five groups, i.e., the model group, the hormone group, the Chinese medicine (CM) group, the CM + hormone group, and the normal control group. The 24-h urine samples were collected on the 7th, 21st, and 35th day after modeling. The 24-h urine protein was measured by biuret colorimetry. Serum levels of osteoprotegerin (OPG), receptor activator of nuclear factor-kappaB ligand (RANKL), osteocalcin (BGP), and tartrate-resistant acid phosphatase (TRACP) were determined by ELISA. Expressions of OPG and RANKL in the tibia tissue were detected using real-time quantitative PCR and Western blot. RESULTS: (1) Compared with the normal control group, the 24-h urine protein increased in each group on the 7th, 21st, and 35th day (P < 0.05, P < 0.01). Compared with the model group, the 24-h urinary protein decreased in the hormone group and the CM + hormone group (P < 0.05, P < 0.01). The decrement was more obvious along with the treatment time went by (P < 0.05, P < 0.01). There was statistical difference in the reduction of urine protein on the 35th day between the CM group and the model group (P < 0.05). (2) Compared with the 21st-day of the same group, the serum levels of TRACP and RANKL increased (P < 0.05, P < 0.01). Compared with the model group, the serum levels of the TRACP and RANKL increased (P < 0.05, P < 0.01), OPG and BGP decreased (P < 0.05, P < 0.01) in the hormone group. Compared with the CM group at the same period, serum OPG level decreased and the RANKL level increased in the hormone group and the CM + hormone group (P < 0.05, P < 0.01). Besides, the serum level of TRACP increased and BGP decreased (P < 0.05, P < 0.01). Compared with the hormone group at the same period, OPG and BGP increased (P < 0.05, P < 0.01), RANKL decreased (P < 0.01) in the CM + hormone group. On the 35th day TRACP decreased (P < 0.01). (3) Compared with the normal group, mRNA expressions of OPG and RANKL on the 21st day increased (P < 0.05, P < 0.01), mRNA expressions of OPG and RANKL on the 35th day decreased in the model group (P < 0.01). Compared with the CM group at the same period, OPG mRNA expression decreased (P < 0.01) and RANKL mRNA expression increased in the hormone group (P < 0.05). OPG mRNA expression decreased in the CM +hormone group (P < 0.05). (4) Compared with the hormone group on the 21st day, the OPG level decreased and the RANKL protein increased (both P < 0.05). RANKL decreased in the CM + hormone group (P < 0.05). Compared with the model group at the same period, OPG decreased and RANKL increased in the hormone group (P < 0.01). Compared with the CM group at the same period, OPG decreased (P < 0.01), RANKL increased (P < 0.01) in the hormone group and the CM + hormone group. Compared with the hormone group at the same period, OPG increased and RANKL decreased in the CM + hormone group (both P < 0.01). CONCLUSIONS: Prednisone could induce osteoporosis through the OPG/RANKL/RANK pathway. MSZ could slow down the formation of prednisone-induced osteoporosis through promoting osteoblast differentiation, and inhibiting osteoclastogenesis.

Effects of Yishenjiangzhuo granules on immunity and bone metabolism in patients with stage 3-4 chronic kidney disease.

OBJECTIVE: To determine the effects of Yishenjiangzhuo granules (YJG) on bone metabolism and to explore the changes in levels of bone Gla protein (BGP), tartrate-resistant acid phosphatase (TRAP), as well as their relationships with levels of B cells, regulatory T cells (Treg) and interleukin (IL)-17 in patients with stage 3-4 chronic kidney disease (CKD) before and after treatment. METHODS: Fifty-three stage 3-4 CKD patients were divided randomly into two groups: YJG treatment and control. Peripheral blood was taken from two groups of CKD patients and 21 healthy subjects in the normal group. The parameters determined were the levels of CD4+, CD19+, CD19+ CD69+, CD19+ av, Treg (CD4 + CD25 + CD127lo), BGP, TRAP, IL-17, calcium, phosphate, blood urea nitrogen, serum creatinine (SCr), hemoglobin (Hb) in peripheral blood, and urinary creatinine. Calcium-phosphate products and endogenous creatinine clearance rate (CCr) were calculated according to standard protocols. RESULTS: In YJG and control groups, SCr levels were lowered (P < 0.01) after treatment, whereas CCr (P < 0.05) as well as Hb and albumin levels (P < 0.01) were increased. The changes in levels of CCr and SCr in the YJG group were more significant. After treatment, CD19+CD69+ and Treg levels in the two groups varied (P < 0.01) compared with those of the normal group; the level of CD19+ increased but the levels of CD4+ and CD19 + AV decreased (P < 0.01) in both groups. Compared with the control group, the changes of CD19+ and CD19 + AV in the YJG group were more apparent (P < 0.05). Compared with the normal group, levels of IL-17 in both groups increased significantly (P < 0.01), and the difference in the control group was more significant (P < 0.05). After treatment, the TRAP level increased (P < 0.05), but the difference in BGP level (P > 0.05) was not significant. CONCLUSION: In stage 3-4 CKD patients, B cells and IL-17 participated in the induction of osteoclast activation. YJG could also elevate the level of B cells and decrease their apoptosis, but showed no significant effects on active B cells, IL-17 or osteoclast activity.

Self-assembled peptide (CADY-1) improved the clinical application of doxorubicin.

CADY-1 is an amphipathic peptide that possesses cell-penetrating activity. As an amphipathic peptide, CADY-1 is capable of forming complexes by self-assembly, and they are these complexes that possess cell-penetrating activity. This distinct characteristic of CADY-1 makes it a potent cell-penetrating drug delivery system. Doxorubicin is a widely used cytotoxic anti-cancer drug but is limited by its toxicity. Although the liposomal formulation of doxorubicin ameliorates its toxicity, its complicated synthesis remains an obstacle to its wide clinical use. In this study, our findings revealed that CADY-1 and doxorubicin form a stable complex at optimised molar ratios in a self-assembling manner. Formation of the complex extended the blood residence time of doxorubicin in a similar fashion to that of liposomal doxorubicin. In addition, the complex was capable of carrying doxorubicin across the cell membrane, which increased the therapeutic index of doxorubicin. Experimental animals treated with a CADY-1/doxorubicin complex exhibited better tolerance and anti-tumour activity than animals treated with either liposomal doxorubicin or the free form of doxorubicin. Collectively, the findings in this study support the advantages of using complexes formed by the self-assembled peptide CADY-1 and suggest that CADY-1 is a potent drug delivery system.

Peptide complex containing GLP-1 exhibited long-acting properties in the treatment of type 2 diabetes.

The multiple physiological characterizations of glucagon-like peptide-1 (GLP-1) make it a promising drug candidate for the treatment of type 2 diabetes. However, in vivo, the half-life of GLP-1 is short, which is caused by the degradation of dipeptidyl peptidase-IV (DPP-IV) and renal clearance. Thus, the stabilization of GLP-1 is critical for its utility in drug development. Peptides known as GLP-1 protectors are predicted to increase the half-life of GLP-1 in vivo. Protecting peptides are able to form stable complexes by non-covalent interactions with human GLP-1. In this study, the stability of the complex was investigated, and the physiological functions of the GLP-1/peptide 1 complex were compared to those of exenatide and liraglutide in animals. The results indicated that the GLP-1/peptide 1 complex remarkably raised the half-life of GLP-1 in vivo and showed better glucose tolerance and higher HbA(1c) reduction than exenatide and liraglutide in rodents. Based upon these results, it is suggested that the GLP-1/peptide 1 complex might be utilized as a possible potent anti-diabetic drug in the treatment of type 2 diabetes mellitus.

Disulfide bond prolongs the half-life of therapeutic peptide-GLP-1.

The multiple physiological characterization of glucagon-like peptide-1 (GLP-1) makes it a promising drug candidate for the therapy of type 2 diabetes. However, the half-life of GLP-1 is short in vivo due to rapid degradation by dipeptidyl peptidase-IV (DPP-IV) and renal clearance. This indicates that the stabilization of GLP-1 is critical for its utility in drug development. In this study, we developed a cluster of GLP-1 homodimeric analogs, which fused the mutated GLP-1 monomer by an intra-disulfide bridge. The stabilities of the GLP-1 homodimeric analogs were investigated and the physiological functions of the analogs were compared with those of wild-type GLP-1 in rats and human serum. Single dose glucose tolerance test was performed to investigate the administration frequency which satisfied the efficient glucose regulatory in rats. Multiple dose glucose tolerance tests were employed also to study the long-acting anti-diabetic activity of GLP-1 homodimeric analog. The results indicated that the GLP-1 homodimeric analog (hdGLP1G10C) remarkably raised the biological half-life of GLP-1; also HDGLP1G10C showed better glucose tolerance and higher HbA(1c) reduction than GLP-1 in rodents. Based upon the results in this study, it was suggested that hdGLP1G10C prolonged the stability of GLP-1 and retained the biological activity of GLP-1. The improved physiological characterization of hdGLP1G10C makes it as possible potent anti-diabetic drug in the treatment of type 2 diabetes mellitus.