[Syntheses and Structure-Activity Relationship Studies of Antitumor Bicyclic Hexapeptide RA-VII Analogues].

A series of antitumor bicyclic hexapeptide RA-VII analogues modified at residue 2, 3, or 6 were prepared by the chemical transformation of the hydroxy, methoxy, or carboxy groups or the aromatic rings of natural peptides RA-II, III, V, VII, and X. Analogues with modified side chains or peptide backbones, which cannot be prepared by the chemical transformation of their natural peptides, and newly isolated peptides from Rubia cordifolia roots were synthesized by using protected cycloisodityrosines prepared by the degradation of bis(thioamide) obtained from RA-VII or the diphenyl ether formation of boronodipeptide under the modified Chan-Lam coupling reaction conditions. Studies of the conformational features of the analogues and the newly isolated peptides and their relationships with cytotoxic activities against the HCT-116, HL-60, KATO-III, KB, L1210, MCF-7, and P-388 cell lines revealed the following: the methoxy group at residue 3 is essential for the potent cytotoxic activity; the methyl group at Ala-2 and Ala-4 but not at D-Ala-1 is required to establish the bioactive conformation; the N-methyl group at Tyr-5 is necessary for the peptides to adopt the active conformation preferentially; and the orientation of Tyr-5 and/or Tyr-6 phenyl rings has a significant effect on the cytotoxic activity.

Activation of Cardiac δ2-Opioid Receptors Increases Heart Tolerance to Reperfusion.

Coronary occlusion (45 min) and reperfusion (120 min) in male Wistar rats in vivo, as well as total ischemia (45 min) of an isolated rat heart followed by reperfusion (30 min) were reproduced. The selective δ2-opioid receptor agonist deltorphin II (0.12 mg/kg and 152 nmol/liter) was administered intravenously 5 min before reperfusion in vivo or added to the perfusion solution at the beginning of reperfusion of the isolated heart. The peripheral opioid receptor antagonist naloxone methiodide and δ2-opioid receptor antagonist naltriben were used in doses of 5 and 0.3 mg/kg, respectively. It was found that the infarct-limiting effect of deltorphin II is associated with the activation of δ2-opioid receptors. We have demonstrated that deltorphin II can improve the recovery of the contractility of the isolated heart after total ischemia.

Multimodal Imaging-Guided Synergistic Photodynamic Therapy Using Carbonized Zn/Co Metal-Organic Framework Loaded with Cytotoxin Against Liver Cancer.

Purpose: The study aimed to address the non-specific toxicity of cytotoxins (CTX) in liver cancer treatment and explore their combined application with the photosensitizer Ce6, co-loaded into carbonized Zn/Co bimetallic organic frameworks. The goal was to achieve controlled CTX release and synergistic photodynamic therapy, with a focus on evaluating anti-tumor activity against human liver cancer cell lines (Hep G2). Methods: Purified cobra cytotoxin (CTX) and photosensitizer Ce6 were co-loaded into carbonized Zn/Co bimetallic organic frameworks, resulting in RGD-PDA@C-ZIF@(CTX+Ce6). The formulation was designed with surface-functionalization using polydopamine and tumor-penetrating peptide RGD. This approach aimed to facilitate controlled CTX release and enhance the synergistic effect of photodynamic therapy. The accumulation of RGD-PDA@C-ZIF@(CTX+Ce6) at tumor sites was achieved through RGD's active targeting and the enhanced permeability and retention (EPR) effect. In the acidic tumor microenvironment, the porous structure of the metal-organic framework disintegrated, releasing CTX and Ce6 into tumor cells. Results: Experiments demonstrated that RGD-PDA@C-ZIF@(CTX+Ce6) nanoparticles, combined with near-infrared laser irradiation, exhibited optimal anti-tumor effects against human liver cancer cells. The formulation showcased heightened anti-tumor activity without discernible systemic toxicity. Conclusion: The study underscores the potential of utilizing metal-organic frameworks as an efficient nanoplatform for co-loading cytotoxins and photodynamic therapy in liver cancer treatment. The developed formulation, RGD-PDA@C-ZIF@(CTX+Ce6), offers a promising avenue for advancing the clinical application of cytotoxins in oncology, providing a solid theoretical foundation for future research and development.

Potency of a small molecule that targets the molluscum contagiosum virus processivity factor increases when conjugated to a tripeptide.

We recently developed compound FC-7269 for targeting the Molluscum contagiosum virus processivity factor (mD4) and demonstrated its ability to inhibit viral processive DNA synthesis in vitro and cellular infection of an mD4-dependent virus (Antiviral Res 211, 2023,105520). However, despite a thorough medicinal chemistry campaign we were unable to generate a potent second analog as a requisite for drug development. We overcame this impasse, by conjugating a short hydrophobic trivaline peptide to FC-7269 to produce FC-TriVal-7269 which significantly increased antiviral potency and reduced cellular toxicity.

A humanized trivalent Nectin-4-targeting nanobody drug conjugate displays potent antitumor activity in gastric cancer.

BACKGROUND: Gastric cancer represents a highly lethal malignancy with an elevated mortality rate among cancer patients, coupled with a suboptimal postoperative survival prognosis. Nectin-4, an overexpressed oncological target for various cancers, has been exploited to create antibody-drug conjugates (ADCs) to treat solid tumors. However, there is limited research on Nectin-4 ADCs specifically for gastric cancer, and conventional immunoglobulin G (IgG)-based ADCs frequently encounter binding site barriers. Based on the excellent tumor penetration capabilities inherent in nanobodies (Nbs), we developed Nectin-4-targeting Nb drug conjugates (NDCs) for the treatment of gastric cancer. RESULTS: An immunized phage display library was established and employed for the selection of Nectin-4-specific Nbs using phage display technology. Subsequently, these Nbs were engineered into homodimers to enhance Nb affinity. To prolong in vivo half-life and reduce immunogenicity, we fused an Nb targeting human serum albumin (HSA), resulting in the development of trivalent humanized Nbs. Further, we site-specifically conjugated a monomethyl auristatin E (MMAE) at the C-terminus of the trivalent Nbs, creating Nectin-4 NDC (huNb26/Nb26-Nbh-MMAE) with a drug-to-antibody ratio (DAR) of 1. Nectin-4 NDC demonstrated excellent in vitro cell-binding activities and cytotoxic efficacy against cells with high Nectin-4 expression. Subsequent administration of Nectin-4 NDC to mice bearing NCI-N87 human gastric cancer xenografts demonstrated rapid tissue penetration and high tumor uptake through in vivo imaging. Moreover, Nectin-4 NDC exhibited noteworthy dose-dependent anti-tumor efficacy in in vivo studies. CONCLUSION: We have engineered a Nectin-4 NDC with elevated affinity and effective tumor uptake, further establishing its potential as a therapeutic agent for gastric cancer.

The Potential of the Fibronectin Inhibitor Arg-Gly-Asp-Ser in the Development of Therapies for Glioblastoma.

Glioblastoma (GBM) is the most lethal and common malignant primary brain tumor in adults. An important feature that supports GBM aggressiveness is the unique composition of its extracellular matrix (ECM). Particularly, fibronectin plays an important role in cancer cell adhesion, differentiation, proliferation, and chemoresistance. Thus, herein, a hydrogel with mechanical properties compatible with the brain and the ability to disrupt the dynamic and reciprocal interaction between fibronectin and tumor cells was produced. High-molecular-weight hyaluronic acid (HMW-HA) functionalized with the inhibitory fibronectin peptide Arg-Gly-Asp-Ser (RGDS) was used to produce the polymeric matrix. Liposomes encapsulating doxorubicin (DOX) were also included in the hydrogel to kill GBM cells. The resulting hydrogel containing liposomes with therapeutic DOX concentrations presented rheological properties like a healthy brain. In vitro assays demonstrated that unmodified HMW-HA hydrogels only caused GBM cell killing after DOX incorporation. Conversely, RGDS-functionalized hydrogels displayed per se cytotoxicity. As GBM cells produce several proteolytic enzymes capable of disrupting the peptide-HA bond, we selected MMP-2 to illustrate this phenomenon. Therefore, RGDS internalization can induce GBM cell apoptosis. Importantly, RGDS-functionalized hydrogel incorporating DOX efficiently damaged GBM cells without affecting astrocyte viability, proving its safety. Overall, the results demonstrate the potential of the RGDS-functionalized hydrogel to develop safe and effective GBM treatments.

Electrospun fibers modified with polydopamine for enhancing human mesenchymal stem cell culture.

In this study, we coated electrospun polycaprolactone (PCL) fibers with polydopamine (PDA) to modify their hydrophobicity and fabricated a matrix for culturing mesenchymal stem cells (MSCs). Additionally, we incorporated Arg-Gly-Asp (RGD) peptides into PDA to enhance MSCs culture performance on PCL fibers. PDA and RGD were successfully coated in one step by immersing the electrospun fibers in a coating solution, without requiring an additional surface activation process. The characteristics of functionalized PCL fibers were analyzed by scanning electron microscopy with energy-dispersive x-ray analysis, Fourier transform infrared spectroscopy, water contact angle measurement, and fluorescence measurements using a carboxylic-modified fluorescent microsphere. MSCs cultured on the modified PCL fibers demonstrated enhanced cell adhesion, proliferation, and osteogenic- and chondrogenic differentiation. This study provides insight into potential applications for scaffold fabrication in MSCs-based tissue engineering, wound dressing, implantation, and a deeper understanding of MSCs behaviorin vitro.

Revealing the ACE receptor binding properties and interaction mechanisms of salty oligopeptides from Stropharia rugosoannulata mushroom by molecular simulation and antihypertensive evaluation.

The salty oligopeptides from Stropharia rugosoannulata have been proven to be potential ACE inhibitors. To investigate the ACE receptor binding properties and interaction mechanisms of salty oligopeptides, the molecular interaction, dynamics simulation, and antihypertensive evaluation cross-validation strategy were employed to reveal the oligopeptides' binding reactions and modes with the ACE receptor. Single oligopeptide (ESPERPFL, KSWDDFFTR) had exothermic and specific binding reactions with the ACE receptor, driven by hydrogen bonds and van der Waals forces. The coexistence of the multiple oligopeptide molecules did not produce the apparent ACE receptor competition binding reactions. The molecular dynamics simulation verified that the two oligopeptides disturbed the ACE receptor's different residue regions. Both oligopeptides could form stable complexes with the ACE receptor. Based on the classification of 50 oligopeptides' binding modes, ESPERPFL and KSWDDFFTR belonged to different classes, and their receptor binding modes and sites complemented, resulting in a potential synergistic effect on ACE inhibition. The antihypertensive effect of KSWDDFFTR and its distribution in the body were evaluated using SHR rats orally and ICR mice by tail vein injection, and KSWDDFFTR had antihypertensive effects within 8 h. The study provides a theoretical basis for understanding salty oligopeptides' ACE receptor binding mechanism and their antihypertensive effects.

Identification of a novel oligopeptide from defatted walnut meal hydrolysate as a potential neuroprotective agent.

Free radical damage and oxidative stress are thought to play a crucial role in the development of neurodegenerative diseases. Walnut peptides, especially walnut oligopeptides, have been shown to protect nerve cells from oxidative stress and inflammatory damage, as well as improve memory function. In this study, walnut peptides were obtained from walnut meal through enzymatic hydrolysis, ultrafiltration, and gel filtration chromatography. A novel oligopeptide called AQ was successfully isolated and its chemical structure was identified as AASCDQ using ESI-MS/MS. AQ demonstrated remarkable scavenging activity against O2- free radicals (81.00%), DPPH free radicals (79.40%), and ABTS free radicals (67.09%) at a concentration of 1 mg mL-1. Furthermore, AQ exhibited strong neuroprotective effects against hydrogen peroxide-induced damage in SH-SY5Y cells, reducing cell injury and apoptosis. AQ also effectively inhibited the secretion of pro-inflammatory factors NO (IC50 = 46.03 ± 0.32 µM) and suppressed the expression of IL-6 and TNF-α in RAW264.7 cells stimulated by LPS. In vivo experiments demonstrated that AQ promoted angiogenesis in the quail chick chorioallantoic membrane assay and reduced ROS accumulation in Caenorhabditis elegans, thereby extending its lifespan. The anti-inflammatory mechanism of AQ was further confirmed by western blotting. In summary, the novel oligopeptide AQ possesses potential neuroprotective effects, including antioxidant, anti-inflammatory, angiogenic, and anti-aging properties, making it a promising candidate for the development of functional foods and pharmaceutical products.

Photodynamically Tumor Vessel Destruction Amplified Tumor Targeting of Nanoparticles for Efficient Chemotherapy.

Efficient tumor-targeted drug delivery is still a challenging and currently unbreakable bottleneck in chemotherapy for tumors. Nanomedicines based on passive or active targeting strategy have not yet achieved convincing chemotherapeutic benefits in the clinic due to the tumor heterogeneity. Inspired by the efficient inflammatory-cell recruitment to acute clots, we constructed a two-component nanosystem, which is composed of an RGD-modified pyropheophorbide-a (Ppa) micelle (PPRM) that mediates the tumor vascular-targeted photodynamic reaction to activate local coagulation and subsequently transmits the coagulation signals to the circulating clot-targeted CREKA peptide-modified camptothecin (CPT)-loaded nanodiscs (CCNDs) for amplifying tumor targeting. PPRM could effectively bind with the tumor vasculature and induce sufficient local thrombus by a photodynamic reaction. Local photodynamic reaction-induced tumor target amplification greatly increased the tumor accumulation of CCND by 4.2 times, thus significantly enhancing the chemotherapeutic efficacy in the 4T1 breast tumor model. In other words, this study provides a powerful platform to amplify tumor-specific drug delivery by taking advantage of the efficient crosstalk between the PPRM-activated coagulation cascade and clot-targeted CCND.

Integrin αVß3 antagonist-c(RGDyk) peptide attenuates the progression of ossification of the posterior longitudinal ligament by inhibiting osteogenesis and angiogenesis.

BACKGROUND: Ossification of the posterior longitudinal ligament (OPLL), an emerging heterotopic ossification disease, causes spinal cord compression, resulting in motor and sensory dysfunction. The etiology of OPLL remains unclear but may involve integrin αVß3 regulating the process of osteogenesis and angiogenesis. In this study, we focused on the role of integrin αVß3 in OPLL and explored the underlying mechanism by which the c(RGDyk) peptide acts as a potent and selective integrin αVß3 inhibitor to inhibit osteogenesis and angiogenesis in OPLL. METHODS: OPLL or control ligament samples were collected in surgery. For OPLL samples, RNA-sequencing results revealed activation of the integrin family, particularly integrin αVß3. Integrin αVß3 expression was detected by qPCR, Western blotting, and immunohistochemical analysis. Fluorescence microscopy was used to observe the targeted inhibition of integrin αVß3 by the c(RGDyk) peptide on ligaments fibroblasts (LFs) derived from patients with OPLL and endothelial cells (ECs). The effect of c(RGDyk) peptide on the ossification of pathogenic LFs was detected using qPCR, Western blotting. Alkaline phosphatase staining or alizarin red staining were used to test the osteogenic capability. The effect of the c(RGDyk) peptide on angiogenesis was determined by EC migration and tube formation assays. The effects of the c(RGDyk) peptide on heterotopic bone formation were evaluated by micro-CT, histological, immunohistochemical, and immunofluorescence analysis in vivo. RESULTS: The results indicated that after being treated with c(RGDyk), the osteogenic differentiation of LFs was significantly decreased. Moreover, the c(RGDyk) peptide inhibited the migration of ECs and thus prevented the nutritional support required for osteogenesis. Furthermore, the c(RGDyk) peptide inhibited ectopic bone formation in mice. Mechanistic analysis revealed that c(RGDyk) peptide could inhibit osteogenesis and angiogenesis in OPLL by targeting integrin αVß3 and regulating the FAK/ERK pathway. CONCLUSIONS: Therefore, the integrin αVß3 appears to be an emerging therapeutic target for OPLL, and the c(RGDyk) peptide has dual inhibitory effects that may be valuable for the new therapeutic strategy of OPLL.

Expression of brain-derived neurotrophic factor and formation of migrasome increases in the glioma cells induced by the adipokinetic hormone.

OBJECTIVE: It has been previously shown that brain-derived neurotrophic factor is linked with various types of cancer. Brain-derived neurotrophic factor is found to be highly expressed in multiple human cancers and associated with tumor growth, invasion, and metastasis. Adipokinetic hormones are functionally related to the vertebrate glucagon, as they have similar functionalities that manage the nutrient-dependent secretion of these two hormones. Migrasomes are new organelles that contain numerous small vesicles, which aid in transmitting signals between the migrating cells. Therefore, the aim of this study was to investigate the effects of Anax imperator adipokinetic hormone on brain-derived neurotrophic factor expression and ultrastructure of cells in the C6 glioma cell line. METHODS: The rat C6 glioma cells were treated with concentrations of 5 and 10 Anax imperator adipokinetic hormone for 24 h. The effects of the Anax imperator adipokinetic hormone on the migrasome formation and brain-derived neurotrophic factor expression were analyzed using immunocytochemistry and transmission electron microscope. RESULTS: The rat C6 glioma cells of the 5 and 10 µM Anax imperator adipokinetic hormone groups showed significantly high expressions of brain-derived neurotrophic factor and migrasomes numbers, compared with the control group. CONCLUSION: A positive correlation was found between the brain-derived neurotrophic factor expression level and the formation of migrasome, which indicates that the increased expression of brain-derived neurotrophic factor and the number of migrasomes may be involved to metastasis of the rat C6 glioma cell line induced by the Anax imperator adipokinetic hormone. Therefore, the expression of brain-derived neurotrophic factor and migrasome formation may be promising targets for preventing tumor proliferation, invasion, and metastasis in glioma.

The role of the Piezo1 channel in osteoblasts under cyclic stretching: A study on osteogenic and osteoclast factors.

OBJECTIVES: Orthodontic tooth movement is a mechanobiological reaction induced by appropriate forces, including bone remodeling. The mechanosensitive Piezo channels have been shown to contribute to bone remodeling. However, information about the pathways through which Piezo channels affects osteoblasts remains limited. Thus, we aimed to investigate the influence of Piezo1 on the osteogenic and osteoclast factors in osteoblasts under mechanical load. MATERIALS AND METHODS: Cyclic stretch (CS) experiments on MC3T3-E1 were conducted using a BioDynamic mechanical stretching device. The Piezo1 channel blocker GsMTx4 and the Piezo1 channel agonist Yoda1 were used 12 h before the application of CS. MC3T3-E1 cells were then subjected to 15% CS, and the expression of Piezo1, Piezo2, BMP-2, OCN, Runx2, RANKL, p-p65/p65, and ALP was measured using quantitative real-time polymerase chain reaction, western blot, alkaline phosphatase staining, and immunofluorescence staining. RESULTS: CS of 15% induced the highest expression of Piezo channel and osteoblast factors. Yoda1 significantly increased the CS-upregulated expression of Piezo1 and ALP activity but not Piezo2 and RANKL. GsMTx4 downregulated the CS-upregulated expression of Piezo1, Piezo2, Runx2, OCN, p-65/65, and ALP activity but could not completely reduce CS-upregulated BMP-2. CONCLUSIONS: The appropriate force is more suitable for promoting osteogenic differentiation in MC3T3-E1. The Piezo1 channel participates in osteogenic differentiation of osteoblasts through its influence on the expression of osteogenic factors like BMP-2, Runx2, and OCN and is involved in regulating osteoclasts by influencing phosphorylated p65. These results provide a foundation for further exploration of osteoblast function in orthodontic tooth movement.

[Integrin and N-cadherin Co-Regulate the Polarity of Mesenchymal Stem Cells via Mechanobiological Mechanisms]. / æ•´åˆç´ å’ŒN-é’™é»ç´ ååŒè°ƒæŽ§é—´å è´¨å¹²ç»†èƒžæžæ€§çš„åŠ›å­¦ç”Ÿç‰©å­¦æœºåˆ¶ç ”ç©¶.

Objective: To investigate the synergistic regulation of the polarization of mesenchymal stem cells by integrin and N-cadherin-mediated mechanical adhesion and the underlying mechanobiological mechanisms. Methods: Bilayer polyethylene glyeol (PEG) hydrogels were formulated and modified with RGD and HAVDI peptides, respectively, to achieve mechanical adhesion to integrin and N-cadherin and to replicate the integrin-mediated mechanical interaction between cells and the extracellular matrix and the N-cadherin-mediated cell-cell mechanical interaction. The polar proteins, phosphatidylinositol 3-kinase (PI3K) and phosphorylated myosin light chain (pMLC), were characterized through immunofluorescence staining in individual cells with or without contact with HAVDI peptides under integrin-mediated adhesion, N-cadherin-mediated adhesion, and different intracellular forces. Their expression levels and polar distribution were analyzed using Image J. Results: Integrin-mediated adhesion induced significantly higher polar strengths of PI3K and pMLC in the contact group than in those in the no contact group, resulting in the concentration of the polar angle of PI3K to ß-catenin in the range of 135° to 180° and the concentration of the polar angle of pMLC to ß-catenin in the range of 0° to 45° in the contact group. Inhibition of integrin function led to inhibition of the polarity distribution of PI3K in the contact group, but did not change the polarity distribution of pMLC protein. The effect of N-cadherin on the polarity distributions of PI3K and pMLC was similar to that of integrin. However, inhibition of the mechanical adhesion of N-cadherin led to inhibition of the polarity intensity and polarity angle distribution of PI3K and pMLC proteins in the contact group. Furthermore, inhibition of the mechanical adhesion of N-cadherin caused weakened polarity intensity of integrin ß1, reducing the proportion of cells with polarity angles between integrin ß1 and ß-catenin concentrating in the range of 135° to 180°. Additionally, intracellular forces influenced the polar distribution of PI3K and pMLC proteins. Reducing intracellular forces weakened the polarity intensity of PI3K and pMLC proteins and their polarity distribution, while increasing intracellular forces enhanced the polarity intensity of PI3K and pMLC proteins and their polarity distribution. Conclusion: Integrin and N-cadherin co-regulate the polarity distribution of cell proteins and N-cadherin can play an important role in the polarity regulation of stem cells through local inhibition of integrin.

Mitochondrial antioxidant elamipretide improves learning and memory impairment induced by chronic sleep deprivation in mice.

BACKGROUND: The inflammation and synaptic dysfunction induced by mitochondrial dysfunction play essential roles in the learning and memory impairment associated with sleep dysfunction. Elamipretide (SS-31), a novel mitochondrion-targeted antioxidant, was proven to improve mitochondrial dysfunction, the inflammatory response, synaptic dysfunction, and cognitive impairment in models of cerebral ischemia, sepsis, and type 2 diabetes. However, the potential for SS-31 to improve the cognitive impairment induced by chronic sleep deprivation (CSD) and its underlying mechanisms is unknown. METHODS: Adult c57BL/6J mice were subjected to CSD for 21 days using an activity wheel accompanied by daily intraperitoneal injection of SS-31 (5 mg/kg). The novel object recognition and Morris water maze test were used to evaluate hippocampus-dependent cognitive function. Western blotting and reverse transcription-quantitative polymerase chain reaction assays were used to determine the effects of CSD and SS-31 on markers of mitochondria, inflammation response, and synaptic function. Enzyme-linked immunosorbent assays were used to examine the levels of proinflammatory cytokines. RESULTS: SS-31 could improve the cognitive impairment induced by CSD. In particular, SS-31 treatment restored the CSD-induced decrease in sirtuin 1 (SIRT1) and peroxisome proliferator-activated receptor γ coactivator alpha levels and the increase in levels nuclear factor kappa-B and inflammatory cytokines, including interleukin (IL)-1ß, IL-6, and tumor necrosis factor-alpha. Furthermore, SS-31 significantly increased the levels of brain-derived neurotrophic factor, postsynaptic density protein-95, and synaptophysin in CSD mice. CONCLUSION: Taken together, these results suggest that SS-31 could improve CSD-induced mitochondrial biogenesis dysfunction, inflammatory response, synaptic dysfunction, and cognitive impairment by increasing SIRT1 expression levels.

Multiple lysine substitutions in the peptaibol trichogin GA IV enhance the antibiotic activity against plant pathogenic Pseudomonas syringae.

Plant diseases caused by Pseudomonas syringae are essentially controlled in the field with the use of copper-based products and antibiotics, raising environmental and safety concerns. Antimicrobial peptides (AMPs) derived from fungi may represent a sustainable alternative to those chemicals. Trichogin GA IV, a non-ribosomal, 11-residue long AMP naturally produced by the fungus Trichoderma longibrachiatum has the ability to insert into phospholipidic membranes and form water-filled pores, thereby perturbing membrane integrity and permeability. In previous studies, peptide analogs modified at the level of specific residues were designed to be water-soluble and active against plant pathogens. Here, we studied the role of glycine-to-lysine substitutions and of the presence of a C-terminal leucine amide on bioactivity against Pseudomonas syringae bacteria. P. syringae diseases affect a wide range of crops worldwide, including tomato and kiwifruit. Our results show that trichogin GA IV analogs containing two or three Gly-to-Lys substitutions are highly effective in vitro against P. syringae pv. tomato (Pst), displaying minimal inhibitory and minimal bactericidal concentrations in the low micromolar range. The same analogs are also able to inhibit in vitro the kiwifruit pathogen P. syringae pv. actinidiae (Psa) biovar 3. When sprayed on tomato plants 24 h before Pst inoculation, only tri-lysine containing analogs were able to significantly reduce bacterial titers and symptom development in infected plants. Our results point to a positive correlation between the number of lysine substitutions and the antibacterial activity. This correlation was supported by microscopy analyses performed with mono-, di- and tri-Lys containing analogs that showed a different degree of interaction with Pst cells and ultrastructural changes that culminated in cell lysis.

Clinical Pharmacology of the Antibody-Drug Conjugate Enfortumab Vedotin in Advanced Urothelial Carcinoma and Other Malignant Solid Tumors.

Enfortumab vedotin is an antibody-drug conjugate comprised of a human monoclonal antibody directed to Nectin-4 and monomethyl auristatin E (MMAE), a microtubule-disrupting agent. The objectives of this review are to summarize the clinical pharmacology of enfortumab vedotin monotherapy and demonstrate that the appropriate dose has been selected for clinical use. Pharmacokinetics (PK) of enfortumab vedotin (antibody-drug conjugate and total antibody) and free MMAE were evaluated in five clinical trials of patients with locally advanced or metastatic urothelial carcinoma (n = 748). Intravenous enfortumab vedotin 0.5-1.25 mg/kg on days 1, 8, and 15 of a 28-day cycle showed linear, dose-proportional PK. No significant differences in exposure or safety of enfortumab vedotin and free MMAE were observed in mild, moderate, or severe renal impairment versus normal renal function. Patients with mildly impaired versus normal hepatic function had a 37% increase in area under the concentration-time curve (0-28 days), a 31% increase in maximum concentration of free MMAE, and a similar adverse event profile. No clinically significant PK differences were observed based on race/ethnicity with weight-based dosing, and no clinically meaningful QT prolongation was observed. Concomitant use with dual P-glycoprotein and strong cytochrome P450 3A4 inhibitors may increase MMAE exposure and the risk of adverse events. Approximately 3% of patients developed antitherapeutic antibodies against enfortumab vedotin 1.25 mg/kg. These findings support enfortumab vedotin 1.25 mg/kg monotherapy on days 1, 8, and 15 of a 28-day cycle. No dose adjustments are required for patients with renal impairment or mild hepatic impairment, or by race/ethnicity.

The effect of calpain inhibitor-I on copper oxide nanoparticle-induced damage and cerebral ischemia-reperfusion in a rat model.

This study aimed to investigate the effects of the calpain inhibitor N-Acetyl-Leu-Leu-norleucinal (ALLN) on neuroapoptotic cell damage caused by Copper Oxide Nanoparticles (CuO-NP) and exacerbation of damage through brain ischemia/reperfusion (I/R) in a rat model. Male Wistar Albino rats (n=80) were divided into eight groups: Control, I/R, CuO-NP, CuO-NP+I/R, I/R+ALLN, CuO-NP+ALLN, CuO-NP+I/R+ALLN, and DMSO. Biochemical markers (MBP, S100B, NEFL, NSE, BCL-2, Cyt-C, Calpain, TNF-α, Caspase-3, MDA, and CAT) were measured in serum and brain tissue samples. Histological examinations (H&E staining), DNA fragmentation analysis (TUNEL) were performed, along with Caspase-3 assessment. The ALLN-treated groups exhibited significant improvements in biochemical markers and a remarkable reduction in apoptosis compared to the damaged groups (CuO-NP and I/R). H&E and Caspase-3 staining revealed damage-related morphological changes and reduced apoptosis in the ALLN-treated group. However, no differences were observed among the groups with TUNEL staining. The findings suggest that ALLN, as a calpain inhibitor, has potential implications for anti-apoptotic treatment, specifically in mitigating neuroapoptotic cell damage caused by CuO-NP and I/R.

A potential strategy for bladder cancer treatment: inhibiting autophagy to enhance antitumor effects of Nectin-4-MMAE.

Research and development on Nectin-4 antibody-drug conjugates (ADC) have been greatly accelerated since the approval of enfortumab vedotin to treat uroepithelial cancer. During the course of this study, we identified that autophagy serves as a cytoprotective mechanism during Nectin-4-MMAE treatment and proposed a strategy to enhance the antitumor effects of Nectin-4-MMAE in bladder cancer. Nectin-4-MMAE rapidly internalized into bladder cancer cells in 30 minutes and released MMAE, inducing the onset of caspase-mediated apoptosis and leading to the inhibition of tumor cell growth. Transcriptomics showed significant alterations in autophagy-associated genes in bladder cancer cells treated with Nectin-4-MMAE, which suggested autophagy was activated by Nectin-4-MMAE. Furthermore, autophagy activation was characterized by ultrastructural analysis of autophagosome accumulation, immunofluorescence of autophagic flux, and immunoblotting autophagy marker proteins SQSTM1 and LC3 I/II. Importantly, inhibiting autophagy by LY294002 and chloroquine significantly enhances the cytotoxicity effects of Nectin-4-MMAE in bladder cancer cells. Additionally, we detected the participation of the AKT/mTOR signaling cascade in the induction of autophagy by Nectin-4-MMAE. The combination of Nectin-4-MMAE and an autophagy inhibitor demonstrated enhanced antitumor effects in the HT1376 xenograft tumor model. After receiving a single dose of Nectin-4-MMAE, the group that received the combination treatment showed a significant decrease in tumor size compared to the group that received only one type of treatment. Notably, one mouse in the combination treatment group achieved complete remission of the tumor. The combination group exhibited a notable rise in apoptosis and necrosis, as indicated by H&E staining and immunohistochemistry (cleaved caspase-3, ki67). These findings demonstrated the cytoprotective role of autophagy during Nectin-4-MMAE treatment and highlighted the potential of combining Nectin-4-MMAE with autophagy inhibitors for bladder cancer treatment.

Dynamic RGD ligands derived from highly mobile cyclodextrins regulate spreading and proliferation of endothelial cells to promote vasculogenesis.

A thiolated RGD was incorporated into the threaded allyl-ß-cyclodextrins (Allyl-ß-CDs) of the polyrotaxane (PR) through a thiol-ene click reaction, resulting in the formation of dynamic RGD ligands on the PR surface (dRGD-PR). When maintaining consistent RGD density and other physical properties, endothelial cells (ECs) cultured on dRGD-PR exhibited significantly increased cell proliferation and a larger cell spreading area compared to those on the non-dynamic RGD (nRGD-PCL). Furthermore, ECs on dRGD-PR demonstrated elevated expression levels of FAK, p-FAK, and p-AKT, along with a larger population of cells in the G2/M stage during cell cycle analysis, in contrast to cells on nRGD-PCL. These findings suggest that the movement of the RGD ligands may exert additional beneficial effects in promoting EC spreading and proliferation, beyond their essential adhesion and proliferation-promoting capabilities, possibly mediated by the RGD-integrin-FAK-AKT pathway. Moreover, in vitro vasculogenesis tests were conducted using two methods, revealing that ECs cultured on dRGD-PR exhibited much better vasculogenesis than nRGD-PCL in vitro. In vivo testing further demonstrated an increased presence of CD31-positive tissues on dRGD-PR. In conclusion, the enhanced EC spreading and proliferation resulting from the dynamic RGD ligands may contribute to improved in vitro vasculogenesis and in vivo vascularization.