OBJECTIVE: To investigate the biological activity and antitumor effect of pegylated recombinant human interleukin 2 (PEG-rhIL-2) obtained by site-specific conjugation of polyethylene glycol (PEG) with non-natural amino acids, and to explore its antitumor mechanism. METHODS: The binding activities of PEG-rhIL-2 at three different sites (T41, Y45, and V91) to human interleukin 2 receptors α (IL-2R_α) and β (IL-2R_β) and were detected by surface plasmon resonance (SPR) technology. Western blot was used to detect the levels of the Janus kinase-signal transducer and activator of transcription 5 (JAK-STAT5) signaling pathway activated by different doses of rhIL-2 and PEG-rhIL-2 in CTTL-2 and YT cells. Blood was collected after a single administration in mice to detect the drug concentration at different time points and evaluate the pharmacokinetic parameters of Y45-PEG-rhIL-2. Mouse hepatoma cell line Hepa1-6, pancreatic cancer cell line Pan-02, and colon cancer cell line MC-38 were selected. Tumor models were constructed in C57BL/6 mice. Different doses of Y45-PEG-rhIL-2 and excipient control were administrated respectively to evaluate the tumor suppression effect of the drug. In the MC-38 colon cancer model, the tumor suppression effect of Y45-PEG-rhIL-2 combined with anti-programmed death-1 (PD-1) monoclonal antibody was evaluated. Hepa1-6 mouse tumor models were constructed and rhIL-2, Y45-rhIL-2 and Y45-PEG-rhIL-2 were administrated respectively. The proportion of tumor-infiltrating lymphocytes was analyzed by flow cytometry. RESULTS: The SPR detection results showed that the binding activities of PEG-rhIL-2 to IL-2R_α/IL-2R_β were both reduced. The affinity of Y45-PEG-rhIL-2 to IL-2R_α was reduced to approximately 1/250, and its affinity to IL-2R_β was reduced to 1/3. Western blot results showed that the activity of Y45-PEG-rhIL-2 in stimulating JAK-STAT5 signaling in CTLL-2 cells expressing heterotrimeric IL-2 receptor complex IL-2R_αβγwas reduced to approximately 1/300, while its activity in YT cells expressing heterodimeric IL-2 receptor complex IL-2R_βγwas reduced to approximately 1/3. The pharmacokinetic evaluation after a single dose in the mice showed that the elimination half-life of Y45-PEG-rhIL-2 was 17.7 h. Y45-PEG-rhIL-2 has pharmacokinetic characteristics superior to those of rhIL-2. Y45-PEG-rhIL-2 showed dose-dependent tumor suppression activity, and the combination of Y45-PEG-rhIL-2 and anti-PD-1 antibody had a better tumor-inhibiting effect than the single use of Y45-PEG-rhIL-2 or anti-PD-1 antibody. Flow cytometry analysis demonstrated that 72 h after the administration of Y45-PEG-rhIL-2, the proportion of tumor-infiltrating cytotoxic T lymphocytes (CD8⁺T cells) increased by 86.84%. At 120 h after administration, the ratio of CD8⁺T cells to regulatory T cells (Treg) increased by 75.10%. CONCLUSION Y45-PEG-rhIL-2 obtained by site-specific conjugation via non-natural amino acids changed its receptor binding activity and inhibited tumor growth in dose-dependent manner in multiple tumor models by regulating CD8⁺T cells.
Interleukin-2/pharmacokinetics* ; Animals ; Mice ; Humans ; Recombinant Proteins/pharmacology* ; Polyethylene Glycols/chemistry* ; Cell Line, Tumor ; Antineoplastic Agents/pharmacokinetics* ; Signal Transduction/drug effects* ; STAT5 Transcription Factor/metabolism* ; Interleukin-2 Receptor alpha Subunit/metabolism* ; Interleukin-2 Receptor beta Subunit/metabolism*

OBJECTIVE: To investigate the biological effect of medical recombinant human-derived collagen functional dressings in wound healing. METHODS: MTT assay and RTCA assay were used to detect cell toxicity and proliferation. Scratch assay and Transwell cell migration assay were used to detect cell motility and migration ability. Enzyme-linked immunosorbent assay was used to detect the contents of vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), and platelet-endothelial cell adhesion molecule (CD31) in the supernatant of four types of cells. After animal surgery, the surgical wound was taken at 1 week, 4 weeks and 13 weeks, respectively, for hematoxylin eosin (HE) staining and immunohistochemistry to observe the inflammatory response and CD31 expression of the wound. RESULTS: Medical recombinant human-derived collagen functional dressing promotes cell proliferation and migration, enhances wound angiogenesis by upregulating the expression of VEGF, FGF, and CD31 in human dermal vascular endothelial cells (HDVEC) and human vascular endothelial cells (HVEC), thereby improving local blood supply to the wound, regulating the inflammatory response of the wound, and accelerating wound healing. CONCLUSION Recombinant type Ⅲ humanized collagen plays an important role in wound healing.
Humans ; Wound Healing/drug effects* ; Recombinant Proteins/pharmacology* ; Animals ; Cell Proliferation ; Cell Movement ; Collagen/pharmacology* ; Vascular Endothelial Growth Factor A/metabolism* ; Bandages ; Platelet Endothelial Cell Adhesion Molecule-1/metabolism* ; Endothelial Cells ; Fibroblast Growth Factors/metabolism*

Reactive oxygen species (ROS) are major contributors to radiation therapy-induced side effects in cancer patients. A fusion antioxidant enzyme comprising glutathione S-transferase (GST), superoxide dismutase 1 (SOD1), and a transmembrane peptide has been shown to effectively mitigate ROS-induced damage. To enhance its targeting capability, the fusion protein was further modified by incorporating a matrix metalloproteinase-2/9 substrate peptide (X) and the transmembrane peptide R9, yielding the antioxidant enzyme GST-SOD1-X-R9 (GS1XR). This modification reduced its transmembrane ability in tumor cells, thereby selectively protecting normal cells from oxidative stress. However, the use of non-human GST poses potential immunogenicity risks. In this study, we employed seamless cloning technology to construct an expression vector containing the human GST gene to replace the non-human GST gene, and then expressed and purified novel fusion antioxidant enzymes GS1R and GS1XR. The protective effects of newly constructed GS1R and GS1XR against hydrogen peroxide (H₂O₂)-induced oxidative damage in L-02 cells were then evaluated using GS1 as a control. Enzymatic activity assays revealed that the specific activity of GST in GS1XR remained unchanged compared to the unmodified protein, while SOD activity was enhanced. Exposure to 200 μmol/L H₂O₂ transiently activated the nuclear factor-erythroid 2-related factor 2 (Nrf2) pathway; however, this activation diminished after 24 h, reducing cell viability to 48.4%. Both GS1R and GS1XR effectively scavenged intracellular ROS, directly counteracting oxidative stress and promoting Nrf2 nuclear translocation, thereby activating antioxidant pathways and restoring cell viability to normal levels. The two enzymes showed comparable efficacy. In contrast, GS1, lacking transmembrane capability, was restricted to scavenging extracellular ROS and provided only limited protection. In conclusion, both novel fusion antioxidant enzymes demonstrated significant potential in safeguarding normal cells from ROS-mediated oxidative damage. The findings provide a foundation for further investigation in related field.
Humans ; Oxidative Stress/drug effects* ; Hydrogen Peroxide ; Antioxidants/metabolism* ; Glutathione Transferase/metabolism* ; Recombinant Fusion Proteins/pharmacology* ; Superoxide Dismutase-1 ; Reactive Oxygen Species/metabolism* ; Superoxide Dismutase/biosynthesis*

The voltage-gated Na channel subtype Nav1.7 is important for pain and itch in rodents and humans. We previously showed that a Nav1.7-targeting monoclonal antibody (SVmab) reduces Na currents and pain and itch responses in mice. Here, we investigated whether recombinant SVmab (rSVmab) binds to and blocks Nav1.7 similar to SVmab. ELISA tests revealed that SVmab was capable of binding to Nav1.7-expressing HEK293 cells, mouse DRG neurons, human nerve tissue, and the voltage-sensor domain II of Nav1.7. In contrast, rSVmab showed no or weak binding to Nav1.7 in these tests. Patch-clamp recordings showed that SVmab, but not rSVmab, markedly inhibited Na currents in Nav1.7-expressing HEK293 cells. Notably, electrical field stimulation increased the blocking activity of SVmab and rSVmab in Nav1.7-expressing HEK293 cells. SVmab was more effective than rSVmab in inhibiting paclitaxel-induced mechanical allodynia. SVmab also bound to human DRG neurons and inhibited their Na currents. Finally, potential reasons for the differential efficacy of SVmab and rSVmab and future directions are discussed.
Animals ; Antibodies, Monoclonal ; therapeutic use ; Biotin ; metabolism ; Cells, Cultured ; Disease Models, Animal ; Female ; Ganglia, Spinal ; cytology ; HEK293 Cells ; Humans ; Hybridomas ; chemistry ; Hyperalgesia ; drug therapy ; Male ; Mice ; Mice, Inbred C57BL ; NAV1.5 Voltage-Gated Sodium Channel ; metabolism ; NAV1.7 Voltage-Gated Sodium Channel ; chemistry ; immunology ; metabolism ; Neuralgia ; drug therapy ; metabolism ; Protein Binding ; drug effects ; Recombinant Proteins ; biosynthesis ; therapeutic use ; Sensory Receptor Cells ; drug effects ; physiology

BACKGROUNDRecombinant human-erythropoietin (rh-EPO) has therapeutic efficacy for premature infants with brain damage during the active rehabilitation and anti-inflammation. In the present study, we found that the rh-EPO was related to the promotion of neovascularization. Our aim was to investigate whether rh-EPO augments neovascularization in the neonatal rat model of premature brain damage through the phosphatidylinositol 3 kinase (PI3K)/protein kinase B (Akt) signaling pathway.

METHODSPostnatal day 5 (PD5), rats underwent permanent ligation of the right common carotid artery and were exposed to hypoxia for 2 h. All the rat pups were randomized into five groups as follows: (1) control group; (2) hypoxia-ischemic (HI) group; (3) HI + LY294002 group; (4) HI + rh-EPO group; and (5) HI + rh-EPO + LY294002 group. The phospho-Akt protein was tested 90 min after the whole operation, and CD34, vascular endothelial growth factor receptor 2 (VEGFR2), and vascular endothelial growth factor (VEGF) were also tested 2 days after the whole operation.

RESULTSIn the hypoxic and ischemic zone of the premature rat brain, the rh-EPO induced CD34+ cells to immigrate to the HI brain zone (P < 0.05) and also upregulated the VEGFR2 protein expression (P < 0.05) and VEGF mRNA level (P < 0.05) through the PI3K/Akt (P < 0.05) signaling pathway when compared with other groups.

CONCLUSIONSThe rh-EPO treatment augments neovascularization responses in the neonatal rat model of premature brain damage through the PI3K/Akt signaling pathway. Besides, the endogenous EPO may exist in the HI zone of rat brain and also has neovascularization function through the PI3K/Akt signaling pathway.

Animals ; Animals, Newborn ; Antigens, CD34 ; metabolism ; Brain ; drug effects ; metabolism ; pathology ; Disease Models, Animal ; Erythropoietin ; genetics ; metabolism ; therapeutic use ; Female ; Humans ; Hypoxia-Ischemia, Brain ; drug therapy ; metabolism ; Neovascularization, Physiologic ; drug effects ; Phosphatidylinositol 3-Kinase ; metabolism ; Pregnancy ; Proto-Oncogene Proteins c-akt ; metabolism ; Rats ; Rats, Sprague-Dawley ; Recombinant Proteins ; genetics ; metabolism ; therapeutic use ; Signal Transduction ; drug effects ; Vascular Endothelial Growth Factor A ; genetics ; Vascular Endothelial Growth Factor Receptor-2 ; metabolism

Entero virus 71 (EV71) causes hand, foot, and mouth disease (HFMD) and occasionally leads to severe neurological complications and even death. Scavenger receptor class B member 2 (SCARB2) is a functional receptor for EV71, that mediates viral attachment, internalization, and uncoating. However, the exact binding site of EV71 on SCARB2 is unknown. In this study, we generated a monoclonal antibody (mAb) that binds to human but not mouse SCARB2. It is named JL2, and it can effectively inhibit EV71 infection of target cells. Using a set of chimeras of human and mouse SCARB2, we identified that the region containing residues 77-113 of human SCARB2 contributes significantly to JL2 binding. The structure of the SCARB2-JL2 complex revealed that JL2 binds to the apical region of SCARB2 involving α-helices 2, 5, and 14. Our results provide new insights into the potential binding sites for EV71 on SCARB2 and the molecular mechanism of EV71 entry.
Amino Acid Sequence ; Animals ; Antibodies, Monoclonal ; chemistry ; genetics ; metabolism ; Binding Sites ; Cell Line ; Crystallography, X-Ray ; Enterovirus A, Human ; drug effects ; genetics ; growth & development ; immunology ; Fibroblasts ; drug effects ; virology ; Gene Expression ; HEK293 Cells ; Humans ; Immunoglobulin Fab Fragments ; chemistry ; genetics ; metabolism ; Lysosome-Associated Membrane Glycoproteins ; chemistry ; genetics ; immunology ; Mice ; Models, Molecular ; Protein Binding ; Protein Conformation, alpha-Helical ; Protein Conformation, beta-Strand ; Protein Interaction Domains and Motifs ; Receptors, Scavenger ; chemistry ; genetics ; immunology ; Receptors, Virus ; chemistry ; genetics ; immunology ; Recombinant Fusion Proteins ; chemistry ; genetics ; immunology ; Sequence Alignment ; Sequence Homology, Amino Acid ; Sf9 Cells ; Spodoptera ; Thermodynamics

Effective expression of pIFN-α in recombinant Pichia pastoris was conducted in a 5 L fermentor. Ethanol accumulation during the late glycerol feeding period inhibited heterologous protein expression. Comparative transcriptome analysis was thus performed to compare the gene transcription profiles of Pichia pastoris KM71H in high and low ethanol concentration environments. The results showed that during the glycerol cultivation stage, 545 genes (265 up-regulated and 280 down-regulated) were differentially expressed with ethanol stress. These genes were mainly involved in protein synthesis, energy metabolism, cell cycle and peroxisome metabolism. During the methanol induction stage, 294 genes (171 up-regulated and 123 down-regulated) were differentially expressed, which were mainly related to methanol metabolism, amino acid metabolism and protein synthesis. Ethanol stress increased protein misfolding and reduced structural integrity of ribosome and mitochondria during cultivation stage, and led to the failure of endoplasmic reticulum stress removal and damaged amino acid metabolism during induction stage in Pichia pastoris.
Amino Acids ; metabolism ; Bioreactors ; Endoplasmic Reticulum Stress ; Energy Metabolism ; Ethanol ; chemistry ; Gene Expression Profiling ; Gene Expression Regulation, Fungal ; Glycerol ; Methanol ; Pichia ; metabolism ; Protein Biosynthesis ; drug effects ; Protein Folding ; Recombinant Proteins ; biosynthesis ; Transcriptome

OBJECTIVETo explore the effect of recombinant human erythropoietin (rhEPO) on expression of brain-derived neurotrophic factor (BDNF) in different brain regions of aging rats.

METHODSForty male SD rats were randomized equally into negative control group, D-galactose group, EPO treatment group, and positive control group. Rat models of subacute aging were established by continuous subcutaneous injection of 5% D-galactose. Immunohistochemical staining was used to analyze the variation of BDNF expressions in different brain regions of the aging rats with different treatments.

RESULTSSignificant brain region-specific differences in BDNF expression were found among the rats in different groups. Compared with those in the negative control group, the numbers of BDNF-positive cells in the hippocampal CA1 region, CA3 region, dentate gyrus (DG) and frontal cortex were all decreased obviously in D-galactose group (P<0.05) but increased in both EPO group and the positive control group (P<0.05) without significant differences between the latter two groups. In the rats in the same group, the number of BDNF-positive cells varied markedly in different brain regions (P<0.05), and the expression level of BDNF was the highest in the frontal cortex followed by the hippocampal CA3 region and the dentate gyrus, and was the lowest in the hippocampal CA1 region.

CONCLUSIONTreatment with rhEPO enhances the expression of BDNF in rat neural cells, suggesting that rhEPO may protect the nervous system from aging by regulating the BDNF pathway.

Aging ; Animals ; Brain-Derived Neurotrophic Factor ; metabolism ; CA1 Region, Hippocampal ; metabolism ; CA3 Region, Hippocampal ; metabolism ; Dentate Gyrus ; metabolism ; Erythropoietin ; pharmacology ; Frontal Lobe ; metabolism ; Galactose ; Humans ; Male ; Neurons ; drug effects ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Recombinant Proteins ; pharmacology

Mammalian pancreatic β-cells play a pivotal role in development and glucose homeostasis through the production and secretion of insulin. Functional failure or decrease in β-cell number leads to type 2 diabetes (T2D). Despite the physiological importance of β-cells, the viability of β-cells is often challenged mainly due to its poor ability to adapt to their changing microenvironment. One of the factors that negatively affect β-cell viability is high concentration of free fatty acids (FFAs) such as palmitate. In this work, we demonstrated that Yes-associated protein (Yap1) is activated when β-cells are treated with palmitate. Our loss- and gain-of-function analyses using rodent insulinoma cell lines revealed that Yap1 suppresses palmitate-induced apoptosis in β-cells without regulating their proliferation. We also found that upon palmitate treatment, re-arrangement of F-actin mediates Yap1 activation. Palmitate treatment increases expression of one of the Yap1 target genes, connective tissue growth factor (CTGF). Our gain-of-function analysis with CTGF suggests CTGF may be the downstream factor of Yap1 in the protective mechanism against FFA-induced apoptosis.
Actins ; metabolism ; Adaptor Proteins, Signal Transducing ; antagonists & inhibitors ; genetics ; metabolism ; Animals ; Apoptosis ; drug effects ; physiology ; Bridged Bicyclo Compounds, Heterocyclic ; pharmacology ; Cell Line, Tumor ; Connective Tissue Growth Factor ; genetics ; metabolism ; pharmacology ; Cytochalasin D ; pharmacology ; Fatty Acids, Nonesterified ; pharmacology ; HEK293 Cells ; Humans ; Immunohistochemistry ; Insulin-Secreting Cells ; cytology ; drug effects ; metabolism ; Mice ; Microscopy, Fluorescence ; Palmitic Acid ; pharmacology ; Phosphoproteins ; antagonists & inhibitors ; genetics ; metabolism ; RNA Interference ; RNA, Small Interfering ; metabolism ; Rats ; Recombinant Proteins ; genetics ; metabolism ; pharmacology ; Thiazolidines ; pharmacology

PURPOSE: To investigate the molecular responses of various genes and proteins related to disc degeneration upon treatment with cytokines that affect disc-cell proliferation and phenotype in living human intervertebral discs (IVDs). Responsiveness to these cytokines according to the degree of disc degeneration was also evaluated. MATERIALS AND METHODS: The disc specimens were classified into two groups: group 1 (6 patients) showed mild degeneration of IVDs and group 2 (6 patients) exhibited severe degeneration of IVDs. Gene expression was analyzed after treatment with four cytokines: recombinant human bone morphogenic protein (rhBMP-2), transforming growth factor-beta (TGF-beta), interleukin-1beta (IL-1beta), and tumor necrosis factor-alpha (TNF-alpha). Molecular responses were assessed after exposure of cells from the IVD specimens to these cytokines via real-time polymerase chain reaction and immunofluorescence staining. RESULTS: mRNA gene expression was significantly greater for aggrecan, type I collagen, type II collagen, alkaline phosphatase, osteocalcin, and Sox9 in group 1 than mRNA gene expression in group 2, when the samples were not treated with cytokines. Analysis of mRNA levels for these molecules after morphogen treatment revealed significant increases in both groups, which were much higher in group 1 than in group 2. The average number of IVD cells that were immunofluorescence stained positive for alkaline phosphatase increased after treatment with rhBMP-2 and TGF-beta in group 1. CONCLUSION: The biologic responsiveness to treatment of rhBMP-2, TGF-beta, TNF-alpha, and IL-1beta in the degenerative living human IVD can be different according to the degree of degeneration of the IVD.
Adult ; Aggrecans/genetics/metabolism ; Alkaline Phosphatase/genetics/metabolism ; Biological Products/pharmacology/*therapeutic use ; Bone Morphogenetic Protein 2/pharmacology/therapeutic use ; Collagen Type I/genetics/metabolism ; Collagen Type II/genetics/metabolism ; Cytokines/*pharmacology/*therapeutic use ; Female ; Fluorescent Antibody Technique ; Gene Expression Regulation/drug effects ; Humans ; Interleukin-1/pharmacology/therapeutic use ; Intervertebral Disc/*drug effects/*pathology ; Intervertebral Disc Degeneration/*drug therapy/genetics/*pathology ; Male ; Middle Aged ; Osteocalcin/genetics/metabolism ; RNA, Messenger/genetics/metabolism ; Recombinant Proteins/pharmacology/therapeutic use ; SOX9 Transcription Factor/genetics/metabolism ; Transforming Growth Factor beta/pharmacology/therapeutic use ; Tumor Necrosis Factor-alpha/pharmacology