Phytoglycoprotein inhibits interleukin-1β and interleukin-6 via p38 mitogen-activated protein kinase in lipopolysaccharide-stimulated RAW 264.7 cells

αVEGFR2-MICA fusion antibodies enhance immunotherapy effect and synergize with PD-1 blockade

Antiangiogenic therapy has shown significant clinical benefits in gastric cancer (GC) and non-small cell lung cancer (NSCLC). However, their effectiveness is limited by the immunosuppressive tumor microenvironment. The MHC class I chain-related molecules A and B (MICA/B) are expressed in many human cancers, enabling elimination of cancer cells by cytotoxic lymphocytes through natural killer group 2D (NKG2D) receptor activation. To improve antiangiogenic therapy and prolong its efficacy, we generated a bi-specific fusion protein (mAb04-MICA). This was comprised of an antibody targeting VEGFR2 fused to a MICA α1-α2 ectodomain. mAb04-MICA inhibited proliferation of GC and NSCLC cells through specific binding to VEGFR2 and had superior anti-tumor efficacy in both GC and NSCLC-bearing mouse models compared with ramucirumab. Further investigation revealed that the mAb04-MICA promoted NKG2D⁺ NK cell activation and induced the tumor-associated macrophage (TAM) polarization from M2 type to M1 type both in vitro and in vivo. The polarization of TAMs upon NKG2D and MICA mediated activation has not yet been reported. Moreover, given the up-regulation of PD-L1 in tumors during anti-angiogenesis therapy, anti-PD-1 antibody enhanced the anti-tumoral activity of mAb04-MICA through stimulating infiltration and activation of NKs and CD8⁺T cells in responding tumors. Our findings demonstrate that dual targeting of angiogenesis and NKG2D, or in combination with the PD-1/PD-L1 blockade, is a promising anti-tumor therapeutic strategy. This is accomplished through maintaining or reinstating tumor immunosurveillance during treatment, which expands the repertoire of anti-angiogenesis-based cancer immunotherapies.

Metabolomic analysis reveals the influence of IC50 vitamin D3 on RAW264.7 cells based on 1 H NMR and UPLC-MS/MS

BACKGROUND

As a lipid-soluble vitamin necessary for normal human physiology, vitamin D is mostly used in fortified foods, medicines and adjuvant treatment of diseases. However, taken in high doses, vitamin D can be toxic.

METHODS

We treated RAW264.7 cells with a semi-inhibitory concentration (IC₅₀ ) of vitamin D₃ . The metabolic changes in the treated cells were analyzed by ¹ H nuclear magnetic resonance (NMR) and ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS).

RESULTS

After treatment of RAW264.7 cells with an IC₅₀ dose of 55 μm vitamin D₃ , tunor necrosis factor-α levels decreased significantly and remarkable metabolic differences were also observed, with 12 types of metabolites were identified by ¹ H NMR and 87 identified by UPLC-MS/MS. Moreover, the metabolism of amino acids, sugars, lipids and other metabolic pathways were also affected.

CONCLUSION

Although vitamin D₃ is an indispensable nutrient in the body, excessive exposure has negative effects on cells and their metabolism. The present study will assist further analyses of the mechanism underlying vitamin D₃ toxicity. © 2022 Society of Chemical Industry.

Research Progress in Anti-Inflammatory Bioactive Substances Derived from Marine Microorganisms, Sponges, Algae, and Corals

Inflammation is the body's defense reaction in response to stimulations and is the basis of various physiological and pathological processes. However, chronic inflammation is undesirable and closely related to the occurrence and development of diseases. The ocean gives birth to unique and diverse bioactive substances, which have gained special attention and been a focus for anti-inflammatory drug development. So far, numerous promising bioactive substances have been obtained from various marine organisms such as marine bacteria and fungi, sponges, algae, and coral. This review covers 71 bioactive substances described during 2015-2020, including the structures (65 of which), species sources, evaluation models and anti-inflammatory activities of these substances. This review aims to provide some reference for the research progress of marine-organism-derived anti-inflammatory metabolites and give more research impetus for their conversion to novel anti-inflammatory drugs.

Structure characterization and in vitro immunomodulatory activities of carboxymethyl pachymaran

Carboxymethyl pachymaran (CMP) was prepared from Poria cocos polysaccharide by carboxymethylation. Two types of CMP (CMP-1 and CMP-2) were further purified by DEAE-52 anion-exchange chromatography. The structure characteristics and immunomodulatory activities of CMP-1 and CMP-2 were investigated. CMP-1 was determined as β-(1 → 3)-d-glucan. A β-(1 → 3)-d-glucan backbone structure was also found in CMP-2, which was mainly consistent of mannose and glucose, with the mole ratio of 0.03:1. The molecular weight of CMP-1 was 126.1 kDa with a 30.4 nm irregular sphere in distilled water. However, the molecular weight of CMP-2 was 172.6 kDa in a 19.9 nm spherical structure in water solution. Both CMP-1 and CMP-2 had triple helical structure, which can promote the proliferation and the phagocytosis of macrophages. Moreover, CMP-1 and CMP-2 both could improve the secretions of NO, TNF-α and IL-6 by increasing the expression of iNOS, TNF-α and IL-6 mRNA, but CMP-1 exhibited a stronger immunomodulatory ability than that of CMP-2. Our results indicated that CMP-1 and CMP-2 can act as potential immunomodulatory agents.

Effects of IC50 dose of retinol on metabolomics of RAW264.7 cells

Vitamin A is one of the most multifunctional vitamins in normal human physiology and is involved in several basic physiological processes from embryonic development to adulthood, such as embryogenesis, vision, immunity, cell differentiation, and proliferation. In this study, we conducted ¹ H- NMR to evaluate the metabolomic changes in RAW264.7 cells after treatment with retinol at an IC₅₀ dose to identify its effects on the differential metabolites and main metabolic pathways. Our results showed that the IC₅₀ dose (140 μM) of retinol affected the metabolism of RAW264.7 cells, with a total of 22 differential metabolites identified via ¹ H-NMR, including amino acids, sugars, organic acids, glutathione, glycerin, and creatine. Additionally, multiple metabolic pathways were affected by retinol treatment, including downregulation of amino acid biosynthesis, protein synthesis, and pyruvate metabolism. We speculate that the cytotoxicity of retinol at the IC₅₀ dose is attributed to mitochondrial dysfunction as a result of oxidative stress or lipid peroxidation. PRACTICAL APPLICATIONS: With the general improvement of people's living standards, people use dietary supplements to improve the level of retinol to prevent non-specific diseases. But there are more and more cases of acute or chronic poisoning caused by excessive intake of vitamin A. Therefore, it is necessary to study the toxicity of vitamin A, and more attention should be paid to the excessive intake of vitamin A. From the perspective of metabolomics, this experiment studies the adverse effects of high dose retinol through the changes of metabolites and metabolic pathways at the cellular level. This study will assist further analyses of the toxic mechanism of excessive retinol as fortified foods and nutrient supplementation.

Anti- inflammatory effect of Prunus tomentosa Thunb total flavones in LPS-induced RAW264.7 cells

In this research, we investigated possible anti-inflammatory roles of Prunus tomentosa Thunb Total Flavones (PTTTF) in LPS-induced RAW264.7 cells. PTTTF (4μg/ml and 40μg/ml) was applied to RAW264.7 cells induced with 1μg/ml LPS to test the impact of these flavones on neutrophil phagocytosis in vitro. Levels of prostaglandin E2 (PGE2) and two pro-inflammatory interleukin cytokines (i.e. IL-6 and IL-1β) in the supernatant fraction were tested via Enzyme-linked immunosorbent assays (ELISA). Expression of cyclooxygenases COX-1 and COX-2 was detected via RT-PCR. Superoxide dismutase (SOD) content was determined with a spectrophotometric assay (Micromethod). The results revealed that PTTTF at doses higher than 4μg/ml reduces the content of IL-6, IL-1β and PGE2 (P < 0.05), and elevates the activity of SOD in LPS-induced RAW264.7 cells significantly (P < 0.05). PTTTF at 40μg/ml showed no significant effect on the expression of COX-1(P>0.05) but resulted in a significant inhibition of COX-2 in LPS-induced RAW264.7 cells (P<0.05). In summary, PTTTF had a substantial potential anti-inflammatory effect through the alteration of the synthesis of some cytokines and other mediators of the process of inflammation. Novelty statement - Prunus tomentosa Thunb Total Flavones (PTTTF) have known roles in the treatment of diabetes, but here we show that they are also potential anti-inflammatory agents. Our results show that PTTTF exhibited anti-inflammatory effects through altering the synthesis of some cytokines and other mediators of the inflammatory process.

Research and Development of Proteins and Peptides with Therapeutic Potential from Yam Tubers

We discuss the diverse biological activities, therapeutic potential, and clinical applications of peptides and proteins isolated from various yams species including Dioscorea opposita Thunb (Chinese yam), D alata, D japonica (Japanese yam), D pseudojaponica, D batatas (Korea yam), and D cayenensis. Yam peptides and proteins have many pharmacological activities including immunomodulatory, antioxidant, estrogen-stimulating, osteogenic, angiotensin I-converting enzyme inhibiting, carbonic anhydrase and trypsin inhibiting, chitinase, anti-insect, anti-dust mite, lectin, and anti-proliferative activities. Yam peptides and proteins have therapeutic potential for treating cardiovascular diseases, inflammatory diseases, cancers, aging disorders, menopause, and osteoporosis.

Ratiometric SERS imaging and selective biosensing of nitric oxide in live cells based on trisoctahedral gold nanostructures

Herein, a ratiometric SERS probe was created for monitoring nitric oxide (NO) by designing a novel molecule, 3,4-diaminobenzene-thiol, and immobilizing this molecule onto trisoctahedral gold nanostructures with superior SERS capability. The established probe possessed good selectivity and biocompatibility, high sensitivity and accuracy, thus enabling imaging and biosensing of NO in live cells.

SERS nanoprobes for the monitoring of endogenous nitric oxide in living cells

Nitric Oxide (NO) is a significant gaseous signalling molecule in various pathological and physiological pathways, whereas many of its functions are still ambiguous in part because of the shortage of powerful detection approaches. Herein, we present a type of reaction-based surface-enhanced Raman scattering (SERS) nanoprobes, o-phenylenediamine-modified gold nanoparticles (AuNPs/OPD), to detect the level of the endogenous NO in living cells. The detection is achieved through the SERS variation of AuNPs/OPD caused by the reaction between NO and OPD on the surface of AuNPs. The proposed SERS nanoprobes have a good stability and a rapid response to NO within 30s Moreover, as a result of the reaction specificity coupled with SERS fingerprinting, AuNPs/OPD nanoprobes demonstrate high selectivity towards NO over other biologically relevant species with a sensitivity at 10(-7)M level. Thereby, this SERS strategy can be used for monitoring NO that is endogenously produced in living macrophages, indicating immense potential in studying NO-involved pathophysiological processes in biological systems.

Simultaneous fluorescence visualization of mitochondrial hydrogen peroxide and zinc ions in live cells and in vivo

We have developed two new fluorescent probes termedM-H2O2andM-Znfor simultaneous imaging of hydrogen peroxide and zinc ions in mitochondria.

Molecular cloning, structural analysis and mass spectrometric identification of native dioscorins of various yam species

BACKGROUND

Dioscorins are the major storage proteins of yam tubers. However, the molecular nature of their heterogeneity in tubers has not been fully elucidated. In this study the authors isolated the dioscorin gene families of Dioscorea japonica and Dioscorea pseudojaponica, performed matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF-MS) and elucidated which dioscorin isoforms are the major constituents in tubers.

RESULTS

The dioscorin gene families of D. japonica (Dj-dioA1-Dj-dioA4, Dj-dioB1 and Dj-dioB2) and D. pseudojaponica (Dp-dioA1-Dp-dioA5 and Dp-dioB1) were cloned from cDNA libraries of yam tubers. The dioscorins isolated from Dioscorea alata (Da-dioscorins), D. japonica (Dj-dioscorins) and D. pseudojaponica (Dp-dioscorins) were mainly monomers, with a few dimers. The monomers contained one intramolecular disulfide bond (Cys(28)-Cys(187)) and belonged to Class A dioscorins with two cysteine residues. The dimers consisted of Class B dioscorins with one intermolecular disulfide bond (Cys(40)-Cys(40)). Results of MALDI-TOF-MS revealed that the Da-dioscorins were mainly encoded by Da-dioA2, Da-dioA3 and Da-dioA4. The majority of the Dj-dioscorins were encoded by Dj-dioA1, Dj-dioA2, Dj-dioA3 and Dj-dioB2. The Dp-dioscorins mainly comprised proteins encoded by Dp-dioA1, Dp-dioA3, Dp-dioA4, Dp-dioB1 and Dp-dioB2.

CONCLUSION

Determination of the constituents of dioscorin isoforms in yam tubers provides a basis for future studies of their physiological and biomedical functions.

Synergistic Induction of iNOS by IFN-γ and Glycoprotein Isolated from Dioscorea batatas

Dioscorea species continue to be used in traditional Chinese medicine, and represent a major source of steroid precursors for conventional medicine. In the previous study, We isolated glycoprotein (GDB) from Dioscorea batatas, characterized, and demonstrated immunostimulating activity in C57BL/6 mice. The aim of this study was to investigate the mechanism whereby GDB activates macrophages. Macrophages activation by GDB was investigated by analyzing the effects of GDB on nitric oxide (NO) production, iNOS expression, mitogen activated protein kinase (MAPK) phosphorylation, and transcription factor activation. In the presence of IFN-γ, GDB strongly stimulated macrophages to express iNOS and produce NO. Furthermore, the activation of p38 was synergistically induced by GDB plus IFN-γ , but SB203580 (a p38 inhibitor) inhibited GDB plus IFN-γ-induced p38 activation. This study indicates that GDB is an important activator of macrophages. Furthermore, due to the critical role that macrophage activation plays in innate immune response, the activation effects of GDB on macrophages suggest that GDB may be a useful immunopotentiating agent.

Extract from Dioscorea batatas ameliorates insulin resistance in mice fed a high-fat diet

The aim of this study was to investigate whether Dioscorea batatas (DB) extract attenuates high-fat diet (HFD)-induced insulin resistance in the visceral adipose tissues of mice, and by what mechanism(s). Mice were fed a HFD for 4 weeks to induce the early development of insulin resistance. The DB extract was administered to mice fed a HFD by oral gavage at a dose of 100 mg/kg body weight daily for 7 weeks. Biochemical parameters in blood were measured using enzymatic kits, and the expression levels of glucose transporter 4 (GLUT4), phosphorylated (p-)S6K1, phosphorylated v-akt murine thymoma viral oncogene homolog (p-AKT), and phosphorylated extracellular regulated kinase (p-ERK) in epididymal fat tissue were determined by western blot analyses. The DB extract effectively reversed the HFD-induced elevations in plasma glucose and insulin levels, and the homeostasis model assessment for insulin resistance and oral glucose tolerance test values. The level of p-AKT protein was up-regulated, whereas the levels of p-ERK and p-S6K1 proteins were down-regulated in the adipose tissues of DB mice compared with HFD mice. Furthermore, the DB extract significantly reversed the HFD-induced decrease in the plasma membrane GLUT4 level in the adipose tissue of mice. The DB extract improved glucose metabolism in HFD-fed mice through the up-regulation of plasma membrane GLUT4 content in the visceral adipose tissue. Activation of the insulin signaling cascade leading to GLUT4 translocation was the mechanism underlying the beneficial effects of the DB extract on early-stage obesity-induced insulin resistance.

Phosphatidylserine-containing liposomes suppress inflammatory bone loss by ameliorating the cytokine imbalance provoked by infiltrated macrophages

Phosphatidylserine (PS)-containing liposomes (PSLs) strongly inhibit inflammatory bone loss in adjuvant arthritic (AA) rats. This effect was attributed to the inhibition of osteoclastogenesis through the secretion of prostaglandin E(2) and transforming growth factor-β1 by osteoclast precursors after the phagocytosis of PSLs. However, infiltrated macrophages are considered to secrete anti-inflammatory mediators after phagocytosis of PSLs, which also contribute to inhibiting osteoclastogenesis. In the present study, we have attempted to elucidate the effects of PSLs on the phenotype of infiltrated macrophages during inflammatory bone loss. In AA rats, the ankle joints swelled with the infiltration of both macrophages and helper T cells into the synovium after a complete Freund's adjuvant injection. In the ankle joints of AA rats, approximately half of the infiltrated macrophages underwent a phenotypic change from interleukin (IL)-1β-producing to IL-10-producing cells after the phagocytosis of PSLs. In lipopolysaccharide (LPS)-stimulated macrophages, PSLs also significantly decreased IL-1β production, but increased IL-10 production. Moreover, PSLs inhibited the rapid activation of p38 mitogen-activated protein kinases (MAPK) and nuclear factor (NF)-κB, but enhanced the delayed activation of extracellular signal-regulated kinase (ERK) in LPS-stimulated macrophages. PSL-induced different influence on the activities of p38 MAPK and ERK is a likely underlying mechanism for phenotypic change of infiltrated macrophages after the phagocytosis of PSLs. This phenotypic change may be responsible for a significant decrease in the mean mRNA level of the receptor activator of NF-κB (RANK) and the RANK ligand (RANKL) in the ankle joint of PSL-treated AA rats, resulting in the inhibition of inflammatory bone loss.

Characterization and immunopotentiating effects of the glycoprotein isolated from dioscorea batatas

We demonstrate that glycoprotein isolated from Dioscorea batatas (GDB) has immunostimulatory effects including macrophage activation. Analysis of infiltration of inflammatory cells into peritoneal cavity showed GDB treatment significantly increased the recruitment of macrophages, lymphocytes, neutrophils, and monocytes into the peritoneal cavity. Treatment of spleen cells isolated from C57BL/6 mice with GDB significantly increased the proliferation of B cells and T cells induced by LPS and ConA, respectively. Treatment with GDB significantly increased the cytolytic capacity of NK cells and macrophages against YAC-1 and B16 cells, respectively. In order to further confirm and investigate the mechanism of GDB on macrophage activation, we analyzed the effects of GDB on the cytokine expression including iNOS, IL-1β, and TNF-α in mouse macrophage cell line, RAW 264.7 cells. RT-PCR and ELISA showed that GDB increased the expression of IL-1β, and TNF-α, whereas iNOS was not induced by GDB. Collectively, this series of experiments indicates that GDB stimulates immune system including macrophage activation.

Yam storage protein dioscorins from Dioscorea alata and Dioscorea japonica exhibit distinct immunomodulatory activities in mice

The aim of this study was to elucidate the effect of the major storage protein dioscorin isolated from two different yam species, Tainong No. 1 (TN1-dioscorins) and Japanese yam (Dj-dioscorins), on the immune activities of mice. Dj-dioscorins, like TN1-dioscorins, could induce expression of the pro-inflammatory cytokines and stimulate phagocytosis of RAW 264.7. Intraperitoneal injection of the TN1-dioscorins into mice stimulated phagocytosis of bone marrow, spleen, and thymic cells. In contrast, the T and B cells in bone marrow, spleen, and thymus isolated from mice injected with Dj-dioscorins had higher proliferative responses to mitogens. Furthermore, Dj-dioscorins enhanced proliferation of CD4(+), CD8(+), and Tim3(+) (Th1) cells in spleen and CD19(+) cells in both spleen and thymus. Supplement of Dj-dioscorins in the lymphoid cells isolated from Dj-dioscorins primed mice induced cell proliferation of both spleen and thymic cells. These findings indicated that TN1-dioscorins have a higher ability to stimulate the phagocytic activity of the lymphoid cells than Dj-dioscorins, whereas Dj-dioscorins possess more abilities than TN1-dioscorins to enhance the proliferation of the lymphoid cells.