Cyclic Peptide Extracts Derived From Pseudostellaria heterophylla Ameliorates COPD via Regulation of the TLR4/MyD88 Pathway Proteins

Andrographolide Attenuates NLRP3 Inflammasome Activation and Airway Inflammation in Exacerbation of Chronic Obstructive Pulmonary Disease

Purpose

The aim of this study is to uncover the anti-inflammatory propertity of andrographolide (AGP) in acute exacerbation of chronic obstructive pulmonary disease (AECOPD) and the underlying mechanisms related to the nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome pathway.

Methods

An in vivo experiment was conducted on murine model of AECOPD through endotracheal atomization of elastase and lipopolysaccharide (LPS). Intraperitoneal AGP was administered four times. NLRP3 inflammasome pathway molecules were examined using real-time quantitative polymerase chain reaction (RT-qPCR) and Western blot analysis. By using enzyme-linked immunosorbent assay (ELISA), we tested interleukin (IL)-1β levels in bronchoalveolar lavage fluid. An in vitro study was conducted to determine how AGP impacts the NLRP3 inflammasome in THP-1 derived macrophages. The levels of molecules involved in the pathway were measured. Furthermore, molecular docking analyses were carried out to investigate the interactions between AGP and pathway targets.

Results

In the in vivo study, NLRP3 inflammasome activation was observed in mice experiencing AECOPD. The administration of high-dose AGP demonstrated a mitigating effect on inflammatory cells infiltration in the lungs. Moreover, AGP administration effectively suppressed the expression of NLRP3, apoptosis associated speck-like protein that contains a CARD (PYCARD), cysteinyl aspartate-specific protease-1 (Caspase-1), IL-1β, and IL-18 at both the genetic and protein levels. In the in vitro experiment, IL-1β levels were significantly elevated in THP-1 derived macrophages with activated inflammasome compared to the control group. Furthermore, the downregulation of NLRP3, CASP1, and IL1B genes was observed upon the inhibition of NLRP3 expression through small interfering RNA (siRNA). AGP demonstrated inhibitory effects on the gene expression and protein levels of NLRP3, Caspase-1, and IL-1β. Additionally, molecular docking analysis confirmed that AGP exhibited a favorable binding affinity with all five targets of the pathway.

Conclusion

AGP effectively inhibited NLRP3 inflammasome activation and mitigated the inflammatory reaction of AECOPD both in animal models and in vitro experiments, highlighting the potential of AGP as a treatment for AECOPD with anti-inflammatory properties.

GRB7 plays a promoting role in the progression of gastric cancer

BACKGROUND

Gastric cancer is a clinically common tumor, showing an upward trend of both incidence and mortality. GRB7 has been identified as a vital regulator in tumor progression. This study aims to uncover the biological function of GRB7 in gastric cancer process.

METHODS

immunohistochemical (IHC) staining using a tissue microarray (TMA), quantitative reverse transcription PCR (qRT-PCR) and Western blotting were performed to detect the expression of genes. Furthermore, gastric cancer cell lines AGS and MGC-803 were transfected with short hairpin RNAs against GRB7. The biological function of GRB7 in gastric cancer cells were examined by CCK-8, flow cytometry, wound healing and Transwell assays. Then, in vivo tumor formation assay was conducted to explore the effects of GRB7 on tumor growth. Finally, expression levels of proteins related to cell functions were determined by Western blotting. Coimmunoprecipitation (CoIP) assay was performed to assess the protein-protein interaction.

RESULTS

GRB7 was up-regulated in gastric cancer tissues and cell lines, and its expression was inversely proportional to survival of gastric cancer patients. Moreover, GRB7 knockdown inhibited proliferative, migratory abilities, as well as promoted cell apoptosis in gastric cancer cells. Further study suggested that GRB7 silencing could suppress gastric cancer tumor growth in vivo. Furthermore, our study uncovered an important interaction between GRB7 and MyD88. Silencing MyD88 was observed to alleviate the malignant phenotypes promoted by GRB7 in gastric cancer cells.

CONCLUSIONS

Together, this study provided evidence that GRB7 may be an effective molecular targets for the treatment of gastric cancer.

Ghrelin attenuates inflammation in diabetic lung disease by TLR4 pathway in vivo and in vitro

INTRODUCTION

Diabetic lung disease is already known as one of the diabetes complications, but report on its therapeutic strategy is rare. The present study aimed to add novel therapeutic strategy for diabetic lung disease, to reveal the protective effect of ghrelin on diabetic lung disease both in vivo and in vitro, and to discuss its probable molecular mechanism.

RESEARCH DESIGN AND METHODS

Diabetic mice and 16HBE cells were our research objects. We surveyed the effect of ghrelin on streptozotocin-induced lung tissue morphology changes by H&E staining. Furthermore, the changes of proinflammatory cytokines (interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α)) were detected by ELISA. To expound the molecular mechanism, we detected critical proteins of TLR4 pathway and observed their changes by immunohistochemistry (IHC), real-time PCR and western blot analysis in vivo and in vitro, respectively.

RESULTS

The results of H&E staining showed that pathological alterations of the lung induced by hyperglycemia were ameliorated by ghrelin. The results of ELISA demonstrated that the elevated levels of IL-1β and TNF-α induced by hyperglycemia turned to decrease in the lung after ghrelin treatment. In the results of IHC, real-time PCR and western blot analysis, we found that the TLR4 pathway was elevated by hyperglycemia or high glucose and is remarkably inhibited by the treatment of ghrelin both in vivo and in vitro.

CONCLUSIONS

Ghrelin could inhibit inflammation of diabetic lung disease by regulating the TLR4 pathway. This study might affect research on diabetic lung disease, and the therapeutic potential of ghrelin for diabetic lung disease is worth considering.

The role of HMGB1/RAGE/TLR4 signaling pathways in cigarette smoke-induced inflammation in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a common chronic respiratory disease with irreversible and continuous progression. It has become the fifth most burdensome disease and the third most deadly disease globally. Therefore, the prevention and treatment of COPD are urgent, and it is also important to clarify the pathogenesis of it. Smoking is the main and most common risk factor for COPD. Cigarette smoke (CS) can cause lung inflammation and other pathological mechanisms in the airways and lung tissue. Airway inflammation is one of the important mechanisms leading to the pathogenesis of COPD. Recent studies have shown that high mobility group box 1 (HMGB1) is involved in the occurrence and development of respiratory diseases, including COPD. HMGB1 is a typical damage-associated molecular pattern (DAMP) protein, which mainly exerts its activity by binding to the receptor for advanced glycation end products (RAGE) and toll-like receptor 4 (TLR4) and further participate in the process of airway inflammation. Studies have shown that the abnormal expression of HMGB1, RAGE, and TLR4 are related to inflammation in COPD. Herein, we discuss the roles of HMGB1, RAGE, and TLR4 in CS/cigarette smoke extract-induced inflammation in COPD, providing a new target for the diagnosis, treatment and prevention of COPD.

Health benefits of flaxseed and its peptides (linusorbs)

Flaxseed (Linum usitatissimum L.) has been associated with numerous health benefits. The flax plant synthesizes an array of biologically active compounds including peptides or linusorbs (LOs, a.k.a., cyclolinopeptides), lignans, soluble dietary fiber and omega-3 fatty acids. The LOs arise from post-translational modification of four or more ribosome-derived precursors. These compounds exhibit an array of biological activities, including suppression of T-cell proliferation, excessive inflammation, and osteoclast replication as well as induction of apoptosis in some cancer cell lines. The mechanisms of LO action are only now being elucidated but these compounds might interact with other active compounds in flaxseed and contribute to biological activity attributed to other flax compounds. This review focuses on both the biological interaction of LOs with proteins and other molecules and comprehensive knowledge of LO pharmacological and biological properties. The physicochemical and nutraceutical properties of LOs, as well as the biological effects of certain LOs, and their underlying mechanisms of action, are reviewed. Finally, strategies for producing LOs by either peptide synthesis or recombinant organisms are presented. This review will be the first to describe LOs as a versatile scaffold for the action of compounds to deliver physiochemically/biologically active molecules for developing novel nutraceuticals and pharmaceuticals.

Investigating Potential GLP-1 Receptor Agonists in Cyclopeptides from Pseudostellaria heterophylla, Linum usitatissimum, and Drymaria diandra, and Peptides Derived from Heterophyllin B for the Treatment of Type 2 Diabetes: An In Silico Study

GLP-1 receptor agonists stimulate GLP-1R to promote insulin secretion, whereas DPP4 inhibitors slow GLP-1 degradation. Both approaches are incretin-based therapies for T2D. In addition to GLP-1 analogs, small nonpeptide GLP-1RAs such as LY3502970, TT-OAD2, and PF-06882961 have been considered as possible therapeutic alternatives. Pseudostellaria heterophylla, Linum usitatissimum, and Drymaria diandra are plants rich in cyclopeptides with hypoglycemic effects. Our previous study demonstrated the potential of their cyclopeptides for DPP4 inhibition. Reports of cyclic setmelanotide as an MC4R (GPCR) agonist and cyclic α-conotoxin chimeras as GLP-1RAs led to docking studies of these cyclopeptides with GLP-1R. Heterophyllin B, Pseudostellarin B, Cyclolinopeptide B, Cyclolinopeptide C, Drymarin A, and Diandrine C are abundant in these plants, with binding affinities of −9.5, −10.4, −10.3, −10.6, −11.2, and −11.9 kcal/mol, respectively. The configuration they demonstrated established multiple hydrogen bonds with the transmembrane region of GLP-1R. DdC:(cyclo)-GGPYWP showed the most promising docking score. The results suggest that, in addition to DPP4, GLP-1R may be a hypoglycemic target of these cyclopeptides. This may bring about more discussion of plant cyclopeptides as GLP-1RAs. Moreover, peptides derived from the HB precursor (IFGGLPPP), including IFGGWPPP, IFPGWPPP, IFGGYWPPP, and IFGYGWPPPP, exhibited diverse interactions with GLP-1R and displayed backbones available for further research.

Use of Fluorescent 2-AB to Explore the Bidirectional Transport Mechanism of Pseudostellaria heterophylla Polysaccharides across Caco-2 Cells

Polysaccharides are abundant in natural resources and perform numerous physiological functions. Polysaccharide structures often lack chromophore groups; thus, current analytical methods cannot distinguish polysaccharide metabolites in the body or polysaccharide prototypes in biological samples. Thus, the measurement of polysaccharides in blood, bodily fluid, and cell-culture medium is difficult. Our early-stage research resulted in the isolation of two homogeneous polysaccharides from Pseudostellaria heterophylla, PHP_0.5MSC-F and PHP_H-1-2, which have anti-hyperglycemia and insulin resistance improvement effects for type 2 diabetes. In this study, the reducing terminal sugars of PHP_0.5MSC-F and PHP_H-1-2 were labeled with 2-aminobenzamide (2-AB) to prepare novel fluorescent probes for HPLC-coupled fluorescence detection (HPLC-FLD). Quantitative analysis was performed in reference to T40, and the detection limit for PHP_0.5MSC-F was found to be 8.84 μg/mL with a linear range of 29.45-683.28 μg/mL. In reference to T70, the detection limit for PHP_H-1-2 was found to be 13.89 μg/mL with a linear range of 46.29-462.76 μg/mL. This method was used to measure the bidirectional transport of polysaccharides across caco-2 cells from apical to basolateral (AP→BL) or from basolateral to apical (BL→AP) directions and to evaluate the polysaccharide bioavailability. The drug absorption capacity was determined based on the apparent permeability coefficient (Papp), and the Papp values for the two polysaccharides were found to be greater than 1 × 10^-6 cm/s, which suggests easy absorption. Regarding bidirectional transport, the AP→BL Papp values were greater than the BL→AP values; thus, PHP_0.5MSC-F and PHP_H-1-2 mainly underwent passive transference. The two membrane permeable polysaccharides were not P-gp efflux transporter substrates. The absorption mechanism of PHP_0.5MSC-F complies with passive diffusion under a concentration gradient, whereas PHP_H-1-2 mainly utilizes a clathrin-mediated endocytic pathway to enter caco-2 cells. This innovative HPLC-FLD method can help to track polysaccharide internalization in vitro and in vivo to facilitate cellular uptake and biodistribution exploration.

The Potential Role of Cyclopeptides from Pseudostellaria heterophylla, Linum usitatissimum and Drymaria diandra, and Peptides Derived from Heterophyllin B as Dipeptidyl Peptidase IV Inhibitors for the Treatment of Type 2 Diabetes: An In Silico Study

Dipeptidyl peptidase 4 (DPP4) inhibitors can treat type 2 diabetes by slowing GLP-1 degradation to increase insulin secretion. Studies have reported that Pseudostellaria heterophylla, Linum usita-tissimum (flaxseed), and Drymaria diandra, plants rich in Caryophyllaceae-type cyclopeptides and commonly used as herbal or dietary supplements, are effective in controlling blood sugar. The active site of DPP4 is in a cavity large enough to accommodate their cyclopeptides. Molecular modeling by AutoDock Vina reveals that certain cyclopeptides in these plants have the potential for DPP4 inhibition. In particular, “Heterophyllin B” from P. heterophylla, “Cyclolinopeptide C” from flaxseed, and “Diandrine C” from D. diandra, with binding affinities of −10.4, −10.0, and −10.7 kcal/mol, are promising. Docking suggests that DPP4 inhibition may be one of the reasons why these three plants are beneficial for lowering blood sugar. Because many protein hydrolysates have shown the effect of DPP4 inhibition, a series of peptides derived from Heterophyllin B precursor “IFGGLPPP” were included in the study. It was observed that IFWPPP (−10.5 kcal/mol), IFGGWPPP (−11.4 kcal/mol), and IFGWPPP (−12.0 kcal/mol) showed good binding affinity and interaction for DPP4. Various IFGGLPPP derivatives have the potential to serve as scaffolds for the design of novel DPP4 inhibitors.

Exogenous Bioactive Peptides Have a Potential Therapeutic Role in Delaying Aging in Rodent Models

In recent years, some exogenous bioactive peptides have been shown to have promising anti-aging effects. These exogenous peptides may have a mechanism similar to endogenous peptides, and some can even regulate the release of endogenous active peptides and play a synergistic role with endogenous active peptides. Most aging studies use rodents that are easy to maintain in the laboratory and have relatively homogenous genotypes. Moreover, many of the anti-aging studies using bioactive peptides in rodent models only focus on the activity of single endogenous or exogenous active peptides, while the regulatory effects of exogenous active peptides on endogenous active peptides remain largely under-investigated. Furthermore, the anti-aging activity studies only focus on the effects of these bioactive peptides in individual organs or systems. However, the pathological changes of one organ can usually lead to multi-organ complications. Some anti-aging bioactive peptides could be used for rescuing the multi-organ damage associated with aging. In this paper, we review recent reports on the anti-aging effects of bioactive peptides in rodents and summarize the mechanism of action for these peptides, as well as discuss the regulation of exogenous active peptides on endogenous active peptides.

Exploring the mechanism of Yixinyin for myocardial infarction by weighted co-expression network and molecular docking

Yixinyin, the traditional Chinese medicine, has the effects of replenishing righteous qi, and promoting blood circulation to eliminate blood stagnation. It is often used to treat patients with acute myocardial infarction (MI). The purpose of our study is to explore the key components and targets of Yixinyin in the treatment of MI. In this study, we analyzed gene expression data and clinical information from 248 samples of MI patients with the GSE34198, GSE29111 and GSE66360 data sets. By constructing a weighted gene co-expression network, gene modules related to myocardial infarction are obtained. These modules can be mapped in Yixinyin PPI network. By integrating differential genes of healthy/MI and unstable angina/MI, key targets of Yixinyin for the treatment of myocardial infarction were screened. We validated the key objectives with external data sets. GSEA analysis is used to identify the biological processes involved in key targets. Through molecular docking screening, active components that can combine with key targets in Yixinyin were obtained. In the treatment of myocardial infarction, we have obtained key targets of Yixinyin, which are ALDH2, C5AR1, FOS, IL1B, TLR2, TXNRD1. External data sets prove that they behave differently in the healthy and MI (P < 0.05). GSEA enrichment analysis revealed that they are mainly involved in pathways associated with myocardial infarction, such as viral myocarditis, VEGF signaling pathway and type I diabetes mellitus. The docking results showed that the components that can be combined with key targets in YixinYin are Supraene, Prostaglandin B1, isomucronulatol-7,2'-di-O-glucosiole, angusifolin B, Linolenic acid ethyl ester, and Mandenol. For that matter, they may be active ingredients of Yixinyin in treating MI. These findings provide a basis for the preliminary research of myocardial infarction therapy in traditional Chinese medicine and provide ideas for the design of related drugs.

Studies on the oral absorption of cyclic peptides from Pseudostellaria heterophylla and interacting with membrane receptors

Pseudostellaria heterophylla (Miq.) Pax. (Taizishen, TZS) contains a variety of natural active cyclic-peptide compounds (CP). In this article, four kinds of CP monomers were isolated by HPLC and the structures were identified by mass spectrometry. The in vivo absorption of CP was detected by UPLC-MS/MS. The interaction between CP and membrane receptor was analyzed by SPR. As a result, the relative absorption rate of CP was Pesudostellarin B > Heterophyllin B > Pesudostellarin C > Pesudostellarin E. The difference in absorption rate of CP in vivo was related to its interaction with membrane receptors. The absorption mechanism of CP might be different. This is the first report that in vivo absorption study of different CP from TZS and explore its absorption mechanism, laying a theoretical foundation for the research and development of its oral drugs, and providing new ideas for the study of the absorption mechanism of CP from traditional Chinese medicine.

Zanthoxylum bungeanum Seed Oil Attenuates LPS-Induced BEAS-2B Cell Activation and Inflammation by Inhibiting the TLR4/MyD88/NF-κB Signaling Pathway

Background

Zanthoxylum bungeanum seed oil (ZBSO) is a natural essential oil derived from the seeds of the Chinese medicinal plant Zanthoxylum bungeanum, which has been investigated for antitumor and anti-inflammatory effects. However, little is known regarding the effects of ZBSO in chronic obstructive pulmonary disease (COPD).

Methods

In this study, lung epithelial cells (BEAS-2B) were induced by lipopolysaccharide (LPS) to establish an in vitro model of COPD, and cytotoxicity was detected by a cell counting kit 8 (CCK-8) assay. Griess test, enzyme-linked immunosorbent assay (ELISA), reverse transcriptase quantitative polymerase chain reaction (RT-qPCR), western blot, immunofluorescence, and molecular docking analyses were used to investigate the effects of ZBSO and its potential mechanisms.

Results

The results showed that LPS promoted the expression of nitric oxide (NO), reactive oxygen species (ROS), malondialdehyde (MDA), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), matrix metalloproteinase-2 (MMP-2), MMP-9, cyclooxygenase-2 (COX-2), and prostaglandin E₂ (PGE2), suggesting that LPS can induce inflammation and oxidative stress in BEAS-2B cells. ZBSO inhibits the LPS-induced expression of inflammatory mediators and proinflammatory cytokines in BEAS-2B cells. The molecular docking results indicated that active components in ZBSO could successfully dock with toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), and p65. Immunofluorescence and western blot analyses further demonstrated that ZBSO repressed protein expression associated with the TLR4/MyD88/nuclear factor-κB (NF-κB) signaling pathway.

Conclusions

ZBSO reduced the inflammatory response and oxidative stress induced by LPS by inhibiting the TLR4/MyD88/NF-κB signaling pathway, thereby suppressing COPD. ZBSO may represent a promising therapeutic candidate for COPD treatment.

A new cyclic peptide from the fibrous root of Pseudostellaria heterophylla

A new cyclic peptide, Pseudostellarin K (1), together with thirteen known compounds, including two cyclic peptides (2 and 3), one β-carboline alkaloid (4), two amides (5 and 6), three phenylpropanoids (7-9) and other compounds (10-14), were isolated from the fibrous root of Pseudostellaria heterophylla. Their structures were elucidated by extensive spectroscopic analysis. Compounds 1, 4-6, 10 were isolated from the genus pseudostellaria for the first time. All compounds were evaluated for cytotoxic activities against MCF-7, A549, HCT-116 and SGC-7901 cell lines by MTT assay. Unfortunately, all these compounds displayed weak cytotoxic activities.