Immune promotive effect of bioactive peptides may be mediated by regulating the expression of SOCS1/miR-155

Pharmacokinetics and safety evaluation of intravenously administered Pseudomonas phage PA_LZ7 in a mouse model

IMPORTANCE

Phage therapy is gaining traction as an alternative to antibiotics due to the rise of multi-drug-resistant (MDR) bacteria. This study assessed the pharmacokinetics and safety of PA_LZ7, a phage targeting MDR Pseudomonas aeruginosa, in mice. After intravenous administration, the phage showed an exponential decay in plasma and its concentration dropped significantly within 24 h for all dosage groups. Although there was a temporary increase in certain plasma cytokines and spleen weight at higher dosages, no significant toxicity was observed. Therefore, PA_LZ7 shows potential as an effective and safe candidate for future phage therapy against MDR P. aeruginosa infections.

Preparation Optimization and Immunological Activity Studies of Portulaca oleracea L. Polysaccharides Liposomes

AIMS

This study combines traditional Chinese medicine polysaccharides with nanomaterials to enhance drug bioavailability and immunological activity.

BACKGROUND

The study of polysaccharide preparation, structure identification, pharmacological activity, and mechanism of action is deepening, but the research combined with the new drug delivery system is relatively weak, so the application of polysaccharides is still facing great limitations. In order to prolong the action time of polysaccharides and improve their bioavailability, liposome has become the most promising delivery carrier.

OBJECTIVES

The purpose of this study was to optimize the preparation process of Portulaca oleracea L. polysaccharides liposomes (POL-PL) and evaluate the immunoactivity in vitro.

METHODS

POL-PL was prepared by reverse evaporation, and the preparation process was optimized using the response surface methodology. The characteristic analysis of POL-PL was detected by the indicators including morphology, particle size, zeta potential, encapsulation efficiency, release, and stability. The effects of POL-PL on the proliferation and immunological activity of mouse spleen lymphocytes and RAW264.7 cells were evaluated in vitro.

RESULTS

POL-PL is highly homogeneous in morphology and particle size, and its sustained release improves the bioavailability of Portulaca oleracea L. polysaccharides (POL-P). Moreover, POL-PL treatment significantly enhanced the proliferation and phagocytic activity of RAW264.7 cells and increased the secretion of IL-6, TNF-α, IL-1β, and NO.

CONCLUSION

This study suggested that POL-PL were prepared successfully by reverse evaporation method, and POL-PL had immunoenhancing activity in vitro. The results provided a theoretical basis for further application of POL-PL.

[Lipopolysaccharide stimulates macrophages to secrete exosomes containing miR-155-5p to promote activation and migration of hepatic stellate cells]

OBJECTIVE

To observe the effect of exosomes secreted by lipopolysaccharides (LPS)-stimulated macrophages on hepatic stellate cell activation and migration and explore the underlying molecular mechanism.

METHODS

Human monocyte THP-1 cells were induced to differentiate into macrophages using propylene glycol methyl ether acetic acid (PMA, 100 ng/mL, 24 h) followed by stimulation with LPS, and the culture supernatant of macrophages was collected for extraction of the exosomes by ultracentrifugation. The expression of miR-155-5p in the exosomes was detected using qRT-PCR. A Transwell co-culture system was used to observe the effects of the macrophage-derived exosomes on LX2 cell (a hepatic stellate cell line) proliferation, migration, oxidative stress and the expression of fibrosis biomarkers, which were also observed in LX2 cells transfected with miR-155-5p-mimics or miR-155-5p-inhibitors. Western blotting was used to detect the expressions of SOCS1 and its downstream signal pathway proteins.

RESULTS

Treatment with the exosomes from LPS-stimulated macrophages significantly enhanced the proliferation and migration ability of LX2 cells and increased the levels of oxidative stress and expressions of the fibrosis markers such as type Ⅰ collagen (P < 0.05). The expression of miR-155-5p in the exosomes secreted by macrophages was significantly increased after LPS treatment (P < 0.01). LX2 cells overexpressing miR-155-5p also exhibited significantly enhanced proliferation and migration with increased oxidative stress levels and expression of type Ⅰ collagen (P < 0.05), and interference of miR-155-5p expression produced the opposite effects. Western blotting showed that miR-155-5p overexpression obviously inhibited SOCS1 expression and promoted p-Smad2/3, Smad2/3 and RhoA protein expressions in LX2 cells (P < 0.05).

CONCLUSION

LPS stimulation of the macrophages increases miR-155-5p expression in the exosomes to promote activation and migration and increase oxidative stress and collagen production in hepatic stellate cells.

Effects of Chinese herbal diet on hematopoiesis, immunity, and intestines of mice exposed to different doses of radiation

Radiotherapy causes a series of side effects in patients with malignant tumors. Polygonati Rhizoma, Achyranthis Bidentatae Radix, and Epimedii Folium are all traditional Chinese herbs with varieties of functions such as anti-radiation and immune regulation. In this study, the above three herbs were used as a herbal diet to study their effects on the hematopoietic, immune, and intestinal systems of mice exposed to three doses of radiation. Our study showed that the diet had no radiation-protective effect on the hematopoietic and immune systems. However, at the radiation dose of 4 Gy and 8 Gy, the diet showed an obvious radiation-protective effect on intestinal crypts. At the dose of 8 Gy, we also found that the Chinese herbal diet had an anti-radiation effect on reducing the loss of the inhibitory nNOS⁺ neurons in the intestine. That provides a new diet for relieving the symptoms of hyperperistalsis and diarrhea in patients after radiotherapy.

Moringa oleifera leaf polysaccharide alleviates experimental colitis by inhibiting inflammation and maintaining intestinal barrier

The characteristic of ulcerative colitis (UC) is extensive colonic mucosal inflammation. Moringa oleifera (M. oleifera) is a medicine food homology plant, and the polysaccharide from M. oleifera leaves (MOLP) exhibits antioxidant and anti-inflammatory activity. The aim of this study to investigate the potential effect of MOLP on UC in a mouse model as well as the underlying mechanism. Dextran sulfate sodium (DSS) 4% in drinking water was given for 7 days to mice with UC, at the same time, MOLP (25, 50, and 100 mg/kg/day) was intragastric administered once daily during the experiment. Structural analysis revealed that MOLP had an average molecular weight (Mw) of 182,989 kDa and consisted of fucose, arabinose, rhamnose, galactose, glucose, xylose, mannose, galactose uronic acid, glucuronic acid, glucose uronic acid and mannose uronic acid, with a percentage ratio of 1.64, 18.81, 12.04, 25.90, 17.57, 12.01, 3.51, 5.28, 0.55, 1.27, and 1.43%, respectively. In addition, the features of MOLP were identified by Fourier-transform infrared (FT-IR) and spectra, X-ray diffraction (XRD). The results showed that MOLP exhibited protective efficacy against UC by alleviating colonic pathological alterations, decreasing goblet cells, crypt destruction, and infiltration of inflammatory cells caused by DSS. Furthermore, MOLP notably repressed the loss of zonula occludens-1 (ZO-1) and occludin proteins in mucosal layer, as well as up-regulating the mRNA expression of interleukin-10 (IL-10) and peroxisome proliferator-activated receptor-γ (PPAR-γ), whereas down-regulating the activation of Toll-like receptor 4 (TLR4), myeloid differentiation primary response 88 (MyD88), nuclear factor-kappa B (NF-κB) signaling pathway and the production of pro-inflammatory cytokines. Therefore, these results will help understand the protective action procedure of MOLP against UC, thereby providing significance for the development of MOLP.

Peptide Biomaterials for Tissue Regeneration

Expanding the toolbox of therapeutic materials for soft tissue and organ repair has become a critical component of tissue engineering. While animal- and plant-derived proteins are the foundation for developing biomimetic tissue constructs, using peptides as either constituents or frameworks for the materials has gained increasing momentum in recent years. This mini review discusses recent advances in peptide-based biomaterials' design and application. We also discuss some of the future challenges posed and opportunities opened by peptide-based structures in the field of tissue engineering and regenerative medicine.

Protective effect of protein hydrolysates from Litopenaeus vannamei waste on oxidative status, glucose regulation, and autophagy genes in non-alcoholic fatty liver disease in Wistar rats

Objective(s):

The effects of protein hydrolysates (FP) from Litopenaeus vannamei on oxidative stress, and autophagy gene expression was investigated in the NAFLD-induced rats.

Materials and Methods:

For this purpose, twenty-four male rats were divided into four groups: Control, High-fat diet (HFD), FP20+HFD, and FP300+HFD (20 and 300 mg FP /kg rat body weight) and fed for 70 days.

Results:

The results indicated that the rat body and relative weight of the liver were not affected by experimental treatments (P>0.05) although the highest relative weight of the liver was observed in HFD treatment. The highest and lowest values for antioxidant enzymes and MDA concentration were observed in FP treatments (P<0.05). Also, the results showed that FP significantly decreased liver enzymes (ALT, AST) in the liver in comparison with HFD treatment (P<0.05). Plasma biochemical indices were investigated and the lowest amylase, ALP, fasting glucose, insulin, HOMA-IR, triglycerides, cholesterol, and inflammation cytokines (TNF-α, IL-6) were seen in the FP treatments which had a significant difference with HFD (P<0.05). Autophagy gene expression in the liver cells was affected by experimental diets and the lowest expression of Beclin-1 and Atg7 was observed in HFD and FP300 treatments. Interestingly, the highest expression of LC3-ɪ and P62 was seen in HFD and FP treatments, not in the control.

Conclusion:

Overall, the results of this experiment indicated that FPs extracted from Whiteleg shrimp at 50 °C improve the oxidative status, glucose metabolism, and autophagy gene expression and could be used as a useful nutritional strategy in fatty liver prevention.

Naringenin and cryptotanshinone shift the immune response towards Th1 and modulate T regulatory cells via JAK2/STAT3 pathway in breast cancer

BACKGROUND

Use of natural products has been proposed as an efficient method in modulation of immune system and treatment of cancers. The aim of this study was to investigate the potential of cryptotanshinone (CPT), naringenin, and their combination in modulating the immune response towards Th1 cells and the involvement of JAK2/STAT3 signaling pathway in these effects.

METHODS

Mouse models of delayed type hypersensitivity (DTH) were produced and treated with naringenin and CPT. The proliferation of spleen cells were assessed by Bromodeoxyuridine (BrdU) assay. Flowcytometry and enzyme-linked immunosorbent assay (ELISA) tests were employed to evaluate subpopulation of T-lymphocytes and the levels of cytokines, respectively. The JAK/STAT signaling pathway was analyzed by Western blotting.

RESULTS

We showed higher DTH, increased lymphocyte proliferation, decreased tumor growth and reduced JAK2/STAT3 phosphorylation in mice treated with naringenin and CPT. Moreover, a significant decline in the production of IL-4 and an upsurge in the production of IFN-γ by splenocytes were observed. Additionally, the population of intra-tumor CD4+CD25+Foxp3+ T cells was significantly lower in naringenin + CPT treated animals than that in controls.

CONCLUSION

Naringenin-CPT combination could exert immunomodulatory effects, suggesting this combination as a novel complementary therapeutic regimen for breast cancer.

Effects of Shrimp Peptide Hydrolysate on Intestinal Microbiota Restoration and Immune Modulation in Cyclophosphamide-Treated Mice

The gut microbiota is important in regulating host metabolism, maintaining physiology, and protecting immune homeostasis. Gut microbiota dysbiosis affects the development of the gut microenvironment, as well as the onset of various external systemic diseases and metabolic syndromes. Cyclophosphamide (CTX) is a commonly used chemotherapeutic drug that suppresses the host immune system, intestinal mucosa inflammation, and dysbiosis of the intestinal flora. Immunomodulators are necessary to enhance the immune system and prevent homeostasis disbalance and cytotoxicity caused by CTX. In this study, shrimp peptide hydrolysate (SPH) was evaluated for immunomodulation, intestinal integration, and microbiota in CTX-induced immunosuppressed mice. It was observed that SPH would significantly restore goblet cells and intestinal mucosa integrity, modulate the immune system, and increase relative expression of mRNA and tight-junction associated proteins (Occludin, Zo-1, Claudin-1, and Mucin-2). It also improved gut flora and restored the intestinal microbiota ecological balance by removing harmful microbes of various taxonomic groups. This would also increase the immune organs index, serum levels of cytokines (IFN-ϒ, IL1β, TNF-α, IL-6), and immunoglobin levels (IgA, IgM). The Firmicutes/Bacteroidetes proportion was decreased in CTX-induced mice. Finally, SPH would be recommended as a functional food source with a modulatory effect not only on intestinal microbiota, but also as a potential health-promoting immune function regulator.

Fluoride Can Damage the Spleen of Mice by Perturbing Th1/Th2 Cell Balance

To investigate the mechanism of fluoride-induced splenic toxicity, 0, 25, 50, and 100 mg/L sodium fluoride (NaF) were administered in male mice via drinking water for 90 days. After NaF treatment, the histological structure of the spleen, the proportion of helper T 1 cell (Th1) and helper T 2 cell (Th2), and the relative expression levels of cytokines and T-bet and GATA3 were analyzed. The results showed that 50 and 100 mg/L NaF consumption can change the normal structure of mouse spleen and the proportion of Th1/Th2 cells. It also decreased the mRNA expression levels of IL-2, INF-γ, and TGF-β, but increased the levels of IL-4, IL-6, and IL-10. Importantly, fluoride increased the protein expression of GATA3 but decreased the expression of T-bet. Our findings indicate that superfluous fluoride intake damages the balance of Th1/Th2 cells by changing the levels of T-bet and GATA3 in the spleen, and further changes the expression of Th1/Th2 cell-related cytokines in the spleen microenvironment, eventually leading to spleen injury.

Clinical Value and Potential Target of miR-27a-3p in Pulpitis

INTRODUCTION

This study investigated the clinical values of miR-27a-3p for pulpitis patients, and its association with TLR4.

METHODS

Sixty-six patients with pulpitis and 34 cases without pulpitis were recruited; the pulp tissue and serum samples were collected from each participant. Real-time polymerase chain reaction was used for measurement of gene expression levels. The diagnosis values were assessed by the receiver operating characteristic curve. The target gene of miR-27a-3p was confirmed by the luciferase reporter assay.

RESULTS

MiR-27a-3p was downregulated in both serum and pulp tissue of pulpitis patients. MiR-27a-3p could distinguish pulpitis patients from healthy controls and might be a predictor for the development of irreversible pulpitis. A high level of TLR4 was also detected in both peripheral blood monocytes and pulp tissues from pulpitis patients and showed a negative association with the miR-27a-3p level. TLR4 was a direct target gene of miR-27a-3p.

DISCUSSION/CONCLUSION

MiR-27a-3p might be a promising biomarker for the diagnosis of pulpitis and predict the development of irreversible pulpitis. MiR-27a-3p might be involved in the pathogenesis of pulpitis via targeting TLR4.

Effect of animal-sourced bioactive peptides on the in vitro development of mouse preantral follicles

The aim of this study was to investigate the effect of bioactive peptides (BAPT) from animal sources on the development of mouse preantral follicles in vitro. Preantral follicles were isolated and randomly divided into the following groups: an untreated group (control) and three groups supplemented with 20, 40 and 60 μg/mL BAPT, respectively. After establishing the in vitro follicle culture, the gene expression levels and hormone levels were quantified. After in vitro maturation, the developmental rates, reactive oxygen species (ROS) production levels and mitochondrial distributions of MII oocytes were investigated, followed by the analyses of embryonic developmental rates after in vitro fertilization.The results showed that BAPT promoted the growth of mouse preantral follicles. Notably, after 14 d of in vitro culture, the levels of 17 β-estradiol and progesterone were up-regulated with BAPT treatments. Moreover, the expression levels of Oct4, Bmp15, GDF9, FOXO3, Zp3, FOXL2, Inhibin alpha, SOD2, Catalase, GPx and Bcl-2 in the developing follicles were significantly up-regulated after BAPT treatments (P < 0.05), while BAPT significantly inhibited the expression levels of BAX (P < 0.05). Following BAPT treatments, the ROS production levels of MII oocytes were decreased while the mitochondrial distributions were significantly enhanced. Furthermore, increased maturation rates, fertilization and embryonic developmental rates were found in these BAPT-treated groups (P < 0.05).These results demonstrated that BAPT significantly improved the development of preantral follicles in vitro by reducing ROS-dependent cellular damages and by enhancing mitochondrial distributions, thereby promoting the further applications of animal-derived BAPT in biomedical research.