Kunming Mice Research Articles

The impact of microplastics polystyrene on the microscopic structure of mouse intestine, tight junction genes and gut microbiota.

Microplastics, which are tiny plastic particles less than 5 mm in diameter, are widely present in the environment, have become a serious threat to aquatic life and human health, potentially causing ecosystem disorders and health problems. The present study aimed to investigate the effects of microplastics, specifically microplastics-polystyrene (MPs-PS), on the structural integrity, gene expression related to tight junctions, and gut microbiota in mice. A total of 24 Kunming mice aged 30 days were randomly assigned into four groups: control male (CM), control female (CF), PS-exposed male (PSM), and PS-exposed female (PSF)(n = 6). There were significant differences in villus height, width, intestinal surface area, and villus height to crypt depth ratio (V/C) between the PS group and the control group(C) (p <0.05). Gene expression analysis demonstrated the downregulation of Claudin-1, Claudin-2, Claudin-15, and Occludin, in both duodenum and jejunum of the PS group (p < 0.05). Analysis of microbial species using 16S rRNA sequencing indicated decreased diversity in the PSF group, as well as reduced diversity in the PSM group at various taxonomic levels. Beta diversity analysis showed a significant difference in gut microbiota distribution between the PS-exposed and C groups (R2 = 0.113, p<0.01), with this difference being more pronounced among females exposed to MPs-PS. KEGG analysis revealed enrichment of differential microbiota mainly involved in seven signaling pathways, such as nucleotide metabolism(p<0.05). The relative abundance ratio of transcriptional pathways was significantly increased for the PSF group (p<0.01), while excretory system pathways were for PSM group(p<0.05). Overall findings suggest that MPs-PS exhibit a notable sex-dependent impact on mouse gut microbiota, with a stronger effect observed among females; reduced expression of tight junction genes may be associated with dysbiosis, particularly elevated levels of Prevotellaceae.

Discovery of novel glucagon-like peptide 1/cholecystokinin 1 receptor dual agonists

The combined use of gastrointestinal hormones for treating metabolic diseases is gaining increasing attention. The potential of developing novel dual agonists targeting both cholecystokinin 1 (CCK-1) receptor and glucagon-like peptide 1 (GLP-1) receptor to improve the treatment of type 2 diabetes and obesity have not been fully explored. In this investigation, we reported a series of novel GLP-1/CCK-1 receptor co-agonists constructed by linking the C-terminus of a GLP-1 receptor agonist (bullfrog GLP-1) to the N-terminus of a CCK-1 receptor selective agonist NN9056. In comprehensive in vitro assays, these co-agonists exhibited complete agonistic potency on GLP-1 and CCK-1 receptor. Remarkably, 1f displayed superior hypoglycemic and insulinotropic effects when compared to NN9056 and semaglutide. Evaluation in Kunming and diet-induced obesity (DIO) mice unveiled significant acute and enduring hypoglycemic effects of 1f. Administration of 1f to DIO mice resulted in substantial weight loss, normalized lipid metabolism, and enhanced glucose regulation. These preclinical observations strongly advocate for the therapeutic potential CCK-1 and GLP-1 pathways could be harnessed in a single fusion peptide, yielding a promising combination therapy strategy for treating metabolic disorders.

Segmentation and quantitative analysis of optical coherence tomography (OCT) images of laser burned skin based on deep learning

Evaluation of skin recovery is an important step in the treatment of burns. However, conventional methods only observe the surface of the skin and cannot quantify the injury volume. Optical coherence tomography (OCT) is a non-invasive, non-contact, real-time technique. Swept source OCT uses near infrared light and analyzes the intensity of light echo at different depths to generate images from optical interference signals. To quantify the dynamic recovery of skin burns over time, laser induced skin burns in mice were evaluated using deep learning of Swept source OCT images. A laser-induced mouse skin thermal injury model was established in thirty Kunming mice, and OCT images of normal and burned areas of mouse skin were acquired at day 0, day 1, day 3, day 7, and day 14 after laser irradiation. This resulted in 7000 normal and 1400 burn B-scan images which were divided into training, validation, and test sets at 8:1.5:0.5 ratio for the normal data and 8:1:1 for the burn data. Normal images were manually annotated, and the deep learning U-Net model (verified with PSPNe and HRNet models) was used to segment the skin into three layers: the dermal epidermal layer, subcutaneous fat layer, and muscle layer. For the burn images, the models were trained to segment just the damaged area. Three-dimensional reconstruction technology was then used to reconstruct the damaged tissue and calculate the damaged tissue volume. The average IoU value and f-score of the normal tissue layer U-Net segmentation model were 0.876 and 0.934 respectively. The IoU value of the burn area segmentation model reached 0.907 and f-score value reached 0.951. Compared with manual labeling, the U-Net model was faster with higher accuracy for skin stratification. OCT and U-Net segmentation can provide rapid and accurate analysis of tissue changes and clinical guidance in the treatment of burns.

High Concentration of Iron Ions Contributes to Ferroptosis-Mediated Testis Injury.

In order to explore the effect of excessive iron supplementation on ferroptosis in mouse testes, Kunming mice received injections of varying concentrations of iron. The organ weight, sperm density, and malformation rate were measured. Observations of pathological and ultrastructural alterations in spermatogenic tubules were conducted using haematoxylin eosin (HE) staining and transmission electron microscopy(TEM). Transcript levels of related genes and serum biochemical indicators were measured in mouse testicular tissue. The results showed that higher iron concentration inhibited the growth of mice; reduced the organ coefficients of the testis, heart, and liver; and increased the rate of sperm malformation and mortality. Supplementation with high levels of iron ions can adversely affect the male reproductive system by reducing sperm count, damaging the structure of the seminiferous tubules and causing sperm cell abnormalities. In addition, the iron levels also affected the immune response and blood coagulation ability by affecting the red blood cells, white blood cells and platelets. The results showed that iron ions can affect mouse testicular tissue and induce ferroptosis by altering the expression of ferroptosis-related genes. However, the degree of effect was different for the different concentrations of iron ions. The study also revealed the potential role of deferoxamine in inhibiting the occurrence of ferroptosis. Nevertheless, the damage caused to the testis by deferoxamine supplementation suggests the need for further research in this direction. This study provides reference for reproductive toxicity induced by environmental iron exposure and clarifies the mechanism of reproductive toxicity caused by iron overload and the important role of iron in the male reproductive system.

Okra extract alleviates lipopolysaccharide-induced inflammation response through the regulation of bile acids, the receptor-mediated pathway, and gut microbiota.

Okra contains flavonoids and vitamin C as antioxidants and it contains polysaccharides as immunomodulators. Flavonoids regulate the inflammatory response in mice and may be related to gut microbiota. This study therefore aimed to investigate the impact of okra extract (OE) on inflammation in mice and to elucidate its underlying mechanism. Forty male Kunming (KM) mice were categorized into four groups: the control (CON) group, the lipopolysaccharide stimulation (LPS) group, the 5 mg mL-1 OE intervention (LPS + OE) group, and the 5 mg mL-1 OE supplementation plus mixed antibiotics (LPS + OE + ABX) group. The results showed that, compared with the OE group, the expression of inflammatory signaling pathway genes was upregulated and gut barrier genes were inhibited in the OE + ABX group. The Fxr receptor was activated and the abundance of Akkermansia was increased after OE supplementation, whereas the effect was reversed in the OE + ABX group. Meanwhile, Fxr was correlated positively with Akkermansia. The OE supplementation alleviated the inflammatory response in mice under LPS stimulation, accompanied by changes in gut microbiota and bile acid receptors, whereas the addition of antibiotics caused a disturbance to the gut microbiota in the OE group, thus reducing the effect of OE in alleviating the inflammatory response. © 2024 Society of Chemical Industry.

A New Mouse Model for Usher Syndrome Crossing Kunming Mice with CBA/J Mice

BackgroundPreviously, we discovered a strain of Kunming mice, referred to as the KMush/ush strain, that exhibited notably abnormal electroretinogram (ERG) readings and elevated thresholds for auditory brainstem responses (ABRs), which resembled the characteristics of Usher Syndrome (USH). We successfully identified the pathogenic genes, Pde6b and Adgrv1, after KMush/ush crossbred with CBA/CaJ mice, referred to as CBA-1ush/ush, CBA-2ush/ush or CBA-2ush/ush. In this investigation, we crossbred KMush/ush and CBA/J mice to establish novel recombinant inbred lines and analysed their phenotypic and genotypic characteristics. MethodsERG readings, ABR testing, fundus morphology, histological examination of the retina and inner ear, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis, western blotting, DNA sequence analysis and behavioural experiments were performed to assess the phenotypes and genotypes of the progeny lines. ResultsNo obvious waveforms in the ERG were detected in F1 hybrid mice while normal ABR results were recorded. The F2 hybrids, which were called J1ush/ush or J2ush/ush, exhibited segregated hearing-loss phenotypes. J1ush/ush mice had a retinitis pigmentosa (RP) phenotype with elevated ABR thresholds, whereas J2ush/ush mice exhibited only the RP phenotype. Interestingly, J1ush/ush mice showed significantly higher ABR thresholds than wild-type mice at 28 days post born (P28), and RT-qPCR and DNA-sequencing analysis showed that Adgrv1 gene expression was significantly altered in J1ush/ush mice, but histological analysis showed no significant structural changes in the organ of Corti or spiral ganglia. Further elevation of ABR-related hearing thresholds by P56 manifested only as a reduced density of spiral ganglion cells, which differed significantly from the previous pattern of cochlear alterations in CBA-2ush/ush mice. ConclusionsWe successfully introduced the hearing-loss phenotype of inbred mice with USH into CBA/J mice, which provides a good animal model for future studies on the important physiological roles of the Adgrv1 gene in inner-ear structure and for therapeutic studies targeting Adgrv1-mutated USH.

Effects of garlic-derived fructan and oligofructose mixtures on intestinal health and constipation relief in mice.

Garlic polysaccharides (GPs) constitute over 75% of the dry weight of garlic. They are characterized by fructan with a 2,1-β-d-Fruf backbone and 2,6-β-d-Fruf branches. Studies have suggested a role for GPs in regulating gut microbiota but whether they possess a comprehensive function in maintaining intestinal well-being and can serve as effective prebiotics remains unknown. To explore this, varied doses of GPs (1.25-5.0 g kg-1 body weight) and inulin (as a positive control) were administered to Kunming mice via gavage, and their effects on the intestinal epithelial, chemical, and biological barriers were assessed. A constipation model was also established using loperamide to investigate the potential effects of GPs on the relief of constipation. Administration of GPs significantly upregulated expression of tight-junction proteins and mucins in Kunming mouse small-intestine tissue. Garlic polysaccharides elevated cecal butyric acid content, reduced the abundance of Desulfobacterota, and decreased the ratio of Firmicutes to Bacteroidetes (the F/B ratio). Garlic polysaccharides also promoted the growth of Bacteroides acidifaciens and Clostridium saccharogumia. Tax4Fun functional predictions suggested the potential of GPs to prevent human diseases, reducing the risk of insulin resistance, infectious diseases, and drug resistance. Garlic polysaccharides also exhibited a beneficial effect in alleviating loperamide-induced constipation symptoms by enhancing small intestinal transit, softening stool consistency, accelerating bowel movements, and promoting the release of excitatory neurotransmitters. These findings highlight the important role of GPs in maintaining gut fitness by enhancing intestinal barrier function and peristalsis. Garlic polysaccharides are promising prebiotics, potentially contributing to overall intestinal well-being and health. © 2024 Society of Chemical Industry.

Anti-aging mechanism and effect of treatment with raw and wine-steamed Polygonatum sibiricum on D-galactose-induced aging in mice by inhibiting oxidative stress and modulating gut microbiota.

Polygonatum sibiricum (PS) is a traditional Chinese medicine (TCM) first recorded in Mingyi Bielu. The book documents that PS can nourish five internal organs, be taken for a long time, relax the body and prolong lifespan. Presently, PS is widely used in TCM to prevent premature graying of hair. Based on TCM theory and clinical trials, the wine steaming processed product from PS provides a better effect. However, no published study has elucidated the anti-aging mechanism. The study aim was to investigate the anti-aging mechanism of PS and its wine steaming processed product in mice, specifically focusing on the effect of D-galactose (D-gal) surrounding the intestinal flora and the Kelch-like ECH-associated protein 1-nuclear factor erythroid 2-related factor 2-antioxidant response elements (Keap1/Nrf2/ARE) pathway. The chemical components in Raw PS (RPS) and Wine-steamed PS (WPS) were identified by ultra-performance liquid chromatography-hybrid quadrupole-Orbitrap high-resolution mass spectrometry (UPLC-Q-Orbitrap HRMS). An aging model using Kunming mice was established through intraperitoneally injected D-gal. Concentrations of RPS and WPS at 5, 10, or 15g/kg/day levels were administered intragastrically, respectively. The body weight, liver and spleen indexes, superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), and malondialdehyde (MDA) activities in serum and brain tissue were recorded. Hematoxylin and eosin (HE) stained brain tissue was histopathologically examined. The expressions of Keap1, Nrf2 and heme oxygenase 1 (HO-1) in the brain tissue at the mRNA and protein levels were respectively detected by reverse transcription-polymerase chain reaction (RT-PCR) and western blot (WB). Moreover, an Illumina Hiseq platform was used for 16S ribosomal RNA (16S rRNA) high-throughput sequencing to evaluate the proportions of intestinal flora in aging mice. The proportions of saccharides, flavonoids, and triterpene acids were different between RPS and WPS. In the aging model mice, WPS outperformed RPS in improving body weight and mental state by increasing the spleen index, SOD and GSH-PX activities, decreasing the liver index and MDA activities, and restoring the histopathological morphology in D-gal-induced aging mice. At the mRNA levels, RPS and WPS significantly reduced the expression of Keap1 and increased the expressions of Nrf2 and HO-1. The trend in protein expressions was similar to that of the mRNA results, and WPS had a stronger effect than RPS. Fecal microbiota analysis showed that RPS and WPS restored intestinal microbiota proportions to normal levels. The results demonstrated that PS and its WPS had a positive effect in relieving oxidative stress in aging mice. WPS outperformed RPS, which might be related to the activation of the Keap1/Nrf2/ARE pathway and regulation of intestinal flora.

Myricetin and dihydromyricetin as JNK1 inhibitors protect against ROS‐mediated oxidative stress and apoptosis

AbstractReactive oxygen species (ROS)‐mediated oxidative stress and apoptosis contribute to the pathogenesis and pathological conditions of various diseases induced by food and environmental pollutants. Myricetin and dihydromyricetin, as natural flavonoids, can counteract oxidative damage, apoptosis, and associated diseases. Molecular docking analysis, ELISA, fluorescence spectroscopy, and Western blot techniques were applied to examine the potential of the two flavonoids as effective therapeutics for ROS‐mediated diseases and the mechanism(s) underlying their protective effects against ethanol/H2O2‐induced damage. In Kunming mice and HepG2 cells, myricetin and dihydromyricetin inhibited ethanol/H2O2‐induced liver damage, ROS accumulation, and oxidative stress and apoptosis. Molecular docking showed that myricetin and dihydromyricetin interacted with JNK1 via hydrophobic interactions and hydrogen bonds, thereby exerting their protective effects. The significant differences in their binding patterns to JNK1 resulted from the different bond types between C2 and C3 on their C ring. Myricetin and dihydromyricetin likely protected liver injury via counteracting ROS/JNK1‐mediated oxidative stress and apoptosis. The finding that the suppression of ROS‐mediated oxidative stress and apoptosis by flavonoids via interacting with functional proteins, such as kinase, may represent an alternative strategy for treating excessive ROS‐induced health problems.

Mechanism of total saponins of Panax japonicus against liver injury induced by acetaminophen in mice based on ERK/NF-κB/COX-2 signaling pathway

This study investigated the effects and mechanisms of total saponins of Panax japonicus(TSPJ) against liver injury induced by acetaminophen(APAP). Male Kunming mice were randomly divided into a blank control group, TSPJ group(200 mg·kg~(-1), ig), model group, APAP+ TSPJ low-dose group(50 mg·kg~(-1), ig), APAP+ TSPJ medium-dose group(100 mg·kg~(-1), ig), APAP+ TSPJ high-dose group(200 mg·kg~(-1), ig), and APAP+ N-acetyl-L-cysteine group(200 mg·kg~(-1), ip). The administration group received the corresponding medications via ig or ip once a day for 14 consecutive days. After the last administration for one hour, except for the blank control group and TSPJ group, all groups of mice were given 500 mg·kg~(-1) APAP by gavage. After 24 hours, mouse serum and liver tissue were collected for serum alanine aminotransferase(ALT), aspartate aminotransferase(AST), reactive oxygen species(ROS), tumor necrosis factor alpha(TNF-α), interleukin-1 beta(IL-1β), cyclooxygenase-2(COX-2), IL-6, IL-4, IL-10, as well as lactate dehydrogenase(LDH), glutathione(GSH), superoxide dismutase(SOD), catalase(CAT), total antioxidant capacity(T-AOC), malondialdehyde(MDA), and myeloperoxidase(MPO) liver tissue. Hematoxylin-eosin staining was used to observe the morphological changes of liver tissue. The mRNA expression levels of lymphocyte antigen 6G(Ly6G), galectin 3(Mac-2), TNF-α, IL-1β, COX-2, IL-6, IL-4, and IL-10 in liver tissue were determined by quantitative real-time polymerase chain reaction(PCR). Western blot was utilized to detect the protein expression levels of Ly6G, Mac-2, extracellular regulated protein kinases(ERK), phosphorylated extracellular regulated protein kinases(p-ERK), COX-2, inhibitor of nuclear factor κB protein α(IκBα), phosphorylated inhibitor of nuclear factor κB protein α(p-IκBα), and nuclear factor-κB subunit p65(NF-κB p65) in cytosol and nucleus in liver tissue. The results manifested that TSPJ dramatically reduced liver coefficient, serum ALT, AST, ROS, TNF-α, IL-1β, IL-6, and COX-2 levels, LDH, MPO, and MDA contents in liver tissue, and mRNA expressions of TNF-α, IL-1β, and IL-6 in APAP-induced liver injury mice. It prominently elevated serum IL-4 and IL-10 levels, GSH, CAT, SOD, and T-AOC contents, and mRNA expressions of IL-4 and IL-10 in liver tissue, improved the degree of liver pathological damage, and suppressed neutrophil infiltration and macrophage recruitment in liver tissue. In addition, TSPJ lessened the mRNA and protein expressions of neutrophil marker Ly6G, macrophage marker Mac-2, and COX-2 in liver tissue, protein expressions of p-ERK, p-IκBα, and NF-κB p65 in nuclear, and p-ERK/ERK and p-IκBα/p-IκBα ratios and hoisted protein expression of NF-κB p65 in cytosol. These results suggest that TSPJ has a significant protective effect on APAP-induced liver injury in mice, and it can alleviate APAP-induced oxidative damage and inflammatory response. Its mechanism may be related to suppressing ERK/NF-κB/COX-2 signaling pathway activation, thus inhibiting inflammatory cell infiltration, cytokine production, and liver cell damage.

Combining large-spot low-fluence 1064-nm and fractional 1064-nm picosecond lasers for promoting protective melanosome autophagy via the PI3K/Akt/mTOR signalling pathway for the treatment of melasma.

Melasma is a common condition of hyperpigmented facial skin. Picosecond lasers are reported to be effective for the treatment of melasma. We aimed to identify the most effective therapeutic mode and elucidate the potential molecular mechanisms of picosecond lasers for the treatment of melasma. Female Kunming mice with melasma-like conditions were treated using four different picosecond laser modes. Concurrently, invitro experiments were conducted to assess changes in melanin and autophagy in mouse melanoma B16-F10 cells treated with these laser modes. Changes in melanin in mouse skin were detected via Fontana-Masson staining, and melanin particles were evaluated in B16-F10 cells. Real-time polymerase chain reaction and western blotting were used to analyse the expression levels of melanosome and autophagy-related messenger ribonucleic acid (mRNA) and proteins. A combination of large-spot low-fluence 1064-nm and fractional 1064-nm picosecond lasers resulted insignificant decreases in melanin as well as in mRNA and protein expression of melanin-synthesizing enzymes (TYR, TRP-1 and MITF). This combination also led to increased expression of the autophagy-related proteins, Beclin1 and ATG5, with a marked decrease in p62 expression. Intervention with the PI3K activator, 740 Y-P, increased TYR, TRP-1, MITF, p-PI3K, p-AKT, p-mTOR and p62 expression but decreased the expression of LC3, ATG5 and Beclin1. A combination of large-spot low-fluence 1064-nm and fractional 1064-nm picosecond lasers proved more effective and safer. It inhibits melanin production, downregulates the PI3K/AKT/mTOR pathway, enhances melanocyte autophagy and accelerates melanin metabolism, thereby reducing melanin content.

Subacute toxicity of isoliquiritigenin-zein phosphatidylcholine nanoparticles on biochemical, hematological, and histopathological parameters in Sprague-Dawley rats

Aim: Isoliquiritigenin (ISL) is a natural flavonoid found in many natural plants, which exhibits numerous pharmacological properties including anti-inflammatory, antioxidant, antitumor, and antiviral activities. However, the low bioavailability and stability of ISL limit its application in clinical practice. To overcome these limitations, ISL-zein phosphatidylcholine hybrid nanoparticles (ISL@ZLH NPs) have been developed to improve the bioavailability and stability of ISL. The present study aimed to evaluate the acute and subacute toxicity of ISL@ZLH NPs in Sprague-Dawley (SD) rats. Methods: The ISL@ZLH NPs were prepared by the solvent evaporation method. The acute toxicity was evaluated by administering a single dose of 110 mg/kg and 160 mg/kg of ISL@ZLH NPs extracted in distilled water via oral gavage in rats and mice, respectively. The subacute toxicity was evaluated by administering doses of 27.5 mg/(kg∙day), 55 mg/(kg∙day), and 110 mg/(kg∙day) of ISL@ZLH NPs for 30 days and 90 days. The biochemical, hematological, and histopathological parameters were analyzed in both studies. Results: In the acute toxicity study, no mortality or significant changes in the biochemical and hematological parameters were observed in both Kunming (KM) mice and SD rats. In the subacute toxicity study, no toxic reactions were observed in both species at all doses tested. Moreover, no significant changes in the biochemical, hematological and histopathological parameters were observed in both species. Conclusions: The results of this study suggest that ISL@ZLH NPs are safe and non-toxic in both KM mice and SD rats. The nanoparticles (NPs) did not induce any adverse effects on the biochemical, hematological, and histopathological parameters in both acute and subacute toxicity studies. These results indicate that ISL@ZLH NPs are safe for prolonged consumption. Further studies are needed to evaluate the long-term toxicity and efficacy of these NPs in vivo.

Therapeutic administration of Luteolin protects against Escherichia coli-derived Lipopolysaccharide-triggered inflammatory response and oxidative injury

Endometritis reduces reproductive effectiveness and leads to significant financial losses in the dairy sector. Luteolin is a natural phyto-flavonoid compound with many biological activities. However, the therapeutic effect of Luteolin against lipopolysaccharides (LPS)-induced endometritis has not yet been explored. A total of eighty female Kunming mice were randomly assigned into four treatment groups (n = 20). Following a successful initiation of the endometritis model by LPS, Luteolin was intraperitoneally administered three times, at six-hour intervals between each injection in the Luteolin groups. The histopathological findings revealed that Luteolin significantly alleviated uterine injury induced by LPS. Moreover, Luteolin suppressed the synthesis of pro-inflammatory mediators [interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α] while promoting the synthesis of an anti-inflammatory mediator (IL-10) altered by LPS. Furthermore, Luteolin significantly mitigated the LPS-induced oxidative stress by scavenging malondialdehyde (MDA) and reactive oxygen species (ROS), accumulation and boosting the capacity of antioxidant enzyme activities such as superoxide dismutase 1 (SOD1), catalase (CAT), and glutathione peroxidase 1 (Gpx1) in the uterine tissue of mice. Additionally, injection of Luteolin markedly increased the expression of Toll-like receptors (TLR) 4 both at mRNA and protein levels under LPS stimulation. Western blotting and ELISA findings demonstrated that Luteolin suppressed the activation of the NF-κB pathway in response to LPS exposure in the uterine tissue of mice. Notably, Luteolin enhanced the anti-oxidant defense system by activating the Nrf2 signaling pathway under LPS exposure in the uterine tissue of mice. Conclusively, our findings demonstrated that Luteolin effectively alleviated LPS-induced endometritis via modulation of TLR4-associated Nrf2 and NF-κB signaling pathways.

The allostery and modification of hGHRH molecules and specific dimer produced significant fertility effect by proliferating and activating in-situ ovarian mesenchymal stem cells

The negative coordination of growth hormone secretagogue receptor (GHS-R) and growth hormone-releasing hormone receptor (GHRH-R) involves in the repair processes of cellular injury. The allosteric U- or H-like modified GHRH dimer Grinodin and 2Y were comparatively evaluated in normal Kunming mice and hamster infertility models induced by CPA treatment. 1–3–9 µg of Grinodin or 2Y per hamster stem-cell-exhaustion model was subcutaneously administered once a week, respectively inducing 75–69–46 or 45–13–50 % of birth rates. In comparison, the similar mole of human menopausal gonadotropin (hMG) or human growth hormone (hGH) was administered once a day but caused just 25 or 20 % of birth rates. Grinodin induced more big ovarian follicles and corpora lutea than 2Y, hMG, hGH. The hMG-treated group was observed many distorted interstitial cells and more connective tissues and the hGH-treated group had few ovarian follicles. 2Y had a plasma lifetime of 21 days and higher GH release in mice, inducing lower birth rate and stronger individual specificity in reproduction as well as only promoting the proliferation of mesenchymal-stem-cells (MSCs) in the models. In comparison, Grinodin had a plasma lifetime of 30 days and much lower GH release in mice. It significantly promoted the proliferation and activation of ovarian MSCs together with the development of follicles in the models by increasing Ki67 and GHS-R expressions, and decreasing GHRH-R expression in a dose-dependent manner. However, the high GH and excessive estrogen levels in the models showed a dose-dependent reduction in fertility. Therefore, unlike 2Y, the low dose of Grinodin specifically shows low GHS-R and high GHRH-R expressions thus evades GH and estrogen release and improves functions of organs, resulting in an increase of fertility.

MiR-1246-overexpressing exosomes improve UVB-induced photoaging by activating autophagy via suppressing GSK3β.

Stem cell paracrine has shown potential application in skin wound repair and photoaging treatment. Our previous study demonstrated that miR-1246-overexpressing Exosomes (OE-EXs) isolated from adipose-derived stem cells (ADSCs) showed superior photo-protecting effects on UVB-induced photoaging than that of the vector, however, the underlying mechanism was unclear. The simultaneous bioinformatics analysis indicated that miR-1246 showed potential binding sites with GSK3β which acted as a negative regulator for autophagy. This study was aimed to explore whether OE-EXs ameliorate skin photoaging by activating autophagy via targeting GSK3β. The results demonstrated that OE-EXs significantly decreased GSK3β expression, enhanced autophagy flux and autophagy-related proteins like LC3II, while suppressed p62 expression. Meanwhile, OE-EXs markedly reversed the levels of intracellular ROS, MMP-1, procollagen type I and DNA damage in human skin fibroblasts caused by UVB irradiation, but the ameliorating effects were significantly inhibited when 3-Methyladenine (3-MA) was introduced to block the autophagy pathway. Further, OE-EXs could reverse UVB-induced wrinkles, epidermal hyperplasia, and collagen fibers reduction in Kunming mice, nevertheless, the therapeutical effects of OE-EXs were attenuated when it was combinative treated with 3-MA. In conclusion, OE-EXs could cure UVB induced skin photoaging by activating autophagy via targeting GSK3β.

Deoxynivalenol Induces Intestinal Epithelial Barrier Damage through RhoA/ROCK Pathway-Mediated Apoptosis and F-Actin-Associated Tight Junction Disruption.

Deoxynivalenol (DON) poses a serious global food safety risk due to its high toxicity and contamination rate. It disrupts the intestinal epithelial barrier, allowing exogenous toxins to enter the circulation and resulting in sepsis and systemic toxicity. In this research, 32 male Kunming mice and Porcine Small Intestinal Epithelial (IPEC-J2) cells were treated with DON at 0-4.8 mg/kg (7 d) and 0-12 μM (24 h), respectively. Histopathological results revealed that DON disrupted the intestinal epithelial barrier, causing apoptosis and tight junction (TJ) injury. Immunofluorescence and protein expression results showed that DON-induced p53-dependent mitochondrial pathway apoptosis and fibrillar actin (F-actin)-associated TJ injury and that the RhoA/ROCK pathway were activated in mice jejunal tissue and IPEC-J2 cells. Pretreatment with RhoA or ROCK inhibitors (Rosin or Y-27632) maintained DON-induced apoptosis and F-actin-associated TJ injury in IPEC-J2 cells. Thus, DON induces damage to the intestinal epithelial barrier through the RhoA/ROCK pathway-mediated apoptosis and F-actin-associated TJ disruption.

Immune protection of three serine protease inhibitors vaccine in mice against Rhipicephalus sanguineus

Bioactive molecules in tick saliva are considered to be key to successful feeding and further the transmission of tick-borne pathogens. Problems such as pathogen transmission and animal weight loss result in tick infestation can cause tremendous economic losses to the livestock industry. Therefore, the development of a universal tick vaccine is urgently needed. In this paper, three serine protease inhibitor (serpin) proteins RMS-3, L7LRK7 and L7LTU1 were analyzed with bioinformatics methods. Subsequently the proteins were expressed and purified, and inoculated into Kunming mice for immune protection analysis. The amino acid sequence similarities between RMS-3, L7LRK7 and L7LTU1 were up to 90% in Rhipicephalus sanguineus. The recombinant RMS-3 + L7LRK7 + L7LTU1 showed anticoagulant reaction function and could inhibit the activity of CD4+ lymphocytes, when inoculated into Kunming mice. Additionally, After the immunized mice were challenged with Rhipicephalus sanguineus, the percentage of larvae and nymphs that were fully engorged dropped to 40.87% (P < 0.05) and 87.68% (P > 0.05) in the RmS-3 + L7LRK7 immune group, 49.57% (P < 0.01) and 52.06% (P < 0.05) in the RmS-3 + L7LTU1 group, and 45.22% (P < 0.05) and 60.28% (P < 0.05) in the RmS-3 + L7LRK7 + L7LTU1 immune group, in comparison with the control group. These data indicate that RmS-3 + L7LRK7 + L7LTU1 has good immune protection and has the potential to be developed into a vaccine against the larvae and nymphs of R. sanguineus.

Production of iron-enriched yeast and it’s application in the treatment of iron-deficiency anemia

Iron deficiency anemia (IDA) is one of the most serious forms of malnutrition. Wild type strains of Saccharomyces cerevisiae have higher tolerance to inorganic iron and higher iron conversion and accumulation capacity. The aim of this study was to investigate the effect of S. cerevisiae enriched iron as a potential organic iron supplement on mice with iron deficiency anemia. 60 male Kunming mice (KM mice, with strong adaptability and high reproduction rate, it can be widely used in pharmacology, toxicology, microbiology and other research) were randomly divided into normal control group and iron deficiency diet model group to establish IDA model. After the model was established, IDA mice were randomly divided into 5 groups: normal control group, IDA group, organic iron group (ferrous glycinate), inorganic iron group (ferrous sulfate) and S. cerevisiae enriched iron group. Mice in the experimental group were given different kinds of iron by intragastric administration once a day for 4w. The results showed that S. cerevisiae enriched iron had an effective recovery function, and the body weight and hematological parameters of IDA mice returned to normal levels. The activities of superoxide dismutase, glutathione peroxidase and total antioxidant capacity in serum were increased. In addition, the strain no. F8, able to grow in an iron-rich environment, was more effective in alleviating IDA and improving organ indices with fewer side effects compared to ferrous glycinate and ferrous sulfate groups. This study suggests that the iron-rich strain no. F8 may play an important role in improving IDA mice and may be developed as a new iron supplement.

Metformin ameliorates PM2.5-induced functional impairment of placental trophoblasts by inhibiting ferroptosis

To investigate the protective effect of metformin against PM2.5-induced functional impairment of placental trophoblasts and explore the underlying mechanism. Sixteen pregnant Kunming mice were randomly assigned into two groups (n=8) for intratracheal instillation of PBS or PM2.5 suspension at 1.5, 7.5, and 12.5 days of gestation. The pregnancy outcome of the mice was observed, and placental zonal structure and vascular density of the labyrinth area were examined with HE staining, followed by detection of ferroptosis-related indexes in the placenta. In cultured human trophoblasts (HTR8/SVneo cells), the effects of PM2.5 exposure and treatment with metformin on cell viability, proliferation, migration, invasion, and tube formation ability were evaluated using CCK8 assay, EDU staining, wound healing assay, Transwell experiment, and tube formation experiment; the cellular expressions of ferroptosis-related proteins were analyzed using ELISA and Western blotting. M2.5 exposure of the mice during pregnancy resulted in significantly decreased weight and number of the fetuses and increased fetal mortality with a reduced placental weight (all P<0.001). PM2.5 exposure also caused obvious impairment of the placental structure and trophoblast ferroptosis. In cultured HTR8/SVneo cells, PM2.5 significantly inhibited proliferation, migration, invasion, and angiogenesis of the cells by causing ferroptosis. Metformin treatment obviously attenuated PM2.5-induced inhibition of proliferation, migration, invasion, and angiogenesis of the cells, and effectively reversed PM2.5-induced ferroptosis in the trophoblasts as shown by significantly increased intracellular GSH level and SOD activity, reduced MDA and Fe2+ levels, and upregulated GPX4 and SLC7A11 protein expression (P<0.05 or 0.01). PM2.5 exposure during pregnancy causes adverse pregnancy outcomes and ferroptosis and functional impairment of placental trophoblasts in mice, and metformin can effectively alleviate PM2.5-induced trophoblast impairment.

Effect of Bacillus subtilis BS-Z15 metabolite mycosubtilin on body weight gain in mice

Our previous study reported that the metabolite of Bacillus subtilis BS-Z15 n-butanol site could reduce body weight gain in mice, showing anti-obesity effects. This study further demonstrated the effects of purified mycosubtilin on the body weight gain and gut microbiota of Kunming mice. 30 male Kunming white mice were randomly selected into three groups at four weeks of age: Control (group A), gavage-administered with saline daily; n-butanol site treated (group B), gavage-administered with n-butanol site metabolites (90 mg/kg); and mycosubtilin treated (group C), gavage-administered with mycosubtilin (6 mg/kg). Different groups’ gut microbiota compositions were analyzed using high-throughput sequencing technology. The results showed that the effects of mycosubtilin and n-butanol sites were consistent; the treatment groups showed a significant reduction in body weight gain as well as triglyceride and low-density lipoprotein contents as compared to the control group (P &amp;lt;0.05). Moreover, the size and contents of epididymal adipocytes were also significantly reduced (P &amp;lt;0.05), and the gavage administration of mycosubtilin could significantly increase the expression levels of lipolysis gene adipose triglyceride lipase (ATGL) in the mice liver. Mycosubtilin and n-butanol site treatments could significantly alter the composition of the gut microbiota as compared to the physiologic saline treatment. B. subtilis BS-Z15 metabolites may regulate weight gain primarily by mycosubtilin, according to these findings. The mycosubtilin might reduce weight gain in mice by regulating lipid metabolism, thereby reducing fat accumulation and altering the composition of gut microbiota.