FVB/NJ strain as a mouse model for cutaneous leishmaniasis by Leishmania (L.) amazonensis

BACKGROUND Leishmaniases encompass a spectrum of neglected diseases caused by parasites of the genus Leishmania, grouped in two forms: tegumentary and visceral leishmaniasis. OBJECTIVES In this study, we propose Friend Virus B NIH Jackson (FVB/NJ) mouse strain as a new experimental model of infection with Leishmania (Leishmania) amazonensis, the second most prevalent agent of tegumentary leishmaniasis in Brazil. METHODS AND FINDINGS We performed in vitro infections of FVB/NJ macrophages and compared them with BALB/c macrophages, showing that BALB/c cells have higher infection percentages and a higher number of amastigotes/cell. Phagocytosis assays indicated that BALB/c and FVB/NJ macrophages have similar capacity to uptake parasites after 5 min incubations. We also investigated promastigotes' resistance to sera from FVB/NJ and BALB/c and observed no difference between the two sera, even though FVB/NJ has a deficiency in complement components. Finally, we subcutaneously infected FVB/NJ and BALB/c mice with 2 × 106 parasites expressing luciferase. Analysis of lesion development for 12 weeks showed that FVB/NJ and BALB/c mice have similar lesion profiles and parasite burdens. MAIN CONCLUSIONS This work characterises for the first time the FVB/NJ mouse as a new model for tegumentary leishmaniasis caused by Leishmania (L.) amazonensis.

Mechanism of Astragaloside Ⅳ on db/db Mice with Type 2 Diabetes Mellitus and Non-alcoholic Fatty Liver Disease Based on AMPK Signaling Pathway / 中国实验方剂学杂志

ObjectiveTo study the mechanism of astragaloside Ⅳ （AS Ⅳ） on db/db mice with type 2 diabetes mellitus （T2DM） and non-alcoholic fatty liver disease （NAFLD） based on network pharmacology and experimental validation. MethodA total of 24 db/db mice were randomly divided into four groups： model group， metformin group， and low-dose and high-dose AS Ⅳ groups. Six C57 mice were used as the blank group. The low-dose and high-dose AS Ⅳ groups were given AS Ⅳ of 0.015 and 0.030 g·kg-1 by gavage， and the metformin group was given 0.067 g·kg-1 by gavage. The blank and model groups were given equal volumes of distilled water by gavage. After intragastric administration， fasting blood glucose （FBG） was detected， and an oral glucose tolerance test was performed. Serum lipid level and liver histopathology were detected. The target and enrichment pathway of AS Ⅳ for treating T2DM and NAFLD were predicted by network pharmacology， and the main enrichment pathway was verified by molecular biology techniques. The protein expressions of AMPK， p-AMPK， sterol regulatory element-binding protein-1 （SREBP-1）， and fatty acid synthetase （FAS） in liver tissue were detected by Western blot. ResultCompared with the blank group， the levels of body mass， liver weight coefficient， fasting blood glucose， serum total cholesterol， triglyceride， and low-density lipoprotein cholesterol in mice treated with AS Ⅳ were decreased （P<0.05， P<0.01）. The pathology of liver tissue showed significant improvement in lipid accumulation， and imaging results showed that the degree of fatty liver was reduced after AS Ⅳ therapy. Network pharmacological prediction results showed that vascular endothelial growth factor α （VEGFA）， galactoagglutinin 3 （LGALS3）， serine/threonine kinase B2 （Akt2）， RHO-associated coiled-coil protein kinase 1 （ROCK1）， serine/threonine kinase B1 （Akt1）， signaling and transcriptional activator protein （STAT3）， and messtimal epidermal transformation factor （MET） were key targets in "drug-disease" network. The results from the Kyoto encyclopedia of genes and genomes （KEGG） enrichment showed that the AMP-dependent protein kinase （AMPK） signaling pathway was strongly associated with T2DM and NAFLD. Western blot results showed that compared with the blank group， the expression levels of p-AMPK/AMPK in the model group were significantly down-regulated， while those of SREBP-1 and FAS proteins were significantly up-regulated （P<0.01）. Compared with the model group， the expression levels of p-AMPK/AMPK in the metformin group and high-dose AS Ⅳ group were significantly up-regulated， while those of SREBP-1 and FAS proteins were significantly down-regulated （P<0.05， P<0.01）. ConclusionAS Ⅳ regulates the expression of lipid proteins by activating the AMPK signaling pathway， thereby improving lipid metabolism.

Efecto de Tropaeolum Tuberosum o "Mashua" (tropaeolaceae) sobre la expresión génica relacionada a espermatogénesis en ratón

Introducción: Tropaeolum tuberosum, conocido comomashua, es un tubérculo andino que tiene un valor tanto económico como nutritivo para las poblaciones de pocos recursos. Se cree que afecta la fertilidad masculina, porque los hombres andinos lo relacionan con impotencia y disminución de la capacidad fecundante. Estudios hechos en ratas que se alimentaron con mashua demostraron que hubo un 45% de decrecimiento de la tasa testosterona/dihidrotestosterona. El efecto de esta planta en la reproducción está relacionada a su contenido de isotiocianatos, compuestos que se unen covalentemente a las proteínas, las cuales pueden estar directa o indirectamente involucradas en el proceso espermatogénico. El propósito de esta investigación fue evaluar el efecto del extracto acuoso de la mashua sobre la espermatogénesis y la fisiología reproductiva de ratones. Métodos: Se evaluaron los parámetros morfofuncionales in vivo de espermios de ratones (espermatograma) y se cuantificó la expresión de: Cytochrome P450 17α-hydroxylase/17,20-lyase, proteína reguladora de esteroidogénesis aguda, ciclina y protamina, relacionados a la espermatogénesis. Resultados: A los 7, 14 y 21 días de dosificación, se vio afectado el conteo de espermatozoides, así como su motilidad progresiva (MP); por otra parte, se observó un retardo en la maduración de los mismos. En cuanto a la expresión génica, no se encontró diferencias significativas entre la expresión de los dos genes estudiados (cytochrome P450 17α-hydroxylase/17,20-lyase, ciclina). Conclusión: El efecto de la mashua no se da a nivel de la expresión de los genes involucrados en la espermatogénesis, sino a nivel de sus funciones como proteína.

Introduction: Tropaeolum tuberosum, known as "mashua" is an Andean tuber that holds both economic and nutritional value for low-income populations. It is believed that it affects male fertility because Andean men associate it with impotence and decreased fertility. Studies conducted on rats fed with "mashua" showed that there was a 45% decrease in the testosterone/dihydrotestosterone ratio. The effect of this plant on reproduction is related to its content of isothiocyanates, compounds that covalently bind to proteins, which may be directly or indirectly involved in the spermatogenic process. The purpose of this research was to evaluate the effect of the aqueous extract of "mashua" on spermatogenesis and reproductive physiology of mice. Methods: In vivo morphofunctional parameters of mouse sperm (spermatogram) were evaluated and the expression of Cytochrome P450 17α-hydroxylase/17,20-lyase, acute steroidogenesis regulatory protein, cyclin, and protamine related to spermatogenesis was quantified. Results: The results indicated that at 7, 14 and 21 days of dosing, the sperm count was affected, as well as their progressive motility (PM), on the other hand, a delay in their maturation was observed. Regarding gene expression, no significant differences were found between the expression of the two genes studied (Cytochrome P450 17α-hydroxylase/17,20-lyase, Cyclin). Conclusion: The effect of "mashua" does not occur at the level of gene expression involved in spermatogenesis, but at the level of its functions as a protein.

Phytochemical evaluation and anti-psoriatic activity of the ethanolic extract of the leaves of Thespesia populnea

Psoriasis is a chronic, mild and common inflammatory skin condition. Still an ideal treatment for psoriasis, effective, safe, convenient, and economical is not available. In this scenario, the search for suitable alternative treatments with minimal side effects is necessary. Plants can be effective and alternative in this regard. Therefore, this article discusses the leaves of the plants Thespesia populnea (Malvaceae) that are traditionally used in the treatment of psoriasis. The present study aimed to assess anti-psoriatic activity. The dried leaves of the plants were subjected to soxhlation with 95% ethanol and phytochemical studies were performed. The anti-psoriatic activity was evaluated by the Mouse-Tail model. It is a relatively sensitive and reproducible morphometric method that allows quantitative evaluation of the effects of anti-psoriatics through epidermal differentiation. Extracts were applied topically at a dose of 500mg/kg over 14 days and at the end, the animals were sacrificed, longitudinal histological sections were made of the tail skin and the degree of orthokeratosis was determined. It was significantly (P <0.05) increased by the ethanolic extract of Thespesia populnea (52.86±2.86) compared to the control (17.30±4.09). In relative epidermal thickness, the ethanolic extract of Thespesia populnea (92.68±8.8) showed a significant difference (P <0.05) compared to the control (100±10.7). The data obtained suggest that the selected plant has anti-psoriatic activity and confirms its traditional use in the treatment of psoriasis.

Efficacy of mouse nerve growth factor combined with edaravone in the treatment of carbon monoxide poisoning and its influence on oxygen free radical-related indicators / 中国医师进修杂志

Objective:To investigate the therapeutic effect of the combination of mouse nerve growth factor and edaravone in the treatment of carbon monoxide poisoning and its effect on patients′ cognitive function, lactic acid clearance rate, and related indicators of oxygen free radicals.Methods:A selection of 158 patients with carbon monoxide poisoning in the Huxi Hospital Affilliated Jining Medical College from May 2017 to June 2020 were divided into study group (80 cases) and control group (78 cases) according to the treatment plan. Both groups were given conventional treatment. On this basis, the control group was given edaravone, and the study group was given mouse nerve growth factor combined with edaravone, both of which were treated for 2 weeks. The clinical efficacy of the two groups was compared with those before treatment and 1 week and 2 weeks after treatment. Neurological impairment score (NIHSS), disease severity score (APACHE Ⅱ), cognitive function score (MMSE), serum inflammatory factors [tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), C-reactive protein (CRP)], oxygen free radical related indicators [lipid peroxide (LPO), superoxide dismutase (SOD), gluten Glutathione peroxidase (GSH-PX), malondialdehyde (MDA)] levels, blood lactic acid levels before treatment and lactic acid clearance rates after 12 h, 24 h, 72 h treatment, and statistics of adverse reactions and 30-day mortality.Results:The total effective rate of the study group was higher than that of the control group after 2 weeks of treatment [95.00% (76/80) vs. 78.21% (61/78)] ( P<0.05); NIHSS and APACHEⅡ scores of the study group after 1 week and 2 weeks of treatment Lower than the control group: (6.08 ± 1.15) points vs. (8.94 ± 1.71) points, (4.58 ± 0.74) points vs. (6.32 ± 0.93) points and (6.79 ± 1.03) points vs. (8.02 ± 1.47) points, (5.94 ± 1.47) points vs. (7.25 ± 0.94) points, the MMSE score was higher than that of the control group: (22.09 ± 4.35) points vs. (19.34 ± 5.32) points, (26.05 ± 2.37) points vs. (22.47 ± 4.64) points ( P<0.05) After 1 and 2 weeks of treatment, the serum TNF-α, IL-6, CRP, LPO and MDA levels in the study group were lower than those in the control group: (22.62 ± 4.12) ng/L vs. (29.43 ± 4.68) ng/L and (18.21 ± 2.09) ng/L vs. (24.37 ± 3.16) ng/L, (39.67 ± 4.35) ng/L vs. (52.14 ± 5.48) ng/L and (34.83 ± 3.75) ng/L vs. (41.07 ± 4.09) ng/L, (12.63 ± 1.85) mg/L vs. (17.02 ± 2.47) mg/L and (8.27 ± 1.16) mg/L vs. (11.05 ± 1.62) mg/L, (11.06 ± 1.28) μmol/L vs. (15.97 ± 1.85) μmol/L and (8.24 ± 1.12) μmol/L vs. (12.97 ± 1.40) μmol/L, (7.15 ± 1.16) μmol/L vs. (9.02 ± 1.47) μmol/L and (6.12 ± 0.96) μmol/L vs. (7.84 ± 1.25) μmol/L, the levels of SOD and GSH-PX were higher than those in the control group ( P<0.05); the lactate clearance rate in the study group was higher than that in the control group after 12, 24 and 72 h of treatment: (18.49 ± 3.63)% vs. (14.62 ± 2.95)%, (23.19 ± 4.20)% vs. (17.42 ± 3.57)%, (29.86 ± 6.37)% vs. (25.38 ± 5.21)% ( P<0.05); the incidence of adverse reactions in the study group during treatment Compared with the control group, there was no significant difference ( P>0.05); there was no significant difference in the 30-day mortality between the study group and the control group ( P>0.05). Conclusions:The combination of mouse nerve growth factor and edaravone in the treatment of carbon monoxide poisoning can reduce the severity of disease and neurological deficits, improve cognitive function and lactate clearance rate, reduce inflammation and oxidative stress, improve efficacy, and have good safety.

The role of surfactant associated protein-A in silicosis / 中国职业医学

Objective: To investigate the role of surfactant associated protein-A (SP-A) in the development and progression of silicosis, and its mechanism. Methods: Homozygous and heterozygous mice of SP-A knockout of specific pathogen free (SPF) grade were selected for mating, and mice with SP-A-/- genotype were selected for subsequent experiments. SP-A wild-type (SP-A+/+) and SP-A-/- mice were divided into SP-A+/+ control group, SP-A-/- control group, SP-A+/+ silicosis group and SP-A-/- silicosis group with six mice in each group by random number table method. Mice in both silicosis groups were given 20.0 μL 250 g/L silica suspension by tracheal exposure, and mice in both control groups were injected with 0.9% sodium chloride solution at the same volume. On the 28th day after modeling, mice were sacrificed. Lung tissues were used for lung histopathology examination. The apoptosis of alveolar type Ⅱ epithelial cells of mice was detected by TUNEL method. The mRNA expression of B-lymphoblastoma 2 (Bcl-2), Bcl-2 associated X protein (Bax), cysteinyl aspartate specific proteinase (Caspase)-3 and Caspase-9 in lung tissues of mice was detected by quantitative real-time polymerase chain reaction. Results: The histopathological result of mice showed that thickened alveolar septum, scattered silicon nodule and collagen fiber formation were observed in the mice lungs of SP-A+/+ silicosis group, and a large number of inflammatory cells were observed in silicosis nodule, after exposure to silica dust. SP-A-/- silicosis group resulted in a more severe pulmonary inflammation and interstitial fibrosis compared to SP-A+/+ silicosis group. The apoptosis of alveolar type Ⅱ epithelial cells and the mRNA relative expression levels of Bax, Caspase-3 and Caspase-9 in lung tissues of mice in each silicosis groups were increased compared with their control groups (all P<0.05). The above four indexes of mice in SP-A-/- silicosis group were higher than those in SP-A+/+ silicosis group (all P<0.05). There was no significant difference in the expression of Bcl-2 mRNA in lung tissues of these four groups (P>0.05). Conclusion: Knockout of SP-A can aggravate inflammation and pulmonary fibrosis in silicosis model mice, and promote apoptosis of alveolar type Ⅱ epithelial cells. The mechanism may be related to the Bcl-2/Bax/Caspase-3 signaling pathway which affects the apoptosis of mitochondrial pathway.

Transcriptomic profiles of paraquat-induced Parkinson-like changes in mouse brains based on single-cell RNA sequencing / 环境与职业医学

Background Paraquat (PQ) is one of the most widely used herbicides in the world and a risk factor for Parkinson's disease (PD), but the mechanisms underlying PD are poorly understood. Single-cell RNA sequencing (scRNA-seq) technology can study cellular heterogeneity at genetic level, providing insights into the pathogenesis of PQ-induced PD. Objective To analyze the brain cell grouping of PQ-infected mice and the biological processes involved in the subpopulation of PD-like changes cells by scRNA-seq, and to provide clues for revealing potential mechanisms of PQ-induced PD-like changes in mouse brains. Methods Six male 6-week-old C57BL/6 mice were randomly divided into a control group and an experimental group, three mice in each group, and were intraperitoneally injected with 0 (saline) and 10.0 mg·kg−1 PD respectively, once every two days, for 10 consecutive injections for modeling. After infection, mouse brains were taken and scRNA-seq was performed. Cell segmentation was performed according to gene expression characteristics of different cell types, PD-related cell subsets were screened by bioinformatics tools, and gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), gene set enrichment analysis (GSEA), protein interaction network analysis, and transcription factor prediction were performed on their characteristic genes. Finally, GO and KEGG analyses were performed on the differential genes of PD-associated cell subsets between the PQ-treated group and the control group, and the biological processes in which these genes may participate were analyzed. Results The sequencing data met quality control standards, a total of 55779 cells were obtained, and all cell dimensionality reduction analysis results showed that they could be further divided into 37 clusters, including 5 major cell types. Based on the KEGG analysis of the top 20 characteristic genes of each subpopulation, the specifically expressed Cluster 33 subpopulation (dopaminergic neurons) was screened and found to be significantly associated with PD. The results of GO analysis showed that the biological function of this subpopulation mainly enriched neurotransmitter transport and regulation. The results of GSEA analysis showed that the tyrosine metabolic pathway and the ligand-receptor interaction pathway of neural activity in brain tissues were significantly enriched. The analysis of transcriptional regulatory networks showed that 39 transcription factors were expressed differently. The metabolic pathway of the dopamine neuronal subset, endocytosis, Ras-associated protein 1 (Rap1) signaling pathway, and mitogen-activated protein kinase (MAPK) signaling pathway were all affected by PQ exposure, according to further analysis of its effects on this subpopulation. The GO analysis showed that differential genes were involved in biological processes such as ion transport and synaptic assembly regulation, and were involved in the cellular component formation of cytoplasm and synapses. Conclusion This study has initially mapped the transcriptome of single cells in the mouse brain after PQ exposure, and screened out the specific expression of Cluster 33 subgroup (dopaminergic neurons), which is significantly correlated with PD, and its biological function changes may be one of the mechanisms of PD-like changes in the mouse brain induced by PQ.

Tumor cell lysate with low content of HMGB1 enhances immune response of dendritic cells against lung cancer in mice / 南方医科大学学报

OBJECTIVE@#To assess the effect of tumor cell lysate (TCL) with low high-mobility group B1 (HMGB1) content for enhancing immune responses of dendritic cells (DCs) against lung cancer.@*METHODS@#TCLs with low HMGB1 content (LH-TCL) and normal HMGB1 content (NH-TCL) were prepared using Lewis lung cancer (LLC) cells in which HMGB1 was inhibited with 30 nmol/L glycyrrhizic acid (GA) and using LLC cells without GA treatment, respectively. Cultured mouse DCs were exposed to different doses of NH-TCL and LH-TCL, using PBS as the control. Flow cytometry was used to detect the expressions of CD11b, CD11c and CD86 and apoptosis of the stimulated DCs, and IL-12 levels in the cell cultures were detected by ELISA. Mouse spleen cells were co-cultured with the stimulated DCs, and the activation of the spleen cells was assessed by detecting CD69 expression using flow cytometry; TNF-β production in the spleen cells was detected with ELISA. The spleen cells were then co-cultured with LLC cells at the effector: target ratios of 5:1, 10:1 and 20:1 to observe the tumor cell killing. In the animal experiment, C57/BL6 mouse models bearing subcutaneous LLC xenograft received multiple injections with the stimulated DCs, and the tumor growth was observed.@*RESULTS@#The content of HMGB1 in the TCL prepared using GA-treated LLC cells was significantly reduced (P < 0.01). Compared with NH-TCL, LH-TCL showed a stronger ability to reduce apoptosis (P < 0.001) and promote activation and IL- 12 production in the DCs. Compared with those with NH-TCL stimulation, the DCs stimulated with LH-TCL more effectively induced activation of splenic lymphocytes and enhanced their anti-tumor immunity (P < 0.05). In the cell co-cultures, the spleen lymphocytes activated by LH-TCL-stimulated DCs showed significantly enhanced LLC cell killing activity (P < 0.01). In the tumor-bearing mice, injections of LH-TCL-stimulated DCs effectively activated host anti-tumor immunity and inhibited the growth of the tumor xenografts (P < 0.05).@*CONCLUSION@#Stimulation of the DCs with LH-TCL enhances the anti-tumor immune activity of the DCs and improve the efficacy of DCbased immunotherapy for LLC in mice.

Application of PDX model in the evaluation of nano-delivery systems / 药学学报

Malignant tumor is a major disease affecting human health. The nano-delivery system itself has a unique size effect and it can achieve tumor-targeted distribution of drug molecules, improve the therapeutic effect, and reduce the toxic and side effects on normal tissues and cells after functional modification. Patient-derived xenografts (PDX) models can be established by transplanting patient-derived cancer cells or small tumor tissue into immunodeficient mice directly. Compared with the tumor cell line model, this model can preserve the key features of the primary tumor such as histomorphology, heterogeneity, and genetic abnormalities, and keep them stable between generations. PDX models are widely used in drug evaluation, target discovery and biomarker development, especially providing a reliable research platform for the diagnosis and treatment evaluation of nano-delivery systems. This review summarizes the application of several common cancer PDX models in the evaluation of nano-delivery systems, in order to provide references for researchers to perform related research.

Expression of CD47 and its ligands in pregnant mice infected with Toxoplasma gondii during pregnancy / 中国血吸虫病防治杂志

Objective To investigate the dynamic expression of cluster of differentiation 47 (CD47) and its ligands signaling regulatory protein α (SIRPα) and thrombospondin-1 (TSP-1) in mice infected with Toxoplasma gondii in the second and third trimesters.. Methods C57BL/6J mice (6 to 8 weeks old) were used for modeling T. gondii infection in the first trimester, and the pregnant mice were randomly divided into the normal control and infection groups, of 10 mice in each group. Pregnant mice in the infection group were intraperitoneally injected with 150 T. gondii tachyzoites on gestational day (Gd) 6.5, while pregnant mice in the normal control group were intraperitoneally injected with the same volume of physiological saline at the same time. The uterine and placental specimens were collected from all pregnant mice on Gd12.5 and Gd18.5, and the pregnant outcomes were recorded. The pathological damages of mouse uterine and placental specimens were observed using hematoxylin-eosin (HE) staining on Gd12.5 and Gd18.5. The relative expression of CD47, SIRPα, TSP-1, surface antigen 1 (SAG1), interferon-γ (IFN-γ), interleukin-2 (IL-2), IL-4 and IL-13 mRNA was quantified in mouse uterine and placental specimens using real-time fluorescence quantitative PCR (qPCR) assay, and the CD47, SIRPα, TSP-1 expression was determined in mouse uterine and placental specimens using immunohistochemical staining. Results As compared with those in the normal control group, the pregnant mice in the infection group showed back arching, bristling, trembling and listlessness during pregnancy, and several mice presented virginal bleeding and abortion. Pathological examinations showed inflammatory cell infiltration, congestion and necrosis in uterine and placental specimens of pregnant mice in the infection group, a higher abortion rate of pregnant mice was seen in the infection group than in the normal control group on Gd12.5 (χ2 = 20.405, P < 0.001) and Gd18.5 (χ2 = 28.644, P < 0.001). qPCR assay showed significant differences in the expression of CD47, SIRPα, TSP-1, SAG1, INF-γ, IL-2, IL-4 and IL-13 genes in mouse placental specimens between the normal control and infection groups on Gd12.5 and Gd18.5 [F′ (F) = 37.511, 29.337, 97.343, 53.755, 67.188, 21.145, 8.658 and 13.930, all P values < 0.001]. Higher CD47, SIRPα and TSP-1 gene expression was quantified in mouse placental specimens in the infection group than in the normal control group on Gd12.5 (all P values < 0.01), and lower CD47, SIRPα and TSP-1 gene expression was quantified in the infection group than in the normal control group on Gd18.5 (all P values < 0.001), while higher SAG1 gene expression was detected in placental specimens of pregnant mice in the infection group than in the normal control group on Gd12.5 and Gd18.5 (both P values < 0.01). In addition, higher INF-γ and IL-2 expression and lower IL-4 and IL-13 expression was detected in mouse placental specimens in the infection group than in the normal control group on Gd12.5 and Gd18.5 (all P values < 0.001), and there were significant differences in the CD47, SIRPα, TSP-1, SAG1, INF-γ, IL-2, IL-4 and IL-13 gene expression in uterine specimens of pregnant mice between the normal control and infection groups on Gd12.5 and Gd18.5 [H(F′ and F) = 14.951, 25.977, 18.711, 48.595, 39.318, 14.248 and 15.468, all P values < 0.01], and higher CD47 and TSP-1 expression was detected in mouse uterine specimens in the infection group than in the control group on Gd12.5 and Gd18.5 (all P values < 0.01); however, no significant difference was found in the SIRPα expression (P > 0.05). Higher SAG1 expression was detected in uterine specimens of pregnant mice in the infection group than in the normal control group on Gd12.5 and Gd18.5 (both P values < 0.01), and higher INF-γ and IL-2 gene expression and lower IL-4 and IL-13 gene expression was found in the placental specimens of pregnant mice in the infection group than in the normal control group on Gd12.5 and Gd18.5 (all P values < 0.001). Spearman correlation analysis showed that the CD47 gene expression correlated positively with IFN-γ (rs = 0.735, P < 0.05) and IL-2 (rs = 0.655, P < 0.05) and negatively with IL-4 (rs = −0.689, P < 0.05) and IL-13 expression (rs = −0.795, P < 0.05) in the placental specimens of pregnant mice in the infection group on Gd12.5, and the CD47 gene expression correlated negatively with IFN-γ (rs = −0.745, P < 0.05) and IL-2 expression (rs = −0.816, P < 0.05) and positively with IL-4 (rs = 0.704, P < 0.05) and IL-13 (rs = 0.802, P < 0.05) in the placental specimens of pregnant mice in the infection group on Gd18.5. Immunohistochemical staining showed mild CD47, SIRPα and TSP-1 expression in uterine and placental specimens of pregnant mice in the normal control group on Gd12.5 and Gd18.5, strong CD47, SIRPα and TSP-1 expression in the placental specimens of pregnant mice in the infection group on Gd12.5 and strong CD47 and TSP-1 expression in the uterine specimens of pregnant mice in the infection group on Gd12.5. Conclusions T. gondii infection in the first trimester may cause abnormal expression of CD47 and its ligands SIRPα and TSP-1 in the maternal-fetal interface of pregnant mice in the second and third trimesters, which may be associated with the immune escape of T. gondii at the maternal-fetal interface.

Advances in Modeling of Multiple Myeloma in Mice / 中国医学科学院学报

Multiple myeloma(MM)is a systemic malignancy of plasma cells.Nowadays,the basic research on MM is flourishing with the continuous optimization and innovation of mouse models of MM.Heterologous mouse models of MM established with human-derived cells and immunodeficient mice have been applied in assessing drug efficacy,exploring drug resistance mechanisms,and observing tumor-bone marrow microenvironment interactions.In the last decades,the homologous mouse models of MM established with murine-derived cells or gene-editing technologies have been widely used in the research on the pathogenesis and drug development.Additionally,the stable modeling of targeted organ injury will be a key problem to be tackled in this field.This review summarizes the characteristics and application progress of mouse models of MM.

Generation of Mlk3 KO mice by CRISPR/Cas9 and its effect on blood pressure / 生物工程学报

To explore the effect of Mlk3 (mixed lineage kinase 3) deficiency on blood pressure, Mlk3 gene knockout (Mlk3KO) mice were generated. Activities of sgRNAs targeted Mlk3 gene were evaluated by T7 endonuclease I (T7E1) assay. CRISPR/Cas9 mRNA and sgRNA were obtained by in vitro transcription, microinjected into zygote, followed by transferring into a foster mother. Genotyping and DNA sequencing confirmed the deletion of Mlk3 gene. Real- time PCR (RT-PCR), Western blotting or immunofluorescence analysis showed that Mlk3KO mice had an undetectable expression of Mlk3 mRNA or Mlk3 protein. Mlk3KO mice exhibited an elevated systolic blood pressure compared with wild-type mice as measured by tail-cuff system. Immunohistochemistry and Western blotting analysis showed that the phosphorylation of MLC (myosin light chain) was significantly increased in aorta isolated from Mlk3KO mice. Together, Mlk3KO mice was successfully generated by CRISPR/Cas9 system. MLK3 functions in maintaining blood pressure homeostasis by regulating MLC phosphorylation. This study provides an animal model for exploring the mechanism by which Mlk3 protects against the development of hypertension and hypertensive cardiovascular remodeling.

Single-cell transcriptomic atlas of mouse cochlear aging

Progressive functional deterioration in the cochlea is associated with age-related hearing loss (ARHL). However, the cellular and molecular basis underlying cochlear aging remains largely unknown. Here, we established a dynamic single-cell transcriptomic landscape of mouse cochlear aging, in which we characterized aging-associated transcriptomic changes in 27 different cochlear cell types across five different time points. Overall, our analysis pinpoints loss of proteostasis and elevated apoptosis as the hallmark features of cochlear aging, highlights unexpected age-related transcriptional fluctuations in intermediate cells localized in the stria vascularis (SV) and demonstrates that upregulation of endoplasmic reticulum (ER) chaperon protein HSP90AA1 mitigates ER stress-induced damages associated with aging. Our work suggests that targeting unfolded protein response pathways may help alleviate aging-related SV atrophy and hence delay the progression of ARHL.

Noninvasive Tracking of Every Individual in Unmarked Mouse Groups Using Multi-Camera Fusion and Deep Learning / 神经科学通报·英文版

Accurate and efficient methods for identifying and tracking each animal in a group are needed to study complex behaviors and social interactions. Traditional tracking methods (e.g., marking each animal with dye or surgically implanting microchips) can be invasive and may have an impact on the social behavior being measured. To overcome these shortcomings, video-based methods for tracking unmarked animals, such as fruit flies and zebrafish, have been developed. However, tracking individual mice in a group remains a challenging problem because of their flexible body and complicated interaction patterns. In this study, we report the development of a multi-object tracker for mice that uses the Faster region-based convolutional neural network (R-CNN) deep learning algorithm with geometric transformations in combination with multi-camera/multi-image fusion technology. The system successfully tracked every individual in groups of unmarked mice and was applied to investigate chasing behavior. The proposed system constitutes a step forward in the noninvasive tracking of individual mice engaged in social behavior.

Disrupted Maturation of Prefrontal Layer 5 Neuronal Circuits in an Alzheimer's Mouse Model of Amyloid Deposition / 神经科学通报·英文版

Mutations in genes encoding amyloid precursor protein (APP) and presenilins (PSs) cause familial forms of Alzheimer's disease (AD), a neurodegenerative disorder strongly associated with aging. It is currently unknown whether and how AD risks affect early brain development, and to what extent subtle synaptic pathology may occur prior to overt hallmark AD pathology. Transgenic mutant APP/PS1 over-expression mouse lines are key tools for studying the molecular mechanisms of AD pathogenesis. Among these lines, the 5XFAD mice rapidly develop key features of AD pathology and have proven utility in studying amyloid plaque formation and amyloid β (Aβ)-induced neurodegeneration. We reasoned that transgenic mutant APP/PS1 over-expression in 5XFAD mice may lead to neurodevelopmental defects in early cortical neurons, and performed detailed synaptic physiological characterization of layer 5 (L5) neurons from the prefrontal cortex (PFC) of 5XFAD and wild-type littermate controls. L5 PFC neurons from 5XFAD mice show early APP/Aβ immunolabeling. Whole-cell patch-clamp recording at an early post-weaning age (P22-30) revealed functional impairments; although 5XFAD PFC-L5 neurons exhibited similar membrane properties, they were intrinsically less excitable. In addition, these neurons received smaller amplitude and frequency of miniature excitatory synaptic inputs. These functional disturbances were further corroborated by decreased dendritic spine density and spine head volumes that indicated impaired synapse maturation. Slice biotinylation followed by Western blot analysis of PFC-L5 tissue revealed that 5XFAD mice showed reduced synaptic AMPA receptor subunit GluA1 and decreased synaptic NMDA receptor subunit GluN2A. Consistent with this, patch-clamp recording of the evoked L23>L5 synaptic responses revealed a reduced AMPA/NMDA receptor current ratio, and an increased level of AMPAR-lacking silent synapses. These results suggest that transgenic mutant forms of APP/PS1 overexpression in 5XFAD mice leads to early developmental defects of cortical circuits, which could contribute to the age-dependent synaptic pathology and neurodegeneration later in life.

Role of selenoprotein M knockdown in the melatonin antagonism of nickel-induced apoptosis and endoplasmic reticulum stress in mouse heart / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

The aim of this study was to investigate the role of selenoprotein M (SelM) in endoplasmic reticulum stress and apoptosis in nickel-exposed mouse hearts and to explore the detoxifying effects of melatonin. At 21 d after intraperitoneal injection of nickel chloride (NiCl2) and/or melatonin into male wild-type (WT) and SelM knockout (KO) C57BL/6J mice, NiCl2 was found to induce changes in the microstructure and ultrastructure of the hearts of both WT and SelM KO mice, which were caused by oxidative stress, endoplasmic reticulum stress, and apoptosis, as evidenced by decreases in malondialdehyde (MDA) content and total antioxidant capacity (T-AOC) activity. Changes in the messenger RNA (mRNA) and protein expression of genes related to endoplasmic reticulum stress (activating transcription factor 4 (ATF4), inositol-requiring protein 1 (IRE1), c-Jun N-terminal kinase (JNK), and C/EBP homologous protein (CHOP)) and apoptosis (B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X protein (Bax), Caspase-3, Caspase-9, and Caspase-12) were also observed. Notably, the observed damage was worse in SelM KO mice. Furthermore, melatonin alleviated the heart injury caused by NiCl2 in WT mice but could not exert a good protective effect in the heart of SelM KO mice. Overall, the findings suggested that the antioxidant capacity of SelM, as well as its modulation of endoplasmic reticulum stress and apoptosis, plays important roles in nickel-induced heart injury.

Asiatic acid improves insulin secretion of β cells in type 2 diabetes through TNF- α/Mfn2 pathway / 浙江大学学报·医学版

OBJECTIVES@#To investigate the effects and molecular mechanisms of asiatic acid on β-cell function in type 2 diabetes mellitus (T2DM).@*METHODS@#The T2DM model was established by high fat diet and streptozotocin injection in ICR mice, and the effects of asiatic acid on glucose regulation were investigated in model mice. The islets were isolated from palmitic acid-treated diabetic mice. ELISA was used to detect the glucose-stimulated insulin secretion, tumor necrosis factor (TNF)-α and interleukin (IL)-6. ATP assay was applied to measure ATP production, and Western blotting was used to detect protein expression of mature β cell marker urocortin (Ucn) 3 and mitofusin (Mfn) 2. The regulatory effects of asiatic acid on glucose-stimulated insulin secretion (GSIS) and Ucn3 expression were also investigated after siRNA interference with Mfn2 or treatment with TNF-α.@*RESULTS@#Asiatic acid with the dose of 25 mg·kg－1·d－1 had the best glycemic control in T2DM mice and improved the homeostasis model assessment β index. Asiatic acid increased the expression of Mfn2 and Ucn3 protein and improved the GSIS function of diabetic β cells in vitro and in vivo (both P<0.05). Moreover, it improved the ATP production of islets of T2DM mice in vitro (P<0.05). Interfering Mfn2 with siRNA blocked the up-regulation of Ucn3 and GSIS induced by asiatic acid. Asiatic acid inhibited islet TNF-α content and increased Mfn2 and Ucn3 protein expression inhibited by TNF-α.@*CONCLUSIONS@#Asiatic acid improves β cell insulin secretion function in T2DM mice by maintaining the β cell maturity, which may be related to the TNF-α/Mfn2 pathway.

Protective effect of melatonin against oxygen-induced retinopathy: a study based on the HMGB1/NF-κB/NLRP3 axis / 中国当代儿科杂志

OBJECTIVES@#To study the protective effect of melatonin (Mel) against oxygen-induced retinopathy (OIR) in neonatal mice and the role of the HMGB1/NF-κB/NLRP3 axis.@*METHODS@#Neonatal C57BL/6J mice, aged 7 days, were randomly divided into a control group, a model group (OIR group), and a Mel treatment group (OIR+Mel group), with 9 mice in each group. The hyperoxia induction method was used to establish a model of OIR. Hematoxylin and eosin staining and retinal flat-mount preparation were used to observe retinal structure and neovascularization. Immunofluorescent staining was used to measure the expression of proteins and inflammatory factors associated with the HMGB1/NF-κB/NLRP3 axis and lymphocyte antigen 6G. Colorimetry was used to measure the activity of myeloperoxidase.@*RESULTS@#The OIR group had destruction of retinal structure with a large perfusion-free area and neovascularization, while the OIR+Mel group had improvement in destruction of retinal structure with reductions in neovascularization and perfusion-free area. Compared with the control group, the OIR group had significant increases in the expression of proteins and inflammatory factors associated with the HMGB1/NF-κB/NLRP3 axis, the expression of lymphocyte antigen 6G, and the activity of myeloperoxidase (P<0.05). Compared with the OIR group, the OIR+Mel group had significant reductions in the above indices (P<0.05). Compared with the control group, the OIR group had significant reductions in the expression of melatonin receptors in the retina (P<0.05). Compared with the OIR group, the OIR+Mel group had significant increases in the expression of melatonin receptors (P<0.05).@*CONCLUSIONS@#Mel can alleviate OIR-induced retinal damage in neonatal mice by inhibiting the HMGB1/NF-κB/NLRP3 axis and may exert an effect through the melatonin receptor pathway.

Role and mechanism of platelet-derived growth factor BB in thrombocytosis in Kawasaki disease / 中国当代儿科杂志

OBJECTIVES@#To study the role and mechanism of platelet-derived growth factor BB (PDGF-BB) on platelet production in Kawasaki disease (KD) mice and human megakaryocytic Dami cells through in vitro and invivo experiments.@*METHODS@#ELISA was used to measure the expression of PDGF in the serum of 40 children with KD and 40 healthy children. C57BL/6 mice were used to establish a model of KD and were then randomly divided into a normal group, a KD group, and an imatinib group (30 mice in each group). Routine blood test was performed for each group, and the expression of PDGF-BB, megakaryocyte colony forming unit (CFU-MK), and the megakaryocyte marker CD41 were measured. CCK-8, flow cytometry, quantitative real-time PCR, and Western blot were used to analyze the role and mechanism of PDGF-BB in platelet production in Dami cells.@*RESULTS@#PDGF-BB was highly expressed in the serum of KD children (P<0.001). The KD group had a higher expression level of PDGF-BB in serum (P<0.05) and significant increases in the expression of CFU-MK and CD41 (P<0.001), and the imatinib group had significant reductions in the expression of CFU-MK and CD41 (P<0.001). In vitro experiments showed that PDGF-BB promoted Dami cell proliferation, platelet production, mRNA expression of PDGFR-β, and protein expression of p-Akt (P<0.05). Compared with the PDGF-BB group, the combination group (PDGF-BB 25 ng/mL + imatinib 20 μmol/L) had significantly lower levels of platelet production, mRNA expression of PDGFR-β, and protein expression of p-Akt (P<0.05).@*CONCLUSIONS@#PDGF-BB may promote megakaryocyte proliferation, differentiation, and platelet production by binding to PDGFR-β and activating the PI3K/Akt pathway, and the PDGFR-β inhibitor imatinib can reduce platelet production, which provides a new strategy for the treatment of thrombocytosis in KD.

Mechanism of miR-26a-5p/cAMP response element binding protein 1 molecular axis regulating osteogenic differentiation of adipose-derived mesenchymal stem cells / 中国修复重建外科杂志

OBJECTIVE@#To investigate the regulatory effects of miR-26a-5p on the osteogenic differentiation of adipose-derived mesenchymal stem cells (ADSCs) by regulating cAMP response element binding protein 1 (CREB1).@*METHODS@#The adipose tissues of four 3-4 weeks old female C57BL/6 mice were collected and the cells were isolated and cultured by digestion separation method. After morphological observation and identification by flow cytometry, the 3rd-generation cells were subjected to osteogenic differentiation induction. At 0, 3, 7, and 14 days after osteogenic differentiation induction, the calcium deposition was observed by alizarin red staining, ALP activity was detected, miR- 26a-5p and CREB1 mRNA expressions were examined by real-time fluorescence quantitative PCR, and CREB1 protein and its phosphorylation (phospho-CREB1, p-CREB1) level were measured by Western blot. After the binding sites between miR-26a-5p and CREB1 was predicted by the starBase database, HEK-293T cells were used to conduct a dual-luciferase reporter gene experiment to verify the targeting relationship (represented as luciferase activity after 48 hours of culture). Finally, miR-26a-p inhibitor (experimental group) and the corresponding negative control (control group) were transfected into ADSCs. Alizarin red staining, ALP activity, real-time fluorescent quantitative PCR (miR-26a-5p) and Western blot [CREB1, p-CREB1, Runt-related transcription factor 2 (RUNX2), and osteocalcin (OCN)] were performed at 7 and 14 days after osteogenic induction culture.@*RESULTS@#The cultured cells were identified as ADSCs. With the prolongation of osteogenic induction culture, the number of calcified nodules and ALP activity significantly increased ( P<0.05). The relative expression of miR-26a-5p in the cells gradually decreased, while the relative expressions of CREB1 mRNA and protein, as well as the relative expression of p-CREB1 protein were increased. The differences were significant between 7, 14 days and 0 day ( P<0.05). There was no significant difference in p-CREB1/CREB1 between different time points ( P>0.05). The starBase database predicted that miR-26a-5p and CREB1 had targeted binding sequences, and the dual-luciferase reporter gene experiment revealed that overexpression of miR-26a-5p significantly suppressed CREB1 wild-type luciferase activity ( P<0.05). After 7 and 14 days of osteogenic induction, compared with the control group, the number of calcified nodules, ALP activity, and relative expressions of CREB1, p-CREB1, OCN, and RUNX2 proteins in the experimental group significantly increased ( P<0.05). There was no significant difference in p-CREB1/CREB1 between the two groups ( P>0.05).@*CONCLUSION@#Knocking down miR-26a-5p promoted the osteogenic differentiation of ADSCs by up-regulating CREB1 and its phosphorylation.