Fucosterol isolated from Sargassum horneri attenuates allergic responses in immunoglobulin E/bovine serum albumin-stimulated mast cells and passive cutaneous anaphylaxis in mice.

Allergic diseases have become a serious problem worldwide and occur when the immune system overreacts to stimuli. Sargassum horneri is an edible marine brown alga with pharmacological relevance in treating various allergy-related conditions. Therefore, this study aimed to investigate the effect of fucosterol (FST) isolated from S. horneri on immunoglobulin E(IgE)/bovine serum albumin (BSA)-stimulated allergic reactions in mouse bone marrow-derived cultured mast cells (BMCMCs) and passive cutaneous anaphylaxis (PCA) in BALB/c mice. The in silico analysis results revealed the binding site modulatory potential of FST on the IgE and IgE-FcεRI complex. The findings of the study revealed that FST significantly suppressed the degranulation of IgE/BSA-stimulated BMCMCs by inhibiting the release of ß-hexosaminidase and histamine in a dose-dependent manner. In addition, FST effectively decreased the expression of FcεRI on the surface of BMCMCs and its IgE binding. FST dose-dependently downregulated the expression of allergy-related cytokines (interleukin (IL)-4, -5, -6, -13, tumor necrosis factor (TNF)-α, and a chemokine (thymus and activation-regulated chemokine (TARC)) by suppressing the activation of nuclear factor-κB (NF-κB) and Syk-LAT-ERK-Gab2 signaling in IgE/BSA-stimulated BMCMCs. As per the histological analysis results of the in vivo studies with IgE-mediated PCA in BALB/c mice, FST treatment effectively attenuated the PCA reactions. These findings suggest that FST has an immunopharmacological potential as a naturally available bioactive compound for treating allergic reactions.

Isolation of Mouse Neutrophils.

Neutrophils represent the first line of defense against bacterial and fungal pathogens. Indeed, patients with inherited or acquired qualitative and quantitative neutrophil defects are at high risk for developing bacterial and fungal infections and suffering adverse outcomes from these infections. Therefore, research aiming at defining the molecular factors that modulate neutrophil effector function under homeostatic conditions and during infection is essential for devising strategies to augment neutrophil function and improve the outcomes of infected individuals. This article describes reproducible density-gradient-centrifugation-based as well as positive and negative immunomagnetic selection protocols that can be applied in any laboratory to harvest large numbers of highly enriched and highly viable neutrophils from the bone marrow of mice. In another protocol, we also present a method that combines gentle enzymatic tissue digestion with a positive immunomagnetic selection technique or fluorescence-activated cell sorting (FACS) to harvest highly pure and highly viable preparations of neutrophils directly from mouse tissues such as the kidney, the liver, or the spleen. Mouse neutrophils isolated by these protocols can be used to examine several aspects of cellular function ex vivo, including pathogen binding, phagocytosis, and killing, neutrophil chemotaxis, oxidative burst, degranulation, and cytokine production, and for performing neutrophil adoptive transfer experiments. © 2023 Wiley Periodicals LLC. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA. Basic Protocol 1: Isolation of Neutrophils from Mouse Bone Marrow Using Positive Immunomagnetic Separation Alternate Protocol 1: Purification of Neutrophils from Bone Marrow Using Negative Immunomagnetic Separation Alternate Protocol 2: Purification of Neutrophils from Bone Marrow Using Histopaque-Based Density Gradient Centrifugation Basic Protocol 2: Isolation of Neutrophils from Mouse Tissues Using Positive Immunomagnetic Separation Alternate Protocol 3: Isolation of Neutrophils from Mouse Tissues Using FACS.

A review of tamoxifen administration regimen optimization for Cre/loxp system in mouse bone study.

Gene knockout is a technique routinely used in basic experimental research, particularly in mouse skeletal and developmental studies. Tamoxifen-induced Cre/loxp system is known for its temporal and spatial precision and commonly utilized by researchers. However, tamoxifen has been shown its side effects on affecting the phenotype of mouse bone directly. This review aimed to optimize tamoxifen administration regimens including its dosage and duration, to identify an optimal induction strategy that minimizes potential side effects while maintaining recombination efficacy. This study will help researchers in designing gene knockout experiments in bone when using tamoxifen.

Mammalian Ste20-like kinase 1 inhibition as a cellular mediator of anoikis in mouse bone marrow mesenchymal stem cells.

BACKGROUND: The low survival rate of mesenchymal stem cells (MSCs) caused by anoikis, a form of apoptosis, limits the therapeutic efficacy of MSCs. As a proapoptotic molecule, mammalian Ste20-like kinase 1 (Mst1) can increase the production of reactive oxygen species (ROS), thereby promoting anoikis. Recently, we found that Mst1 inhibition could protect mouse bone marrow MSCs (mBMSCs) from H2O2-induced cell apoptosis by inducing autophagy and reducing ROS production. However, the influence of Mst1 inhibition on anoikis in mBMSCs remains unclear. AIM: To investigate the mechanisms by which Mst1 inhibition acts on anoikis in isolated mBMSCs. METHODS: Poly-2-hydroxyethyl methacrylate-induced anoikis was used following the silencing of Mst1 expression by short hairpin RNA (shRNA) adenovirus transfection. Integrin (ITGs) were tested by flow cytometry. Autophagy and ITGα5ß1 were inhibited using 3-methyladenine and small interfering RNA, respectively. The alterations in anoikis were measured by Terminal-deoxynucleoitidyl Transferase Mediated Nick End Labeling and anoikis assays. The levels of the anoikis-related proteins ITGα5, ITGß1, and phospho-focal adhesion kinase and the activation of caspase 3 and the autophagy-related proteins microtubules associated protein 1 light chain 3 II/I, Beclin1 and p62 were detected by Western blotting. RESULTS: In isolated mBMSCs, Mst1 expression was upregulated, and Mst1 inhibition significantly reduced cell apoptosis, induced autophagy and decreased ROS levels. Mechanistically, we found that Mst1 inhibition could upregulate ITGα5 and ITGß1 expression but not ITGα4, ITGαv, or ITGß3 expression. Moreover, autophagy induced by upregulated ITGα5ß1 expression following Mst1 inhibition played an essential role in the protective efficacy of Mst1 inhibition in averting anoikis. CONCLUSION: Mst1 inhibition ameliorated autophagy formation, increased ITGα5ß1 expression, and decreased the excessive production of ROS, thereby reducing cell apoptosis in isolated mBMSCs. Based on these results, Mst1 inhibition may provide a promising strategy to overcome anoikis of implanted MSCs.

Quantitatively Assessing the Respiratory Burst in Innate Immune Cells.

The respiratory burst is a rapid cellular consumption of oxygen resulting in abundant production of reactive oxygen species (ROS), most often associated with primary mediators of innate immunity, neutrophils and macrophages. These myeloid cells convert ROS into potent antimicrobial oxidants that efficiently kill pathogens. The respiratory burst also can have destructive consequences, as ROS are well known to support chronic inflammation and aberrant autoimmune responses. Interestingly, ROS perform conflicting roles in the tumor microenvironment; ROS and derived cytotoxic products can destroy cancer cells but also suppress important tumor-fighting functions of T cells or natural killer cells, or yield mutagenized proteins that can promote tumorigenesis or support tumor cell growth. Moreover, high numbers of neutrophils or macrophages in tumors are associated with poor prognosis. Therefore, accurate and quantitative assays to assess the respiratory burst are an important tool for measuring ROS production by neutrophils or cells of the monocyte/macrophage system, each recently identified in the tumor microenvironment. Described are methods to derive mouse or human models of neutrophils or macrophages, which are then used in a detailed assay to quantitatively measure ROS produced by either cell type using luminescence-enhanced reagents and a multi-well platform along with different stimulants that cause rapid ROS production.

A comparative study of mouse bone marrow mesenchymal stem cells isolated using three easy-to-perform approaches.

Mouse bone marrow mesenchymal stem cells (mBM-MSCs) are important for preclinical tissue regeneration and repair studies. In the present study, we isolated mBM-MSCs using three easy-to-perform methods (whole bone marrow-adherent culture, density-gradient centrifugation, and bone digestion), and then compared the morphology, proliferation, differentiation, and paracrine factor profiles of the isolated mBM-MSCs. Of these three isolation methods, the bone digestion method resulted in the highest quantity of mBM-MSCs with high growth potential and moderate differentiation. Conversely, the mBM-MSCs isolated through the whole bone marrow-adherent method exhibited the lowest potency for proliferation and differentiation. The differentially expressed factors between mBM-MSCs were primarily those involved in immune responses. The highly expressed secreted factors included cytokines/members of the chemokine family, growth factors, and protein binding/proteinase activity. These findings provide a fundamental reference for development of MSC isolation methods.

MiR-20a: a mechanosensitive microRNA that regulates fluid shear stress-mediated osteogenic differentiation via the BMP2 signaling pathway by targeting BAMBI and SMAD6.

Background: MicroRNAs (miRNAs) are crucial regulators of diverse biological and pathological processes. This study aimed to investigate the role of microRNA 20a (miR-20a) in fluid shear stress (FSS)-mediated osteogenic differentiation. Methods: In the present study, we subjected osteoblast MC3T3-E1 cells or mouse bone marrow stromal cells (BMSCs) to single bout short duration FSS (12 dyn/cm2 for 1 hour) using a parallel plate flow system. The expression of miR-20a was quantified by miRNA array profiling and real-time quantitative polymerase chain reaction (qRT-PCR) during FSS-mediated osteogenic differentiation. The expression of osteogenic differentiation markers such as Runt-related transcription factor 2 (RUNX2), alkaline phosphatase (ALP), and SP7 transcription factor (SP7) was detected. Bioinformatics analysis and a luciferase assay were performed to confirm the potential targets of miR-20a. Results: Osteoblast-expressed miR-20a is sensitive to the mechanical environments of FSS, which are differentially up-regulated during steady FSS-mediated osteogenic differentiation. MiR-20a enhances FSS-induced osteoblast differentiation by activating the bone morphogenetic protein 2 (BMP2) signaling pathway. Both BMP and activin membrane-bound inhibitor (BAMBI) and mothers against decapentaplegic family member 6 (SMAD6) are targets of miR-20a that negatively regulate the BMP2 signaling pathway. Conclusions: MiR-20a is a novel mechanosensitive miRNA that can enhance osteoblast differentiation in FSS mechanical environments, implying that this miRNA might be a target for bone tissue engineering and orthodontic bone remodeling for regenerative medicine applications.

CircularRNA CDR1as promotes osteogenic differentiation and angiogenesis related genes expression in mouse bone marrow mesenchymal stem cells / 口腔疾病防治

Objective@# To investigate the effects of over expression and low expression of antisense transcripts of circular RNA cerebellar degeneration associated protein 1 (CDR1as) in Balb/C mouse bone marrow mesenchymal stem cells (BMSCs) on factors related to osteogenesis and angiogenesis.@*Methods@#BMSCs were cultured and identified in vitro. The lentiviral (LV) vector containing the overexpressed and silenced circRNA CDR1as genes and the control lentivirus were respectively transfected into mouse BMSCs, and stable cell lines were screened. The cells were divided into the circRNACDR1as over expression group and the over expression control group, and the CircRNACDR1as low expression group and the low expression control group. The components were stained with Alizarin Red S and alkaline phosphatase after 14 and 21 days of osteoinduction; qRT-PCR was used to detect the target genes circRNA CDR1as, osteogenic differentiation markers alkaline phosphatase (ALP), runt- related transcription factor 2 (RUNX2), osteocalcin (OCN), osteopontin (OPN), osterix(Osx), collagen I (COL-1), and the mRNA expression levels of vascular endothelial grown factor (VEGF) and angiogenin-1 (Ang-1). @*Results@# The results of alizarin red staining and alkaline phosphatase staining showed that the extracellular matrix calcium precipitation and ALP staining area of the over expression experimental group was greater than its control group, and those of the low expression experimental group was less than its control group. As the number of days of osteogenic induction increased, the calcium precipitation and ALP staining in each group also increased. RT-PCR results showed that the mRNA expression levels of circRNA CDR1as, ALP, RUNX2, OCN, OPN, OSX, COL-1, VEGF and Ang-1 in the over expression experimental group BMSCs were significantly increased (P<0.001). In the low expression experimental group, the mRNA expression levels of circRNA CDR1as, ALP, RUNX2, OCN, OPN, OSX, COL-1, VEGF and Ang-1 in BMSCs were significantly reduced (P<0.001). @*Conclusion@# Over expression of the circRNA CDR1as gene promotes the osteogenic differentiation and angiogenesis of BMSCs. Low expression of the circRNA CDR1as gene inhibits the osteogenic differentiation and angiogenesis of BMSCs.

Comparative Evaluation of Mouse Bone Marrow Mesenchymal Stromal Cells Characteristics Cultured in Two Different Supplemented Media

@#Introduction: Preclinical studies on mesenchymal stromal cells (MSC) have allowed the cells to be considered as a promising candidate for cellular therapy. In recent years, conflicting data have been reported regarding various aspects of their characteristics, development and differentiation potential, which may be due to arrange of factors. Among the factors worth investigating is the culture medium formulation. Methods: Here we have made a comparative characterization of mouse bone marrow mesenchymal stromal cells (mBM-MSC) that were cultured using two common supplements, MesenCult™ Stimulatory Supplement (MSS) and fetal bovine serum (FBS), under the same experimental conditions at different passages. Clonogenic potential, cumulative population doubling level (CPDL), population doubling time (PDT), immunophenotyping, differentiation, immunosuppression potentials and chromosome analysis of early and late passages mBM-MSC were assessed. Results: Our findings showed that the CPDL, immunophenotype and immunosuppression potential of mBM-MSC were similar. However, variations were seen in their clonogenicity, population doubling time and differentiation efficacy whereby all of these were enhanced in DMSS. These observations suggest that their genetic make-up may be affected by both supplements upon prolonged culture. Interestingly, this conjecture was supported when chromosomal analysis revealed genetic instability of mBM-MSCs cultured in both supplements. Conclusion: In conclusion, culture medium formulation was shown to cause variations and spontaneous transformation in mBM-MSCs raising concerns on the usage of late passages mBMMSCs in fundamental and preclinical downstream experiments.

Isolation of CD31+ Bone Marrow Endothelial Cells (BMECs) from Mice.

In the bone marrow microenvironment, endothelial cells (ECs) play a pivotal role in regulating the production of both growth and inhibiting factors. They are held together by adherence molecules that interact with hematopoietic progenitor cells. The study of ECs in the hematopoietic stem cell niche is limited due to the lack of efficient protocols for isolation. In this protocol, we developed a two-step approach to extract bone marrow endothelial cells (BMECs) to unlock the challenges researchers face in understanding the function of the endothelial vascular niche in in-vitro studies.

Gamma-irradiation fluctuates the mRNA N6-methyladenosine (m6A) spectrum of bone marrow in hematopoietic injury.

Humans benefit from nuclear technologies but consequently experience nuclear disasters or side effects of iatrogenic radiation. Hematopoietic system injury first arises upon radiation exposure. As an intricate new layer of genetic control, the posttranscriptional m6A modification of RNA has recently come under investigation and has been demonstrated to play pivotal roles in multiple physiological and pathological processes. However, how the m6A methylome functions in the hematopoietic system after irradiation remains ambiguous. Here, we uncovered the time-varying epitranscriptome-wide m6A methylome and transcriptome alterations in γ-ray-exposed mouse bone marrow. 4 Gy γ-irradiation rapidly (5 min and 2 h) and severely impaired the mouse hematopoietic system, including spleen and thymus weight, blood components, tissue inflammation and malondialdehyde (MDA) levels. The m6A content and expression of m6A related enzymes were altered. Gamma-irradiation triggered dynamic and reversible m6A modification profiles and altered mRNA expression, where both m6A fold-enrichment and mRNA expression most followed the (5 min_up/2 h_down) pattern. The CDS enrichment region preferentially upregulated m6A peaks at 5 min. Moreover, the main GO and KEGG pathways were closely related to metabolism and the classical radiation response. Finally, m6A modifications correlated with transcriptional regulation of genes in multiple aspects. Blocking the expression of m6A demethylases FTO and ALKBH5 mitigated radiation hematopoietic toxicity. Together, our findings present the comprehensive landscape of mRNA m6A methylation in the mouse hematopoietic system in response to γ-irradiation, shedding light on the significance of m6A modifications in mammalian radiobiology. Regulation of the epitranscriptome may be exploited as a strategy against radiation damage.

A comprehensive study of the genotoxic and anti-genotoxic effects of homocysteine in HUVECs and mouse bone marrow cells.

Elevated Homocysteine (Hcy) is associated with increased risk of vascular disease, but whether it induces genotoxicity to vascular endothelial cells remains unknown. Here, we conducted a comprehensive study of the genotoxicity, and unexpected anti-genotoxicity, of Hcy by cytokinesis-blocked micronucleus assay in HUVECs and erythrocyte micronucleus test in mouse bone marrow cells. Our experiments led to several important findings. First, while supraphysiological Hcy (SP-Hcy) exhibited remarkable genotoxicity, physiologically-relevant Hcy (PR-Hcy) reduced the basal genotoxicity. Second, among the metabolites of Hcy, cysteine phenocopied the anti-genotoxicity of PR-Hcy and, methionine, S-adenosylhomocysteine and H2S phenocopied the genotoxicity of SP-Hcy. Third, the genotoxicity of SP-Hcy was mitigated by vitamin B6, Fe2+ and Cu2+, but was exacerbated by N-acetylcysteine. Fourth, under pre-, co- or post-treatment protocol, both SP-Hcy and PR-Hcy attenuated the genotoxicity of cisplatin, mitomycin-C, nocodazole or deoxycholate. Finally, 100 and 250 mg/kg Hcy ameliorated cisplatin-induced genotoxicity in bone marrow cells of CF-1 and Kunming mice. Our results suggest that genotoxicity may be one mechanism through which Hcy confers an increased risk for vascular disease, but more importantly, they challenge the long-standing paradigm that Hcy is always harmful to human health. Our study calls for a more systematic effort in understanding the molecular mechanisms underlying the anti-genotoxicity of Hcy.

Evaluation of oral toxicity and genotoxicity of Achyranthis Radix extract.

ETHNOPHARMACOLOGICAL RELEVANCE: The root of Achyranthes bidentata Blume, Achyranthis Radix (AR), is used as a traditional medicine ingredient in East Asia. It has anti-inflammatory, anti-oxidative, and anti-diabetic activities. AIM OF THE STUDY: In the present study, we aimed to evaluate the oral toxicity and genotoxicity of single-dose and 4-week repeated-doses of AR hot water extract (ARE), under the good laboratory practice principles. MATERIALS AND METHODS: For oral toxicity studies, SD rats (n = 5 per sex and group) were administered ARE at concentrations of 500, 1000, and 2000 mg/kg/day once (single dose) or once per day for 4 weeks (repeated dose). The non-clinical genotoxicity study consisted of bacterial reverse mutation using Escherichia coli (WP2 uvrA) and Salmonella typhimurium (TA98, TA100, TA1535, and TA1537), in vitro chromosomal aberration test with Chinese hamster lung cells (CHL/IU), and in vivo mouse bone marrow micronucleus test using bone marrow cells collected from male ICR mice (n = 5) that were orally administered ARE. RESULTS: In the single-dose oral toxicity study, mortality and treatment-related changes in body weight were not observed throughout the study, and the lethal dose was estimated to be > 2000 mg/kg in rats. In the 4-week repeated-dose oral toxicity study, ARE did not induce significant changes in body weight, organ weight, food intake, or hematological and serum biochemical parameters in any group. In the bacterial reverse mutation test, ARE did not induce gene mutations in any tested strain. In the chromosomal aberration test, ARE did not cause chromosomal aberrations. The micronucleus test showed no significant increase in the number of micronucleated polychromatic erythrocytes or the mean ratio of polychromatic to total erythrocytes. CONCLUSIONS: These results showed that ARE does not induce oral toxicity and genotoxicity in the in vivo and in vitro test systems.

Characterization of Microstructural Changes on Biglycan Induced Mice Bone by Low-Field Nuclear Magnetic Resonance.

A NMR spin-spin (T2) relaxation technique has been described for determining the porosity, and the bound water distribution in biglycan induced mouse bone and correlate to their mechanical properties. The technique of low-field proton NMR involves spin-spin relaxation and free induction decay (FID) measurements, and the computational inversion methods for decay data analysis. The CPMG T2 relaxation data can be inverted to T2 relaxation distribution and this distribution then can be transformed to a pore size distribution with the longer relaxation times corresponding to larger pores. The FID T2 relaxation data of dried bone (mobile water removed) can be inverted to T2 relaxation distribution and this distribution then can be transformed to bound and solid-like water distribution with the longest relaxation time corresponding to bound water component. These techniques are applied to quantify apparent changes in porosity, and bound water in controlled and biglycan knockout mouse bone. Overall bone porosity from CPMG T2 relaxation is determined using the calibrated NMR fluid volume from the proton relaxation data divided by overall bone volume. Ignore the physical sample differences, from the inversion FID T2 relaxation spectrum, the ratio of the bound to solid-like water components is used to calibrate the bound water inside bone, and the results can be used to correlated bone mechanical properties. Hydration status significantly affects the toughness of bone, and bound water has been considered as a biomarker for prediction of bone fragility fractures. In addition to the collagen phase, recent evidence shows that glycosaminoglycans (GAGs) of proteoglycans (PGs) in the extracellular matrix also play a pivotal role in regulating the tissue-level hydration status of bone, there by affecting the tissue-level toughness of bone. Furthermore, biglycan and decorin are two major types of PGs in bone reports. Biglycan knockout induced changes in GAGs, bound water, as well as bone tissue toughness. Among all subtypes of PGs, biglycan is identified as a major subtype in the bone mineral matrix. In this study, we used a biglycan mouse model and the obtained bone samples were measured by low-field NMR to determine the bone porosity and bound water changes, and used to predict if knockout of biglycan may affect the amount of bound water and subsequently lead to reduce toughness of bone.

Secretome Analysis of Inductive Signals for BM-MSC Transdifferentiation into Salivary Gland Progenitors.

Severe dry mouth in patients with Sjögren's Syndrome, or radiation therapy for patients with head and neck cancer, significantly compromises their oral health and quality of life. The current clinical management of xerostomia is limited to palliative care as there are no clinically-proven treatments available. Previously, our studies demonstrated that mouse bone marrow-derived mesenchymal stem cells (mMSCs) can differentiate into salivary progenitors when co-cultured with primary salivary epithelial cells. Transcription factors that were upregulated in co-cultured mMSCs were identified concomitantly with morphological changes and the expression of acinar cell markers, such as α-amylase (AMY1), muscarinic-type-3-receptor(M3R), aquaporin-5(AQP5), and a ductal cell marker known as cytokeratin 19(CK19). In the present study, we further explored inductive molecules in the conditioned media that led to mMSC reprogramming by high-throughput liquid chromatography with tandem mass spectrometry and systems biology. Our approach identified ten differentially expressed proteins based on their putative roles in salivary gland embryogenesis and development. Additionally, systems biology analysis revealed six candidate proteins, namely insulin-like growth factor binding protein-7 (IGFBP7), cysteine-rich, angiogenetic inducer, 61(CYR61), agrin(AGRN), laminin, beta 2 (LAMB2), follistatin-like 1(FSTL1), and fibronectin 1(FN1), for their potential contribution to mMSC transdifferentiation during co-culture. To our knowledge, our study is the first in the field to identify soluble inductive molecules that drive mMSC into salivary progenitors, which crosses lineage boundaries.

Investigating the radioprotective effect of sesamol oral consumption against gamma irradiation in mice by micronucleus and alkaline comet assays.

INTRODUCTION: Ionizing radiations induce damage to the bone marrow and blood cells. The aim of this study was to investigate the radioprotective effect of sesamol oral consumption on mice bone marrow and peripheral blood cells using micronuclei and alkaline comet assay. MATERIALS AND METHODS: This experimental-quantitative study was performed on 50 mice in 5 equal groups. One group received 50 mg/kg of sesamol for 7 consecutive days and another group received 100 mg/kg of this extract 2 h before irradiation (3 Gy gamma-rays of Cobalt-60). Irradiation without consuming sesamol and sesamol without irradiation were applied in other groups. Micronucleus and alkaline comet assays were used to measure the DNA damages in bone marrow and peripheral blood cells. The data were statistically compared using one-way ANOVA, and Tukey HSD test. RESULTS: In comparison with the only-irradiated group, oral consumption of sesamol 2 h and 7 days before irradiation decreased remarkably micro-nucleated normochromatid erythrocytes (mnNCE) as 54.5% and 70.4% (P < 0.0001), and micro-nucleated nucleated polychromatid erythrocytes (mnPCE) as 49% and 66% (P < 0.001), respectively. Furthermore, the number of PCE/NCE ratio increased as 47% and 83.6% (P < 0.0001) compared to the irradiated group. The percentage of DNA in tail and apoptotic comets decreased significantly with oral consumption of sesamol (daily or single dose) compared to the irradiated group (P < 0.005). These variations were greater in 7-day continuous pre-irradiation method. CONCLUSION: Sesamol as a radioprotector can reduce the effects of gamma irradiation on mice bone marrow and blood cells. The daily oral consumption of this extract is more effective in comparison with the single consumption before irradiation.

Mouse bone marrow mesenchymal stem cells with distinct p53 statuses display differential characteristics.

Mesenchymal stem cells (MSCs) affect diverse aspects of tumor progression, such as angiogenesis, tumor growth and metastasis. Bone marrow MSCs (BM­MSCs) are fibroblast­like cells with multipotent differentiation ability, that localize to areas of tissue damage, including wounds and solid tumors. The tumor suppressor gene, p53, is functionally involved in cell cycle control, apoptosis and genomic stability, and is mutated and inactivated in most human cancers. The present study aimed to investigate the role of p53 in the biology of BM­MSCs. In the present study, p53 wild­type (p53+/+), knockdown (p53+/­) and knockout (p53­/­) mouse BM­MSCs (mBM­MSCs) were observed to be similar in appearance and in the expression of cell surface biomarkers, but expressed differential p53 protein levels. The p53+/­ and p53­/­ mBM­MSCs demonstrated an increased proliferation rate compared with mBM­MSCs derived from p53+/+ mice. mBM­MSCs from all three groups, representing distinct p53 statuses, were unable to form tumors over a 3­month period in vivo. The adipogenic and osteogenic differentiation of mBM­MSCs was increased in the absence of p53. The colony formation and migratory abilities of p53+/­ and p53­/­ mBM­MSCs were markedly enhanced, and the expression levels of stem cell­associated proteins were significantly increased compared with p53+/+. The expression levels of microRNA (miR)­3152 and miR­337 were significantly increased in p53+/­ and p53­/­ mBM­MSCs, whereas the expression levels of miR­221, miR­155, miR­1288 and miR­4669 were significantly decreased. The expression levels of tumor necrosis factor­α and interferon­Î³­inducible protein­10 were significantly upregulated in the supernatant of p53+/­ and p53­/­ mBM­MSCs. Ubiquitin protein ligase E3 component n­recognin 2, RING­finger protein 31 and matrix metalloproteinase 19 were highly expressed in p53+/­ and p53­/­ mBM­MSCs. The results of the present study indicated that p53 may serve an important role in the biology of mBM­MSCs, and may provide novel insights into the role of cells with different p53 statuses in cancer progression.

Multi-lineage Lung Regeneration by Stem Cell Transplantation across Major Genetic Barriers.

Induction of lung regeneration by transplantation of lung progenitor cells is a critical preclinical challenge. Recently, we demonstrated that robust lung regeneration can be achieved if the endogenous stem cell niches in the recipient's lung are vacated by sub-lethal pre-conditioning. However, overcoming MHC barriers is an additional requirement for clinical application of this attractive approach. We demonstrate here that durable tolerance toward mis-matched lung progenitors and their derivatives can be achieved without any chronic immune suppression, by virtue of co-transplantation with hematopoietic progenitors from the same donor. Initial proof of concept of this approach was attained by transplantation of fetal lung cells comprising both hematopoietic and non-hematopoietic progenitors. Furthermore, an even higher rate of blood and epithelial lung chimerism was attained by using adult lung cells supplemented with bone marrow hematopoietic progenitors. These results lay the foundation for repair of lung injury through a procedure akin to bone marrow transplantation.

Reproducibility and Radiation Effect of High-Resolution In Vivo Micro Computed Tomography Imaging of the Mouse Lumbar Vertebra and Long Bone.

A moderate radiation dose, in vivo µCT scanning protocol was developed and validated for long-term monitoring of multiple skeletal sites (femur, tibia, vertebra) in mice. A customized, 3D printed mouse holder was designed and utilized to minimize error associated with animal repositioning, resulting in good to excellent reproducibility in most cortical and trabecular bone microarchitecture and density parameters except for connectivity density. Repeated in vivo µCT scans of mice were performed at the right distal femur and the 4th lumbar vertebra every 3 weeks until euthanized at 9 weeks after the baseline scan. Comparing to the non-radiated counterparts, no radiation effect was found on trabecular bone volume fraction, osteoblast and osteoblast number/surface, or bone formation rate at any skeletal site. However, trabecular number, thickness, and separation, and structure model index were sensitive to ionizing radiation associated with the µCT scans, resulting in subtle but significant changes over multiple scans. Although the extent of radiation damage on most trabecular bone microarchitecture measures are comparable or far less than the age-related changes during the monitoring period, additional considerations need to be taken to minimize the confounding radiation factors when designing experiments using in vivo µCT imaging for long-term monitoring of mouse bone.

Overexpressed GATA-4 bone marrow-derived mesenchymal stem cell exosomes improve myocardial infarction via miRNA-673-5p/Tsc-1 molecular axis / 医学研究生学报

ObjectiveExosomes secreted by BMSC overexpressing GATA-4 gene (BMSCGATA-4-exosome) can promote the differentiation of BMSC into cardiomyocyte-like cells, thereby improve cardiac function after myocardial infarction. However, the molecular mechanism of BMSCGATA-4-exosome in cardiomyocyte-like cell differentiation is unknown. The effect of the secretion of BMSCGATA-4 exosome from bone marrow mesenchymal stem cells (BMSC) in the differentiation of stem cells into cardiomyocytes was determined in miRNA-673-5p/Tsc-1 axis dependent manner.MethodsMouse models of myocardial infarction were established and divided into seven groups. Simulation group (BMSCmiR-673-5p-mimic exosome), inhibition group (BMSCmiR-673-5p-inhibitor exosome), GATA-4 group (BMSCGATA-4 exosome), empty vector group (BMSCempty vector exosome）, and BMSC group (BMSC exosome) were injected into the tail vein for 48 h, and the untreated and normal mice were used as the control group. Cardiac ultrasound was used to detect cardiac function in each group. miRNA-673-5p expression in myocardial infarction was detected using real-time polymerase chain reaction (RT-PCR). The myocardial tissues were extracted from the same myocardial infarction site. Myocardial-specific molecules, such as α-actin, Desmin, cTnT, and Cx43, were detected using RT-PCR. Western blot was used to determine the expression of the corresponding target gene of miRNA-673-5p, Tsc-1, Erk1/2, and Mef2c proteins.ResultsThe simulation group wan shown the most significantly improved myocardial function (P<0.05) with an expression peak of miRNA-673-5p in cardiomyocytes (P<0.05). The highest content of myocardial-specific molecules including α-actin, Desmin, cTnT, and Cx43 was found in the simulation group. The simulation group had the lowest expression of Tsc-1 in cardiomyocytes (P<0.05).ConclusionOverexpressed BMSCGATA-4 exosomes inhibit Tsc-1 expression through miRNA-673-5p to improve cardiac function during myocardial infarction.