Deciphering Microbiome, Transcriptome, and Metabolic Interactions in the Presence of Probiotic Lactobacillus acidophilus against Salmonella Typhimurium in a Murine Model.

Salmonella enterica serovar Typhimurium (S. Typhimurium), a foodborne pathogen that poses significant public health risks to humans and animals, presents a formidable challenge due to its antibiotic resistance. This study explores the potential of Lactobacillus acidophilus (L. acidophilus 1.3251) probiotics as an alternative strategy to combat antibiotic resistance associated with S. Typhimurium infection. In this investigation, twenty-four BALB/c mice were assigned to four groups: a non-infected, non-treated group (CNG); an infected, non-treated group (CPG); a group fed with L. acidophilus but not infected (LAG); and a group fed with L. acidophilus and challenged with Salmonella (LAST). The results revealed a reduction in Salmonella levels in the feces of mice, along with restored weight and improved overall health in the LAST compared to the CPG. The feeding of L. acidophilus was found to downregulate pro-inflammatory cytokine mRNA induced by Salmonella while upregulating anti-inflammatory cytokines. Additionally, it influenced the expression of mRNA transcript, encoding tight junction protein, oxidative stress-induced enzymes, and apoptosis-related mRNA expression. Furthermore, the LEfSe analysis demonstrated a significant shift in the abundance of critical commensal genera in the LAST, essential for maintaining gut homeostasis, metabolic reactions, anti-inflammatory responses, and butyrate production. Transcriptomic analysis revealed 2173 upregulated and 506 downregulated differentially expressed genes (DEGs) in the LAST vs. the CPG. Functional analysis of these DEGs highlighted their involvement in immunity, metabolism, and cellular development. Kyoto Encyclopedia of Genes and Genome (KEGG) pathway analysis indicated their role in tumor necrosis factor (TNF), mitogen-activated protein kinase (MAPK), chemokine, Forkhead box O (FOXO), and transforming growth factor (TGF-ß) signaling pathway. Moreover, the fecal metabolomic analysis identified 929 differential metabolites, with enrichment observed in valine, leucine, isoleucine, taurine, glycine, and other metabolites. These findings suggest that supplementation with L. acidophilus promotes the growth of beneficial commensal genera while mitigating Salmonella-induced intestinal disruption by modulating immunity, gut homeostasis, gut barrier integrity, and metabolism.

Echinatin mitigates sevoflurane-induced neurotoxicity through regulation of ferroptosis and iron homeostasis.

Surgery and anesthesia are vital medical interventions, but concerns over their potential cognitive side effects, particularly with the use of inhalational anesthetics like sevoflurane, have surfaced. This study delves into the neuroprotective potential of Echinatin against sevoflurane-induced neurotoxicity and the underlying mechanisms. Echinatin, a natural compound, has exhibited anti-inflammatory, antioxidant, and anticancer properties. Sevoflurane, while a popular anesthetic, is associated with perioperative neurocognitive disorders (PND) and neurotoxicity. Our investigation began with cellular models, where Echinatin demonstrated a significant reduction in sevoflurane-induced apoptosis. Mechanistically, we identified ferroptosis, a novel form of programmed cell death characterized by iron accumulation and lipid peroxidation, as a key player in sevoflurane-induced neuronal injury. Echinatin notably suppressed ferroptosis in sevoflurane-exposed cells, suggesting a pivotal role in neuroprotection. Expanding our research to a murine model, we observed perturbations in iron homeostasis, inflammatory cytokines, and antioxidants due to sevoflurane exposure. Echinatin treatment effectively restored iron balance, mitigated inflammation, and preserved antioxidant levels in vivo. Behavioral assessments using the Morris water maze further confirmed Echinatin's neuroprotective potential, as it ameliorated sevoflurane-induced spatial learning and memory impairments. In conclusion, our study unveils Echinatin as a promising candidate for mitigating sevoflurane-induced neurotoxicity. Through the regulation of ferroptosis, iron homeostasis, and inflammation, Echinatin demonstrates significant neuroprotection both in vitro and in vivo. These findings illuminate the potential for Echinatin to enhance the safety of surgical procedures involving sevoflurane anesthesia, minimizing the risk of cognitive deficits and neurotoxicity.

Rosmarinic acid mitigates acrylamide induced neurotoxicity via suppressing endoplasmic reticulum stress and inflammation in mouse hippocampus.

BACKGROUND: Acrylamide (ACR) is a widely used compound that is known to be neurotoxic to both experimental animals and humans, causing nerve damage. The widespread presence of ACR in the environment and food means that the toxic risk to human health can no longer be ignored. Rosmarinic acid (RA), a natural polyphenolic compound extracted from the perilla plant, exhibits anti-inflammatory, antioxidant, and other properties. It has also been demon strated to possess promising potential in neuroprotection. However, its role and potential mechanism in treating ACR induced neurotoxicity are still elusive. PURPOSE: This study explores whether RA can improve ACR induced neurotoxicity and its possible mechanism. METHODS: The behavioral method was used to study RA effect on ACR exposed mice's neurological function. We studied its potential mechanism through metabolomics, Nissl staining, HE staining, immunohistochemical analysis, and Western blot. RESULTS: RA pretreatment reversed the increase in mouse landing foot splay and decrease in spontaneous activity caused by 3 weeks of exposure to 50 mg/kg/d ACR. Further experiments demonstrated that RA could prevent ACR induced neuronal apoptosis, significantly downregulate nuclear factor-κB and tumor necrosis factor-α expression, and inhibit NOD-like receptor protein 3 inflammasome activation, thereby reducing inflammation as confirmed by metabolomics results. Additionally, RA treatment prevented endoplasmic reticulum stress (ERS) caused by ACR exposure, as evidenced by the reversal of significant P-IRE1α,TRAF2,CHOP expression increase. CONCLUSION: RA alleviates ACR induced neurotoxicity by inhibiting ERS and inflammation. These results provide a deeper understanding of the mechanism of ACR induced neurotoxicity and propose a potential new treatment method.

Human neural stem cells promote mitochondrial genesis to alleviate neuronal damage in MPTP-induced cynomolgus monkey models.

Currently, there is no effective treatment for Parkinson's disease (PD), and the regenerative treatment of neural stem cells (NSCs) is considered the most promising method. This study aimed to investigate the protective effect and mechanism of NSCs on neurons in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) induced cynomolgus monkey (Macaca fascicularis) model of PD. We first found that injecting NSCs into the subarachnoid space relieved motor dysfunction in PD cynomolgus monkeys, as well as reduced dopaminergic neuron loss and neuronal damage in the substantia nigra (SN) and striatum. Besides, NSCs decreased 17-estradiol (E2) level, an estrogen, in the cerebrospinal fluid (CSF) of PD cynomolgus monkeys, which shows NSCs may provide neuro-protection by controlling estrogen levels in the CSF. Furthermore, NSCs elevated proliferator-activated receptor gamma coactivator-1 alpha (PGC-1a), mitofusin 2 (MFN2), and optic atrophy 1 (OPA1) expression, three genes mediating mitochondrial biogenesis, in the SN and striatum of PD monkeys. In addition, NSCs suppress reactive oxygen species (ROS) production caused by MPTP, as well as mitochondrial autophagy, therefore preserving dopaminergic neurons. In summary, our findings show that NSCs may preserve dopaminergic and neuronal cells in an MPTP-induced PD cynomolgus monkey model. These protective benefits might be attributed to NSCs' ability of modulating estrogen balance, increasing mitochondrial biogenesis, and limiting oxidative stress and mitochondrial autophagy. These findings add to our understanding of the mechanism of NSC treatment and shed light on further clinical treatment options.

Divergent and Stereoselective Synthesis of Ustusal A, (-)-Albrassitriol, and Elegansin D.

The first synthesis of ustusal A as well as expeditious access to (-)-albrassitriol is described as featuring a singlet oxygen [4 + 2] cycloaddition, achieving the desired stereoselectivity for the 1,4-cis-hydroxyl groups. Transformation of (+)-sclareolide to III followed by a key Horner-Wadsworth-Emmons (HWE) reaction and stereospecific allylic oxidation facilitated the first synthesis of elegansin D. The biological evaluation of these natural products together with seven elegansin D analogues was performed, among which several elegansin D analogues exhibited potential anticancer activity against liver cancer HepG2 cells (IC50 = 11.99-25.58 µM) with low cytotoxicity on normal liver HL7702 cells (IC50 > 100 µM).

Homoharringtonine promotes heart allograft acceptance by enhancing regulatory T cells induction in a mouse model.

BACKGROUND: Homoharringtonine (HHT) is an effective anti-inflammatory, anti-viral, and anti-tumor protein synthesis inhibitor that has been applied clinically. Here, we explored the therapeutic effects of HHT in a mouse heart transplant model. METHODS: Healthy C57BL/6 mice were used to observe the toxicity of HHT in the liver, kidney, and hematology. A mouse heart transplantation model was constructed, and the potential mechanism of HHT prolonging allograft survival was evaluated using Kaplan-Meier analysis, immunostaining, and bulk RNA sequencing analysis. The HHT-T cell crosstalk was modeled ex vivo to further verify the molecular mechanism of HHT-induced regulatory T cells (Tregs) differentiation. RESULTS: HHT inhibited the activation and proliferation of T cells and promoted their apoptosis ex vivo. Treatment of 0.5 mg/kg HHT for 10 days significantly prolonged the mean graft survival time of the allografts from 7 days to 48 days (P <0.001) without non-immune toxicity. The allografts had long-term survival after continuous HHT treatment for 28 days. HHT significantly reduced lymphocyte infiltration in the graft, and interferon-γ-secreting CD4+ and CD8+ T cells in the spleen (P <0.01). HHT significantly increased the number of peripheral Tregs (about 20%, P <0.001) and serum interleukin (IL)-10 levels. HHT downregulated the expression of T cell receptor (TCR) signaling pathway-related genes (CD4, H2-Eb1, TRAT1, and CD74) and upregulated the expression of IL-10 and transforming growth factor (TGF)-ß pathway-related genes and Treg signature genes (CTLA4, Foxp3, CD74, and ICOS). HHT increased CD4+ Foxp3+ cells and Foxp3 expression ex vivo, and it enhanced the inhibitory function of inducible Tregs. CONCLUSIONS: HHT promotes Treg cell differentiation and enhances Treg suppressive function by attenuating the TCR signaling pathway and upregulating the expression of Treg signature genes and IL-10 levels, thereby promoting mouse heart allograft acceptance. These findings may have therapeutic implications for organ transplant recipients, particularly those with viral infections and malignancies, which require a more suitable anti-rejection medication.

SIRT2 inhibitor SirReal2 enhances anti-tumor effects of PI3K/mTOR inhibitor VS-5584 on acute myeloid leukemia cells.

BACKGROUND: Acute myeloid leukemia (AML) is a highly aggressive form of cancer that is frequently diagnosed in adults and small molecule inhibitors have gained significant attention as a potential treatment option for AML. METHODS: The up-regulated genes in AML were identified through bioinformatics analysis. Potential candidate agents were selected through pharmacogenomics analysis. Proteomic experiments were conducted to determine the molecular mechanism after inhibitor treatment. To evaluate drug synergy, both cellular functional experiments and an AML mouse model were used. RESULTS: Through bioinformatics analysis, we conducted a screening for genes that are highly expressed in AML, which led to the identification of nine small-molecule inhibitors. Among these inhibitors, the PI3K/mTOR inhibitor VS-5584 demonstrated significant effectiveness in inhibiting AML cell proliferation at low concentrations. Further testing revealed that VS-5584 induced apoptosis and cycle arrest of AML cells in a dose- and time-dependent manner. Proteomics analysis showed significant changes in protein expression profiles of AML cells after VS-5584 treatment, with 287 proteins being down-regulated and 71 proteins being up-regulated. The proteins that exhibited differential expression were primarily involved in regulating the cell cycle and apoptosis, as determined by GO analysis. Additionally, KEGG analysis indicated that the administration of VS-5584 predominantly affected the P53 and SIRT2 signaling pathways. The use of SIRT2 inhibitor SirReal2 alongside VS-5584 caused a significant reduction in the half-maximal inhibitory concentration (IC50 ) of VS-5584 on AML cells. In vivo, experiments suggested that VS-5584 combined with SirReal2 suppressed tumor growth in the subcutaneous model and extended the survival rate of mice injected with tumor cells via tail vein. CONCLUSIONS: Taken together, the PI3K/mTOR inhibitor VS-5584 was effective in suppressing AML cell proliferation. PI3K/mTOR inhibitor combined with SIRT2 inhibitor exhibited a synergistic inhibitory effect on AML cells. Our findings offer promising therapeutic strategies and drug candidates for the treatment of AML.

Thermos-responsive hydrogel system encapsulated engineered exosomes attenuate inflammation and oxidative damage in acute spinal cord injury.

Introduction: Spinal cord injury (SCI) is a serious and disabling condition, and the effectiveness of conventional treatment is limited, such as supportive treatment and emergency surgery. Exosomes derived from umbilical cord mesenchymal stem cells (UCMSC-Exos) have potential therapeutic effects on SCI but are limited by delivery efficiency. Our study aimed to further investigate the therapeutic effects of miR-138-modified UCMSC-exosomes (Exos-138) following SCI. Methods: We developed an injectable triblock polymer of polyglycolic acid copolymer and polyethylene glycol (PLGA-PEG-PLGA)-loaded temperature-sensitive hydrogel of miR-138-modified stem cell exosomes and characterised its biocompatibility in vitro. In Sprague-Dawley rats with SCI, the hydrogel was injected into the injury site, behavioural scores were measured, and pathological analysis was conducted postoperatively to assess neurological recovery. Results: In vitro, our data demonstrated that miR-138-5p-modified UCMSC-Exos can reduce inflammation levels in BV-2 cells through the NLRP3-caspase1 signalling pathway and reduce neuronal apoptosis by downregulating intracellular reactive oxygen species levels through the Nrf2-keap1 signalling cascade. The results of in vivo experiments showed that the P-Exos-138 hydrogel promoted neurological recovery in rats with SCI. Discussion: Our study explored a novel exosome delivery system that can be a potential therapeutic strategy for SCI. Our study, currently, has theoretical value; however, it can serve as a basis for further investigations on the treatment approaches at various stages of SCI development in inflammation-dependent injury of the central nervous system.

[Human Umbilical Cord-Derived Mesenchymal Stem Cells Prevent Acute Graft-Versus-Host Disease after Hematopoietic Stem Cell Transplantation Via Exosome-Mediated MicroRNA and Its Mechanism].

OBJECTIVE: To explore molecular mechanisms by which umbilical cord-derived mesenchymal stem cells suppress the development of GVHD after bone marrow hematopoietic stem cell transplantation. METHODS: A mouse model of aGVHD was constructed after bone marrow hematopoietic stem cell transplantation, and the umbilical cord-derived mesenchymal stem cells were cultured, and then injected into the aGVHD mouse model, so as to investigate its prophylactic efficacy. Prophylactic effect of the exosomes isolated from umbilical cord-derived mesenchymal stem cells on aGVHD mice was assessed. Sequencing analysis of miRNA from exosomes was performed. RESULTS: aGVHD model was successfully constructed after hematopoietic stem cell transplantation. By injecting umbilical cord-derived mesenchymal stem cells into the GVHD mouse model, it was found that the treatment significantly prolonged survival time of mice compared to the untreated group. Injection exosomes derived from umbilical cord-derived mesenchymal stem cells into the GVHD mouse model significantly prolonged the survival time of mice compared to the untreated group. High-throughput sequencing data showed that microRNA such as miR-21 in exosomes isolated from umbilical cord-derived mesenchymal stem cells, which mainly affected the signaling pathways such as cell adhesion, RNA degradation. CONCLUSION: The umbilical cord-derived mesenchymal stem cells can prevent the occurrence of aGVHD after HSCT, which is mediate by MicroRNA in the exosomes derived from umbilical cord-derived mesenchymal stem cells.

DsbA-L deletion attenuates LPS-induced acute kidney injury by modulating macrophage polarization.

Disulfide bond A oxidoreductase-like protein (DsbA-L) drives acute kidney injury (AKI) by directly upregulating the expression of voltage-dependent anion-selective channels in proximal tubular cells. However, the role of DsbA-L in immune cells remains unclear. In this study, we used an LPS-induced AKI mouse model to assess the hypothesis that DsbA-L deletion attenuates LPS-induced AKI and explore the potential mechanism of DsbA-L action. After 24 hours of LPS exposure, the DsbA-L knockout group exhibited lower serum creatinine levels compared to the WT group. Furthermore, peripheral levels of the inflammatory cytokine IL-6 were decreased. Transcriptomic data analysis revealed a significant down-regulation in the IL-17 and tumor necrosis factor pathways in DsbA-L knockout mice following LPS induction. Metabolomic analysis suggested that arginine metabolism was significantly different between the WT and DsbA-L knockout groups after LPS treatment. Notably, the M1 polarization of macrophages in the kidneys of DsbA-L knockout AKI mice was significantly reduced. Expression of the transcription factors NF-κB and AP-1 was downregulated after DsbA-L knockout. Our results suggest that DsbA-L regulates LPS-mediated oxidative stress, promotes M1 polarization of macrophages, and induces expression of inflammatory factors via the NF-κB/AP-1 pathway.

TIPE2 deficiency prolongs mouse heart allograft survival by facilitating immature DCs-induced Treg generation.

It has been reported that deletion of tumor necrosis factor-α-induced protein-8 like 2 (TNFAIP8L2, TIPE2) facilitates the activation of T-cell receptors. However, the role of TIPE2 in T-cell-mediated acute transplant rejection remains unclear. To illustrate the underlying cellular mechanisms, we transplanted BALB/c hearts into C57BL/6 wild-type (WT) or C57BL/6 mice deficient for TIPE2 (TIPE2-/-) and found that TIPE2-/- recipient mice showed significantly prolonged survival of heart allografts and suppressed maturation of CD11c+ dendritic cells (DCs), which largely abolished the activation and proliferation of alloreactive T cells and their cytotoxic activity. TIPE2-/- DCs increased CD4+CD25+Foxp3+CD127- regulatory T cells (Tregs)generation, likely by inhibiting DCs maturation and CD80 and CD86 expression. Administration of anti-CD25 abolished the allograft survival induced by TIPE2 deficiency. Moreover, TIPE2 deficiency increased IL-10 production in T cells and in recipient serum and allografts. Mechanistic studies revealed that TIPE2-/- restrained the maturation of DCs via inhibition of PI3K/AKT phosphorylation during alloantigen stimulation. Taken together, TIPE2 deficiency in recipient mice inhibited acute rejection by increasing Tregs generated by immature DCs. Thus, TIPE2 could be a therapeutic target for suppressing rejection in organ transplantation.

Aristolochic acid I exposure triggers ovarian dysfunction by activating NLRP3 inflammasome and affecting mitochondrial homeostasis.

Aristolochic acids are widely distributed in the plants of Aristolochiaceae family and Asarum species. Aristolochic acid I (AAI) is the most frequent compound of aristolochic acids, which can accumulate in the soil, and then contaminates crops and water and enters the human body. Research has shown that AAI affects the reproductive system. However, the mechanism of AAI's effects on the ovaries at the tissue level still needs to be clarified. In this research, we found AAI exposure reduced the body and ovarian growth in mice, decreased the ovarian coefficient, prevented follicular development, and increased atretic follicles. Further experiments showed that AAI upregulated nuclear factor-κB and tumor necrosis factor-α expression, activated the NOD-like receptor protein 3 inflammasome, and led to ovarian inflammation and fibrosis. AAI also affected mitochondrial complex function and the balance between mitochondrial fusion and division. Metabolomic results also showed ovarian inflammation and mitochondrial dysfunction due to AAI exposure. These disruptions reduced the oocyte developmental potential by forming abnormal microtubule organizing centers and expressing abnormal BubR1 to destroy spindle assembly. In summary, AAI exposure triggers ovarian inflammation and fibrosis, affecting the oocyte developmental potential.

Functionalized Exosomes Promote Neural Differentiation of P19 Cells by Activating the Wnt Signaling Pathway.

BACKGROUND: Global population growth and population aging continue to accelerate, and lead to a further increase in the risk of neurological diseases worldwide. Extracellular vesicles secreted by mesenchymal stem cells carry many proteins, lipids, and genetic material that mediate cell-to-cell communication and improve therapeutic outcomes for neurological disorders. Stem cells from human exfoliated deciduous teeth are considered a suitable cell source for tissue regeneration, which exerts therapeutic effects via the secretion of exosomes. METHODS: This study was performed to assess the effect of functionalized exosomes on neural differentiation of embryonic carcinoma cell line P19. We stimulated stem cells from human exfoliated deciduous teeth with the glycogen synthase kinase-3ß inhibitor TWS119 and then extracted its exosomes. P19 cells were induced to differentiate using functionalized exosomes, and the biological functions and involved signaling pathways of differentially expressed genes were analyzed by RNA-sequencing. Immunofluorescence techniques detected neuronal specific markers. RESULTS: It was found that TWS119 activated the Wnt signaling pathway in stem cells from human exfoliated deciduous teeth. RNA-sequencing showed that upregulated differentially expressed genes in the functionalized exosome-treated group were responsible for cell differentiation, neurofilament, and structural constituent of the synapse. Kyoto Encyclopedia of Genes and Genomes enrichment analysis revealed that the functionalized exosome-treated group activated the Wnt signaling pathway. Immunofluorescence showed that functionalized exosomes induced neurite outgrowth in P19 cells. CONCLUSION: Our results demonstrated that functionalized exosomes promoted neural differentiation of P19 cells by activating the Wnt signaling pathway.

Quantitative proteomic analysis of exosomes from umbilical cord mesenchymal stem cells and rat bone marrow stem cells.

Exosomes derived from mesenchymal stem cells (MSCs) have been used for cancer treatment, however, an in-depth analysis of the exosomal proteomes is lacking. In this manuscript, we use the diaPASEF (parallel accumulation serial fragmentation combined with the data-independent acquisition) method to quantify exosomes derived from human umbilical cord mesenchymal stem cells (UCMSCs) and rat bone marrow stem cells (BMSCs), resulting in identification of 4200 human proteins and 5362 rat proteins. Comparison of human exosomal proteins and total cellular proteins reveals that some proteins exist in the exosomes exclusively that can be served as potential markers for exosomes. Quantitative proteomic analysis of exosomes from different passages of BMSCs shows that the proteins involved in TGF-ß signaling pathway are regulated in abundance, which could be markers for the therapeutic ability of BMSC exosomes. Collectively, the data presented by this study can be a resource for further study of exosome research.

Triptolide exposure induces oxidative stress and decreases oocyte quality in mouse.

Triptolide is a major active ingredient isolated from the traditional Chinese medicine Tripterygium wilfordii, which has anti-inflammatory, anti-cancer, and immunomodulatory effects. However, in clinical studies, triptolide has toxic side effects on the heart, kidney, liver and reproductive organs. With respect to female reproductive toxicity, damaging effects of triptolide on the ovary have been reported, but it has remained unknown whether oocytes are affected by triptolide. Therefore, this study established a concentration gradient of triptolide exposure in mice using 0 (control), 30, 60, and 90 µg triptolide/kg body weight/day administered by gavage. Triptolide administration for 28 d reduced body weight and ovarian weight and affected the developmental potential of oocytes. The triptolide-treated group exhibited meiotic failure of oocytes due to impaired spindle assembly, chromosome alignment, and tubulin stability. Triptolide was also found to induce mitochondrial dysfunction, autophagy and early apoptosis, iron homeostasis, and abnormal histone modifications. These adverse effects could be associated with oxidative stress induced by triptolide. In conclusion, our findings suggest detrimental effects of triptolide on mouse oocytes and, thus, on female reproduction.

Preparation of carrier-free astaxanthin nanoparticles with improved antioxidant capacity.

Astaxanthin (AST), a red pigment of the carotenoids, has various advantageous biological activities. Nevertheless, the wide application of AST is restricted due to its poor water solubility and highly unsaturated structure. To overcome these limitations, carrier-free astaxanthin nanoparticles (AST-NPs) were fabricated through the anti-solvent precipitation method. The AST-NPs had a small particle size, negative zeta potential and high loading capacity. Analysis of DSC and XRD demonstrated that amorphous AST existed in AST-NPs. In comparison with free AST, AST-NPs displayed enhanced stability during storage. Besides, it also showed outstanding stability when exposed to UV light. Furthermore, the antioxidant capacity of AST-NPs was significantly increased. In vitro release study showed that AST-NPs significantly delayed the release of AST in the releasing medium. These findings indicated that AST-NPs would be an ideal formulation for AST, which could contribute to the development of novel functional foods.

Safety and biodistribution of exosomes derived from human induced pluripotent stem cells.

As a new cell-free therapy, exosomes have provided new ideas for the treatment of various diseases. Human induced pluripotent stem cells (hiPSCs) cannot be used in clinical trials because of tumorigenicity, but the exosomes derived from hiPSCs may combine the advantages of iPSC pluripotency and the nanoscale size of exosomes while avoiding tumorigenicity. Currently, the safety and biodistribution of hiPSC-exosomes in vivo are unclear. Here, we investigated the effects of hiPSC-exosomes on hemolysis, DNA damage, and cytotoxicity through cell experiments. We also explored the safety of vein injection of hiPSC-exosomes in rabbits and rats. Differences in organ distribution after nasal administration were compared in normal and Parkinson's disease model mice. This study may provide support for clinical therapy and research of intravenous and nasal administration of hiPSC-exosomes.

microRNA-93 packaged in extracellular vesicles from mesenchymal stem cells reduce neonatal hypoxic-ischemic brain injury.

OBJECTIVE: Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) have been proposed as a promising strategy for treating ischemia-related diseases. Herein, we probed into the role of miR-93 delivered by BMSC-EVs in hypoxic-ischemic brain injury (HIBD). METHODS: Neonatal HIBD mouse models and hippocampal neuron models of oxygen glucose deprivation (OGD) were constructed. EVs were isolated from the culture medium of bone marrow MSCs (BMSCs). After co-culture of BMSC-EVs with OGD-exposed hippocampal neurons, the effect of microRNA-93 (miR-93) delivered by BMSC-EVs on OGD-induced hippocampal neurons as well as on HIBD in vivo under transfection of miR-93 mimic or inhibitor was explored. The interaction among miR-93, JMJD3, and p53/KLF2 axis was assessed. RESULTS: BMSC-EVs prevented OGD-induced hippocampal neuron apoptosis and inflammation, which was associated with their transfer of miR-93 into the hippocampal neurons. miR-93 targeted JMJD3 and downregulated its expression, thus inhibiting the OGD-induced hippocampal neuron apoptosis. By regulating the JMJD3/p53/KLF2 axis, miR-93 in BMSC-EVs reduced the OGD-induced hippocampal neuron apoptosis in vitro as well as alleviating HIBD in vivo. CONCLUSIONS: The current study highlighted that miR-93 delivered by BMSC-EVs alleviated HIBD in neonatal mice through the JMJD3-dependent p53/KLF2 axis.

Novel immunosuppressive effect of FK506 by upregulation of PD-L1 via FKBP51 in heart transplantation.

The calcineurin inhibitor-FK506-is a first-line immunosuppressant that regulates T cell secretion of IL-2 and other cytokines. However, the mechanism of its protective effect on target cells and its role on tumour recurrence and interaction with anti-tumour immune checkpoint inhibitors, such as PD-L1 blocking, are still unclear. Here, in a murine heart transplantation model, we observed the upregulation of programmed death-ligand 1 (PD-L1) expression by FK506 in both dendritic cells (DCs) and allografts. Blocking PD-L1 during FK506 treatment increased IFN-γ and TNF-α expression, enhanced CD4+ and CD8+ T cell proliferation, and suppressed Treg differentiation. Moreover, PD-L1 decreased T cell infiltration and induced T cell apoptosis in both the spleen and graft. PD-L1 was not only required in FK506-mediated immunosuppression but also upregulated by FK506. Treatment with SAFit2, a FKBP51 selective inhibitor, reduced the expression of PD-L1 on DCs and the grafts and interfered with the immunosuppressive effect of FK506, suggesting that the mechanism depends on FK506-binding protein (FKBP) 51 expression. Overall, our results add new insights into the role of FK506, not only on T cell cytokine secretion but also on co-inhibitory molecular regulation and target cell immune privilege.

miR-150-3p enhances neuroprotective effects of neural stem cell exosomes after hypoxic-ischemic brain injury by targeting CASP2.

Brains are vulnerable to ischemic/hypoxic damage, which are directly caused by stroke, hypoxic-ischemic encephalopathy and other cerebral diseases. Currently, therapeutic strategies against cerebral ischemia and hypoxia are extremely limited. Recent studies have indicated that stem cell-derived exosomes play a neuroprotective role in hypoxic-ischemic brain injury. However, the treatment mechanism remains unclear. In this study, we cultured neural stem cells (NSCs) in vitro successfully. Exosomes isolated from NSCs (NSCs-Ex) inhibited the apoptosis while promoting the proliferation of SH-SY5Y cells both in normal and oxygen-glucose deprivation (OGD) culture conditions. Moreover, in vivo studies demonstrated that NSCs-Ex significantly reduced the infarction area in the middle cerebral artery occlusion (MCAO) model and suppressed the apoptosis of neurons. Furthermore, miR-150-3p was identified as the most abundantly expressed miRNA in exosomes compared to their parent NSCs. The miR-150-3p mimic displayed neuroprotective effects while miR-150-3p inhibitor exacerbated nerve injury both in vivo and in vitro. We further identified CASP2 as a miR-150-3p target. Thus, our data indicate that NSC-Ex facilitate the neuroprotective effects via transfer of miR-150-3p which targets CASP2, thus suppressing neuronal apoptosis after brain injury. Our results suggest that NSCs-Ex prevent cerebral injury by transferring miR-150-3p which promotes neurons proliferation by inhibiting CASP2 signaling pathway.