Guanylate-binding protein 1 (GBP1) contributes to the immunity of human mesenchymal stromal cells against Toxoplasma gondii.

Mesenchymal stromal cells (MSCs) have recently been shown to play important roles in mammalian host defenses against intracellular pathogens, but the molecular mechanism still needs to be clarified. We confirmed that human MSCs (hMSCs) prestimulated with IFN-γ showed a significant and dose-dependent ability to inhibit the growth of two types of Toxoplasma gondii [type I RH strain with green fluorescent proteins (RH/GFP) or type II PLK strain with red fluorescent proteins (PLK/RED)]. However, in contrast to previous reports, the anti-T. gondii activity of hMSCs was not mediated by indoleamine 2,3-dioxygenase (IDO). Genome-wide RNA sequencing (RNA-seq) analysis revealed that IFN-γ increased the expression of the p65 family of human guanylate-binding proteins (hGBPs) in hMSCs, especially hGBP1. To analyze the functional role of hGBPs, stable knockdowns of hGBP1, -2, and -5 in hMSCs were established using a lentiviral transfection system. hGBP1 knockdown in hMSCs resulted in a significant loss of the anti-T. gondii host defense property, compared with hMSCs infected with nontargeted control sequences. hGBP2 and -5 knockdowns had no effect. Moreover, the hGBP1 accumulation on the parasitophorous vacuole (PV) membranes of IFN-γ-stimulated hMSCs might protect against T. gondii infection. Taken together, our results suggest that hGBP1 plays a pivotal role in anti-T. gondii protection of hMSCs and may shed new light on clarifying the mechanism of host defense properties of hMSCs.

AAV-mediated gene therapy restores natural fertility and improves physical function in the Lhcgr-deficient mouse model of Leydig cell failure.

Leydig cell failure (LCF) caused by gene mutations leads to testosterone deficiency, infertility and reduced physical function. Adeno-associated virus serotype 8 (AAV8)-mediated gene therapy shows potential in treating LCF in the Lhcgr-deficient (Lhcgr-/-) mouse model. However, the gene-treated mice still cannot naturally sire offspring, indicating the modestly restored testosterone and spermatogenesis in AAV8-treated mice remain insufficient to support natural fertility. Recognizing this, we propose that enhancing gene delivery could yield superior results. Here, we screened a panel of AAV serotypes through in vivo transduction of mouse testes and identified AAVDJ as an impressively potent vector for testicular cells. Intratesticular injection of AAVDJ achieved markedly efficient transduction of Leydig cell progenitors, marking a considerable advance over conventional AAV8 vectors. AAVDJ-Lhcgr gene therapy was well tolerated and resulted in significant recovery of testosterone production, substantial improvement in sexual development, and remarkable restoration of spermatogenesis in Lhcgr-/- mice. Notably, this therapy restored fertility in Lhcgr-/- mice through natural mating, enabling the birth of second-generation. Additionally, this treatment led to remarkable improvements in adipose, muscle, and bone function in Lhcgr-/- mice. Collectively, our findings underscore AAVDJ-mediated gene therapy as a promising strategy for LCF and suggest its broader potential in addressing various reproductive disorders.

Disruption of Cdyl gene impairs mouse lung epithelium differentiation and maturation.

CDYL is a chromodomain protein that has been identified as a transcriptional co-repressor that is primarily involved in the formation of repressor complexes which coordinate histone modifications to repress gene transcription. However, most functions and mechanisms of action of the CDYL protein are unknown. In this study, we show that Cdyl-/- mice died of respiratory distress immediately at birth because of distinct abnormalities in distal lung morphogenesis which was characterized by thickened septal and expiratory alveolus atelectasis. Furthermore, Cdyl deletion in mice led to excessive proliferation of immature epithelial cells and an arrest in alveolar epithelium cell differentiation in late gestation which were associated with decreased secretion of mature surfactant proteins in alveolus. Microarray analysis showed that Cdyl gene deletion influenced the expression of genes regulating neuroactive ligand-receptor interactions, cell adhesion, and cell cycle. We validated that Cdyl repressed the transcriptional activity of Cks1 in vitro. In conclusion, Cdyl gene participates in the perinatal respiratory epithelium differentiation and maturation that is important for normal lung function at birth.

Nestin regulates neural stem cell migration via controlling the cell contractility.

Neural stem cells (NSCs) migration is essential for neurogenesis and neuroregeneration after brain injury. Nestin, a widely used marker of NSCs, is expressed abundantly in several cancers, where it may correlate with tumor migration and invasion. However, it is not yet known whether nestin participates in NSC migration. Here, we show that nestin down-regulation significantly inhibits the migration and contraction of murine neural stem cells, but does not obviously influence the proliferation, filamentous actin (F-actin) content, distribution or focal adhesion assembly of these cells. Mechanistically, nestin knockdown was found to affect the phosphorylation state of myosin regulatory light chain (MRLC) and regulate the activity of myosin light chain kinase (MLCK). Co-immunoprecipitation experiments showed that it interacts with MLCK and MRLC. Together, our results indicate that nestin may increase NSC motility via elevating MLCK activity through direct binding and provide new insight into the roles of nestin in NSC migration and repair.

Generation and neuronal differentiation of induced pluripotent stem cells in Cdyl-/- mice.

Chromodomain on Y-like (CDYL) is a chromodomain protein that has sequence homology to members of the enoyl CoA hydratase family. Although the chromodomain of CDYL has been implicated in chromatin remodeling during mammalian spermatogenesis, the function of the Cdyl gene remains unclear. Recently, induced pluripotent stem cells (iPS cells) have been derived from somatic cells by the forced expression of several transcription factors. iPS cells resemble embryonic stem cells in many respects. Therefore, iPS cells represent a powerful tool for the study of gene function. In this study, we have investigated whether iPS cells derived from Cdyl-/- and Cdyl+/+ fibroblasts have different characteristics. Our results showed that both Cdyl-/- and Cdyl+/+ fibroblasts could be induced to become iPS cells, but the spontaneous neuronal differentiation capacity of Cdyl-/- iPS cells was much greater than that of the Cdyl+/+ iPS cells. These results provide some insight into the molecular function of the Cdyl gene, showing that it inhibited the neuronal differentiation of iPS cells.

IFN-γ-primed human bone marrow mesenchymal stem cells induce tumor cell apoptosis in vitro via tumor necrosis factor-related apoptosis-inducing ligand.

Human mesenchymal stem cells hold promise as gene therapy vectors for delivery of various genes to solid tumors for either therapeutic or tumor-tracing purposes. However, whether Mesenchymal stem cells support or inhibit tumor growth remains unknown. Herein, we first observed that mesenchymal stem cells primed with IFN-γ selectively induced the death of tumor cell lines, but not normal cells. We further identified that IFN-γ-primed mesenchymal stem cells expressed tumor necrosis factor-related apoptosis-inducing ligand. Tumor-suppressive effect of IFN-γ-primed mesenchymal stem cells could be blocked by activity neutralization or expression reduction of tumor necrosis factor-related apoptosis-inducing ligand. Moreover, mesenchymal stem cells mediated apoptosis of tumor cells by activating caspase-3 in such cells, via a mechanism involving tumor necrosis factor-related apoptosis-inducing ligand. However, when IFN-γ-primed or non-primed mesenchymal stem cells were co-injected into nude mice along with H460 cells, tumor growth was much faster than that of the group receiving only tumor cells (p<0.01) because of the promoting vascularization effect of mesenchymal stem cells, although IFN-γ-primed mesenchymal stem cells also exerted a certain degree of tumor-suppressive effect compared with non-primed cells (2.79±0.9 g versus 2.03±0.6 g). Collectively, our findings show that IFN-γ-primed human mesenchymal stem cells could induce cancer cell apoptosis via TRAIL-mediated pathway. In addition, our data afford a novel explanation of the opposing effects of hMSCs presence on tumor growth in vitro and in vivo. Thus, more attention needs to be paid when seeking to exploit mesenchymal stem cells as a therapeutic option under the condition of malignant tumor.

[Expression status of diabetes-associated genes in middle and aged cynomolgus monkeys].

A total of 138 middle and aged cynomolgus monkeys (Macaca fascicularis) (above 10 years) were classified into three groups based on fasting plasma glucose (FPG) values, specifically low FPG, normal FPG, and high FPG group. Total cholesterol (TCHO), triglycerides (TG), high density lipoprotein cholesterol (HDL-C), and low density lipoprotein cholesterol (LDL-C) were detected in blood by automatic biochemical analyzer. The mRNA expressions of 37 diabetes-associated genes were analyzed with Real-time PCR in monocytes isolated from monkey peripheral blood. No significant correlation between the four serum lipid indictors HDL-C, LDL-C, TCHO, TG and FPG (P>0.05) were found. However, the expressions of ACE, ACLY, PRKCB1, SLC2A4, SNAP23, VAPA, IGF2BP2, and IFNG were significantly enhanced when FPG increased (P<0.05).