Mice deficient in the ataxia telangiectasia mutated (ATM) kinase have impaired responses to genotoxic and oxidative stressors, predisposing them to develop thymic T-cell lymphoblastic lymphomas (T-LBL) resembling human T-cell acute lymphoblastic leukemias (T-ALL). A previous study identified genomic deletions of the gene encoding PTEN, a negative regulator of PI3K/AKT/mTOR signaling, in a subset of murine ATM-deficient (ATMKO) thymic T-LBLs; however, the frequency and consequences of these deletions were not defined. The present study demonstrates that the majority of established cultures of ATMKO T-LBLs isolated from ATMKO thymi have a variety of genomic Pten alterations and fail to express functional PTEN protein. In addition, all T-LBLs demonstrate constitutive expression of pAKT, indicating the presence of activated AKT signaling, and are sensitive to treatment with the pan-AKT inhibitor MK-2206, suggesting that these lymphomas are dependent on pAKT signaling for their survival. Lastly, ATM-deficiency itself does not cause loss of PTEN or dysregulated AKT signaling, as ATM-deficient non-malignant thymocytes express wild-type levels of PTEN and lack detectable pAKT. This study demonstrates for the first time that the majority of ATM-deficient thymic T-LBLs lose PTEN expression and all depend on AKT signaling for survival, suggesting their potential use as an animal model for PI3K/AKT/MTOR pathway dysfunction in human T-ALL.
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The ovary is crucial for female reproduction and health, as it generates oocytes and secretes sex hormones. Transplantation of mesenchymal stem cells (MSCs) has been shown to alleviate pathological ovarian aging. However, it is unclear whether MSCs could benefit the naturally aging ovary. In this study, we first examined the dynamics of ovarian reserve of Chinese women during perimenopause. Using a naturally aging cynomolgus monkey (Macaca fascicularis) model, we found that transplanting human embryonic stem cells-derived MSC-like cells, which we called M cells, into the aging ovaries significantly decreased ovarian fibrosis and DNA damage, enhanced secretion of sex hormones and improved fertility. Encouragingly, a healthy baby monkey was born after M-cell transplantation. Moreover, single-cell RNA sequencing analysis and in vitro functional validation suggested that apoptosis, oxidative damage, inflammation, and fibrosis were mitigated in granulosa cells and stromal cells following M-cell transplantation. Altogether, these findings demonstrate the beneficial effects of M-cell transplantation on aging ovaries and expand our understanding of the molecular mechanisms underlying ovarian aging and stem cell-based alleviation of this process.
© 2024. The Author(s).

Chronic pancreatitis (CP) is characterized by chronic inflammation and the progressive fibrotic replacement of exocrine and endocrine pancreatic tissue. We identify Treg cells as central regulators of the fibroinflammatory reaction by a selective depletion of FOXP3-positive cells in a transgenic mouse model (DEREG-mice) of experimental CP. In Treg-depleted DEREG-mice, the induction of CP results in a significantly increased stroma deposition, the development of exocrine insufficiency and significant weight loss starting from day 14 after disease onset. In CP, FOXP3+CD25+ Treg cells suppress the type-2 immune response by a repression of GATA3+ T helper cells (Th2), GATA3+ innate lymphoid cells type 2 (ILC2) and CD206+ M2-macrophages. A suspected pathomechanism behind the fibrotic tissue replacement may involve an observed dysbalance of Activin A expression in macrophages and of its counter regulator follistatin. Our study identified Treg cells as key regulators of the type-2 immune response and of organ remodeling during CP. The Treg/Th2 axis could be a therapeutic target to prevent fibrosis and preserve functional pancreatic tissue.
© 2022. The Author(s).

Mutations in bone morphogenetic protein type II receptor (BMPR2) have been found in patients with congenital heart disease-associated pulmonary arterial hypertension (CHD-PAH). Our study aimed to clarify whether deficient BMPR2 signalling acts through downstream effectors, inhibitors of DNA-binding proteins (IDs) during heart development to contribute to the progress of PAH in CHD patients.
To confirm that IDs are downstream effectors of BMPR2 signalling in cardiac mesoderm progenitors (CMPs) and contribute to PAH, we generated cardiomyocyte-specific Id 1/3 knockout mice (Ids cDKO), and 12 out of 25 developed mild PAH with altered haemodynamic indices and pulmonary vascular remodelling. Moreover, we generated ID1 and ID3 double-knockout (IDs KO) human embryonic stem cells that recapitulated the BMPR2 signalling deficiency of CHD-PAH induced pluripotent stem cells (iPSCs).
Cardiomyocytes differentiated from iPSCs derived from CHD-PAH patients with BMP receptor mutations exhibited dysfunctional cardiac differentiation and reduced calcium (Ca2+) transients, as evidenced by confocal microscopy experiments. Smad1/5 phosphorylation and ID1 and ID3 expression were reduced in CHD-PAH iPSCs and in Bmpr2 +/- rat right ventricles. Moreover, ultrasound revealed that 33% of Ids cDKO mice had detectable defects in their ventricular septum and pulmonary regurgitation. Cardiomyocytes isolated from mouse right ventricles also showed reduced Ca2+ transients and shortened sarcomeres. Single-cell RNA sequencing analysis revealed impaired differentiation of CMPs and downregulated USP9X expression in IDs KO cells compared with wild-type cells.
We found that BMPR2 signals through IDs and USP9X to regulate cardiac differentiation, and the loss of ID1 and ID3 expression contributes to cardiomyocyte dysfunction in CHD-PAH patients with BMPR2 mutations.
Copyright ©The authors 2022.

Intervertebral disc (IVD) diseases are common spinal disorders that cause neck or back pain in the presence or absence of an underlying neurological disorder. IVD diseases develop on the basis of degeneration, and there are no established treatments for degeneration. IVD diseases may therefore represent a candidate for the application of regenerative medicine, potentially employing normal human dermal fibroblasts (NHDFs) induced to differentiate into nucleus pulposus (NP) cells. Here, we used a three-dimensional culture system to demonstrate that ectopic expression of MYC, KLF4, NOTO, SOX5, SOX6, and SOX9 in NHDFs generated NP-like cells, detected using Safranin-O staining. Quantitative PCR, microarray analysis, and fluorescence-activated cell sorting revealed that the induced NP cells exhibited a fully differentiated phenotype. These findings may significantly contribute to the development of effective strategies for treating IVD diseases.