Autism-relevant behaviors are minimally impacted by conditional deletion ofPtenin oxytocinergic neurons

Excess inflammation and canonical BMP receptor (BMPR) signaling are coinciding hallmarks of the early stages of injury-induced endochondral heterotopic ossification (EHO), especially in the rare genetic disease fibrodysplasia ossificans progressiva (FOP). Multiple inflammatory signaling pathways can synergistically enhance BMP-induced Smad1/5/8 activity in multiple cell types, suggesting the importance of pathway crosstalk in EHO and FOP. Toll-like receptors (TLRs) and IL-1 receptors mediate many of the earliest injury-induced inflammatory signals largely via MyD88-dependent pathways. Thus, the hypothesis that MyD88-dependent signaling is required for EHO was tested in vitro and in vivo using global or Pdgfrα-conditional deletion of MyD88 in FOP mice. As expected, IL-1β or LPS synergistically increased Activin A (ActA)-induced phosphorylation of Smad 1/5 in fibroadipoprogenitors (FAPs) expressing Alk2R206H. However, conditional deletion of MyD88 in Pdgfrα-positive cells of FOP mice did not significantly alter the amount of muscle injury-induced EHO. Even more surprisingly, injury-induced EHO was not significantly affected by global deletion of MyD88. These studies demonstrate that MyD88-dependent signaling is dispensable for injury-induced EHO in FOP mice.

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METTL3-dependent m6A modification programs T follicular helper cell differentiation

Nature Communications ◽

10.1038/s41467-021-21594-6 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Yingpeng Yao ◽

Ying Yang ◽

Wenhui Guo ◽

Lifan Xu ◽

Menghao You ◽

...

Keyword(s):

T Cells ◽

Transcriptional Regulation ◽

Cell Differentiation ◽

Ectopic Expression ◽

Signature Genes ◽

Follicular Helper ◽

Conditional Deletion ◽

A Cell ◽

A Site ◽

Post Transcriptional Regulation

AbstractT follicular helper (TFH) cells are specialized effector CD4+ T cells critical to humoral immunity. Whether post-transcriptional regulation has a function in TFH cells is unknown. Here, we show conditional deletion of METTL3 (a methyltransferase catalyzing mRNA N6-methyladenosine (m6A) modification) in CD4+ T cells impairs TFH differentiation and germinal center responses in a cell-intrinsic manner in mice. METTL3 is necessary for expression of important TFH signature genes, including Tcf7, Bcl6, Icos and Cxcr5 and these effects depend on intact methyltransferase activity. m6A-miCLIP-seq shows the 3′ UTR of Tcf7 mRNA is subjected to METTL3-dependent m6A modification. Loss of METTL3 or mutation of the Tcf7 3′ UTR m6A site results in accelerated decay of Tcf7 transcripts. Importantly, ectopic expression of TCF-1 (encoded by Tcf7) rectifies TFH defects owing to METTL3 deficiency. Our findings indicate that METTL3 stabilizes Tcf7 transcripts via m6A modification to ensure activation of a TFH transcriptional program, indicating a pivotal function of post-transcriptional regulation in promoting TFH cell differentiation.

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BMP2 Is Required for Postnatal Maintenance of Osteochondral Tissues of the Temporomandibular Joint

Cartilage ◽

10.1177/1947603520980158 ◽

2020 ◽

pp. 194760352098015

Author(s):

Mara H. O’Brien ◽

Eliane H. Dutra ◽

Shivam Mehta ◽

Po-Jung Chen ◽

Sumit Yadav

Keyword(s):

Age Groups ◽

Mandibular Condyle ◽

Bone Morphogenetic Protein 2 ◽

Matrix Synthesis ◽

Cartilage Growth ◽

Chondrocyte Proliferation ◽

Conditional Deletion ◽

Morphogenetic Protein

Objective Bone morphogenetic protein 2 (BMP2) plays important roles in cartilage growth and development. Paradoxically, elevated levels of BMP2 leads to hypertrophic differentiation and osteoarthritis of cartilage. We examined the in vivo loss of BMP2 in cells expressing aggrecan of the mandibular condyle and knee. Design Three-week-old BMP2 flox/flox- CreER-positive mice and their Cre-negative littermates were treated with tamoxifen and raised until 3 or 6 months. We also investigated the direct effects of BMP2 on chondrocytes in vitro. Cells from the mandibular condyle of mice were treated with recombinant human BMP2 (rhBMP2) or rhNoggin (inhibitor of BMP2 signaling). Results Conditional deletion of BMP2 caused breakage of the cartilage integrity in the mandibular condyle of mice from both age groups, accompanied by a decrease in cartilage thickness, matrix synthesis, mineralization, chondrocyte proliferation, and increased expression of degeneration markers, while the effects at articular cartilage were not significant. In vitro results revealed that rhBMP2 increased chondrocyte proliferation, mineralization, and differentiation, while noggin induced opposite effects. Conclusions In conclusion, BMP2 is essential for postnatal maintenance of the osteochondral tissues of the mandibular condyle.

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In situ imaging reveals disparity between prostaglandin localization and abundance of prostaglandin synthases

Communications Biology ◽

10.1038/s42003-021-02488-1 ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Kyle D. Duncan ◽

Xiaofei Sun ◽

Erin S. Baker ◽

Sudhansu K. Dey ◽

Ingela Lanekoff

Keyword(s):

Mass Spectrometry Imaging ◽

Rna Localization ◽

Imaging Method ◽

Related Protein ◽

Uterine Tissue ◽

Tissue Localization ◽

Physiological Processes ◽

Conditional Deletion ◽

Regional Abundance

AbstractProstaglandins are important lipids involved in mediating many physiological processes, such as allergic responses, inflammation, and pregnancy. However, technical limitations of in-situ prostaglandin detection in tissue have led researchers to infer prostaglandin tissue distributions from localization of regulatory synthases, such as COX1 and COX2. Herein, we apply a novel mass spectrometry imaging method for direct in situ tissue localization of prostaglandins, and combine it with techniques for protein expression and RNA localization. We report that prostaglandin D2, its precursors, and downstream synthases co-localize with the highest expression of COX1, and not COX2. Further, we study tissue with a conditional deletion of transformation-related protein 53 where pregnancy success is low and confirm that PG levels are altered, although localization is conserved. Our studies reveal that the abundance of COX and prostaglandin D2 synthases in cellular regions does not mirror the regional abundance of prostaglandins. Thus, we deduce that prostaglandins tissue localization and abundance may not be inferred by COX or prostaglandin synthases in uterine tissue, and must be resolved by an in situ prostaglandin imaging.

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Abstract 531: Tie-2/Cre--Mediated Conditional Deletion of Lipid Phosphate Phosphatase-3 Reveals Its Role in Endothelial Cell Apoptosis

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/atvb.32.suppl_1.a531 ◽

2012 ◽

Vol 32 (suppl_1) ◽

Author(s):

Ishita Chatterjee ◽

Kishore K Wary

Keyword(s):

Endothelial Cells ◽

Endothelial Cell ◽

Genome Wide Association Study ◽

Vascular Endothelial Cell ◽

Protein Levels ◽

Conditional Deletion ◽

Transmission Electron ◽

Increased Risk

Rationale: A recent genome-wide association study (GWAS) has linked a frequently occurring variation in the LPP3 (also known as PPAP2b) loci to increased risk of coronary heart disease (CAD). However, the in vivo function of LPP3 in vascular endothelial cell is incompletely understood. Goal: To address the endothelial cell (EC) specific function of Lpp3 in mice. Results: Tie-2/Cre mediated Lpp3 deletion did not affect normal vasculogenesis in early embryonic development, in contrast, in late embryonic stages it led to impaired angiogenesis associated with hemorrhage, edema and late embryonic lethal phenotype. Immunohistochemical staining followed by microscopic analyses of mutant embryos revealed reduced fibronectin and VE-cadherin expression throughout different vascular bed, and increased apoptosis in CD31+ vascular structures. Transmission electron microscopy (TEM) showed the presence of apoptotic endothelial cells and disruption of adherens junctions in mutant embryos. LPP3-knockdown in vitro showed an increase in p53 and p21 protein levels, with concomitant decrease in cell proliferation. LPP3-knockdown also decreased transendothelial electrical resistance (TER), interestingly re-expression of ß-catenin cDNA into LPP3-depleted endothelial cells partially restored the effect of loss of LPP3. Conclusion: These results suggest the ability of LPP3 to regulate survival and apoptotic activities of endothelial cells during patho/physiological angiogenesis.

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