Prenatal exposure to viral pathogens has been known to cause the development of neuropsychiatric disorders in adulthood. Furthermore, COVID-19 has been associated with a variety of neurological manifestations, raising the question of whether in utero SARS-CoV-2 exposure can affect neurodevelopment, resulting in long-lasting behavioral and cognitive deficits. Using a human ACE-2-knock-in mouse model, we have previously shown that prenatal exposure to SARS-CoV-2 at later stages of development leads to fetal brain infection and gliosis in the hippocampus and cortex. In this study, we aimed to determine if infection of the fetal brain results in long-term neuroanatomical alterations of the cortex and hippocampus, as well as any cognitive deficits in adulthood. Here, we show that infected mice developed slower and weighed less in adulthood. We also found altered hippocampal and amygdala volume and aberrant newborn neuron morphology in the hippocampus of adult mice infected in utero. Furthermore, we observed sex-dependent alterations in anxiety-like behavior and locomotion, as well as hippocampal-dependent spatial memory. Taken together, our study revealed long-lasting neurological and cognitive changes as a result of prenatal SARS-CoV-2 infection, identifying a window for early intervention and highlighting the importance of immunization and antiviral intervention in pregnant women.
Courtney L. McMahon, Erin M. Hurley, Aranis Muniz Perez, Manuel Estrada, Daniel J. Lodge, Jenny Hsieh
We present a transcriptomic analysis that provides a better understanding of regulatory mechanisms within the healthy and injured periosteum. The focus of this work is on characterizing early events controlling bone healing during formation of periosteal callus on day 3 post fracture. Building upon our previous findings showing that induced Notch1 signaling in osteoprogenitors leads to better healing, we compared samples in which Notch 1 intracellular domain is overexpressed by periosteal stem/progenitor cells with control intact and fractured periosteum. Molecular mechanisms and changes in skeletal stem/progenitor cells (SSPCs) and other cell populations within the callus, including hematopoietic lineages were determined. Notably, Notch ligands were differentially expressed in endothelial and mesenchymal populations, with Dll4 restricted to endothelial cells, whereas Jag1 was expressed by mesenchymal populations. Targeted deletion of Dll4 in endothelial cells using Cdh5CreER resulted in negative effects on early fracture healing, while deletion in SSPCs using α-smooth muscle actin-CreER did not impact bone healing. Translating these observations into clinically relevant model of bone healing revealed the beneficial effects of delivering Notch ligands alongside osteogenic inducer, BMP2. These findings provide insights into the regulatory mechanisms within the healthy and injured periosteum, paving the way for novel translational approaches to bone healing.
Sanja Novak, Hitoshi Tanigawa, Vijender Singh, Sierra H. Root, Tannin A. Schmidt, Kurt D. Hankenson, Ivo Kalajzic
Dendritic cell inhibitory receptor (DCIR) is a C-type lectin receptor selectively expressed on myeloid cells, including monocytes, macrophage, dendritic cells, and neutrophils. Its role in immune regulation has been implicated in murine models and human genome-wide association studies (GWAS), suggesting defective DCIR function associates with increased susceptibility to autoimmune diseases such as rheumatoid arthritis, lupus and Sjogren’s syndrome. However, little is known about the mechanisms underlying DCIR activation to dampen inflammation. Here, we developed anti-DCIR agonistic antibodies that promote phosphorylation on DCIR’s immune receptor tyrosine-based inhibitory motifs (ITIM) and recruitment of SH2 containing protein tyrosine phosphatase-2 (SHP2) for reducing inflammation. We also explored the inflammation resolution by depleting DCIR+ cells with antibodies. Utilizing a human DCIR knock-in mouse model, we validated the anti-inflammatory properties of the agonistic anti-DCIR antibody in experimental peritonitis and colitis. These findings provide critical evidence for targeting DCIR to develop transformative therapies for inflammatory diseases.
Liang Chen, Suresh Patil, Jeffrey Barbon, James Waire, F. Stephen Laroux, Donna McCarthy, Mishra Pratibha, Suju Zhong, Feng Dong, Karin Orsi, Gunarso Nguyen, Yingli Yang, Nancy Crosbie, Eric Dominguez, Arun Deora, Geertruida Veldman, Susan V. Westmoreland, Liang Jin, Timothy Radstake, Kevin White, Hsi-Ju Wei
The most common subtype of lymphoma globally, diffuse large B-cell lymphoma (DLBCL) is a leading cause of cancer death in people with HIV (HIV+). The restructuring of the T-cell compartment due to HIV infection and antiretroviral therapy (ART) may have implications for modern treatment selection, but current understanding of these dynamic interactions is limited. Here, we investigated the T-cell response to DLBCL by sequencing the T-cell receptor (TCR) repertoire in a cohort of HIV-negative (HIV-), HIV+/ART-experienced and HIV+/ART-naïve DLBCL patients. HIV+/ART-naïve tumor TCR repertoires were more clonal and more distinct from each other than HIV- and HIV+/ART-experienced. Further, increased overlap between tumor and blood TCR repertoires was associated with improved survival and HIV/ART status. Our study describes TCR repertoire characteristics for the first time in an African DLBCL cohort and demonstrates contributions of HIV infection and ART exposure to the DLBCL TCR repertoire.
Sophia M. Roush, Jenny Coelho, Alexander M. Xu, Kaushik Puranam, Marriam Mponda, Edwards Kasonkanji, Maurice Mulenga, Tamiwe Tomoka, Jonathan Galeotti, Amy Brownlee, Hormas Ghadially, Maganizo Chagomerana, Blossom Damania, Matthew Painschab, Akil Merchant, Satish Gopal, Yuri Fedoriw
Immunosuppression is a common feature of esophageal adenocarcinoma (EAC) and has been linked to poor overall survival (OS). We hypothesized that upstream factors might negatively influence CD3 levels and T-cell activity, thus promoting immunosuppression and worse survival. We used clinical data and patient samples of those who progressed from Barrett’s (BE) to dysplasia to EAC, investigated gene (RNAseq), protein (tissue microarray) expression and performed cell biology studies to delineate a pathway impacting CD3 protein stability that might influence EAC outcome. We show that the loss of both CD3-ε expression and CD3+ T-cell number are correlated with worse OS in EAC. The GRAIL (gene related to anergy in lymphocytes) isoform 1 (GRAIL1), which is the prominent isoform in EACs, degrades (ε, γ, δ) CD3s and inactivates T-cells. In contrast, isoform 2 (GRAIL2), which is reduced in EACs, stabilizes CD3s. Further, GRAIL1 mediated CD3 degradation is facilitated by interferon stimulated gene 15 (ISG15), a ubiquitin-like protein. Consequently, either the overexpression of a ligase-dead GRAIL1, ISG15 knockdown, or the overexpression of a conjugation-defective ISG15-LRAA mutant can increase CD3 levels. Together, we identified that an ISG15→GRAIL1→mutant p53 amplification loop negatively influencing CD3 levels and T-cell activity, thus promoting immunosuppression in EAC.
Dyke P. McEwen, Paramita Ray, Derek J. Nancarrow, Zhuwen Wang, Srimathi Kasturirangan, Saeed Abdullah, Ayushi Balan, Rishi Hoskeri, Dafydd Thomas, Theodore S. Lawrence, David G. Beer, Kiran H. Lagisetty, Dipankar Ray
Acute Pancreatitis (AP) is among the most common hospital gastrointestinal diagnosis; understanding the mechanisms underlying the severity of AP are critical for development of new treatment options for this disease. Here, we evaluate the biological function of phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3) in AP pathogenesis in two independent genetically engineered mouse models of AP. PFKFB3 is elevated in AP and severe AP (SAP) and knockout of Pfkfb3 abrogates the severity of alcoholic SAP (FAEE-SAP). Using a combination of genetic, pharmacological, and molecular studies we define the interaction of PFKFB3 with inositol 1,4,5-trisphosphate receptor (IP3R) as a key event mediating this phenomenon. Further analysis demonstrated that the interaction between PFKFB3 and IP3R promotes FAEE-SAP severity by altering intracellular calcium homeostasis in acinar cells. Together our results support a PFKFB3-driven mechanism controlling AP pathobiology and define this enzyme as a therapeutic target to ameliorate the severity of this dismal condition.
Tan Zhang, Shengchuan Chen, Liang Li, Yuepeng Jin, Siying Liu, Zhu Liu, Fengyu Shi, Lifen Xie, Panpan Guo, Andrew C. Cannon, Akmal Ergashev, Haiping Yao, Chaohao Huang, Baofu Zhang, Lijun Wu, Hongwei Sun, Siming Chen, Yunfeng Shan, Zhengping Yu, Ezequiel J. Tolosa, Jianghuai Liu, Martin E. Fernandez-Zapico, Feng Ma, Gang Chen
Caloric restriction improves metabolic health, but is often complicated by bone loss. We studied bone parameters in humans during a 10-day fast and identified candidate metabolic regulators of bone turnover. P1NP, a bone formation marker, decreased within 3 days of fasting. Whereas dual-energy X-ray absorptiometry measures of bone mineral density were unchanged after 10 days of fasting, high-resolution peripheral quantitative CT demonstrated remodeling of bone microarchitecture. Pathway analysis of longitudinal metabolomics data identified one-carbon metabolism as fasting-dependent. In cultured osteoblasts, we tested the functional significance of one-carbon metabolites modulated by fasting, finding that methionine — which surged after 3 days of fasting — impacted markers of osteoblast cell state in a concentration dependent manner, in some instances exhibiting a U-shaped response with both low and high concentrations driving putative anti-bone responses. Administration of methionine to mice for 5 days recapitulated some fasting effects on bone, including a reduction in serum P1NP. In conclusion, a 10-day fast in humans led to remodeling of bone microarchitecture, potentially mediated by a surge in circulating methionine. These data support an emerging model that points to a window of optimal methionine exposure for bone health.
Tânia Amorim, Naveen G.V. Kumar, Natalie L. David, William Dion, Trishya Pagadala, Nandini K. Doshi, Bokai Zhu, Andrey Parkhitko, Matthew L. Steinhauser, Pouneh K. Fazeli
Pathogenic variants in SCN8A, which encodes the voltage-gated sodium (NaV) channel NaV1.6, associate with neurodevelopmental disorders including developmental and epileptic encephalopathy. Previous approaches to determine SCN8A variant function may be confounded by use of a neonatal-expressed alternatively spliced isoform of NaV1.6 (NaV1.6N), and engineered mutations rendering the channel tetrodotoxin (TTX) resistant. We investigated the impact of SCN8A alternative splicing on variant function by comparing the functional attributes of 15 variants expressed in two developmentally regulated splice isoforms (NaV1.6N, NaV1.6A). We employed automated patch clamp recording to enhance throughput, and developed a novel neuronal cell line (ND7/LoNav) with low levels of endogenous NaV current to obviate the need for TTX-resistance mutations. Expression of NaV1.6N or NaV1.6A in ND7/LoNav cells generated NaV currents with small but significant differences in voltage-dependence of activation and inactivation. TTX-resistant versions of both isoforms exhibited significant functional differences compared to the corresponding wild-type (WT) channels. We demonstrated that many of the 15 disease-associated variants studied exhibited isoform-dependent functional effects, and that many of the studied SCN8A variants exhibited functional properties that were not easily classified as either gain- or loss-of-function. Our work illustrated the value of considering molecular and cellular context when investigating SCN8A variants.
Carlos G. Vanoye, Tatiana V. Abramova, Jean-Marc Dekeyser, Nora F. Ghabra, Madeleine J. Oudin, Christopher B. Burge, Ingo Helbig, Christopher H. Thompson, Alfred L. George Jr.
Hypotrichosis is a genetic disorder which characterized by a diffuse and progressive loss of scalp and/or body hair. Nonetheless, the causative genes for several affected individuals remain elusive, and the underlying mechanisms have yet to be fully elucidated. Here, we discovered a dominant variant in ADAM17 gene caused hypotrichosis with woolly hair. Adam17 (p.D647N) knock-in mice model mimicked the hair abnormality in patients. ADAM17 (p.D647N) mutation led to hair follicle stem cells (HFSCs) exhaustion and caused abnormal hair follicles, ultimately resulting in alopecia. Mechanistic studies revealed that ADAM17 binds directly to E3 ubiquitin ligase TRIM47. ADAM17 (p.D647N) variant enhanced the association between ADAM17 and TRIM47, leading to an increase in ubiquitination and subsequent degradation of ADAM17 protein. Furthermore, reduced ADAM17 protein expression affected Notch signaling pathway, impairing the activation, proliferation, and differentiation of HFSCs during hair follicle regeneration. Overexpression of NICD rescued the reduced proliferation ability caused by Adam17 variant in primary fibroblast cells.
Xiaoxiao Wang, Chaolan Pan, Luyao Zheng, Jianbo Wang, Quan Zou, Peiyi Sun, Kaili Zhou, Anqi Zhao, Qiaoyu Cao, Wei He, Yumeng Wang, Ruhong Cheng, Zhirong Yao, Si Zhang, Hui Zhang, Ming Li
Alloreactive memory, unlike naïve, CD8+ T cells resist transplantation tolerance protocols and are a critical barrier to long-term graft acceptance in the clinic. We here show that semi-allogeneic pregnancy successfully reprogrammed memory fetus/graft-specific CD8+ T cells (TFGS) towards hypofunction. Female C57BL/6 mice harboring memory CD8+ T cells generated by the rejection of BALB/c skin grafts and then mated with BALB/c males achieved rates of pregnancy comparable to naive controls. Post-partum fetus/graft-specific CD8+ T cells (TFGS) from skin-sensitized dams upregulated expression of T cell exhaustion (TEX) markers (Tox, Eomes, PD-1, TIGIT, and Lag3). Transcriptional analysis corroborated an enrichment of canonical T exhaustion (TEX) genes in post-partum memory TFGS and additionally, revealed a downregulation of a subset of memory-associated transcripts. Strikingly, pregnancy induced extensive epigenetic modifications of exhaustion- and memory-associated genes in memory TFGS, whereas minimal epigenetic modifications were observed in naive TFGS cells. Finally, post-partum memory TFGS durably expressed the exhaustion-enriched phenotype, and their susceptibility to transplantation tolerance was significantly restored compared to memory TFGS. These findings advance the concept of pregnancy as an epigenetic modulator inducing hypofunction in memory CD8+ T cells that has relevance not only for pregnancy and transplantation tolerance, but also for tumor immunity and chronic infections.
Jared M. Pollard, Grace Hynes, Dengping Yin, Malay Mandal, Fotini Gounari, Maria-Luisa Alegre, Anita S. Chong
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