Häberlein, F;Mingardo, E;Merten, N;Schulze Köhling, NK;Reinoß, P;Simon, K;Japp, A;Nagarajan, B;Schrage, R;Pegurier, C;Gillard, M;Monk, KR;Odermatt, B;Kostenis, E;Gomeza, J;
PMID: 36126653 | DOI: 10.1016/j.chembiol.2022.08.007
Therapies that promote neuroprotection and axonal survival by enhancing myelin regeneration are an unmet need to prevent disability progression in multiple sclerosis. Numerous potentially beneficial compounds have originated from phenotypic screenings but failed in clinical trials. It is apparent that current cell- and animal-based disease models are poor predictors of positive treatment options, arguing for novel experimental approaches. Here we explore the experimental power of humanized zebrafish to foster the identification of pro-remyelination compounds via specific inhibition of GPR17. Using biochemical and imaging techniques, we visualize the expression of zebrafish (zf)-gpr17 during the distinct stages of oligodendrocyte development, thereby demonstrating species-conserved expression between zebrafish and mammals. We also demonstrate species-conserved function of zf-Gpr17 using genetic loss-of-function and rescue techniques. Finally, using GPR17-humanized zebrafish, we provide proof of principle for in vivo analysis of compounds acting via targeted inhibition of human GPR17. We anticipate that GPR17-humanized zebrafish will markedly improve the search for effective pro-myelinating pharmacotherapies.
Palikuqi, B;Rispal, J;Reyes, EA;Vaka, D;Boffelli, D;Klein, O;
PMID: 35931034 | DOI: 10.1016/j.stem.2022.07.007
The intestinal epithelium undergoes continuous renewal and has an exceptional capacity to regenerate after injury. Maintenance and proliferation of intestinal stem cells (ISCs) are regulated by their surrounding niche, largely through Wnt signaling. However, it remains unclear which niche cells produce signals during different injury states, and the role of endothelial cells (ECs) as a component of the ISC niche during homeostasis and after injury has been underappreciated. Here, we show that lymphatic endothelial cells (LECs) reside in proximity to crypt epithelial cells and secrete molecules that support epithelial renewal and repair. LECs are an essential source of Wnt signaling in the small intestine, as loss of LEC-derived Rspo3 leads to a lower number of stem and progenitor cells and hinders recovery after cytotoxic injury. Together, our findings identify LECs as an essential niche component for optimal intestinal recovery after cytotoxic injury.
Kaur, G;Porter, CBM;Ashenberg, O;Lee, J;Riesenfeld, SJ;Hofree, M;Aggelakopoulou, M;Subramanian, A;Kuttikkatte, SB;Attfield, KE;Desel, CAE;Davies, JL;Evans, HG;Avraham-Davidi, I;Nguyen, LT;Dionne, DA;Neumann, AE;Jensen, LT;Barber, TR;Soilleux, E;Carrington, M;McVean, G;Rozenblatt-Rosen, O;Regev, A;Fugger, L;
PMID: 35906236 | DOI: 10.1038/s41467-022-32171-w
Fetal growth restriction (FGR) affects 5-10% of pregnancies, and can have serious consequences for both mother and child. Prevention and treatment are limited because FGR pathogenesis is poorly understood. Genetic studies implicate KIR and HLA genes in FGR, however, linkage disequilibrium, genetic influence from both parents, and challenges with investigating human pregnancies make the risk alleles and their functional effects difficult to map. Here, we demonstrate that the interaction between the maternal KIR2DL1, expressed on uterine natural killer (NK) cells, and the paternally inherited HLA-C*0501, expressed on fetal trophoblast cells, leads to FGR in a humanized mouse model. We show that the KIR2DL1 and C*0501 interaction leads to pathogenic uterine arterial remodeling and modulation of uterine NK cell function. This initial effect cascades to altered transcriptional expression and intercellular communication at the maternal-fetal interface. These findings provide mechanistic insight into specific FGR risk alleles, and provide avenues of prevention and treatment.
Liu, Y;Zhang, J;Wang, Z;Ma, J;Wang, K;Rao, D;Zhang, M;Lin, Y;Wu, Y;Yang, Z;Dong, L;Ding, Z;Zhang, X;Fan, J;Shi, Y;Gao, Q;
| DOI: 10.1016/j.isci.2022.104921
The molecular landscape and pathogenesis of focal nodular hyperplasia (FNH) have yet to be elucidated. We performed multi-omics approaches on FNH and paired normal liver tissues from 22 patients, followed by multi-level bioinformatic analyses and experimental validations. Generally, FNH had low mutation burden with low variant allele frequencies, and the mutation frequency significantly correlated with proliferation rate. Although no recurrently deleterious genomic events were found, some putative tumor suppressors or oncogenes were involved. Mutational signatures indicated potential impaired mismatch function and possible poison contact. Integrated analyses unveiled a group of FNH specific endothelial cells that uniquely expressed SOST and probably had strong interaction with fibroblasts through PDGFB/PDGFRB pathway to promote fibrosis. Notably, in one atypical FNH (patient No.11) with pronounced copy number variations, we observed a unique immune module. Most FNH are benign, but molecularly atypical FNH still exist; endothelial cell derived PDGFB probably promotes the fibrogenic process in FNH.
Dong, X;Limjunyawong, N;Sypek, EI;Wang, G;Ortines, RV;Youn, C;Alphonse, MP;Dikeman, D;Wang, Y;Lay, M;Kothari, R;Vasavda, C;Pundir, P;Goff, L;Miller, LS;Lu, W;Garza, LA;Kim, BS;Archer, NK;Dong, X;
PMID: 35882236 | DOI: 10.1016/j.immuni.2022.06.021
Healthy skin maintains a diverse microbiome and a potent immune system to fight off infections. Here, we discovered that the epithelial-cell-derived antimicrobial peptides defensins activated orphan G-protein-coupled receptors (GPCRs) Mrgpra2a/b on neutrophils. This signaling axis was required for effective neutrophil-mediated skin immunity and microbiome homeostasis. We generated mutant mouse lines lacking the entire Defensin (Def) gene cluster in keratinocytes or Mrgpra2a/b. Def and Mrgpra2 mutant animals both exhibited skin dysbiosis, with reduced microbial diversity and expansion of Staphylococcus species. Defensins and Mrgpra2 were critical for combating S. aureus infections and the formation of neutrophil abscesses, a hallmark of antibacterial immunity. Activation of Mrgpra2 by defensin triggered neutrophil release of IL-1β and CXCL2 which are vital for proper amplification and propagation of the antibacterial immune response. This study demonstrated the importance of epithelial-neutrophil signaling via the defensin-Mrgpra2 axis in maintaining healthy skin ecology and promoting antibacterial host defense.
Hu, B;Lelek, S;Spanjaard, B;El-Sammak, H;Simões, MG;Mintcheva, J;Aliee, H;Schäfer, R;Meyer, AM;Theis, F;Stainier, DYR;Panáková, D;Junker, JP;
PMID: 35864193 | DOI: 10.1038/s41588-022-01129-5
The adult zebrafish heart has a high capacity for regeneration following injury. However, the composition of the regenerative niche has remained largely elusive. Here, we dissected the diversity of activated cell states in the regenerating zebrafish heart based on single-cell transcriptomics and spatiotemporal analysis. We observed the emergence of several transient cell states with fibroblast characteristics following injury, and we outlined the proregenerative function of collagen-12-expressing fibroblasts. To understand the cascade of events leading to heart regeneration, we determined the origin of these cell states by high-throughput lineage tracing. We found that activated fibroblasts were derived from two separate sources: the epicardium and the endocardium. Mechanistically, we determined Wnt signalling as a regulator of the endocardial fibroblast response. In summary, our work identifies specialized activated fibroblast cell states that contribute to heart regeneration, thereby opening up possible approaches to modulating the regenerative capacity of the vertebrate heart.
De Luca, R;Nardone, S;Grace, KP;Venner, A;Cristofolini, M;Bandaru, SS;Sohn, LT;Kong, D;Mochizuki, T;Viberti, B;Zhu, L;Zito, A;Scammell, TE;Saper, CB;Lowell, BB;Fuller, PM;Arrigoni, E;
PMID: 35851580 | DOI: 10.1038/s41467-022-31591-y
Humans and animals lacking orexin neurons exhibit daytime sleepiness, sleep attacks, and state instability. While the circuit basis by which orexin neurons contribute to consolidated wakefulness remains unclear, existing models posit that orexin neurons provide their wake-stabilizing influence by exerting excitatory tone on other brain arousal nodes. Here we show using in vivo optogenetics, in vitro optogenetic-based circuit mapping, and single-cell transcriptomics that orexin neurons also contribute to arousal maintenance through indirect inhibition of sleep-promoting neurons of the ventrolateral preoptic nucleus. Activation of this subcortical circuit rapidly drives wakefulness from sleep by differentially modulating the activity of ventrolateral preoptic neurons. We further identify and characterize a feedforward circuit through which orexin (and co-released glutamate) acts to indirectly target and inhibit sleep-promoting ventrolateral preoptic neurons to produce arousal. This revealed circuitry provides an alternate framework for understanding how orexin neurons contribute to the maintenance of consolidated wakefulness and stabilize behavioral state.
Igarashi, N;Miyata, K;Loo, TM;Chiba, M;Hanyu, A;Nishio, M;Kawasaki, H;Zheng, H;Toyokuni, S;Kon, S;Moriyama, K;Fujita, Y;Takahashi, A;
PMID: 35851277 | DOI: 10.1038/s41467-022-31642-4
Cellular senescence and cell competition are important tumor suppression mechanisms that restrain cells with oncogenic mutations at the initial stage of cancer development. However, the link between cellular senescence and cell competition remains unclear. Senescent cells accumulated during the in vivo aging process contribute toward age-related cancers via the development of senescence-associated secretory phenotype (SASP). Here, we report that hepatocyte growth factor (HGF), a SASP factor, inhibits apical extrusion and promotes basal protrusion of Ras-mutated cells in the cell competition assay. Additionally, cellular senescence induced by a high-fat diet promotes the survival of cells with oncogenic mutations, whereas crizotinib, an inhibitor of HGF signaling, provokes the removal of mutated cells from mouse livers and intestines. Our study provides evidence that cellular senescence inhibits cell competition-mediated elimination of oncogenic cells through HGF signaling, suggesting that it may lead to cancer incidence during aging.
Proceedings of the National Academy of Sciences of the United States of America
Gao, P;Liu, Y;Wang, H;Chai, Y;Weng, W;Zhang, Y;Zhou, L;Ge, X;Guo, X;Han, J;Yang, H;
PMID: 35858300 | DOI: 10.1073/pnas.2201169119
Protein kinase R (PKR) is a critical host restriction factor against invading viral pathogens. However, this molecule is inactivated in the cells infected with porcine reproductive and respiratory syndrome virus (PRRSV), an economically devastating pathogen to the world swine industry. Here, we report that this event is to suppress cellular inflammation and is mediated by the viral replicase protein nsp1β. We show that nsp1β is a stress-responsive protein, enters virus-induced stress granules (SGs) during infection, and repurposes SGs into a proviral platform, where it co-opts the SG core component G3BP1 to interact with PKR in a regulated manner. RNA interference silencing of G3BP1 or mutation of specific nsp1β residues (VS19GG) can abolish the antagonization of PKR activation. The viral mutant carrying the corresponding mutations induces elevated level of PKR phosphorylation and pronounced production of inflammatory cytokines (e.g., tumor necrosis factor-α, interleukin [IL]-6, and IL-8), whereas small-interfering RNA knockdown of PKR or treatment with C16, a PKR inhibitor, blocks this effect. Thus, PRRSV has evolved a unique strategy to evade PKR restriction to suppress host inflammatory responses.
Vladimirovich, NP;Railevna, MG;Nikolaevich, PV;Nikolaevich, GD;Mikhailovich, KV;Leonard, W;Mauric, K;Sergeevich, TP;
PMID: 35876685 | DOI: 10.5146/tjpath.2022.01582
IDH wild-type glioblastomas (GBM) are one of the most malignant and complex tumors for treatment. The urgent question of new therapeutic and diagnostic tools searching should be resolved based on cellular and molecular pathogenesis mechanisms, which remain insufficiently studied. In this study, we aimed to investigate GBM pathogenesis.Using the isolation of different GBM cell populations and the cell cultures, animal models, and molecular genetic methods, we tried to clarify the picture of GBM pathogenesis by constructing a projection from different glioma stem cells types to an integral neoplasm.We have shown a potential transformation pathway for both glioma stem cells and four definitive cell populations during gliomagenesis. Moreover, we have characterized each population, taking into account its place in the pathogenetic continuum, with a description of the most fundamental molecular and functional properties.Finally, we have formed a complex holistic concept of the pathogenetic evolution of GBM at the cell-population level by integrating our results with the data of the world literature.
Rasmussen, SA;Lewis, JS;Mirabello, L;Bass, S;Yeager, M;Corsten, MJ;Bullock, MJ;
PMID: 35771403 | DOI: 10.1007/s12105-022-01463-4
Oropharyngeal squamous cell carcinoma is frequently associated with high-risk HPV infection, which confers a good prognosis. Immunohistochemistry for p16 is used as a surrogate for HPV status, but discrepant results are occasionally seen. Here, we report a case with a unique pattern of partial loss of p16.A 63 year old male presented with a base of tongue nonkeratinizing squamous cell carcinoma and a large metastatic neck mass. The primary lesion and multiple regions of the metastatic mass were assessed with p16 immunohistochemistry, RNA in situ hybridization for high-risk HPV, and HPV16 genome sequencing.The primary lesion was p16 negative, and the metastatic neck mass had large, confluent regions that were either strongly p16 positive or entirely p16 negative. All of these regions were positive for high-risk HPV with identical HPV16 genomes.This unusual case illustrates a potential diagnostic pitfall, and it raises important questions regarding molecular mechanisms and prognostic implications of p16 staining in oropharyngeal squamous cell carcinoma.
Morrow, MR;Batchuluun, B;Wu, J;Ahmadi, E;Leroux, JM;Mohammadi-Shemirani, P;Desjardins, EM;Wang, Z;Tsakiridis, EE;Lavoie, DCT;Reihani, A;Smith, BK;Kwiecien, JM;Lally, JSV;Nero, TL;Parker, MW;Ask, K;Scott, JW;Jiang, L;Paré, G;Pinkosky, SL;Steinberg, GR;
PMID: 35675800 | DOI: 10.1016/j.cmet.2022.05.004
Elevated liver de novo lipogenesis contributes to non-alcoholic steatohepatitis (NASH) and can be inhibited by targeting acetyl-CoA carboxylase (ACC). However, hypertriglyceridemia limits the use of pharmacological ACC inhibitors as a monotherapy. ATP-citrate lyase (ACLY) generates acetyl-CoA and oxaloacetate from citrate, but whether inhibition is effective for treating NASH is unknown. Here, we characterize a new mouse model that replicates many of the pathological and molecular drivers of NASH and find that genetically inhibiting ACLY in hepatocytes reduces liver malonyl-CoA, oxaloacetate, steatosis, and ballooning as well as blood glucose, triglycerides, and cholesterol. Pharmacological inhibition of ACLY mirrors genetic inhibition but has additional positive effects on hepatic stellate cells, liver inflammation, and fibrosis. Mendelian randomization of human variants that mimic reductions in ACLY also associate with lower circulating triglycerides and biomarkers of NASH. These data indicate that inhibiting liver ACLY may be an effective approach for treatment of NASH and dyslipidemia.
