Foster BL, Ao M, Salmon CR, Chavez MB, Kolli TN, Tran AB, Chu EY, Kantovitz KR, Yadav M, Narisawa S, Millán JL, Nociti Jr FH, Somerman MJ.
PMID: - | DOI: 10.1016/j.bone.2017.12.004
The periodontal complex is essential for tooth attachment and function and includes the mineralized tissues, cementum and alveolar bone, separated by the unmineralized periodontal ligament (PDL). To gain insights into factors regulating cementum-PDL and bone-PDL borders and protecting against ectopic calcification within the PDL, we employed a proteomic approach to analyze PDL tissue from progressive ankylosis knock-out (Ank−/−) mice, featuring reduced PPi, rapid cementogenesis, and excessive acellular cementum. Using this approach, we identified the matrix protein osteopontin (Spp1/OPN) as an elevated factor of interest in Ank−/− mouse molar PDL. We studied the role of OPN in dental and periodontal development and function. During tooth development in wild-type (WT) mice, Spp1 mRNA was transiently expressed by cementoblasts and strongly by alveolar bone osteoblasts. Developmental analysis from 14 to 240 days postnatal (dpn) indicated normal histological structures in Spp1−/− comparable to WT control mice. Microcomputed tomography (micro-CT) analysis at 30 and 90 dpn revealed significantly increased volumes and tissue mineral densities of Spp1−/− mouse dentin and alveolar bone, while pulp and PDL volumes were decreased and tissue densities were increased. However, acellular cementum growth was unaltered in Spp1−/− mice. Quantitative PCR of periodontal-derived mRNA failed to identify potential local compensators influencing cementum in Spp1−/− vs. WT mice at 26 dpn. We genetically deleted Spp1 on the Ank−/− mouse background to determine whether increased Spp1/OPN was regulating periodontal tissues when the PDL space is challenged by hypercementosis in Ank−/− mice. Ank−/−; Spp1−/−double deficient mice did not exhibit greater hypercementosis than that in Ank−/− mice. Based on these data, we conclude that OPN has a non-redundant role regulating formation and mineralization of dentin and bone, influences tissue properties of PDL and pulp, but does not control acellular cementum apposition. These findings may inform therapies targeted at controlling soft tissue calcification.
Charron Y, Willert J, Lipkowitz B, Kusecek B, Herrmann BG, Bauer H.
PMID: 30817801 | DOI: 10.1371/journal.pgen.1007964
Transmission ratio distortion (TRD) by the mouse t-haplotype, a variant region on chromosome 17, is a well-studied model of non-Mendelian inheritance. It is characterized by the high transmission ratio (up to 99%) of the t-haplotype from t/+ males to their offspring. TRD is achieved by the exquisite ability of the responder (Tcr) to trigger non-Mendelian inheritance of homologous chromosomes. Several distorters (Tcd1-Tcd4), which act cumulatively, together promote the high transmission ratio of Tcr and the t-haplotype. Molecularly, TRD is brought about by deregulation of Rho signaling pathways via the distorter products, which impair sperm motility, and the t-sperm specific rescue of sperm motility by the responder. The t-sperm thus can reach the egg cells faster than +-sperm and fertilize them. Previously we have shown that the responder function is accomplished by a dominant negative form of sperm motility kinase (SMOKTCR), while the distorter functions are accomplished by the Rho G protein regulators TAGAP, FGD2 and NME3 proposed to function in two oppositely acting pathways. Here we identify the RAC1-specific guanine nucleotide exchange factor TIAM2 as modifier of t-haplotype TRD. Tiam2 is expressed in two isoforms, the full-length (Tiam2l) and a short transcript (Tiam2s). Tiam2s expression from the t-allele is strongly increased compared to the wild-type allele. By transgenic approaches we show that Tiam2s enhances t-haplotype transmission, while Tiam2l has the opposite effect. Our data show that a single modifier locus can encode different gene products exerting opposite effects on a trait. They also suggest that the expression ratio of the isoforms determines if the outcome is an enhancing or a suppressive effect on the trait.
Ayyaz A, Kumar S, Sangiorgi B, Ghoshal B, Gosio J, Ouladan S, Fink M, Barutcu S, Trcka D, Shen J, Chan K, Wrana JL, Gregorieff A.
PMID: 31019301 | DOI: 10.1038/s41586-019-1154-y
The turnover of the intestinal epithelium is driven by multipotent LGR5+ crypt-base columnar cells (CBCs) located at the bottom of crypt zones1. However, CBCs are lost following injury, such as irradiation2, but the intestinal epithelium is nevertheless able to recover3. Thus, a second population of quiescent '+4' cells, or reserve stem cells (RSCs), has previously been proposed to regenerate the damaged intestine4-7. Although CBCs and RSCs were thought to be mutually exclusive4,8, subsequent studies have found that LGR5+ CBCs express RSC markers9 and that RSCs were dispensable-whereas LGR5+ cells were essential-for repair of the damaged intestine3. In addition, progenitors of absorptive enterocytes10, secretory cells11-15 and slow cycling LGR5+ cells16 have been shown to contribute to regeneration whereas the transcriptional regulator YAP1, which is important for intestinal regeneration, was suggested to induce a pro-survival phenotype in LGR5+cells17. Thus, whether cellular plasticity or distinct cell populations are critical for intestinal regeneration remains unknown. Here we applied single-cell RNA sequencing to profile the regenerating mouse intestine and identified a distinct, damage-induced quiescent cell type that we term the revival stem cell (revSC). revSCs are marked by high clusterin expression and are extremely rare under homoeostatic conditions, yet give rise-in a temporal hierarchy-to all the major cell types of the intestine, including LGR5+ CBCs. After intestinal damage by irradiation, targeted ablation of LGR5+ CBCs, or treatment with dextran sodium sulfate, revSCs undergo a YAP1-dependent transient expansion, reconstitute the LGR5+ CBC compartment and are required to regenerate a functional intestine. These studies thus define a unique stem cell that is mobilized by damage to revive the homoeostatic stem cell compartment and regenerate the intestinal epithelium.
Nagler, A;Wu, CJ;
PMID: 36095842 | DOI: 10.1182/blood.2021014669
Single-cell analysis has emerged over the past decade as a transformative technology informative for the systematic analysis of complex cell populations such as in cancers and the tumor immune microenvironment. The methodologic and analytical advancements in this realm have evolved rapidly, scaling from but a few cells at its outset to the current capabilities of processing and analyzing hundreds of thousands of individual cells at a time. The types of profiling attainable at individual cell resolution now range from genetic and transcriptomic characterization and extend to epigenomic and spatial analysis. Additionally, the increasing ability to achieve multiomic integration of these data layers now yields ever richer insights into diverse molecular disease subtypes and the patterns of cellular circuitry on a per-cancer basis. Over the years, chronic lymphocytic leukemia (CLL) consistently has been at the forefront of genomic investigation, given the ready accessibility of pure leukemia cells and immune cells from circulating blood of patients with this disease. Herein, we review the recent forays into the application of single-cell analysis to CLL, which are already revealing a new understanding of the natural progression of CLL, the impact of novel therapies, and the interactions with coevolving nonmalignant immune cell populations. As we emerge from the end of the beginning of this technologic revolution, CLL stands poised to reap the benefits of single-cell analysis from the standpoints of uncovering fresh fundamental biological knowledge and of providing a path to devising regimens of personalized diagnosis, treatment, and monitoring.
Yang, X;Hu, C;Zhao, H;Zhang, Z;Zhao, L;Yu, J;Ni, X;Guo, H;
PMID: 36513056 | DOI: 10.1159/000527951
Regarding a small proportion of oropharyngeal squamous cell carcinoma (OPSCC) patients who tested p16-positive but human papillomavirus (HPV)-negative, we attempted to perform HPV testing to improve the accuracy of HPV detection in OPSCC patients.We simultaneously performed Aptima HPV testing of cytological specimens and p16 immunohistochemistry (IHC) staining of histologic biopsies from the same cohort of patients with head and neck SCC (HNSCC). The cytological specimens included fine-needle aspiration specimens from patients with enlarged nodes and endoscopic brushing specimens from the primary lesions of patients without enlarged nodes. Cases with discordant results for p16 IHC staining and Aptima HPV testing were reexamined by a third method, RNAscope testing.Sixty patients with HNSCC (39 OPSCC and 21 non-OPSCC) were recruited for examination of HPV status. Among these patients, 28 were p16+/HPV+, 29 were p16-/HPV-, 2 were p16+/HPV-, and 1 was p16-/HPV+. The overall concordance rate between Aptima HPV testing and p16 IHC was 95.0%. Three cases with discordant results for these two methods were reexamined by RNAscope testing, and all were confirmed to be HPV negative. The prevalence of HPV in OPSCC and non-OPSCC patients was 61.5% (24/39) and 19.0% (4/21), respectively. The sensitivity and negative predictive values of Aptima HPV testing and p16 IHC were consistent at 100%, while the specificity and positive predictive values were 96.9% and 96.6% versus 93.8% and 93.3%, respectively. Additionally, 30 OPSCCs were simultaneously examined and diagnosed by both brush cytology and biopsy pathology; six of these SCCs were underdiagnosed by histopathology but accurately diagnosed by supplemental brush cytology.Aptima HPV testing of cytology specimens can be used as an adjuvant examination to identify false-positive OPSCC patients after p16 IHC of biopsies, while brush cytology may be a supplemental method for the histologic diagnosis of malignant oropharyngeal tumors.
Christiansen, P;Andreasen, C;Laursen, K;Delaisse, J;Andersen, T;
| DOI: 10.2139/ssrn.4224428
Background: Recruitment and proliferation of osteoprogenitors during the reversal-resorption phase, and their differentiation into mature bone-forming osteoblasts is crucial for initiation of bone formation during bone remodeling. This study investigates the osteoprogenitors’ gradual recruitment, proliferation, and differentiation into bone-forming osteoblasts within intracortical remodeling events of healthy adolescent humans. Methods: The study was conducted on cortical bone specimens from 11 healthy adolescent humans. The osteoprogenitor recruitment route and differentiation into osteoblasts were backtracked using immunostainings and in situ hybridizations with osteoblastic markers (CD271, osterix, collage type 1 and 3). The osteoblastic cell populations were defined based on the pore surfaces and their proliferation index (Ki67), density, and number/circumference were estimated in multiplex-immunofluorescence (Ki67, TRAcP, CD34, SMA) stained sections. Results: During the reversal-resorption phase, osteoclasts are intermixed with osteoblastic reversal cells (COL3A1 high CD271 high COL1A1 low Osterix neg ), which are considered to be spatiotemporal osteoprogenitors of bone-forming osteoblasts. Initiation of bone formation requires a critical density of these osteoblastic reversal cells (43±9 cells/mm), which is reached though proliferation (4.4±0.5% proliferative) and even more so through recruitment of osteoprogenitors, but challenged by the ongoing expansion of the canal circumference. These osteoprogenitors most likely originate from osteoblastic bone lining cells and mainly osteoblastic lumen cells, which expand their population though proliferation (4.6±0.3%) and vascular recruitment. These lumen cells resemble canopy cells above trabecular remodeling sites, and like canopy cells they extend above bone-forming osteoblasts where they may rejuvenate the osteoblast population during bone formation. Conclusion: Initiation of bone formation during intracortical remodeling requires a critical density osteoblastic reversal cells, which is reached though proliferation and recruitment of local osteoprogenitors: bone lining cells and osteoblastic lumen cells.
Kedmi, R;Najar, TA;Mesa, KR;Grayson, A;Kroehling, L;Hao, Y;Hao, S;Pokrovskii, M;Xu, M;Talbot, J;Wang, J;Germino, J;Lareau, CA;Satpathy, AT;Anderson, MS;Laufer, TM;Aifantis, I;Bartleson, JM;Allen, PM;Paidassi, H;Gardner, JM;Stoeckius, M;Littman, DR;
PMID: 36071167 | DOI: 10.1038/s41586-022-05089-y
The mutualistic relationship of gut-resident microbiota and the host immune system promotes homeostasis that ensures maintenance of the microbial community and of a largely non-aggressive immune cell compartment1,2. The consequences of disturbing this balance include proximal inflammatory conditions, such as Crohn's disease, and systemic illnesses. This equilibrium is achieved in part through the induction of both effector and suppressor arms of the adaptive immune system. Helicobacter species induce T regulatory (Treg) and T follicular helper (TFH) cells under homeostatic conditions, but induce inflammatory T helper 17 (TH17) cells when induced Treg (iTreg) cells are compromised3,4. How Helicobacter and other gut bacteria direct T cells to adopt distinct functions remains poorly understood. Here we investigated the cells and molecular components required for iTreg cell differentiation. We found that antigen presentation by cells expressing RORγt, rather than by classical dendritic cells, was required and sufficient for induction of Treg cells. These RORγt+ cells-probably type 3 innate lymphoid cells and/or Janus cells5-require the antigen-presentation machinery, the chemokine receptor CCR7 and the TGFβ activator αv integrin. In the absence of any of these factors, there was expansion of pathogenic TH17 cells instead of iTreg cells, induced by CCR7-independent antigen-presenting cells. Thus, intestinal commensal microbes and their products target multiple antigen-presenting cells with pre-determined features suited to directing appropriate T cell differentiation programmes, rather than a common antigen-presenting cell that they endow with appropriate functions.
Science translational medicine
Kim, GB;Fritsche, J;Bunk, S;Mahr, A;Unverdorben, F;Tosh, K;Kong, H;Maldini, CR;Lau, C;Srivatsa, S;Jiang, S;Glover, J;Dopkin, D;Zhang, CX;Schuster, H;Kowalewski, DJ;Goldfinger, V;Ott, M;Fuhrmann, D;Baues, M;Boesmueller, H;Schraeder, C;Schimmack, G;Song, C;Hoffgaard, F;Roemer, M;Tsou, CC;Hofmann, M;Treiber, T;Hutt, M;Alten, L;Jaworski, M;Alpert, A;Missel, S;Reinhardt, C;Singh, H;Schoor, O;Walter, S;Wagner, C;Maurer, D;Weinschenk, T;Riley, JL;
PMID: 36044599 | DOI: 10.1126/scitranslmed.abo6135
T cell receptor (TCR)-based immunotherapy has emerged as a promising therapeutic approach for the treatment of patients with solid cancers. Identifying peptide-human leukocyte antigen (pHLA) complexes highly presented on tumors and rarely expressed on healthy tissue in combination with high-affinity TCRs that when introduced into T cells can redirect T cells to eliminate tumor but not healthy tissue is a key requirement for safe and efficacious TCR-based therapies. To discover promising shared tumor antigens that could be targeted via TCR-based adoptive T cell therapy, we employed population-scale immunopeptidomics using quantitative mass spectrometry across ~1500 tumor and normal tissue samples. We identified an HLA-A*02:01-restricted pan-cancer epitope within the collagen type VI α-3 (COL6A3) gene that is highly presented on tumor stroma across multiple solid cancers due to a tumor-specific alternative splicing event that rarely occurs outside the tumor microenvironment. T cells expressing natural COL6A3-specific TCRs demonstrated only modest activity against cells presenting high copy numbers of COL6A3 pHLAs. One of these TCRs was affinity-enhanced, enabling transduced T cells to specifically eliminate tumors in vivo that expressed similar copy numbers of pHLAs as primary tumor specimens. The enhanced TCR variants exhibited a favorable safety profile with no detectable off-target reactivity, paving the way to initiate clinical trials using COL6A3-specific TCRs to target an array of solid tumors.
Shih, BB;Brown, SM;Barrington, J;Lefevre, L;Mabbott, NA;Priller, J;Thompson, G;Lawrence, AB;McColl, BW;
PMID: 36120803 | DOI: 10.1002/glia.24274
Microglia play key roles in brain homeostasis as well as responses to neurodegeneration and neuroinflammatory processes caused by physical disease and psychosocial stress. The pig is a physiologically relevant model species for studying human neurological disorders, many of which are associated with microglial dysfunction. Furthermore, pigs are an important agricultural species, and there is a need to understand how microglial function affects their welfare. As a basis for improved understanding to enhance biomedical and agricultural research, we sought to characterize pig microglial identity at genome-wide scale and conduct inter-species comparisons. We isolated pig hippocampal tissue and microglia from frontal cortex, hippocampus, and cerebellum, as well as alveolar macrophages from the lungs and conducted RNA-sequencing (RNAseq). By comparing the transcriptomic profiles between microglia, macrophages, and hippocampal tissue, we derived a set of 239 highly enriched genes defining the porcine core microglial signature. We found brain regional heterogeneity based on 150 genes showing significant (adjusted p < 0.01) regional variations and that cerebellar microglia were most distinct. We compared normalized gene expression for microglia from human, mice and pigs using microglia signature gene lists derived from each species and demonstrated that a core microglial marker gene signature is conserved across species, but that species-specific expression subsets also exist. Our data provide a valuable resource defining the pig microglial transcriptome signature that validates and highlights pigs as a useful large animal species bridging between rodents and humans in which to study the role of microglia during homeostasis and disease.
American journal of physiology. Renal physiology
Clayton, DR;Ruiz, WG;Dalghi, MG;Montalbetti, N;Carattino, MD;Apodaca, G;
PMID: 35834272 | DOI: 10.1152/ajprenal.00135.2022
Fibroblasts are crucial to normal and abnormal organ and tissue biology, yet we lack basic insights into the fibroblasts that populate the bladder wall. Candidates may include bladder interstitial cells (also referred to as myofibroblasts, telocytes, interstitial cells of Cajal-like cells), which express the fibroblast-associated marker PDGFRA (along with VIM and CD34) but whose form and function remains enigmatic. By applying the latest insights in fibroblast transcriptomics, coupled with studies of gene expression, ultrastructure, and marker analysis, we observe the following: (1) that mouse bladder PDGFRA-positive cells exhibit all of the ultrastructural hallmarks of fibroblasts including spindle shape, lack of basement membrane, abundant ER and Golgi, and formation of homotypic cell-cell contacts (but not heterotypic ones); (2) that they express multiple canonical fibroblast markers (including Col1a2, CD34, LY6A, and PDGFRA) along with the universal fibroblast genes Col15a1 and Pi16; (3) that PDGFRA-positive fibroblasts include suburothelial ones (which express ACTA2, CAR3, LY6A, MYH10, TNC, VIM, Col1a2, Col15a1),outer lamina propria ones (which express CD34, LY6A, PI16, VIM, Col1a2, Col15a1, Pi16), intermuscular ones (which express CD34, VIM, Col1a2, Col15a1, Pi16), and serosal ones (which express CD34, PI16, VIM, Col1a2, Col15a1,Pi16). Collectively, our studies reveal that the ultrastructure of PDFRA-positiveinterstitial cells combined with their expression of multiple canonical and universal fibroblast-associated gene products indicates they are fibroblasts. We further propose that there are four regionally distinct populations of fibroblasts in the bladder wall, which likely contribute to bladder function and dysfunction.
Zhao, Q;Yu, CD;Wang, R;Xu, QJ;Dai Pra, R;Zhang, L;Chang, RB;
PMID: 35296859 | DOI: 10.3760/cma.j.cn112151-20210719-00516
Interoception, the ability to timely and precisely sense changes inside the body, is critical for survival1-4. Vagal sensory neurons (VSNs) form an important body-to-brain connection, navigating visceral organs along the rostral-caudal axis of the body and crossing the surface-lumen axis of organs into appropriate tissue layers5,6. The brain can discriminate numerous body signals through VSNs, but the underlying coding strategy remains poorly understood. Here we show that VSNs code visceral organ, tissue layer and stimulus modality-three key features of an interoceptive signal-in different dimensions. Large-scale single-cell profiling of VSNs from seven major organs in mice using multiplexed projection barcodes reveals a 'visceral organ' dimension composed of differentially expressed gene modules that code organs along the body's rostral-caudal axis. We discover another 'tissue layer' dimension with gene modules that code the locations of VSN endings along the surface-lumen axis of organs. Using calcium-imaging-guided spatial transcriptomics, we show that VSNs are organized into functional units to sense similar stimuli across organs and tissue layers; this constitutes a third 'stimulus modality' dimension. The three independent feature-coding dimensions together specify many parallel VSN pathways in a combinatorial manner and facilitate the complex projection of VSNs in the brainstem. Our study highlights a multidimensional coding architecture of the mammalian vagal interoceptive system for effective signal communication.
Clinical cancer research : an official journal of the American Association for Cancer Research
Hemming, ML;Bhola, P;Loycano, MA;Anderson, JA;Taddei, ML;Doyle, LA;Lavrova, E;Andersen, JL;Klega, KS;Benson, MR;Crompton, BD;Raut, CP;George, S;Letai, A;Demetri, GD;Sicinska, E;
PMID: 35325095 | DOI: 10.1158/1078-0432.CCR-21-3523
Leiomyosarcoma (LMS) is a neoplasm characterized by smooth muscle differentiation, complex copy-number alterations, tumor suppressor loss and the absence of recurrent driver mutations. Clinical management for advanced disease relies on the use of empiric cytotoxic chemotherapy with limited activity, and novel targeted therapies supported by preclinical research on LMS biology are urgently needed. A lack of fidelity of established LMS cell lines to their mesenchymal neoplasm of origin has limited translational understanding of this disease, and few other preclinical models have been established. Here, we characterize LMS patient derived xenograft (PDX) models of LMS, assessing fidelity to their tumors of origin and performing preclinical evaluation of candidate therapies.We implanted 49 LMS surgical samples into immunocompromised mice. Engrafting tumors were characterized by histology, targeted next-generation sequencing, RNA-seq and ultra-low passage whole-genome sequencing. Candidate therapies were selected based on prior evidence of pathway activation or high-throughput dynamic BH3 profiling.We show that LMS PDX maintain the histologic appearance, copy-number alterations and transcriptional program of their parental tumors across multiple xenograft passages. Transcriptionally, LMS PDX co-cluster with paired LMS patient-derived samples and differ primarily in host-related immunologic and microenvironment signatures. We identify susceptibility of LMS PDX to transcriptional CDK inhibition, which disrupts an E2F-driven oncogenic transcriptional program and inhibits tumor growth.Our results establish LMS PDX as valuable preclinical models and identify strategies to discover novel vulnerabilities in this disease. These data support the clinical assessment of transcriptional CDK inhibitors as a therapeutic strategy for LMS patients.
