"Boldog E, Bakken TE, Hodge RD, Novotny M, Aevermann BD, Baka J, Bordé S, Close JL, Diez-Fuertes F, Ding SL, Faragó N, Kocsis AK, Kovács B, Maltzer Z, McCorrison JM, Miller JA, Molnár G, Oláh G, Ozsvár A, Rózsa M, Shehata SI, Smith KA, Sunkin SM, Tran D
PMID: 30150662 | DOI: 10.1038/s41593-018-0205-2
We describe convergent evidence from transcriptomics, morphology, and physiology for a specialized GABAergic neuron subtype in human cortex. Using unbiased single-nucleus RNA sequencing, we identify ten GABAergic interneuron subtypes with combinatorial gene signatures in human cortical layer 1 and characterize a group of human interneurons with anatomical features never described in rodents, having large 'rosehip'-like axonal boutons and compact arborization. These rosehip cells show an immunohistochemical profile (GAD1+CCK+, CNR1-SST-CALB2-PVALB-) matching a single transcriptomically defined cell type whose specific molecular marker signature is not seen in mouse cortex. Rosehip cells in layer 1 make homotypic gap junctions, predominantly target apical dendritic shafts of layer 3 pyramidal neurons, and inhibit backpropagating pyramidal action potentials in microdomains of the dendritic tuft. These cells are therefore positioned for potent local control of distal dendritic computation in cortical pyramidal neurons.
Ruscitto A, Morel MM, Shawber CJ, Reeve G, Lecholop MK, Bonthius D, Yao H, Embree MC
PMID: 32030828 | DOI: 10.1096/fj.201902287R
Temporomandibular joint osteoarthritis (TMJ OA) leads to permanent cartilage destruction, jaw dysfunction, and compromises the quality of life. However, the pathological mechanisms governing TMJ OA are poorly understood. Unlike appendicular articular cartilage, the TMJ has two distinct functions as the synovial joint of the craniofacial complex and also as the site for endochondral jaw bone growth. The established dogma of endochondral bone ossification is that hypertrophic chondrocytes undergo apoptosis, while invading vasculature with osteoprogenitors replace cartilage with bone. However, contemporary murine genetic studies support the direct differentiation of chondrocytes into osteoblasts and osteocytes in the TMJ. Here we sought to characterize putative vasculature and cartilage to bone transdifferentiation using healthy and diseased TMJ tissues from miniature pigs and humans. During endochondral ossification, the presence of fully formed vasculature expressing CD31+ endothelial cells and ?-SMA+ vascular smooth muscle cells were detected within all cellular zones in growing miniature pigs. Arterial, endothelial, venous, angiogenic, and mural cell markers were significantly upregulated in miniature pig TMJ tissues relative to donor matched knee meniscus fibrocartilage tissue. Upon surgically creating TMJ OA in miniature pigs, we discovered increased vasculature and putative chondrocyte to osteoblast transformation dually marked by COL2 and BSP or RUNX2 within the vascular bundles. Pathological human TMJ tissues also exhibited increased vasculature, while isolated diseased human TMJ cells exhibited marked increased in vasculature markers relative to control 293T cells. Our study provides evidence to suggest that the TMJ in higher order species are in fact vascularized. There have been no reports of cartilage to bone transdifferentiation or vasculature in human-relevant TMJ OA large animal models or in human TMJ tissues and cells. Therefore, these findings may potentially alter the clinical management of TMJ OA by defining new drugs that target angiogenesis or block the cartilage to bone transformation
American journal of translational research
Jiao, Q;Zou, F;Li, S;Wang, J;Xiao, Y;Guan, Z;Dong, L;Tian, J;Li, S;Wang, R;Zhang, J;Li, H;
PMID: 36105026
To validate that dexlansoprazole, an anti-acid drug, can prevent pulmonary artery hypertension (PAH) in preclinical animal models and find the possible mechanism of action of dexlansoprazole for this new indication.The efficacy of dexlansoprazole to attenuate PAH in vivo was evaluated in PAH animal models. Plasma guanosine 3', 5'-cyclic phosphate (cGMP) in PAH rats was measured by enzyme linked immunosorbent assay (ELISA). To investigate the anti-PAH effect of dexlansoprazole in vitro, proliferation and migration assays of primary cultured pulmonary artery smooth muscle cells (PASMCs) were performed. Furthermore, dexlansoprazole's function on fibroblast transition of vascular smooth muscle cells (VSMC) was explored by single cell ribonucleic acid (RNA) sequencing and RNAscope.Dexlansoprazole could attenuate the pathologic process in monocrotaline (MCT)-, hypoxia-induced PAH rats and SU5416/hypoxia (SuHy)-induced PAH mice. The intervention with dexlansoprazole significantly inhibited elevated right ventricular systolic pressure (RVSP), right ventricular hypertrophy, and pulmonary vascular wall thickness. Furthermore, plasma cGMP in MCT-induced PAH rats was restored after receiving dexlansoprazole. In vitro, dexlansoprazole could inhibit PASMCs' proliferation and migration stimulated by platelet derived growth factor-BB (PDGF-BB). Moreover, dexlansoprazole significantly ameliorated pulmonary vascular remodeling by inhibiting VSMC phenotypic transition to fibroblast-like cells in a VSMC-specific multispectral lineage-tracing mouse.Dexlansoprazole can prevent PAH through promoting cGMP generation and inhibiting pulmonary vascular remodeling through restraining PASMCs' proliferation, migration, and phenotypic transition to fibroblast-like cells. Consequently, PAH might be a new indication for dexlansoprazole.AJTR
Du, Y;Yu, K;Yan, C;Wei, C;Zheng, Q;Qiao, Y;Liu, Y;Han, J;Ren, W;Liu, Z;
PMID: 35613854 | DOI: 10.1523/ENEURO.0487-21.2022
The endogenous opioid system plays a crucial role in stress-induced analgesia. Mu-opioid receptors (MORs), one of the major opioid receptors, are expressed widely in subpopulations of cells throughout the CNS. However, the potential roles of MORs expressed in glutamatergic (MORGlut) and γ-aminobutyric acidergic (MORGABA) neurons in stress-induced analgesia remain unclear. By examining tail-flick latencies to noxious radiant heat of male mice, here we investigated the contributions of MORGABA and MORGlut to behavioral analgesia and activities of neurons projecting from periaqueductal gray (PAG) to rostral ventromedial medulla (RVM) induced by a range of time courses of forced swim exposure. The moderate but not transitory or prolonged swim exposure induced a MOR-dependent analgesia, although all of these three stresses enhanced β-endorphin release. Selective deletion of MORGABA but not MORGlut clearly attenuated analgesia and blocked the enhancement of activities of PAG-RVM neurons induced by moderate swim exposure. Under transitory swim exposure, in contrast, selective deletion of MORGlut elicited an analgesia behavior via strengthening the activities of PAG-RVM neurons. These results indicate that MOR-dependent endogenous opioid signaling participates in nociceptive modulation in a wide range, not limited to moderate, of stress intensities. Endogenous activation of MORGABA exerts analgesia, whereas MORGlut produces antianalgesia. More importantly, with an increase of stress intensities, the efficiencies of MORs on nociception shifts from balance between MORGlut and MORGABA to biasing toward MORGABA-mediated processes. Our results point to the cellular dynamic characteristics of MORs expressed in excitatory and inhibitory neurons in pain modulation under various stress intensities.
Quina LA1, Walker A1, Morton G1, Han V1, Turner EE2,3
PMID: 32332079 | DOI: 10.1523/ENEURO.0527-19.2020
The lateral habenula (LHb) sends complex projections to several areas of the mesopontine tegmentum, the raphe, and the hypothalamus. However, few markers have been available to distinguish subsets of LHb neurons that may serve these pathways. In order to address this complexity, we examined the mouse and rat LHb for neurons that express the GABA biosynthesis enzymes glutamate decarboxylase 1 and 2 (GAD1, GAD2), and the vesicular GABA transporter (VGAT). The mouse LHb contains a population of neurons that express GAD2, while the rat LHb contains discrete populations of neurons that express GAD1 and VGAT. However, we could not detect single neurons in either species that co-express a GABA synthetic enzyme and VGAT, suggesting that these LHb neurons do not use GABA for conventional synaptic transmission. Instead, all of the neuronal types expressing a GABAergic marker in both species showed co-expression of the glutamate transporter VGluT2. Anterograde tract-tracing of the projections of GAD2-expressing LHb neurons in Gad2Cre mice, combined with retrograde tracing from selected downstream nuclei, show that LHb-GAD2 neurons project selectively to the midline structures in the mesopontine tegmentum, including the median raphe and nucleus incertus, and only sparsely innervate the hypothalamus, rostromedial tegmental nucleus, and ventral tegmental area. Postsynaptic recording of LHb-GAD2 neuronal input to tegmental neurons confirms that glutamate, not GABA, is the fast neurotransmitter in this circuit. Thus GAD2 expression can serve as a marker for functional studies of excitatory neurons serving specific LHb output pathways in mice.SIGNFICANCE STATEMENT The lateral habenula provides a major link between subcortical forebrain areas and the dopamine (DA) and serotonin (5HT) systems of the midbrain and pons, and it has been implicated in reward mechanisms and the regulation of mood states. Few markers have been available for the specific cell types and complex output pathways of the lateral habenula. Here we examined the expression of genes mediating GABAergic and glutamatergic transmission in the mouse and rat LHb, where no neurons in either species expressed a full complement of GABAergic markers, and all expressed the glutamatergic marker VGluT2. Consistent with this, in mice the LHb GAD2 neurons are excitatory and appear to use only glutamate for fast synaptic transmission.
Taieb, M;Ghannoum, D;Barré, L;Ouzzine, M;
PMID: 37296099 | DOI: 10.1038/s41419-023-05875-0
Genetic mutations in the Xylt1 gene are associated with Desbuquois dysplasia type II syndrome characterized by sever prenatal and postnatal short stature. However, the specific role of XylT-I in the growth plate is not completely understood. Here, we show that XylT-I is expressed and critical for the synthesis of proteoglycans in resting and proliferative but not in hypertrophic chondrocytes in the growth plate. We found that loss of XylT-I induces hypertrophic phenotype-like of chondrocytes associated with reduced interterritorial matrix. Mechanistically, deletion of XylT-I impairs the synthesis of long glycosaminoglycan chains leading to the formation of proteoglycans with shorter glycosaminoglycan chains. Histological and Second Harmonic Generation microscopy analysis revealed that deletion of XylT-I accelerated chondrocyte maturation and prevents chondrocytes columnar organization and arrangement in parallel of collagen fibers in the growth plate, suggesting that XylT-I controls chondrocyte maturation and matrix organization. Intriguingly, loss of XylT-I induced at embryonic stage E18.5 the migration of progenitor cells from the perichondrium next to the groove of Ranvier into the central part of epiphysis of E18.5 embryos. These cells characterized by higher expression of glycosaminoglycans exhibit circular organization then undergo hypertrophy and death creating a circular structure at the secondary ossification center location. Our study revealed an uncovered role of XylT-I in the synthesis of proteoglycans and provides evidence that the structure of glycosaminoglycan chains of proteoglycans controls chondrocyte maturation and matrix organization.
Larsen, F;Hansen, D;Terkelsen, M;Bendixen, S;Avolio, F;Wernberg, C;Lauridsen, M;Grønkjaer, L;Jacobsen, B;Klinggaard, E;Mandrup, S;Di Caterino, T;Siersbæk, M;Chandran, V;Graversen, J;Krag, A;Grøntved, L;Ravnskjaer, K;
| DOI: 10.1016/j.jhepr.2022.100615
Background & Aims Non-alcoholic fatty liver disease (NAFLD) and its progressive form, non-alcoholic steatohepatitis (NASH), are the hepatic manifestations of metabolic syndrome. Histological assessment of liver biopsies is the gold standard for diagnosis of NASH. A Liver biopsy is resource heavy, can lead to complications such as bleeding, and does not fully capture tissue heterogeneity of the fibrotic liver. Therefore, non-invasive biomarkers that can reflect an integrated state of the liver are highly needed to improve diagnosis and sampling bias. Hepatic stellate cells (HSCs) are central in development of hepatic fibrosis, a hallmark of NASH. Secreted HSC-specific proteins may, therefore, reflect disease state in the NASH liver and serve as non-invasive diagnostic biomarkers. Methods We performed RNA-sequencing on liver biopsies from a histological characterised cohort of obese patients (n = 30, body mass index > 35 kg/m2) to identify and evaluate HSC-specific genes encoding secreted proteins. Bioinformatics was used to identify potential biomarkers and their expression at single-cell resolution. We validated our findings by single-molecule fluorescence in situ hybridisation (smFISH) and ELISA to detect mRNA in liver tissue and protein levels in plasma, respectively. Results Hepatic expression of SPARC-related modular calcium-binding protein 2 (SMOC2) was increased in NASH compared no-NAFLD (p.adj < 0.001). Single-cell RNA-sequencing data indicated SMOC2 expression by HSCs, which was validated using smFISH. Finally, plasma SMOC2 was elevated in NASH compared to no-NAFLD (p < 0.001) with a predictive accuracy of AUROC 0.88. Conclusions We propose increased SMOC2 in plasma reflects HSC activation, a key cellular event associated with NASH progression, and may serve as a non-invasive biomarker of NASH.
Garcia-Alonso, L;Lorenzi, V;Mazzeo, CI;Alves-Lopes, JP;Roberts, K;Sancho-Serra, C;Engelbert, J;Marečková, M;Gruhn, WH;Botting, RA;Li, T;Crespo, B;van Dongen, S;Kiselev, VY;Prigmore, E;Herbert, M;Moffett, A;Chédotal, A;Bayraktar, OA;Surani, A;Haniffa, M;Vento-Tormo, R;
PMID: 35794482 | DOI: 10.1038/s41586-022-04918-4
Gonadal development is a complex process that involves sex determination followed by divergent maturation into either testes or ovaries1. Historically, limited tissue accessibility, a lack of reliable in vitro models and critical differences between humans and mice have hampered our knowledge of human gonadogenesis, despite its importance in gonadal conditions and infertility. Here, we generated a comprehensive map of first- and second-trimester human gonads using a combination of single-cell and spatial transcriptomics, chromatin accessibility assays and fluorescent microscopy. We extracted human-specific regulatory programmes that control the development of germline and somatic cell lineages by profiling equivalent developmental stages in mice. In both species, we define the somatic cell states present at the time of sex specification, including the bipotent early supporting population that, in males, upregulates the testis-determining factor SRY and sPAX8s, a gonadal lineage located at the gonadal-mesonephric interface. In females, we resolve the cellular and molecular events that give rise to the first and second waves of granulosa cells that compartmentalize the developing ovary to modulate germ cell differentiation. In males, we identify human SIGLEC15+ and TREM2+ fetal testicular macrophages, which signal to somatic cells outside and inside the developing testis cords, respectively. This study provides a comprehensive spatiotemporal map of human and mouse gonadal differentiation, which can guide in vitro gonadogenesis.
Ma F, Ye H, He HH, Gerrin SJ, Chen S, Tanenbaum BA, Cai C, Sowalsky AG, He L, Wang H, Balk SP, Yuan X.
PMID: 27043282 | DOI: 10.1172/JCI78815.
The transcription factor SOX9 is critical for prostate development, and dysregulation of SOX9 is implicated in prostate cancer (PCa). However, the SOX9-dependent genes and pathways involved in both normal and neoplastic prostate epithelium are largely unknown. Here, we performed SOX9 ChIP sequencing analysis and transcriptome profiling of PCa cells and determined that SOX9 positively regulates multiple WNT pathway genes, including those encoding WNT receptors (frizzled [FZD] and lipoprotein receptor-related protein [LRP] family members) and the downstream β-catenin effector TCF4. Analyses of PCa xenografts and clinical samples both revealed an association between the expression of SOX9 and WNT pathway components in PCa. Finally, treatment of SOX9-expressing PCa cells with a WNT synthesis inhibitor (LGK974) reduced WNT pathway signaling in vitro and tumor growth in murine xenograft models. Together, our data indicate that SOX9 expression drives PCa by reactivating the WNT/β-catenin signaling that mediates ductal morphogenesis in fetal prostate and define a subgroup of patients who would benefit from WNT-targeted therapy.
Grienberger C, Milstein AD, Bittner KC, Romani S, Magee JC.
PMID: 28114296 | DOI: 10.1038/nn.4486
Place cells in the CA1 region of the hippocampus express location-specific firing despite receiving a steady barrage of heterogeneously tuned excitatory inputs that should compromise output dynamic range and timing. We examined the role of synaptic inhibition in countering the deleterious effects of off-target excitation. Intracellular recordings in behaving mice demonstrate that bimodal excitation drives place cells, while unimodal excitation drives weaker or no spatial tuning in interneurons. Optogenetic hyperpolarization of interneurons had spatially uniform effects on place cell membrane potential dynamics, substantially reducing spatial selectivity. These data and a computational model suggest that spatially uniform inhibitory conductance enhances rate coding in place cells by suppressing out-of-field excitation and by limiting dendritic amplification. Similarly, we observed that inhibitory suppression of phasic noise generated by out-of-field excitation enhances temporal coding by expanding the range of theta phase precession. Thus, spatially uniform inhibition allows proficient and flexible coding in hippocampal CA1 by suppressing heterogeneously tuned excitation.
Hrvatin S, Hochbaum DR, Nagy MA, Cicconet M, Robertson K, Cheadle L, Zilionis R, Ratner A, Borges-Monroy R, Klein AM, Sabatini BL, Greenberg ME.
PMID: 29230054 | DOI: 10.1038/s41593-017-0029-5
Activity-dependent transcriptional responses shape cortical function. However, a comprehensive understanding of the diversity of these responses across the full range of cortical cell types, and how these changes contribute to neuronal plasticity and disease, is lacking. To investigate the breadth of transcriptional changes that occur across cell types in the mouse visual cortex after exposure to light, we applied high-throughput single-cell RNA sequencing. We identified significant and divergent transcriptional responses to stimulation in each of the 30 cell types characterized, thus revealing 611 stimulus-responsive genes. Excitatory pyramidal neurons exhibited inter- and intralaminar heterogeneity in the induction of stimulus-responsive genes. Non-neuronal cells showed clear transcriptional responses that may regulate experience-dependent changes in neurovascular coupling and myelination. Together, these results reveal the dynamic landscape of the stimulus-dependent transcriptional changes occurring across cell types in the visual cortex; these changes are probably critical for cortical function and may be sites of deregulation in developmental brain disorders.
Kim, S;Oh, H;Choi, SH;Yoo, YE;Noh, YW;Cho, Y;Im, GH;Lee, C;Oh, Y;Yang, E;Kim, G;Chung, WS;Kim, H;Kang, H;Bae, Y;Kim, SG;Kim, E;
PMID: 36130507 | DOI: 10.1016/j.celrep.2022.111398
Myelin transcription factor 1 like (Myt1l), a zinc-finger transcription factor, promotes neuronal differentiation and is implicated in autism spectrum disorder (ASD) and intellectual disability. However, it remains unclear whether Myt1l promotes neuronal differentiation in vivo and its deficiency in mice leads to disease-related phenotypes. Here, we report that Myt1l-heterozygous mutant (Myt1l-HT) mice display postnatal age-differential ASD-related phenotypes: newborn Myt1l-HT mice, with strong Myt1l expression, show ASD-like transcriptomic changes involving decreased synaptic gene expression and prefrontal excitatory synaptic transmission and altered righting reflex. Juvenile Myt1l-HT mice, with markedly decreased Myt1l expression, display reverse ASD-like transcriptomes, increased prefrontal excitatory transmission, and largely normal behaviors. Adult Myt1l-HT mice show ASD-like transcriptomes involving astrocytic and microglial gene upregulation, increased prefrontal inhibitory transmission, and behavioral deficits. Therefore, Myt1l haploinsufficiency leads to ASD-related phenotypes in newborn mice, which are temporarily normalized in juveniles but re-appear in adults, pointing to continuing phenotypic changes long after a marked decrease of Myt1l expression in juveniles.
