Zhang N, Zhang HY, Bi SA, Moran TH and Bi S
PMID: 30902570 | DOI: 10.1016/j.neulet.2019.03.030
Thyrotropin-releasing hormone (TRH) plays an important role in the regulation of energy balance. While the regulation of TRH in the paraventricular nucleus (PVN) in response to changes of energy balance has been well studied, how TRH is regulated in the dorsomedial hypothalamus (DMH) in maintaining energy homeostasis remains unclear. Here, we assessed the effects of food restriction and exercise on hypothalamic Trh expression using Otsuka Long-Evens Tokushima Fatty (OLETF) rats. Sedentary ad lib fed OLETF rats (OLETF-SED) became hyperphagic and obese. These alterations were prevented in OLETF rats with running wheel access (OLETF-RW) or food restriction in which their food was pair-fed (OLETF-PF) to the intake of lean control rats (LETO-SED). Evaluation of hypothalamic gene expression revealed that Trh mRNA expression was increased in the PVN of OLETF-SED rats and normalized in OLETF-RW and OLETF-PF rats compared to LETO-SED rats. In contrast, the expression of Trh in the DMH was decreased in OLETF-SED rats relative to LETO-SED rats. This alteration was reversed in OLETF-RW rats as seen in LETO-SED rats, but food restriction resulted in a significant increase in DMH Trh expression in OLETF-PF rats compared to LETO-SED rats. Strikingly, while Trh mRNA expression was decreased in the PVN of intact rats in response to acute food deprivation, food deprivation resulted in increased expression of Trh in the DMH. Together, these results demonstrate the differential regulation of Trh expression in the PVN and DMH in OLETF rats and suggest that DMH TRH also contributes to hypothalamic regulation of energy balance.
Revue des Maladies Respiratoires
Tanguy, J;Boutanquoi, P;Dondaine, L;Burgy, O;Bellaye, P;Beltramo, G;Garrido, C;Bonniaud, P;Goirand, F;
| DOI: 10.1016/j.rmr.2022.11.068
Introduction Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive and lethal disease of unknown aetiology. In France, it ranks among the most frequent interstitial pathologies and affects 6 out of 8 people per 100,000 each year. IPF is characterized by dysregulated healing mechanisms that leads to the accumulation of large amounts of collagen in the lung tissue that disrupts the alveolar architecture. Nintedanib and Pirfenidone are the only currently available treatments even though they are only able to slow down the disease without being curative. In this context, inhibiting HSPB5, a low molecular weight heat shock protein known to be involved in the development of fibrosis, could constitute a potential therapeutic target. Our aim consist to explore how NCI-41356 (a chemical inhibitor of HSPB5) can limit the development of pulmonary fibrosis. Methods In vivo, fibrosis was assessed in mice injected intratracheally (i.t.) with Bleomycin (BLM) and treated with NaCl or NCI-41356 (3 times i.t. or 3 times a week i.v.). Fibrosis was evaluated by collagen quantification (Sircol, Sirius Red staining), Immunofluorescence, TGF-β gene expression (RNAscope). In vitro, TGF-β1 signaling was evaluated in epithelial cells treated by TGF-β1 with or without NCI-41356 (Western Blot, Immunofluorescence, Proximity ligation assay). Results In vivo, NCI-41356 reduced the accumulation of collagen, the expression of TGF-β1 and several pro-fibrotic markers (PAI-1, α-SMA). In vitro, NCI-41356 decreased the interaction between HSPB5 and SMAD4 explaining NCI-41356 anti-fibrotic properties. Conclusion In this study, we determined that inhibition of HSPB5/SMAD4 could limit IPF in mice. NCI-41356 modulates SMAD4 nuclear translocation thus limiting TGF-β1 signaling and synthesis of collagen and pro-fibrotic markers. Further investigations with human fibrotic lung tissues are needed to determine if these results can be transposed in human.
The Journal of neuroscience : the official journal of the Society for Neuroscience
Ambler, M;Hitrec, T;Wilson, A;Cerri, M;Pickering, A;
PMID: 35440490 | DOI: 10.1523/JNEUROSCI.2102-21.2022
Torpor is a naturally occurring, hypometabolic, hypothermic state engaged by a wide range of animals in response to imbalance between the supply and demand for nutrients. Recent work has identified some of the key neuronal populations involved in daily torpor induction in mice, in particular projections from the preoptic area of the hypothalamus (POA) to the dorsomedial hypothalamus (DMH). The DMH plays a role in thermoregulation, control of energy expenditure, and circadian rhythms, making it well positioned to contribute to the expression of torpor. We used activity dependent genetic TRAPing techniques to target DMH neurons that were active during natural torpor bouts in female mice. Chemogenetic reactivation of torpor-TRAPed DMH neurons in calorie-restricted mice promoted torpor, resulting in longer and deeper torpor bouts. Chemogenetic inhibition of torpor-TRAPed DMH neurons did not block torpor entry, suggesting a modulatory role for the DMH in the control of torpor. This work adds to the evidence that the POA and the DMH form part of a circuit within the mouse hypothalamus that controls entry into daily torpor.SIGNIFICANCEDaily heterotherms such as mice employ torpor to cope with environments in which the supply of metabolic fuel is not sufficient for the maintenance of normothermia. Daily torpor involves reductions in body temperature, as well as active suppression of heart rate and metabolism. How the central nervous system controls this profound deviation from normal homeostasis is not known, but a projection from the preoptic area to the dorsomedial hypothalamus has recently been implicated. We demonstrate that the dorsomedial hypothalamus contains neurons that are active during torpor. Activity in these neurons promotes torpor entry and maintenance, but their activation alone does not appear to be sufficient for torpor entry.
Espinosa MG, Taber LA, Wagenseil JE.
PMID: 29696727 | DOI: 10.1002/dvdy.24635
Background Perturbations to embryonic hemodynamics are known to adversely affect cardiovascular development. Vitelline vein ligation (VVL) is a model of reduced placental blood flow used to induce cardiac defects in early chick embryo development. The effect of these hemodynamic interventions on maturing elastic arteries is largely unknown. We hypothesize that hemodynamic changes impact maturation of the dorsal aorta (DA). Results We examined the effects of VVL on hemodynamic properties well into the maturation process and the corresponding changes in aortic dimensions, wall composition, and gene expression. In chick embryos, we found that DA blood velocity was reduced immediately post-surgery at Hamburger-Hamilton stage (HH) 18 and later at HH36, but not in the interim. Throughout this period, DA diameter adapted to maintain a constant shear stress. At HH36, we found that VVL DAs showed a substantial decrease in elastin and modest increase in collagen protein content. In VVL DAs, upregulation of elastic fiber related genes followed the downregulation of flow-dependent genes. Together, these suggest the existence of a compensatory mechanism in response to shear induced delays in maturation. Conclusions The DA's response to hemodynamic perturbations invokes coupled mechanisms for shear regulation and matrix maturation, potentially impacting the course of vascular development.
The American journal of pathology
Kobayashi, Y;Yokoi, A;Hashimura, M;Oguri, Y;Konno, R;Matsumoto, T;Tochimoto, M;Nakagawa, M;Ishibashi, Y;Ito, T;Ohhigata, K;Harada, Y;Fukagawa, N;Kodera, Y;Saegusa, M;
PMID: 37169340 | DOI: 10.1016/j.ajpath.2023.04.011
Epithelial-mesenchymal transition is a hallmark of uterine carcinosarcoma (UCS). Here, we used shotgun proteomics analysis to identify biomarkers associated with blebbistatin-mediated epithelial-mesenchymal transition in UCS, and found up-regulation of nucleobindin-2 (NUCB2) in endometrial carcinoma (Em Ca) cells. Expression of N-cadherin, Snail, Slug, and ZEB1 was reduced in NUCB2 knockout Em Ca cells, whereas ZEB1, Twist1, and vimentin were up-regulated in NUCB2-overexpressing Em Ca cells. NUCB2 knockout reduced cell proliferation and migration, whereas NUCB2 overexpression had the opposite effect. Treatment of Em Ca cells with transforming growth factor (TGF)-β1 dramatically altered morphology toward a fibroblastic appearance; concomitantly, expression of NUCB2 and ZEB1 increased. The NUCB2 promoter was also activated by transfection of Smad2. In UCS tissues, NUCB2 expression was significantly higher in sarcomatous compared with carcinomatous components; this was consistent with increased TGF-β1 mRNA expression in stromal and sarcomatous components compared with carcinomatous components. In addition, NUCB2 score correlated positively with ZEB1 and vimentin scores, whereas ZEB1 score correlated positively with Slug and vimentin scores and inversely with the E-cadherin score. We therefore suggest that TGF-β-dependent up-regulation of NUCB2 and ZEB1 contributes to the phenotypic characteristics of sarcomatous components in UCS.
Kaiser J, Maibach M, Salpeter I, Hagenbuch N, Souza VBC, Robinson MD, Schwab ME.
PMID: 30962276 | DOI: 10.1523/JNEUROSCI.2571-18.2019
In response to cortical stroke and unilateral corticospinal tract degeneration, compensatory sprouting of spared corticospinal fibers is associated with recovery of skilled movement in rodents. To date, little is known about the molecular mechanisms orchestrating this spontaneous rewiring. In this study, we provide insights into the molecular changes in the spinal cord tissue after large ischemic cortical injury in adult female mice, with a focus on factors that might influence the re-innervation process by contralesional corticospinal neurons. We mapped the area of cervical grey matter re-innervation by sprouting contralesional corticospinal axons after unilateral photothrombotic stroke of the motor cortex in mice using anterograde tracing. The mRNA profile of this re-innervation area was analyzed using whole-genome sequencing to identify differentially expressed genes at selected time points during the recovery process. Bioinformatic analysis revealed two phases of processes: Early after stroke (4-7 days post injury), the spinal transcriptome is characterized by inflammatory processes, including phagocytic processes as well as complement cascade activation. Microglia are specifically activated in the denervated corticospinal projection fields in this early phase. In a later phase (28-42 days post injury), biological processes include tissue repair pathways with up-regulated genes related to neurite outgrowth. Thus, the stroke-denervated spinal grey matter, in particular its intermediate laminae, represents a growth-promoting environment for sprouting corticospinal fibers originating from the contralesional motor cortex. This data set provides a solid starting point for future studies addressing key elements of the post-stroke recovery process, with the goal to improve neuroregenerative treatment options for stroke patients.SIGNIFICANCE STATEMENTWe show that the molecular changes in the spinal cord target tissue of the stroke-affected corticospinal tract are mainly defined by two phases: an early inflammatory phase during which microglia are specifically activated in the target area of re-innervating corticospinal motor neurons; and a late phase during which growth-promoting factors are upregulated which can influence the sprouting response, arborization and synapse formation. By defining for the first time the endogenous molecular machinery in the stroke-denervated cervical spinal grey matter with a focus on promotors of axon growth through the growth-inhibitory adult CNS, this study will serve as a basis to address novel neuroregenerative treatment options for chronic stroke patients.
Clinical science (London, England : 1979)
Kumar, R;Lee, MH;Kassa, B;Fonseca Balladares, DC;Mickael, C;Sanders, L;Andruska, A;Kumar, M;Spiekerkoetter, E;Bandeira, A;Stenmark, KR;Tuder, RM;Graham, BB;
PMID: 37014925 | DOI: 10.1042/CS20220642
Pulmonary hypertension (PH) can occur as a complication of schistosomiasis. In humans, schistosomiasis-PH persists despite antihelminthic therapy and parasite eradication. We hypothesized that persistent disease arises as a consequence of exposure repetition.Following intraperitoneal sensitization, mice were experimentally exposed to Schistosoma eggs by intravenous injection, either once or three times repeatedly. The phenotype was characterized by right heart catheterization and tissue analysis.Following intraperitoneal sensitization, a single intravenous Schistosoma egg exposure resulted in a PH phenotype that peaked at 7-14 days, followed by spontaneous resolution. Three sequential exposures resulted in a persistent PH phenotype. Inflammatory cytokines were not significantly different between mice exposed to one or three egg doses, but there was an increase in perivascular fibrosis in those who received three egg doses. Significant perivascular fibrosis was also observed in autopsy specimens from patients who died of this condition.Repeatedly exposing mice to schistosomiasis causes a persistent PH phenotype, accompanied by perivascular fibrosis. Perivascular fibrosis may contribute to the persistent schistosomiasis-PH observed in humans with this disease.
Jiang H, Liu X, Knolhoff BL, Hegde S, Lee KB, Jiang H, Fields RC, Pachter JA, Lim KH, DeNardo DG.
PMID: 31076405 | DOI: 10.1136/gutjnl-2018-317424
Abstract
OBJECTIVE:
We investigated how pancreatic cancer developed resistance to focal adhesion kinase (FAK) inhibition over time.
DESIGN:
Pancreatic ductal adenocarcinoma (PDAC) tumours from KPC mice (p48-CRE; LSL-KRasG12D/wt; p53flox/wt) treated with FAK inhibitor were analysed for the activation of a compensatory survival pathway in resistant tumours. We identified pathways involved in the regulation of signal transducer and activator of transcription 3 (STAT3) signalling on FAK inhibition by gene set enrichment analysis and verified these outcomes by RNA interference studies. We also tested combinatorial approaches targeting FAK and STAT3 in syngeneic transplantable mouse models of PDAC and KPC mice.
RESULTS:
In KPC mice, the expression levels of phosphorylated STAT3 (pSTAT3) were increased in PDAC cells as they progressed on FAK inhibitor therapy. This progression corresponded to decreased collagen density, lowered numbers of SMA+ fibroblasts and downregulation of the transforming growth factor beta (TGF-β)/SMAD signalling pathway in FAK inhibitor-treated PDAC tumours. Furthermore, TGF-β production by fibroblasts in vitro drives repression of STAT3 signalling and enhanced responsiveness to FAK inhibitor therapy. Knockdown of SMAD3 in pancreatic cancer cells abolished the inhibitory effects of TGF-β on pSTAT3. We further found that tumour-intrinsic STAT3 regulates the durability of the antiproliferative activity of FAK inhibitor, and combinatorial targeting of FAK and Janus kinase/STAT3 act synergistically to suppress pancreatic cancer progression in mouse models.
CONCLUSION:
Stromal depletion by FAK inhibitor therapy leads to eventual treatment resistance through the activation of STAT3 signalling. These data suggest that, similar to tumour-targeted therapies, resistance mechanisms to therapies targeting stromal desmoplasia may be critical to treatment durability.
Tanguy, J;Boutanquoi, P;Burgy, O;Dondaine, L;Beltramo, G;Uyanik, B;Garrido, C;Bonniaud, P;Bellaye, P;Goirand, F;
| DOI: 10.3390/ph16020177
Idiopathic pulmonary fibrosis is a chronic, progressive and lethal disease of unknown etiology that ranks among the most frequent interstitial lung diseases. Idiopathic pulmonary fibrosis is characterized by dysregulated healing mechanisms that lead to the accumulation of large amounts of collagen in the lung tissue that disrupts the alveolar architecture. The two currently available treatments, nintedanib and pirfenidone, are only able to slow down the disease without being curative. We demonstrated in the past that HSPB5, a low molecular weight heat shock protein, was involved in the development of fibrosis and therefore was a potential therapeutic target. Here, we have explored whether NCI-41356, a chemical inhibitor of HSPB5, can limit the development of pulmonary fibrosis. In vivo, we used a mouse model in which fibrosis was induced by intratracheal injection of bleomycin. Mice were treated with NaCl or NCI-41356 (six times intravenously or three times intratracheally). Fibrosis was evaluated by collagen quantification, immunofluorescence and TGF-β gene expression. In vitro, we studied the specific role of NCI-41356 on the chaperone function of HSPB5 and the inhibitory properties of NCI-41356 on HSPB5 interaction with its partner SMAD4 during fibrosis. TGF-β1 signaling was evaluated by immunofluorescence and Western Blot in epithelial cells treated with TGF-β1 with or without NCI-41356. In vivo, NCI-41356 reduced the accumulation of collagen, the expression of TGF-β1 and pro-fibrotic markers (PAI-1, α-SMA). In vitro, NCI-41356 decreased the interaction between HSPB5 and SMAD4 and thus modulated the SMAD4 canonical nuclear translocation involved in TGF-β1 signaling, which may explain NCI-41356 anti-fibrotic properties. In this study, we determined that inhibition of HSPB5 by NCI-41356 could limit pulmonary fibrosis in mice by limiting the synthesis of collagen and pro-fibrotic markers. At the molecular level, this outcome may be explained by the effect of NCI-41356 inhibiting HSPB5/SMAD4 interaction, thus modulating SMAD4 and TGF-β1 signaling. Further investigations are needed to determine whether these results can be transposed to humans.
An amygdala circuit that suppresses social engagement
Kwon, JT;Ryu, C;Lee, H;Sheffield, A;Fan, J;Cho, DH;Bigler, S;Sullivan, HA;Choe, HK;Wickersham, IR;Heiman, M;Choi, GB;
PMID: 33790466 | DOI: 10.1038/s41586-021-03413-6
Innate social behaviours, such as mating and fighting, are fundamental to animal reproduction and survival1. However, social engagements can also put an individual at risk2. Little is known about the neural mechanisms that enable appropriate risk assessment and the suppression of hazardous social interactions. Here we identify the posteromedial nucleus of the cortical amygdala (COApm) as a locus required for the suppression of male mating when a female mouse is unhealthy. Using anatomical tracing, functional imaging and circuit-level epistatic analyses, we show that suppression of mating with an unhealthy female is mediated by the COApm projections onto the glutamatergic population of the medial amygdalar nucleus (MEA). We further show that the role of the COApm-to-MEA connection in regulating male mating behaviour relies on the neuromodulator thyrotropin-releasing hormone (TRH). TRH is expressed in the COApm, whereas the TRH receptor (TRHR) is found in the postsynaptic MEA glutamatergic neurons. Manipulating neural activity of TRH-expressing neurons in the COApm modulated male mating behaviour. In the MEA, activation of the TRHR pathway by ligand infusion inhibited mating even towards healthy female mice, whereas genetic ablation of TRHR facilitated mating with unhealthy individuals. In summary, we reveal a neural pathway that relies on the neuromodulator TRH to modulate social interactions according to the health status of the reciprocating individual. Individuals must balance the cost of social interactions relative to the benefit, as deficits in the ability to select healthy mates may lead to the spread of disease.
Steuernagel, L;Lam, BYH;Klemm, P;Dowsett, GKC;Bauder, CA;Tadross, JA;Hitschfeld, TS;Del Rio Martin, A;Chen, W;de Solis, AJ;Fenselau, H;Davidsen, P;Cimino, I;Kohnke, SN;Rimmington, D;Coll, AP;Beyer, A;Yeo, GSH;Brüning, JC;
PMID: 36266547 | DOI: 10.1038/s42255-022-00657-y
The hypothalamus plays a key role in coordinating fundamental body functions. Despite recent progress in single-cell technologies, a unified catalog and molecular characterization of the heterogeneous cell types and, specifically, neuronal subtypes in this brain region are still lacking. Here, we present an integrated reference atlas, 'HypoMap,' of the murine hypothalamus, consisting of 384,925 cells, with the ability to incorporate new additional experiments. We validate HypoMap by comparing data collected from Smart-Seq+Fluidigm C1 and bulk RNA sequencing of selected neuronal cell types with different degrees of cellular heterogeneity. Finally, via HypoMap, we identify classes of neurons expressing glucagon-like peptide-1 receptor (Glp1r) and prepronociceptin (Pnoc), and validate them using single-molecule in situ hybridization. Collectively, HypoMap provides a unified framework for the systematic functional annotation of murine hypothalamic cell types, and it can serve as an important platform to unravel the functional organization of hypothalamic neurocircuits and to identify druggable targets for treating metabolic disorders.
The Journal of clinical investigation
Horn, LA;Chariou, PL;Gameiro, SR;Qin, H;Iida, M;Fousek, K;Meyer, TJ;Cam, M;Flies, D;Langermann, S;Schlom, J;Palena, C;
PMID: 35230974 | DOI: 10.1172/JCI155148
Collagens in the extracellular matrix (ECM) provide a physical barrier to tumor immune infiltration, while also acting as a ligand for immune inhibitory receptors. Transforming growth factor-β (TGF-β) is a key contributor to shaping the ECM by stimulating the production and remodeling of collagens. TGF-β-activation signatures and collagen-rich environments have both been associated with T-cell exclusion and lack of responses to immunotherapy. Here we describe the effect of targeting collagens that signal through the inhibitory leukocyte-associated immunoglobulin-like receptor-1 (LAIR-1) in combination with blockade of TGF-β and programmed cell death ligand 1 (PD-L1). This approach remodeled the tumor collagenous matrix, enhanced tumor infiltration and activation of CD8+ T cells, and repolarized suppressive macrophage populations resulting in high cure rates and long-term tumor-specific protection across murine models of colon and mammary carcinoma. The results highlight the advantage of direct targeting of ECM components in combination with immune checkpoint blockade therapy.
