Lui, JC;Raimann, A;Hojo, H;Dong, L;Roschger, P;Kikani, B;Wintergerst, U;Fratzl-Zelman, N;Jee, YH;Haeusler, G;Baron, J;
PMID: 35121733 | DOI: 10.1038/s41467-022-28318-4
SP7/Osterix is a transcription factor critical for osteoblast maturation and bone formation. Homozygous loss-of-function mutations in SP7 cause osteogenesis imperfecta type XII, but neomorphic (gain-of-new-function) mutations of SP7 have not been reported in humans. Here we describe a de novo dominant neomorphic missense variant (c.926 C > G:p.S309W) in SP7 in a patient with craniosynostosis, cranial hyperostosis, and long bone fragility. Histomorphometry shows increased osteoblasts but decreased bone mineralization. Mice with the corresponding variant also show a complex skeletal phenotype distinct from that of Sp7-null mice. The mutation alters the binding specificity of SP7 from AT-rich motifs to a GC-consensus sequence (typical of other SP family members) and produces an aberrant gene expression profile, including increased expression of Col1a1 and endogenous Sp7, but decreased expression of genes involved in matrix mineralization. Our study identifies a pathogenic mechanism in which a mutation in a transcription factor shifts DNA binding specificity and provides important in vivo evidence that the affinity of SP7 for AT-rich motifs, unique among SP proteins, is critical for normal osteoblast differentiation.
Rodríguez, JMM;Fonfara, S;Hetzel, U;Kipar, A;
PMID: 34955067 | DOI: 10.1177/03009858211062631
The sequence of pathological events in feline hypertrophic cardiomyopathy (fHCM) is still largely unknown, although we know that fHCM is characterized by interstitial remodeling in a macrophage-driven pro-inflammatory environment and that myocardial ischemia might contribute to its progression. This study aimed to gain further insights into the structural changes associated with interstitial remodeling in fHCM with special focus on the myocardial microvasculature and the phenotype of the interstitial cells. Twenty-eight hearts (16 hearts with fHCM and 12 without cardiac disease) were evaluated in the current study, with immunohistochemistry, RNA-in situ hybridization, and transmission electron microscopy. Morphometrical evaluations revealed a statistically significant lower microvascular density in fHCM. This was associated with structural alterations in capillaries that go along with a widening of the interstitium due to the accumulation of edema fluid, collagen fibers, and mononuclear cells that also proliferated locally. The interstitial cells were mainly of fibroblastic or vascular phenotype, with a substantial contribution of predominantly resident macrophages. A large proportion expressed CD34 mRNA, which suggests a progenitor cell potential. Our results indicate that microvascular alterations are key events in the pathogenesis of fHCM and that myocardial interstitial cell populations with CD34+ phenotype play a role in the pathogenesis of the disease.
International journal of molecular sciences
Son, M;Kim, GY;Yang, Y;Ha, S;Kim, J;Kim, D;Chung, HY;Moon, HR;Chung, KW;
PMID: 36902313 | DOI: 10.3390/ijms24054882
The peroxisome proliferator-activated receptor (PPAR) nuclear receptor has been an interesting target for the treatment of chronic diseases. Although the efficacy of PPAR pan agonists in several metabolic diseases has been well studied, the effect of PPAR pan agonists on kidney fibrosis development has not been demonstrated. To evaluate the effect of the PPAR pan agonist MHY2013, a folic acid (FA)-induced in vivo kidney fibrosis model was used. MHY2013 treatment significantly controlled decline in kidney function, tubule dilation, and FA-induced kidney damage. The extent of fibrosis determined using biochemical and histological methods showed that MHY2013 effectively blocked the development of fibrosis. Pro-inflammatory responses, including cytokine and chemokine expression, inflammatory cell infiltration, and NF-κB activation, were all reduced with MHY2013 treatment. To demonstrate the anti-fibrotic and anti-inflammatory mechanisms of MHY2013, in vitro studies were conducted using NRK49F kidney fibroblasts and NRK52E kidney epithelial cells. In the NRK49F kidney fibroblasts, MHY2013 treatment significantly reduced TGF-β-induced fibroblast activation. The gene and protein expressions of collagen I and α-smooth muscle actin were significantly reduced with MHY2013 treatment. Using PPAR transfection, we found that PPARγ played a major role in blocking fibroblast activation. In addition, MHY2013 significantly reduced LPS-induced NF-κB activation and chemokine expression mainly through PPARβ activation. Taken together, our results suggest that administration of the PPAR pan agonist effectively prevented renal fibrosis in both in vitro and in vivo models of kidney fibrosis, implicating the therapeutic potential of PPAR agonists against chronic kidney diseases.
Peisker, F;Halder, M;Nagai, J;Ziegler, S;Kaesler, N;Hoeft, K;Li, R;Bindels, EMJ;Kuppe, C;Moellmann, J;Lehrke, M;Stoppe, C;Schaub, MT;Schneider, RK;Costa, I;Kramann, R;
PMID: 35641541 | DOI: 10.1038/s41467-022-30682-0
The cardiac vascular and perivascular niche are of major importance in homeostasis and during disease, but we lack a complete understanding of its cellular heterogeneity and alteration in response to injury as a major driver of heart failure. Using combined genetic fate tracing with confocal imaging and single-cell RNA sequencing of this niche in homeostasis and during heart failure, we unravel cell type specific transcriptomic changes in fibroblast, endothelial, pericyte and vascular smooth muscle cell subtypes. We characterize a specific fibroblast subpopulation that exists during homeostasis, acquires Thbs4 expression and expands after injury driving cardiac fibrosis, and identify the transcription factor TEAD1 as a regulator of fibroblast activation. Endothelial cells display a proliferative response after injury, which is not sustained in later remodeling, together with transcriptional changes related to hypoxia, angiogenesis, and migration. Collectively, our data provides an extensive resource of transcriptomic changes in the vascular niche in hypertrophic cardiac remodeling.
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.
Shen, TH;Stauber, J;Xu, K;Jacunski, A;Paragas, N;Callahan, M;Banlengchit, R;Levitman, AD;Desanti De Oliveira, B;Beenken, A;Grau, MS;Mathieu, E;Zhang, Q;Li, Y;Gopal, T;Askanase, N;Arumugam, S;Mohan, S;Good, PI;Stevens, JS;Lin, F;Sia, SK;Lin, CS;D'Agati, V;Kiryluk, K;Tatonetti, NP;Barasch, J;
PMID: 35230973 | DOI: 10.1172/jci.insight.146374
The current strategy to detect acute injury of kidney tubular cells relies on changes in serum levels of creatinine. Yet serum creatinine (sCr) is a marker of both functional and pathological processes and does not adequately assay tubular injury. In addition, sCr may require days to reach diagnostic thresholds, yet tubular cells respond with programs of damage and repair within minutes or hours. To detect acute responses to clinically relevant stimuli, we created mice expressing Rosa26-floxed-stop uracil phosphoribosyltransferase (Uprt) and inoculated 4-thiouracil (4-TU) to tag nascent RNA at selected time points. Cre-driven 4-TU-tagged RNA was isolated from intact kidneys and demonstrated that volume depletion and ischemia induced different genetic programs in collecting ducts and intercalated cells. Even lineage-related cell types expressed different genes in response to the 2 stressors. TU tagging also demonstrated the transient nature of the responses. Because we placed Uprt in the ubiquitously active Rosa26 locus, nascent RNAs from many cell types can be tagged in vivo and their roles interrogated under various conditions. In short, 4-TU labeling identifies stimulus-specific, cell-specific, and time-dependent acute responses that are otherwise difficult to detect with other technologies and are entirely obscured when sCr is the sole metric of kidney damage.
Yang, Y;Ha, S;Jeong, S;Jang, CW;Kim, J;Im, DS;Chung, HY;Chung, KW;
PMID: 34619300 | DOI: 10.1016/j.tox.2021.152973
Chronic kidney disease (CKD) is characterized by persistent abnormalities in kidney function, accompanied by structural changes. Interstitial fibrosis, characterized by the accumulation of extracellular matrix (ECM) proteins, is frequently detected during CKD development. Given the multiple underlying causes of CKD, numerous animal models have been developed to advance our understanding of human nephropathy. Herein, we compared two reliable toxin-induced mouse kidney fibrosis models in terms of fibrosis and inflammation. Administration of folic acid (250 mg/kg, intraperitoneal injection) or an adenine diet (0.25 % for three weeks) afforded similar effects on kidney function, as detected by increased serum nitrogen levels. In addition, the kidneys exhibited a similar extent of tubule dilation and kidney damage. The degree of fibrosis was compared using various biological methods. Although both models developed a significant fibrotic phenotype, the adenine diet-fed model showed a marginally higher increase in fibrosis than the folic acid model, as reflected by increased kidney ECM gene and protein levels. We further compared inflammatory responses in the kidneys. Interestingly, pro-inflammatory responses, including cytokine expression and immune cell infiltration, were significantly increased in adenine diet-fed kidneys. Furthermore, collagen expression was identified in the macrophage-infiltrated region, implying the importance of inflammation in fibrogenesis. Collectively, we observed that the adenine diet-fed kidney fibrosis model presented a higher inflammatory response with increased fibrosis when compared with the folic acid-induced kidney fibrosis model, indicating the importance of the inflammatory response in fibrosis development.
CB1 R and iNOS are distinct players promoting pulmonary fibrosis in Hermansky-Pudlak syndrome
Clinical and translational medicine
Cinar, R;Park, JK;Zawatsky, CN;Coffey, NJ;Bodine, SP;Abdalla, J;Yokoyama, T;Jourdan, T;Jay, L;Zuo, MXG;O'Brien, KJ;Huang, J;Mackie, K;Alimardanov, A;Iyer, MR;Gahl, WA;Kunos, G;Gochuico, BR;Malicdan, MCV;
PMID: 34323400 | DOI: 10.1002/ctm2.471
Hermansky-Pudlak syndrome (HPS) is a rare genetic disorder which, in its most common and severe form, HPS-1, leads to fatal adult-onset pulmonary fibrosis (PF) with no effective treatment. We evaluated the role of the endocannabinoid/CB1 R system and inducible nitric oxide synthase (iNOS) for dual-target therapeutic strategy using human bronchoalveolar lavage fluid (BALF), lung samples from patients with HPS and controls, HPS-PF patient-derived lung fibroblasts, and bleomycin-induced PF in pale ear mice (HPS1ep/ep ). We found overexpression of CB1 R and iNOS in fibrotic lungs of HPSPF patients and bleomycin-infused pale ear mice. The endocannabinoid anandamide was elevated in BALF and negatively correlated with pulmonary function parameters in HPSPF patients and pale ear mice with bleomycin-induced PF. Simultaneous targeting of CB1 R and iNOS by MRI-1867 yielded greater antifibrotic efficacy than inhibiting either target alone by attenuating critical pathologic pathways. Moreover, MRI-1867 treatment abrogated bleomycin-induced increases in lung levels of the profibrotic interleukin-11 via iNOS inhibition and reversed mitochondrial dysfunction via CB1 R inhibition. Dual inhibition of CB1 R and iNOS is an effective antifibrotic strategy for HPSPF.
Modelling TGFβR and Hh pathway regulation of prognostic matrisome molecules in ovarian cancer
Delaine-Smith, R;Maniati, E;Malacrida, B;Nichols, S;Roozitalab, R;Jones, R;Lecker, L;Pearce, O;Knight, M;Balkwill, F;
| DOI: 10.1016/j.isci.2021.102674
In a multi-level ‘deconstruction’ of omental metastases, we previously identified a prognostic matrisome gene expression signature in high-grade serous ovarian cancer (HGSOC) and twelve other malignancies. Here, our aim was to understand how six of these extracellular matrix, ECM, molecules, COL11A1, COMP, FN1, VCAN, CTSB and COL1A1, are up-regulated in cancer. Using biopsies, we identified significant associations between TGFβR activity, Hedgehog signalling and these ECM molecules and studied the associations in mono-, co- and tri-culture. Activated omental fibroblasts produced more matrix than malignant cells, directed by TGFβR and Hedgehog signalling crosstalk. We ‘reconstructed’ omental metastases in tri-cultures of HGSOC cells, omental fibroblasts and adipocytes. This combination was sufficient to generate all six ECM proteins and the matrisome expression signature. TGFβR and Hedgehog inhibitor combinations attenuated fibroblast activation, gel and ECM remodelling in these models. The tri-culture model reproduces key features of omental metastases and allows study of diseased-associated ECM.
Jin Y, Cong Q, Gvozdenovic-Jeremic J, Hu J, Zhang Y, Terkeltaub R, Yang Y.
PMID: 30111653 | DOI: 10.1242/dev.164830
The differentiated phenotype of articular chondrocytes of synovial joints needs to be maintained throughout life. Disruption of the articular cartilage, frequently associated with chondrocyte hypertrophy and calcification, is a central feature in osteoarthritis (OA). However, the molecular mechanisms whereby phenotypes of articular chondrocytes are maintained and pathological calcification is inhibited remain poorly understood. Recently, the ecto-enzyme ENPP1, a suppressor of pathological calcification, was reported to be decreased in joint cartilage with OA in both human and mouse, and Enpp1 deficiency causes joint calcification. Here we found that Hedgehog signaling activation contributes to ectopic joint calcification in the Enpp1-/- mice. In the Enpp1-/- joints, Hedgehog signaling was upregulated. Further activation of Hedgehog signaling by removing Patched 1 in the Enpp1-/- mice enhanced ectopic joint calcification, while removing Gli2 partially rescued the ectopic calcification phenotype. Additionally, reduction of Gαs in the Enpp1-/- mice also enhanced joint calcification, suggesting Enpp1 inhibited Hedgehog signaling and chondrocyte hypertrophy by activating Gαs-PKA signaling. Our findings provide new insights in the mechanisms underlying Enpp1 regulation of joint integrity.
Duan L, Zhang XD, Miao WX, Sun YJ, Xiong G, Wu Q, Li G, Yang P, Yu H, Li H, Wang Y, Zhang M, Hu LY, Tong X, Zhou WH, Yu X.
PMID: - | DOI: 10.1016/j.neuron.2018.08.030
Acute infection, if not kept in check, can lead to systemic inflammatory responses in the brain. Here, we show that within 2 hr of systemic inflammation, PDGFRβ mural cells of blood vessels rapidly secrete chemokine CCL2, which in turn increases total neuronal excitabilityby promoting excitatory synaptic transmission in glutamatergic neurons of multiple brain regions. By single-cell RNA sequencing, we identified Col1a1 and Rgs5 subgroups of PDGFRβ cells as the main source of CCL2. Lipopolysaccharide (LPS)- or Poly(I:C)-treated pericyte culture medium induced similar effects in a CCL2-dependent manner. Importantly, in Pdgfrb-Cre;Ccl2fl/fl mice, LPS-induced increase in excitatory synaptic transmission was significantly attenuated. These results demonstrate in vivo that PDGFRβ cells function as initial sensors of external insults by secreting CCL2, which relays the signal to the central nervous system. Through their gateway position in the brain, PDGFRβ cells are ideally positioned to respond rapidly to environmental changes and to coordinate responses.
Nabhan, AN;Webster, JD;Adams, JJ;Blazer, L;Everrett, C;Eidenschenk, C;Arlantico, A;Fleming, I;Brightbill, HD;Wolters, PJ;Modrusan, Z;Seshagiri, S;Angers, S;Sidhu, SS;Newton, K;Arron, JR;Dixit, VM;
PMID: 37321220 | DOI: 10.1016/j.cell.2023.05.022
Wnt ligands oligomerize Frizzled (Fzd) and Lrp5/6 receptors to control the specification and activity of stem cells in many species. How Wnt signaling is selectively activated in different stem cell populations, often within the same organ, is not understood. In lung alveoli, we show that distinct Wnt receptors are expressed by epithelial (Fzd5/6), endothelial (Fzd4), and stromal (Fzd1) cells. Fzd5 is uniquely required for alveolar epithelial stem cell activity, whereas fibroblasts utilize distinct Fzd receptors. Using an expanded repertoire of Fzd-Lrp agonists, we could activate canonical Wnt signaling in alveolar epithelial stem cells via either Fzd5 or, unexpectedly, non-canonical Fzd6. A Fzd5 agonist (Fzd5ag) or Fzd6ag stimulated alveolar epithelial stem cell activity and promoted survival in mice after lung injury, but only Fzd6ag promoted an alveolar fate in airway-derived progenitors. Therefore, we identify a potential strategy for promoting regeneration without exacerbating fibrosis during lung injury.
