Retinoic acid receptor responder1 promotes development of glomerular diseases via the Nuclear Factor-κB signaling pathway
Mo Ller-Hackbarth, K;Dabaghie, D;Charrin, E;Zambrano, S;Genové, G;Li, X;Wernerson, A;Lal, M;Patrakka, J;
PMID: 34147551 | DOI: 10.1016/j.kint.2021.05.036
Inflammatory pathways are activated in most glomerular diseases but molecular mechanisms driving them in kidney tissue are poorly known. We identified retinoic acid receptor responder 1 (Rarres1) as a highly podocyte-enriched protein in healthy kidneys. Studies in podocyte-specific knockout animals indicated that Rarres1 was not needed for the normal development or maintenance of the glomerulus filtration barrier, and did not modulate the outcome of kidney disease in a model of glomerulonephritis. Interestingly, we detected an induction of Rarres1 expression in glomerular and peritubular capillary endothelial cells in IgA and diabetic kidney disease, as well as in ANCA-associated vasculitis. Analysis of publicly available RNA data sets showed that the induction of Rarres1 expression was a common molecular mechanism in chronic kidney diseases. A conditional knock-in mouse line, overexpressing Rarres1 specifically in endothelial cells, did not show any obvious kidney phenotype. However, the overexpression promoted the progression of kidney damage in a model of glomerulonephritis. In line with this, conditional knock-out mice, lacking Rarres1 in endothelial cells, were partially protected in the disease model. Mechanistically, Rarres1 promoted inflammation and fibrosis via transcription factor Nuclear Factor-κB signaling pathway by activating receptor tyrosine kinase Axl. Thus, induction of Rarres1 expression in endothelial cells is a prevalent molecular mechanism in human glomerulopathies and this seems to have a pathogenic role in driving inflammation and fibrosis via the Nuclear Factor-κB signaling pathway.
Hebsgaard JB, Pyke C, Yildirim E, Knudsen LB, Heegaard S, Kvist PH.
PMID: 29707863 | DOI: 10.1111/dom.13339
Semaglutide is a human glucagon-like peptide-1 (GLP-1) analogue that is in development for the treatment of type 2 diabetes. In the pre-approval cardiovascular outcomes trial SUSTAIN 6, semaglutide was associated with a significant increase in the risk of diabetic retinopathy (DR) complications vs placebo. GLP-1 receptor (GLP-1R) expression has previously been demonstrated in the retina in animals and humans; however, antibodies used to detect expression have been documented to be non-specific and fail to detect the GLP-1R using immunohistochemistry (IHC), a problem common for many G-protein coupled receptors. Using a validated GLP-1R antibody for IHC and in situ hybridization for GLP-1R mRNA in normal human eyes, GLP-1Rs were detected in a small fraction of neurons in the ganglion cell layer. In advanced stages of DR, GLP-1R expression was not detected at the protein or mRNA level. Specifically, no GLP-1R expression was found in the eyes of people with long-standing proliferative DR (PDR). In conclusion, GLP-1R expression is low in normal human eyes and was not detected in eyes exhibiting advanced stages of PDR.
Hypertension research : official journal of the Japanese Society of Hypertension
Ochiai, K;Mochida, Y;Nagase, T;Fukuhara, H;Yamaguchi, Y;Nagase, M;
PMID: 36810623 | DOI: 10.1038/s41440-023-01219-9
The recent discovery of mechanosensitive ion channels has promoted mechanobiological research in the field of hypertension and nephrology. We previously reported Piezo2 expression in mouse mesangial and juxtaglomerular renin-producing cells, and its modulation by dehydration. This study aimed to investigate how Piezo2 expression is altered in hypertensive nephropathy. The effects of the nonsteroidal mineralocorticoid receptor blocker, esaxerenone, were also analyzed. Four-week-old Dahl salt-sensitive rats were randomly assigned to three groups: rats fed a 0.3% NaCl diet (DSN), rats fed a high 8% NaCl diet (DSH), and rats fed a high salt diet supplemented with esaxerenone (DSH + E). After six weeks, DSH rats developed hypertension, albuminuria, glomerular and vascular injuries, and perivascular fibrosis. Esaxerenone effectively decreased blood pressure and ameliorated renal damage. In DSN rats, Piezo2 was expressed in Pdgfrb-positive mesangial and Ren1-positive cells. Piezo2 expression in these cells was enhanced in DSH rats. Moreover, Piezo2-positive cells accumulated in the adventitial layer of intrarenal small arteries and arterioles in DSH rats. These cells were positive for Pdgfrb, Col1a1, and Col3a1, but negative for Acta2 (αSMA), indicating that they were perivascular mesenchymal cells different from myofibroblasts. Piezo2 upregulation was reversed by esaxerenone treatment. Furthermore, Piezo2 inhibition by siRNA in the cultured mesangial cells resulted in upregulation of Tgfb1 expression. Cyclic stretch also upregulated Tgfb1 in both transfections of control siRNA and Piezo2 siRNA. Our findings suggest that Piezo2 may have a contributory role in modulating the pathogenesis of hypertensive nephrosclerosis and have also highlighted the therapeutic effects of esaxerenone on salt-induced hypertensive nephropathy. Mechanochannel Piezo2 is known to be expressed in the mouse mesangial cells and juxtaglomerular renin-producing cells, and this was confirmed in normotensive Dahl-S rats. In salt-induced hypertensive Dahl-S rats, Piezo2 upregulation was observed in the mesangial cells, renin cells, and notably, perivascular mesenchymal cells, suggesting its involvement in kidney fibrosis.
Pflugers Archiv : European journal of physiology
Heinl, ES;Broeker, KA;Lehrmann, C;Heydn, R;Krieger, K;Ortmaier, K;Tauber, P;Schweda, F;
PMID: 36480070 | DOI: 10.1007/s00424-022-02774-9
The natriuretic peptides (NPs) ANP (atrial natriuretic peptide) and BNP (B-type natriuretic peptide) mediate their widespread effects by activating the natriuretic peptide receptor-A (NPR-A), while C-type natriuretic peptide (CNP) acts via natriuretic peptide receptor-B (NPR-B). NPs are removed from the circulation by internalization via the natriuretic peptide clearance receptor natriuretic peptide receptor-C (NPR-C). In addition to their well-known functions, for instance on blood pressure, all three NPs confer significant cardioprotection and renoprotection. Since neither the NP-mediated renal functions nor the renal target cells of renoprotection are completely understood, we performed systematic localization studies of NP receptors using in situ hybridization (RNAscope) in mouse kidneys. NPR-A mRNA is highly expressed in glomeruli (mainly podocytes), renal arterioles, endothelial cells of peritubular capillaries, and PDGFR-receptor β positive (PDGFR-β) interstitial cells. No NPR-A mRNA was detected by RNAscope in the tubular system. In contrast, NPR-B expression is highest in proximal tubules. NPR-C is located in glomeruli (mainly podocytes), in endothelial cells and PDGFR-β positive cells. To test for a possible regulation of NPRs in kidney diseases, their distribution was studied in adenine nephropathy. Signal intensity of NPR-A and NPR-B mRNA was reduced while their spatial distribution was unaltered compared with healthy kidneys. In contrast, NPR-C mRNA signal was markedly enhanced in cell clusters of myofibroblasts in fibrotic areas of adenine kidneys. In conclusion, the primary renal targets of ANP and BNP are glomerular, vascular, and interstitial cells but not the tubular compartment, while the CNP receptor NPR-B is highly expressed in proximal tubules. Further studies are needed to clarify the function and interplay of this specific receptor expression pattern.
Histopathology. 2018 Oct 4.
Sun C, Jia Y, Wang W, Bi R, Wu L, Bai Q, Zhou X.
PMID: 30286249 | DOI: 10.1111/his.13765
Abstract AIMS: The Protein expression of Programmed Death-Ligand 1 (PD-L1) has been recognized a poor prognostic biomarker in diffuse large B-cell lymphoma (DLBCL). We aim to detect PD-L1 DNA and mRNA status, and explore whether they contribute to protein expression and their clinicopathological correlation in DLBCL. METHODS AND RESULTS: In the study, we detected PD-L1 status in three different levels by Fluorescence in situ hybridization, RNA in situ hybridization and immunohistochemistry in 287 DLBCL samples with follow-ups, respectively. Their correlation and clinical pathological relevance was further analyzed. Our results showed that 1.7% (3/175) patients had PD-L1 amplification, 19.9% (57/287) PD-L1 mRNA high expression and 11.8% (34/287) high protein expression. Both mRNA and protein high expression of PD-L1 was significantly elevated in non-GCB than that in GCB DLBCL (P<0.05). In addition, the patients with PD-L1 mRNA or protein high expression but not DNA amplification have significantly poorer overall survival (OS) than that with PD-L1 low expression (P<0.05). Furthermore, we found that PD-L1 mRNA and protein expression are highly correlated (P=0.012), which was observed in all three samples with PD-L1 DNA amplification. CONCLUSIONS: PD-L1 DNA amplification is a rare event, PD-L1 mRNA mainly contribute to the protein high expression, and the latter two will serve as important biomarkers for predicting prognosis and selecting patients for immunotherapy in DLBCL.
Journal of Hematopathology
Shi, Y;Mi, L;Lai, Y;Zhao, M;Jia, L;Du, T;Song, Y;Li, X;
| DOI: 10.1007/s12308-023-00530-1
Overexpression of PD-L1 can be a predictive marker for anti-PD-1 therapeutic efficacy in classic Hodgkin lymphoma (CHL); however, harmonization of different IHC assays remains to be accomplished, and interpretations of PD-L1 immunostaining results remain controversial in CHL. In this study, we sought to optimize the PD-L1 immunohistochemistry (IHC) assay in CHL. All tests were performed on a tumour tissue microarray established from 54 CHL cases. Three IHC antibodies (405.9A11, SP142, 22C3) for detecting PD-L1 expression were compared semi quantitatively with the RNAscope assay (No. 310035, ACD), and the difference in the expression in background immune cells (ICs) between assays and the associations of expression levels with densities of TILs/TAMs were also analysed. 405.9A11 demonstrated best specificity in HRS cells and best sensitivity in ICs. Positive expression of PD-L1 was more frequent in ICs (85.2%) than in HRS cells (48.1%). Different subgroups of background ICs, including tumour-associated macrophages (TAMs), were assessed and scored for CD4, CD8, FOXP3, and CD163 expression. PD-L1 expression on ICs was the factor most associated with the density of TAMs. 405.9A11 provided the most convincing PD-L1 expression results. Pathologists should report PD-L1 expression in a combined manner, including both the status of HRS cells and the percentage of PD-L1-positive ICs.
Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism
Vazquez-Liebanas, E;Nahar, K;Bertuzzi, G;Keller, A;Betsholtz, C;Mäe, MA;
PMID: 34689641 | DOI: 10.1177/0271678X211056395
Platelet-derived growth factor B (PDGFB) released from endothelial cells is indispensable for pericyte recruitment during angiogenesis in embryonic and postnatal organ growth. Constitutive genetic loss-of-function of PDGFB leads to pericyte hypoplasia and the formation of a sparse, dilated and venous-shifted brain microvasculature with dysfunctional blood-brain barrier (BBB) in mice, as well as the formation of microvascular calcification in both mice and humans. Endothelial PDGFB is also expressed in the adult quiescent microvasculature, but here its importance is unknown. We show that deletion of Pdgfb in endothelial cells in 2-months-old mice causes a slowly progressing pericyte loss leading, at 12-18 months of age, to ≈50% decrease in endothelial:pericyte cell ratio, ≈60% decrease in pericyte longitudinal capillary coverage and >70% decrease in pericyte marker expression. Similar to constitutive loss of Pdgfb, this correlates with increased BBB permeability. However, in contrast to the constitutive loss of Pdgfb, adult-induced loss does not lead to vessel dilation, impaired arterio-venous zonation or the formation of microvascular calcifications. We conclude that PDFGB expression in quiescent adult microvascular brain endothelium is critical for the maintenance of pericyte coverage and normal BBB function, but that microvessel dilation, rarefaction, arterio-venous skewing and calcification reflect developmental roles of PDGFB.
Magno L, Lessard CB, Martins M, Lang V, Cruz P, Asi Y, Katan M, Bilsland J, Lashley T, Chakrabarty P, Golde TE, Whiting PJ.
PMID: 30711010 | DOI: 10.1186/s13195-019-0469-0
Abstract
BACKGROUND:
Recent Genome Wide Association Studies (GWAS) have identified novel rare coding variants in immune genes associated with late onset Alzheimer's disease (LOAD). Amongst these, a polymorphism in phospholipase C-gamma 2 (PLCG2) P522R has been reported to be protective against LOAD. PLC enzymes are key elements in signal transmission networks and are potentially druggable targets. PLCG2 is highly expressed in the hematopoietic system. Hypermorphic mutations in PLCG2 in humans have been reported to cause autoinflammation and immune disorders, suggesting a key role for this enzyme in the regulation of immune cell function.
METHODS:
We assessed PLCG2 distribution in human and mouse brain tissue via immunohistochemistry and in situ hybridization. We transfected heterologous cell systems (COS7 and HEK293T cells) to determine the effect of the P522R AD-associated variant on enzymatic function using various orthogonal assays, including a radioactive assay, IP-One ELISA, and calcium assays.
RESULTS:
PLCG2 expression is restricted primarily to microglia and granule cells of the dentate gyrus. Plcg2 mRNA is maintained in plaque-associated microglia in the cerebral tissue of an AD mouse model. Functional analysis of the p.P522R variant demonstrated a small hypermorphic effect of the mutation on enzyme function.
CONCLUSIONS:
The PLCG2 P522R variant is protective against AD. We show that PLCG2 is expressed in brain microglia, and the p.P522R polymorphism weakly increases enzyme function. These data suggest that activation of PLCγ2 and not inhibition could be therapeutically beneficial in AD. PLCγ2 is therefore a potential target for modulating microglia function in AD, and a small molecule drug that weakly activates PLCγ2 may be one potential therapeutic approach.
Lab Invest. 2014 Jan;94(1):107-16.
Velcheti V, Schalper KA, Carvajal DE, Anagnostou VK, Syrigos KN, Sznol M, Herbst RS, Gettinger SN, Chen L, Rimm DL (2014).
PMID: 24217091doi
Recent strategies targeting the interaction of the programmed cell death ligand-1 (PD-L1, B7-H1, CD274) with its receptor, PD-1, resulted in promising activity in early phase clinical trials. In this study, we used various antibodies and in situ mRNA hybridization to measure PD-L1 in non-small cell lung cancer (NSCLC) using a quantitative fluorescence (QIF) approach to determine the frequency of expression and prognostic value in two independent populations. A control tissue microarray (TMA) was constructed using PD-L1-transfected cells, normal human placenta and known PD-L1-positive NSCLC cases. Only one of four antibodies against PD-L1 (5H1) validated for specificity on this TMA. In situ PD-L1 mRNA using the RNAscope method was similarly validated. Two cohorts of NSCLC cases in TMAs including 340 cases from hospitals in Greece and 204 cases from Yale University were assessed. Tumors showed PD-L1 protein expression in 36% (Greek) and 25% (Yale) of the cases. PD-L1 expression was significantly associated with tumor-infiltrating lymphocytes in both cohorts. Patients with PD-L1 (both protein and mRNA) expression above the detection threshold showed statistically significant better outcome in both series (log-rank P=0.036 and P=0.027). Multivariate analysis showed that PD-L1 expression was significantly associated with better outcome independent of histology. Measurement of PD-L1 requires specific conditions and some commercial antibodies show lack of specificity. Expression of PD-L1 protein or mRNA is associated with better outcome. Further studies are required to determine the value of this marker in prognosis and prediction of response to treatments targeting this pathway.
Coy S, Rashid R, Lin JR, Du Z, Donson AM, Hankinson TC, Foreman NK, Manley PE, Kieran MW, Reardon DA, Sorger PK, Santagata S.
PMID: 29509940 | DOI: 10.1093/neuonc/noy035
Abstract
BACKGROUND:
Craniopharyngiomas are neoplasms of the sellar/parasellar region that are classified into adamantinomatous (ACP) and papillary (PCP) subtypes. Surgical resection of craniopharyngiomas is challenging, and recurrence is common, frequently leading to profound morbidity. BRAF V600E mutations render PCP susceptible to BRAF/MEK inhibitors, but effective targeted therapies are needed for ACP. We explored the feasibility of targeting the PD-1/PD-L1 immune checkpoint pathway in ACP and PCP.
METHODS:
We mapped and quantified PD-L1 and PD-1 expression in ACP and PCP resections using immunohistochemistry, immunofluorescence, and RNA in situ hybridization. We used tissue-based cyclic immunofluorescence (t-CyCIF) to map the spatial distribution of immune cells and characterize cell cycle and signaling pathways in ACP tumor cells which intrinsically express PD-1.
RESULTS:
All ACP (15±14% of cells, n=23, average±S.D.) and PCP (35±22% of cells, n=18) resections expressed PD-L1. In ACP, PD-L1 was predominantly expressed by tumor cells comprising the cyst-lining. In PCP, PD-L1 was highly-expressed by tumor cells surrounding the stromal fibrovascular cores. ACP also exhibited tumor cell-intrinsic PD-1 expression in whorled epithelial cells with nuclear-localized beta-catenin. These cells exhibited evidence of elevated mTOR and MAPK signaling. Profiling of immune populations in ACP and PCP showed a modest density of CD8+ T-cells.
CONCLUSIONS:
ACP exhibit PD-L1 expression in the tumor cyst-lining and intrinsic PD-1 expression in cells proposed to comprise an oncogenic stem-like population. In PCP, proliferative tumor cells express PD-L1 in a continuous band at the stromal-epithelial interface. Targeting PD-L1 and/or PD-1 in both subtypes of craniopharyngioma might therefore be an effective therapeutic strategy.
Heydarian, M;Oak, P;Zhang, X;Kamgari, N;Kindt, A;Koschlig, M;Pritzke, T;Gonzalez-Rodriguez, E;Förster, K;Morty, RE;Häfner, F;Hübener, C;Flemmer, AW;Yildirim, AO;Sudheendra, D;Tian, X;Petrera, A;Kirsten, H;Ahnert, P;Morrell, N;Desai, TJ;Sucre, J;Spiekerkoetter, E;Hilgendorff, A;
PMID: 35580897 | DOI: 10.1136/thoraxjnl-2021-218083
Chronic lung disease, that is, bronchopulmonary dysplasia (BPD) is the most common complication in preterm infants and develops as a consequence of the misguided formation of the gas-exchange area undergoing prenatal and postnatal injury. Subsequent vascular disease and its progression into pulmonary arterial hypertension critically determines long-term outcome in the BPD infant but lacks identification of early, disease-defining changes.We link impaired bone morphogenetic protein (BMP) signalling to the earliest onset of vascular pathology in the human preterm lung and delineate the specific effects of the most prevalent prenatal and postnatal clinical risk factors for lung injury mimicking clinically relevant conditions in a multilayered animal model using wild-type and transgenic neonatal mice.We demonstrate (1) the significant reduction in BMP receptor 2 (BMPR2) expression at the onset of vascular pathology in the lung of preterm infants, later mirrored by reduced plasma BMP protein levels in infants with developing BPD, (2) the rapid impairment (and persistent change) of BMPR2 signalling on postnatal exposure to hyperoxia and mechanical ventilation, aggravated by prenatal cigarette smoke in a preclinical mouse model and (3) a link to defective alveolar septation and matrix remodelling through platelet derived growth factor-receptor alpha deficiency. In a treatment approach, we partially reversed vascular pathology by BMPR2-targeted treatment with FK506 in vitro and in vivo.We identified impaired BMP signalling as a hallmark of early vascular disease in the injured neonatal lung while outlining its promising potential as a future biomarker or therapeutic target in this growing, high-risk patient population.
Du Z, Abedalthagafi M, Aizer AA, McHenry AR, Sun HH, Bray MA, Viramontes O, Machaidze R, Brastianos PK, Reardon DA, Dunn IF, Freeman GJ, Ligon KL, Carpenter AE, Alexander BM, Agar NY, Rodig SJ, Bradshaw EM, Santagata S
PMID: 25609200
There are no effective medical treatments for WHO grade III (anaplastic) meningioma. Patients with this high-grade malignancy have a median survival of less than two years. Therapeutics that modulate the mechanisms that inhibit local immune responses in the tumor microenvironment are showing significant and durable clinical responses in patients with treatment refractory high-grade tumors. We examined the immune infiltrate of 291 meningiomas including WHO grade I-III meningiomas using immunohistochemistry and we examined the expression of PD-L1 mRNA by RNAscope in situ hybridization and PD-L1 protein by immunohistochemistry. In meningioma, the tumor infiltrating lymphocytes are predominantly T cells. In anaplastic meningioma, there is a sharp decrease in the number of T cells, including the numbers of CD4+ and CD8+ T cells and cells expressing PD-1 and there is also an increase in the number of FOXP3 expressing immunoregulatory (Treg) cells. PD-L1 expression is increased in anaplastic meningioma - both mRNA and protein. Using patient derived meningioma cell, we confirm that PD-L1 is expressed in meningioma cells themselves, and not solely in infiltrating immune cells. This work indicates that high-grade meningioma harbor an immunosuppressive tumor microenviroment and that increased Treg cells and elevated PD-L1 may contribute to the aggressive phenotype of these tumors.
