| 1. |
- Albrecht, Inka, et al.
(författare)
-
Development of autoantibodies against muscle-specific FHL1 in severe inflammatory myopathies
- 2015
-
Ingår i: Journal of Clinical Investigation. - : AMER SOC CLINICAL INVESTIGATION INC. - 0021-9738 .- 1558-8238. ; 125:12, s. 4612-4624
-
Tidskriftsartikel (refereegranskat)abstract
- Mutations of the gene encoding four-and-a-half LIM domain 1 (FHL1) are the causative factor of several X-linked hereditary myopathies that are collectively termed FHL1-related myopathies. These disorders are characterized by severe muscle dysfunction and damage. Here, we have shown that patients with idiopathic inflammatory myopathies (IIMs) develop autoimmunity to FHL1, which is a muscle-specific protein. Anti-FHL1 autoantibodies were detected in 25% of IIM patients, while patients with other autoimmune diseases or muscular dystrophies were largely anti-FHL1 negative. Anti-FHL1 reactivity was predictive for muscle atrophy, dysphagia, pronounced muscle fiber damage, and vasculitis. FHL1 showed an altered expression pattern, with focal accumulation in the muscle fibers of autoantibody-positive patients compared with a homogeneous expression in anti-FHL1-negative patients and healthy controls. We determined that FHL1 is a target of the cytotoxic protease granzyme B, indicating that the generation of FHL1 fragments may initiate FHL1 autoimmunity. Moreover, immunization of myositis-prone mice with FHL1 aggravated muscle weakness and increased mortality, suggesting a direct link between anti-FHL1 responses and muscle damage. Together, our findings provide evidence that FHL1 may be involved in the pathogenesis not only of genetic FHL1-related myopathies but also of autoimmune IIM. Importantly, these results indicate that anti-FHL1 autoantibodies in peripheral blood have promising potential as a biomarker to identify a subset of severe IIM.
|
|
| 2. |
- Apollonio, Benedetta, et al.
(författare)
-
Tumor-activated lymph node fibroblasts suppress T cell function in diffuse large B cell lymphoma
- 2023
-
Ingår i: Journal of Clinical Investigation. - : American Society for Clinical Investigation. - 0021-9738 .- 1558-8238. ; 133:13
-
Tidskriftsartikel (refereegranskat)abstract
- Recent transcriptomic-based analysis of diffuse large B cell lymphoma (DLBCL) has highlighted the clinical relevance of LN fibroblast and tumor-infiltrating lymphocyte (TIL) signatures within the tumor microenvironment (TME). However, the immunomodulatory role of fibroblasts in lymphoma remains unclear. Here, by studying human and mouse DLBCL-LNs, we identified the presence of an aberrantly remodeled fibroblastic reticular cell (FRC) network expressing elevated fibroblast activated protein (FAP). RNA-Seq analyses revealed that exposure to DLBCL reprogrammed key immunoregulatory pathways in FRCs, including a switch from homeostatic to inflammatory chemokine expression and elevated antigen-presentation molecules. Functional assays showed that DLBCL-activated FRCs (DLBCL-FRCs) hindered optimal TIL and chimeric antigen receptor (CAR) T cell migration. Moreover, DLBCL-FRCs inhibited CD'+ TIL cytotoxicity in an antigen-specific manner. Notably, the interrogation of patient LNs with imaging mass cytometry identified distinct environments differing in their CD'+ TIL-FRC composition and spatial organization that associated with survival outcomes. We further demonstrated the potential to target inhibitory FRCs to rejuvenate interacting TILs. Cotreating organotypic cultures with FAP-targeted immunostimulatory drugs and a bispecific antibody (glofitamab) augmented antilymphoma TIL cytotoxicity. Our study reveals an immunosuppressive role of FRCs in DLBCL, with implications for immune evasion, disease pathogenesis, and optimizing immunotherapy for patients.
|
|
| 3. |
- Aspelund, Aleksanteri, et al.
(författare)
-
The Schlemm's canal is a VEGF-C/VEGFR-3-responsive lymphatic-like vessel
- 2014
-
Ingår i: Journal of Clinical Investigation. - 0021-9738 .- 1558-8238. ; 124:9, s. 3975-3986
-
Tidskriftsartikel (refereegranskat)abstract
- In glaucoma, aqueous outflow into the Schlemm's canal (SC) is obstructed. Despite striking structural and functional similarities with the lymphatic vascular, system, it is unknown whether the SC is a blood or lymphatic vessel. Here, we demonstrated the expression of lymphatic endothelial cell markers by the SC in murine and zebrafish models as well as in human eye tissue. The initial stages of SC development involved induction of the transcription factor PROX1 and the lymphangiogenic receptor tyrosine kinase VEGFR-3 in venous endothelial cells in postnatal mice. Using gene deletion and function-blocking antibodies in mice, we determined that the lymphangiogenic growth factor VEGF-C and its receptor, VEGFR-3, are essential for SC development. Delivery of VEGF-C into the adult eye resulted in sprouting, proliferation, and growth of SC endothelial cells, whereas VEGF-A obliterated the aqueous outflow system. Furthermore, a single injection of recombinant VEGF-C induced SC growth and was associated with trend toward a sustained decrease in intraocular pressure in adult mice. These results reveal the evolutionary conservation of the lymphatic-like phenotype of the SC, implicate VEGF-C and VEGFR-3 as critical regulators of SC lymphangiogenesis, and provide a basis for further studies on therapeutic manipulation of the SC with VEGF-C in glaucoma treatment.
|
|
| 4. |
- Bazigou, Eleni, et al.
(författare)
-
Genes regulating lymphangiogenesis control venous valve formation and maintenance in mice.
- 2011
-
Ingår i: Journal of Clinical Investigation. - 0021-9738 .- 1558-8238. ; 121:8
-
Tidskriftsartikel (refereegranskat)abstract
- Chronic venous disease and venous hypertension are common consequences of valve insufficiency, yet the molecular mechanisms regulating the formation and maintenance of venous valves have not been studied. Here, we provide what we believe to be the first description of venous valve morphogenesis and identify signaling pathways required for the process. The initial stages of valve development were found to involve induction of ephrin-B2, a key marker of arterial identity, by venous endothelial cells. Intriguingly, developing and mature venous valves also expressed a repertoire of proteins, including prospero-related homeobox 1 (Prox1), Vegfr3, and integrin-α9, previously characterized as specific and critical regulators of lymphangiogenesis. Using global and venous valve-selective knockout mice, we further demonstrate the requirement of ephrin-B2 and integrin-α9 signaling for the development and maintenance of venous valves. Our findings therefore identified molecular regulators of venous valve development and maintenance and highlighted the involvement of common morphogenetic processes and signaling pathways in controlling valve formation in veins and lymphatic vessels. Unexpectedly, we found that venous valve endothelial cells closely resemble lymphatic (valve) endothelia at the molecular level, suggesting plasticity in the ability of a terminally differentiated endothelial cell to take on a different phenotypic identity.
|
|
| 5. |
- Bode, Lars, et al.
(författare)
-
Heparan sulfate and syndecan-1 are essential in maintaining murine and human intestinal epithelial barrier function
- 2008
-
Ingår i: Journal of Clinical Investigation. - 0021-9738 .- 1558-8238. ; 118:1, s. 229-238
-
Tidskriftsartikel (refereegranskat)abstract
- Patients with protein-losing enteropathy (PLE) fail to maintain intestinal epithelial barrier function and develop an excessive and potentially fatal efflux of plasma proteins. PLE occurs in ostensibly unrelated diseases, but emerging commonalities in clinical observations recently led us to identify key players in PLE pathogenesis. These include elevated IFN-gamma, TNF-alpha, venous hypertension, and the specific loss of heparan sulfate proteoglycans from the basolateral surface of intestinal epithelial cells during PLE episodes. Here we show that heparan sulfate and syndecan-1, the predominant intestinal epithelial heparan sulfate proteoglycan, are essential in maintaining intestinal epithelial barrier function. Heparan sulfate- or syndecan-1-deficient mice and mice with intestinal-specific loss of heparan sulfate had increased basal protein leakage and were far more susceptible to protein loss induced by combinations of IFN-gamma, TNF-alpha, and increased venous pressure. Similarly, knockdown of syndecan-1 in human epithelial cells resulted in increased basal and cytokine-induced protein leakage. Clinical application of heparin has been known to alleviate PLE in some patients but its unknown mechanism and severe side effects due to its anticoagulant activity limit its usefulness. We demonstrate here that non-anticoagulant 2,3-de-O-sulfated heparin could prevent intestinal protein leakage in syndecan-deficient mice, suggesting that this may be a safe and effective therapy for PLE patients.
|
|
| 6. |
- Chen, Chiu-Yu, et al.
(författare)
-
Blood flow reprograms lymphatic vessels to blood vessels.
- 2012
-
Ingår i: Journal of Clinical Investigation. - 0021-9738 .- 1558-8238. ; 122:6
-
Tidskriftsartikel (refereegranskat)abstract
- Human vascular malformations cause disease as a result of changes in blood flow and vascular hemodynamic forces. Although the genetic mutations that underlie the formation of many human vascular malformations are known, the extent to which abnormal blood flow can subsequently influence the vascular genetic program and natural history is not. Loss of the SH2 domain-containing leukocyte protein of 76 kDa (SLP76) resulted in a vascular malformation that directed blood flow through mesenteric lymphatic vessels after birth in mice. Mesenteric vessels in the position of the congenital lymphatic in mature Slp76-null mice lacked lymphatic identity and expressed a marker of blood vessel identity. Genetic lineage tracing demonstrated that this change in vessel identity was the result of lymphatic endothelial cell reprogramming rather than replacement by blood endothelial cells. Exposure of lymphatic vessels to blood in the absence of significant flow did not alter vessel identity in vivo, but lymphatic endothelial cells exposed to similar levels of shear stress ex vivo rapidly lost expression of PROX1, a lymphatic fate-specifying transcription factor. These findings reveal that blood flow can convert lymphatic vessels to blood vessels, demonstrating that hemodynamic forces may reprogram endothelial and vessel identity in cardiovascular diseases associated with abnormal flow.
|
|
| 7. |
- Claesson-Welsh, Lena
(författare)
-
How the matrix metalloproteinase MMP14 contributes to the progression of colorectal cancer : Comment
- 2020
-
Ingår i: Journal of Clinical Investigation. - 0021-9738 .- 1558-8238. ; 130:3, s. 1093-1095
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Certain matrix metalloproteinase (MMP) family proteins have been associated with cell proliferation and invasion in aggressive cancers. However, attempts to target the MMPs with the hope of treating tumors have thus far failed. In this issue of the JCI, Ragusa and coworkers identified an intestinal cancer subgroup of slow-growing, chemotherapy-resistant, and very aggressive matrix-rich tumors that mimic a hard-to-treat colorectal cancer subtype in humans. These tumors showed downregulated levels of the transcription factor prospero homeobox protein 1 (PROX1), which relieved repression of the matrix metalloproteinase MMP14. Upregulated MMP14 levels correlated with blood vessel dysfunction and a lack of cytotoxic T cells. Notably, blockade of proangiogenic factors in combination with stimulation of the CD40 pathway in the mouse cancer model boosted cytotoxic T cell infiltration. The study illustrates how combinatorial treatments for aggressive, T cell-deficient cancers can launch an antitumor immune response.
|
|
| 8. |
- Crowley, S. D., et al.
(författare)
-
Glomerular type 1 angiotensin receptors augment kidney injury and inflammation in murine autoimmune nephritis
- 2009
-
Ingår i: J Clin Invest. - 1558-8238 .- 1558-8238 .- 0021-9738. ; 119:4, s. 943-53
-
Tidskriftsartikel (refereegranskat)abstract
- Studies in humans and animal models indicate a key contribution of angiotensin II to the pathogenesis of glomerular diseases. To examine the role of type 1 angiotensin (AT1) receptors in glomerular inflammation associated with autoimmune disease, we generated MRL-Faslpr/lpr (lpr) mice lacking the major murine type 1 angiotensin receptor (AT1A); lpr mice develop a generalized autoimmune disease with glomerulonephritis that resembles SLE. Surprisingly, AT1A deficiency was not protective against disease but instead substantially accelerated mortality, proteinuria, and kidney pathology. Increased disease severity was not a direct effect of immune cells, since transplantation of AT1A-deficient bone marrow did not affect survival. Moreover, autoimmune injury in extrarenal tissues, including skin, heart, and joints, was unaffected by AT1A deficiency. In murine systems, there is a second type 1 angiotensin receptor isoform, AT1B, and its expression is especially prominent in the renal glomerulus within podocytes. Further, expression of renin was enhanced in kidneys of AT1A-deficient lpr mice, and they showed evidence of exaggerated AT1B receptor activation, including substantially increased podocyte injury and expression of inflammatory mediators. Administration of losartan, which blocks all type 1 angiotensin receptors, reduced markers of kidney disease, including proteinuria, glomerular pathology, and cytokine mRNA expression. Since AT1A-deficient lpr mice had low blood pressure, these findings suggest that activation of type 1 angiotensin receptors in the glomerulus is sufficient to accelerate renal injury and inflammation in the absence of hypertension.
|
|
| 9. |
- de Luca, Carl, et al.
(författare)
-
Complete rescue of obesity, diabetes, and infertility in db/db mice by neuron-specific LEPR-B transgenes
- 2005
-
Ingår i: Journal of Clinical Investigation. - 0021-9738 .- 1558-8238. ; 115:12, s. 3484-3493
-
Tidskriftsartikel (refereegranskat)abstract
- We have generated mice that carry a neuron-specific leptin receptor (LEPR) transgene whose expression is driven by the rat synapsin I promoter synapsin-LEPR B (SYN-LEPR-B). We have also generated mice that are compound hemizygotes for the transgenes SYN-LEPR-B and neuron-specific enolase-LEPR B (NSE-LEPR-B). We observed a degree of correction in db/db mice that are hemizygous (Syn db/db) and homozygous (Syn/Syn db/db) for the SYN-LEPR-B transgene similar to that previously reported for the NSE-LEPR-B transgene. We also show complete correction of the obesity and related phenotypes of db/db mice that are hemizygous for both NSE-LEPR-B and SYN-LEPR-B transgenes (Nse+Syn db/db). Body composition, insulin sensitivity, and cold tolerance were completely normalized in Nse+Syn db/db mice at 12 weeks of age compared with lean controls. In situ hybridization for LEPR B isoform expression in Nse+Syn db/db mice showed robust expression in the energy homeostasis-relevant regions of the hypothalamus. Expression of 3 neuropeptide genes, agouti-related peptide (Agrp), neuropeptide Y (Npy), and proopiomelanocortin (Pomc), was fully normalized in dual transgenic db/db mice. The 2 transgenes in concert conferred normal fertility to male and female db/db mice. Male mice with partial peripheral deletion of Lepr, induced in the periweaning phase, did not show alterations in body composition or mass. In summary, we show that brain-specific leptin signaling is sufficient to reverse the obesity, diabetes, and infertility of db/db mice.
|
|
| 10. |
- Elgendy, Mohamed, et al.
(författare)
-
Dual modulation of MCL-1 and mTOR determines the response to sunitinib
- 2017
-
Ingår i: Journal of Clinical Investigation. - 0021-9738 .- 1558-8238. ; 127:1, s. 153-168
-
Tidskriftsartikel (refereegranskat)abstract
- Most patients who initially respond to treatment with the multi-tyrosine kinase inhibitor sunitinib eventually relapse. Therefore, developing a deeper understanding of the contribution of sunitinib's numerous targets to the clinical response or to resistance is crucial. Here, we have shown that cancer cells respond to clinically relevant doses of sunitinib by enhancing the stability of the antiapoptotic protein MCL-1 and inducing mTORC1 signaling, thus evoking little cytotoxicity. Inhibition of MCL-1 or mTORC1 signaling sensitized cells to clinically relevant doses of sunitinib in vitro and was synergistic with sunitinib in impairing tumor growth in vivo, indicating that these responses are triggered as prosurvival mechanisms that enable cells to tolerate the cytotoxic effects of sunitinib. Furthermore, higher doses of sunitinib were cytotoxic, triggered a decline in MCL-1 levels, and inhibited mTORC1 signaling. Mechanistically, we determined that sunitinib modulates MCL-1 stability by affecting its proteasomal degradation. Dual modulation of MCL-1 stability at different dose ranges of sunitinib was due to differential effects on ERK and GSK3 beta activity, and the latter also accounted for dual modulation of mTORC1 activity. Finally, comparison of patient samples prior to and following sunitinib treatment suggested that increases in MCL-1 levels and mTORC1 activity correlate with resistance to sunitinib in patients.
|
|
