A Phase 2 Randomized Trial of Survodutide in MASH and Fibrosis.

BACKGROUND: Dual agonism of glucagon receptor and glucagon-like peptide-1 (GLP-1) receptor may be more effective than GLP-1 receptor agonism alone for treating metabolic dysfunction-associated steatohepatitis (MASH). The efficacy and safety of survodutide (a dual agonist of glucagon receptor and GLP-1 receptor) in persons with MASH and liver fibrosis are unclear. METHODS: In this 48-week, phase 2 trial, we randomly assigned adults with biopsy-confirmed MASH and fibrosis stage F1 through F3 in a 1:1:1:1 ratio to receive once-weekly subcutaneous injections of survodutide at a dose of 2.4, 4.8, or 6.0 mg or placebo. The trial had two phases: a 24-week rapid-dose-escalation phase, followed by a 24-week maintenance phase. The primary end point was histologic improvement (reduction) in MASH with no worsening of fibrosis. Secondary end points included a decrease in liver fat content by at least 30% and biopsy-assessed improvement (reduction) in fibrosis by at least one stage. RESULTS: A total of 293 randomly assigned participants received at least one dose of survodutide or placebo. Improvement in MASH with no worsening of fibrosis occurred in 47% of the participants in the survodutide 2.4-mg group, 62% of those in the 4.8-mg group, and 43% of those in the 6.0-mg group, as compared with 14% of those in the placebo group (P<0.001 for the quadratic dose-response curve as best-fitting model). A decrease in liver fat content by at least 30% occurred in 63% of the participants in the survodutide 2.4-mg group, 67% of those in the 4.8-mg group, 57% of those in the 6.0-mg group, and 14% of those in the placebo group; improvement in fibrosis by at least one stage occurred in 34%, 36%, 34%, and 22%, respectively. Adverse events that were more frequent with survodutide than with placebo included nausea (66% vs. 23%), diarrhea (49% vs. 23%), and vomiting (41% vs. 4%); serious adverse events occurred in 8% with survodutide and 7% with placebo. CONCLUSIONS: Survodutide was superior to placebo with respect to improvement in MASH without worsening of fibrosis, warranting further investigation in phase 3 trials. (Funded by Boehringer Ingelheim; 1404-0043 ClinicalTrials.gov number, NCT04771273; EudraCT number, 2020-002723-11.).

Efficacy, tolerability and pharmacokinetics of survodutide, a glucagon/glucagon-like peptide-1 receptor dual agonist, in cirrhosis.

BACKGROUND & AIMS: Survodutide is a glucagon/glucagon-like peptide-1 receptor dual agonist in development for treatment of metabolic dysfunction-associated steatohepatitis (MASH). We investigated survodutide in people with cirrhosis. METHODS: This multinational, non-randomized, open-label, phase 1 clinical trial initially evaluated a single subcutaneous (s.c.) dose of survodutide 0.3 mg in people with Child-Pugh class A, B or C cirrhosis and healthy individuals with or without overweight/obesity matched for age, sex, and weight; the primary endpoints were the area under the plasma concentration-time curve from 0 to infinity (AUC0-∞) and maximal plasma concentration (Cmax). Subsequently, people with overweight/obesity with or without cirrhosis and Child-Pugh class A or B received once-weekly s.c. doses escalated from 0.3 mg to 6.0 mg over 24 weeks then maintained for 4 weeks; the primary endpoint was drug-related treatment-emergent adverse events, with MASH/cirrhosis-related endpoints explored. RESULTS: In the single-dose cohorts (n = 41), mean AUC0-∞ and Cmax were similar in those with cirrhosis compared with healthy individuals (90% confidence intervals for adjusted geometric mean ratios spanned 1). Drug-related adverse events occurred in 25.0% of healthy individuals and ≤25.0% of those with cirrhosis after single doses, and 82.4% and 87.5%, respectively, of the multiple-dose cohorts (n = 41) over 28 weeks. Liver fat content, liver stiffness, liver volume, body weight, and other hepatic and metabolic disease markers were generally reduced after 28 weeks of survodutide treatment. CONCLUSIONS: Survodutide is generally tolerable in people with compensated or decompensated cirrhosis, does not require pharmacokinetic-related dose adjustment, and may improve liver-related non-invasive tests, supporting its investigation for MASH-related cirrhosis. Clinical trial number; ClinicalTrials.gov identifier: NCT05296733. IMPACT AND IMPLICATIONS: Survodutide is a glucagon receptor/glucagon-like peptide-1 receptor dual agonist in development for treatment of metabolic dysfunction-associated steatohepatitis (MASH), which causes cirrhosis in ∼20% of cases. This trial delineates the pharmacokinetic and safety profile of survodutide in people with compensated or decompensated cirrhosis, and revealed associated reductions in liver fat content, markers of liver fibrosis and body weight. These findings have potential relevance for people with MASH-including those with decompensated cirrhosis, who are usually excluded from clinical trials of investigational drugs. Based on this study, further investigation of survodutide for MASH-related cirrhosis is warranted.

Prevention of autoimmune diabetes and islet allograft rejection by beta cell expression of XIAP: Insight into possible mechanisms of local immunomodulation.

Overexpression of the X-linked inhibitor of apoptosis (XIAP) prevents islet allograft rejection. We constructed an adeno-associated virus expressing XIAP driven by the rat insulin promoter (dsAAV8-RIP-XIAP) for long-term beta-cell gene expression in vivo. Pancreatic delivery of dsAAV8-RIP-XIAP prevented autoimmune diabetes in 70% of non-obese diabetic (NOD) mice, associated with decreased insulitis. Islets from Balb/c mice transduced with dsAAV8-RIP-XIAP were protected following transplantation into streptozotocin (STZ)-diabetic Bl/6 recipients, associated with decreased graft infiltration. Interestingly, dsAAV8-RIP-XIAP transduction induced expression of lactate dehydrogenase (LDHA) and monocarboxylate transporter 1 (MCT1), two genes normally suppressed in beta cells and involved in production and release of lactate, a metabolite known to suppress local immune responses. Transduction of Balb/c islets with AAV8-RIP-LDHA-MCT1 tended to prolong allograft survival following transplant into STZ-diabetic Bl/6 recipients. These findings suggest that XIAP has therapeutic potential in autoimmune diabetes and raise the possibility that local lactate production may play a role in XIAP-mediated immunomodulation.

Fibroblast Cell-Based Therapy for Experimental Autoimmune Diabetes.

Type 1 diabetes (T1D) results from autoimmune destruction of insulin producing ß cells of the pancreatic islets. Curbing autoimmunity at the initiation of T1D can result in recovery of residual ß cells and consequently remission of diabetes. Here we report a cell-based therapy for autoimmune diabetes in non-obese diabetic (NOD) mice using dermal fibroblasts. This was achieved by a single injection of fibroblasts, expressing the immunoregulatory molecule indoleamine 2,3 dioxygenase (IDO), into peritoneal cavity of NOD mice shortly after the onset of overt hyperglycemia. Mice were then monitored for reversal of hyperglycemia and changes in inflammatory/regulatory T cell profiles. Blood glucose levels dropped into the normal range in 82% of NOD mice after receiving IDO-expressing fibroblasts while all control mice remained diabetic. We found significantly reduced islet inflammation, increased regulatory T cells, and decreased T helper 17 cells and ß cell specific autoreactive CD8+ T cells following IDO cell therapy. We further showed that some of intraperitoneal injected fibroblasts migrated to local lymph nodes and expressed co-inhibitory molecules. These findings suggest that IDO fibroblasts therapy can reinstate self-tolerance and alleviate ß cell autoreactivity in NOD mice, resulting in remission of autoimmune diabetes.

Immunoprotection and Functional Improvement of Allogeneic Islets in Diabetic Mice, Using a Stable Indoleamine 2,3-Dioxygenase Producing Scaffold.

BACKGROUND: We have previously shown that an immunomodulatory enzyme, indoleamine 2,3-dioxygenase (IDO) in dermal fibroblasts generates a tryptophan-deficient environment that selectively inhibits proliferation and induces apoptosis of bystander CD4+ and CD8+ T cells, but not pancreatic islets. Because these immune cells are involved in islet allograft rejection, we hypothesized that transplantation of islets embedded in a novel 3-dimensional composite scaffold within which stable IDO-expressing fibroblasts serve as source of local immunosuppression would lead to normoglycemia in a streptozotocin-induced diabetic mouse model. METHODS: Islet grafts were prepared by embedding stable IDO-expressing fibroblasts and allogeneic islets into a protease-resistant composite scaffold. Islets function and survival were evaluated in vitro using immunohistochemistry. Allografts were transplanted under the kidney capsule of streptozotocin-induced diabetic mice; viability, function, and criteria for graft take were evaluated. Flow cytometry was performed to determine specific intragraft, draining lymph nodes and spleen T-cell population, and splenocytes alloantigen responsiveness of graft recipients. RESULTS: The results of a series of in vitro experiments revealed that IDO-expressing fibroblasts do not compromise islet function or survival. The expression of IDO suppressed the proliferation of alloantigen-stimulated splenocytes. The in vivo experiments revealed that local IDO expression delivered by lentiviral vector prolonged islet allograft survival (51.0 ± 2.9 days) by increasing the population of FOXP3+ regulatory T cells at the graft site and graft-draining lymph nodes and preventing T-cell infiltration. CONCLUSIONS: This study shows that incorporation of islets within our novel matrix that is equipped with stable IDO-expressing fibroblasts prolongs allograft survival.

Embedding islet in a liquid scaffold increases islet viability and function.

INTRODUCTION: Islet transplantation is a promising strategy to restore efficient insulin regulation in type 1 diabetes mellitus patients. However, shortage of islet donors, poor islet survival and toxicity of immunosuppressants often reduce the graft functional lifetime. METHODS: We previously showed that a fibroblast populated-collagen matrix (CM) significantly improved engrafted islet viability/function. However, this composite was prone to gradual biodegradation and contraction. Moreover, to avoid use of systemic immunosuppressants, we proposed the use of a local immunosuppressive enzyme, indoleamine-2,3-dioxygenase (IDO). We developed a novel bioengineered crosslinked CM (CCM) to provide optimal matrix biomimetic. Viability and insulin secretory function of islets embedded within fibroblast populated CCM (FP-CCM) was evaluated in vitro and in vivo. IDO expression was transduced in fibroblasts by a lentiviral vector carrying IDO gene and islet viability was evaluated in the presence and absence of IDO producing cells. RESULTS: Islet survival/function markedly improved within FP-CCM. Furthermore, our data shows that local lentiviral induction of IDO delivered by FP-CCM is nontoxic to the embedded islets. CONCLUSIONS: This promising finding offers a new approach to improving islet transplant outcome.

Immuno-regulatory function of indoleamine 2,3 dioxygenase through modulation of innate immune responses.

Successful long-term treatment of type-1 diabetes mainly relies on replacement of ß-cells via islet transplantation. Donor shortage is one of the main obstacles preventing transplantation from becoming the treatment of choice. Although animal organs could be an alternative source for transplantation, common immunosuppressive treatments demonstrate low efficacy in preventing xenorejection. Immunoprotective effects of indoleamine 2,3-dioxygenase (IDO) on T-cell mediated allorejection has been extensively studied. Our studies revealed that IDO expression by fibroblasts, induced apoptosis in T-cells while not affecting non-immune cell survival/function. Since macrophages play a pivotal role in xenograft rejection, herein we investigated the effect of IDO-induced tryptophan deficiency/kynurenine accumulation on macrophage function/survival. Moreover, we evaluated the local immunosuppressive effect of IDO on islet-xenograft protection. Our results indicated that IDO expression by bystander fibroblasts significantly reduced the viability of primary macrophages via apoptosis induction. Treatment of peritoneal macrophages by IDO-expressing fibroblast conditioned medium significantly reduced their proinflammatory activity through inhibition of iNOS expression. To determine whether IDO-induced tryptophan starvation or kynurenine accumulation is responsible for macrophage apoptosis and inhibition of their proinflammatory activity, Raw264.7 cell viability and proinflammatory responses were evaluated in tryptophan deficient medium or in the presence of kynurenine. Tryptophan deficiency, but not kynurenine accumulation, reduced Raw264.7 cell viability and suppressed their proinflammatory activity. Next a three-dimensional islet-xenograft was engineered by embedding rat islets within either control or IDO-expressing fibroblast-populated collagen matrix. Islets morphology and immune cell infiltration were then studied in the xenografts transplanted into the C57BL/6 mouse renal sub-capsular space. Local IDO significantly decreased the number of infiltrating macrophages (11 ± 1.47 vs. 70.5 ± 7.57 cells/HPF), T-cells (8.75 ± 1.03 vs. 75.75 ± 5.72 cells/HPF) and iNOS expression in IDO-expressing xenografts versus controls. Islet morphology remained intact in IDO-expressing grafts and islets were strongly stained for insulin/glucagon compared to control. These findings support the immunosuppressive role of IDO on macrophage-mediated xeno-rejection.

Topical application of aminopeptidase N-neutralizing antibody accelerates wound closure.

Upon release from keratinocytes, 14-3-3 sigma (also known as stratifin) acts on the dermal fibroblast and modulates its production of extracellular matrix proteins. Subsequent to the recent identification as a receptor responsible for stratifin-mediated matrix turnover in dermal fibroblasts, aminopeptidase N has been implicated in the regulation of epidermal-dermal communication and expression of key matrix proteases and adhesion molecules. In light of the growing importance of aminopeptidase N in modulation of the fibroblast phenotype, the present study evaluates the potential of targeting the ectoenzyme in cutaneous repair, and demonstrates that neutralization of aminopeptidase N led to acceleration of wound closure. This was attributed to at least in part an increase of collagen deposition and fibroblast contractility in the granulation tissue. These findings confirmed the important role of aminopeptidase N in post-injury tissue remodeling and wound contraction.

Mechanism underlying defective interferon gamma-induced IDO expression in non-obese diabetic mouse fibroblasts.

Indoleamine 2,3-dioxygenase (IDO) can locally suppress T cell-mediated immune responses. It has been shown that defective self-tolerance in early prediabetic female non-obese diabetic (NOD) mice can be attributed to the impaired interferon-gamma (IFN-γ)- induced IDO expression in dendritic cells of these animals. As IFN-γ can induce IDO in both dendritic cells and fibroblasts, we asked the question of whether there exists a similar defect in IFN-γ-induced IDO expression in NOD mice dermal fibroblasts. To this end, we examined the effect of IFN-γ on expression of IDO and its enzymatic activity in NOD dermal fibroblasts. The results showed that fibroblasts from either prediabetic (8 wks of age) female or male, and diabetic female or male (12 and 24 wks of age respectively) NOD mice failed to express IDO in response to IFN-γ treatment. To find underlying mechanisms, we scrutinized the IFN- γ signaling pathway and investigated expression of other IFN-γ-modulated factors including major histocompatibility complex class I (MHC-I) and type I collagen (COL-I). The findings revealed a defect of signal transducer and activator of transcription 1 (STAT1) phosphorylation in NOD cells relative to that of controls. Furthermore, we found an increase in MHC-I and suppression of COL-I expression in fibroblasts from both NOD and control mice following IFN-γ treatment; indicating that the impaired response to IFN-γ in NOD fibroblasts is specific to IDO gene. Finally, we showed that an IFN-γ-independent IDO expression pathway i.e. lipopolysaccharide (LPS)-mediated-c-Jun kinase is operative in NOD mice fibroblast. In conclusion, the findings of this study for the first time indicate that IFN-γ fails to induce IDO expression in NOD dermal fibroblasts; this may partially be due to defective STAT1 phosphorylation in IFN-γ-induced-IDO signaling pathway.

Extracellular 14-3-3 from human lung epithelial cells enhances MMP-1 expression.

Airway remodelling in asthma involves various mediators modulating the production/breakdown of collagen by lung fibroblasts. Matrix metalloproteinase-1 (MMP-1) plays an important role in collagen breakdown. We recently showed that epithelial cell-derived extracellular form of 14-3-3σ is an important inducer of MMP-1 expression in skin fibroblasts. Thus, we hypothesized that 14-3-3 proteins are important regulators of MMP-1 expression in the respiratory airway. We examined the presence of extracellular 14-3-3 proteins in conditioned media obtained from primary lung epithelial cells, A549 and HS24 cells, and their effect on MMP-1 expression by lung fibroblasts (IMR-90). In addition, we evaluated IMR-90 response to 14-3-3 proteins in the presence of transforming growth factor-ß(1) (TGF-ß(1)), a cytokine known to decrease MMP-1 expression by fibroblasts. Extracellular 14-3-3α/ß, but not -σ, is released by the human-derived lung epithelial cell lines, A549 and HS24. Unlike dermal fibroblasts, IMR-90 cells do not produce MMP-1 in response to 14-3-3σ. Conversely, MMP-1 production was induced following treatment of IMR-90 with recombinant or lung epithelial cell-derived 14-3-3α/ß. These findings were also confirmed using primary human bronchial epithelial cells and lung fibroblasts obtained from non-asthmatic patients. The MMP-1-inducing effect of 14-3-3α/ß on IMR-90 was not inhibited by TGF-ß(1). Lung epithelial cell-derived 14-3-3α/ß has a potent MMP-1-inducing effect on airway fibroblasts. Modulation of MMP-1 by 14-3-3α/ß, may be important in the alteration of collagenase production associated with airway remodelling in obstructive lung diseases. Our data indicate that 14-3-3 proteins may be potential targets for future therapeutic strategies aimed at modulating tissue remodelling in asthma.

Fibroblast populated collagen matrix promotes islet survival and reduces the number of islets required for diabetes reversal.

Islet transplantation represents a viable treatment for type 1 diabetes. However, due to loss of substantial mass of islets early after transplantation, islets from two or more donors are required to achieve insulin independence. Islet-extracellular matrix disengagement, which occurs during islet isolation process, leads to subsequent islet cell apoptosis and is an important contributing factor to early islet loss. In this study, we developed a fibroblast populated collagen matrix (FPCM) as a novel scaffold to improve islet cell viability and function post-transplantation. FPCM was developed by embedding fibroblasts within type-I collagen and used as scaffold for islet grafts. Viability and insulin secretory function of islets embedded within FPCM was evaluated in vitro and in a syngeneic murine islet transplantation model. Islets embedded within acellular matrix or naked islets were used as control. Islet cell survival and function was markedly improved particularly after embedding within FPCM. The composite scaffold significantly promoted islet isograft survival and reduced the critical islet mass required for diabetes reversal by half (from 200 to 100 islets per recipient). Fibroblast embedded within FPCM produced fibronectin and growth factors and induced islet cell proliferation. No evidence of fibroblast over-growth within composite grafts was noticed. These results confirm that FPCM significantly promotes islet viability and functionality, enhances engraftment of islet grafts and decreases the critical islet mass needed to reverse hyperglycemia. This promising finding offers a new approach to reducing the number of islet donors per recipient and improving islet transplant outcome.

Potassium channel openers and improvement of toxic stress: do they have role in the management of inflammatory bowel disease?

Inflammatory bowel disease (IBD) is a progressive condition in gastrointestinal tract, which refers to two idiopathic diseases; ulcerative colitis and Crohn's disease. Although certain etiology of these conditions is not known, it seems that an abnormality in reaction and regulation of the immune system plays an important role in adventure of the disease. According to the investigations, it is likely that oxidative and nitrosative stress have etiologic roles in IBD. Their destructive effects may contribute to the initiation or progression of the disease. Nowadays, the effectiveness of different medicines in the treatment of IBD has been proved, but none of them has shown a desirable result. Potassium channel openers (PCOs) are a class of drugs with various usages in the aspects of cardiovascular diseases and urinary incontinence. Their major mechanism is the opening of ATP-sensitive potassium (K-ATP) channels and contribute to the relaxation of smooth muscles. Nicorandil is a member of PCOs, with a special chemical structure. Recent investigations mention some novel effects and functions for this drug. Nicorandil reveals an anti-apoptosis property not only via a nitric oxide (NO)/cGMP-dependent mechanism, but also through activating mitochondrial K-ATP channels. Nicorandil can also elevate cGMP levels in some tissues, without direct NO generation. Gastroprotective activity via opening of the K channels, free radical scavenging, prostaglandin E2 elevation, decreasing pepsin and acid secretion, and prevention of the detrimental rise in NO has been proposed for nicorandil. According to these protective mechanisms and the role of oxidative/nitrosative stress in the expression of IBD, we herein hypothesize that nicorandil and other PCOs with similar structure can be used in the management of IBD. This approach offers new hope for the successful treatment of IBD. Further investigations on animal models are needed, to place nicorandil and similar drugs alongside IBD therapy.