DACRA induces profound weight loss, satiety control, and increased mitochondrial respiratory capacity in adipose tissue.

BACKGROUND AND OBJECTIVES: Dual amylin and calcitonin receptor agonists (DACRAs) are therapeutic candidates in the treatment of obesity with beneficial effects on weight loss superior to suppression of food intake. Hence, suggesting effects on energy expenditure by possibly targeting mitochondria in metabolically active tissue. METHODS: Male rats with HFD-induced obesity received a DACRA, KBP-336, every third day for 8 weeks. Upon study end, mitochondrial respiratory capacity (MRC), - enzyme activity, - transcriptional factors, and -content were measured in perirenal (pAT) and inguinal adipose tissue. A pair-fed group was included to examine food intake-independent effects of KBP-336. RESULTS: A vehicle-corrected weight loss (23.4 ± 2.8%) was achieved with KBP-336, which was not observed to the same extent with the food-restricted weight loss (12.4 ± 2.8%) (P < 0.001). Maximal coupled respiration supported by carbohydrate and lipid-linked substrates was increased after KBP-336 treatment independent of food intake in pAT (P < 0.01). Moreover, oligomycin-induced leak respiration and the activity of citrate synthase and ß-hydroxyacetyl-CoA-dehydrogenase were increased with KBP-336 treatment (P < 0.05). These effects occurred without changes in mitochondrial content in pAT. CONCLUSIONS: These findings demonstrate favorable effects of KBP-336 on MRC in adipose tissue, indicating an increased energy expenditure and capacity to utilize fatty acids. Thus, providing more mechanistic insight into the DACRA-induced weight loss.

The sclerotic component of metabolic syndrome: Fibroblast activities may be the central common denominator driving organ function loss and death.

Fibrosis is a common feature of more than 50 different diseases and the cause of more than 35% of deaths worldwide, of which liver, kidney, skin, heart and, recently, lungs are receiving the most attention. Tissue changes, resulting in loss of organ function, are both a cause and consequence of disease and outcome. Fibrosis is caused by an excess deposition of extracellular matrix proteins, which over time results in impaired organ function and organ failure, and the pathways leading to increased fibroblast activation are many. This narrative review investigated the common denominator of fibrosis, fibroblasts, and the activation of fibroblasts, in response to excess energy consumption in liver, kidney, heart, skin and lung fibrosis. Fibroblasts are the main drivers of organ function loss in lung, liver, skin, heart and kidney disease. Fibroblast activation in response to excess energy consumption results in the overproduction of a range of collagens, of which types I, III and VI seem to be the essential drivers of disease progression. Fibroblast activation may be quantified in serum, enabling profiling and selection of patients. Activation of fibroblasts results in the overproduction of collagens, which deteriorates organ function. Patient profiling of fibroblast activities in serum, quantified as collagen production, may identify an organ death trajectory, better enabling identification of the right treatment for use in different metabolic interventions. As metabolically activated patients have highly elevated risk of kidney, liver and heart failure, it is essential to identify which organ to treat first and monitor organ status to correct treatment regimes. In direct alignment with this, it is essential to identify the right patients with the right organ deterioration trajectory for enrolment in clinical studies.

Association of type III collagen turnover with cardiovascular outcomes and impact with canagliflozin in the CANVAS Program: A post hoc analysis.

AIM: To investigate type III collagen (COL III) turnover in participants from the CANVAS Program biomarker substudy. METHODS: Biomarkers of COL III formation (PRO-C3) and COL III degradation fragments (C3M and CTX-III) were assessed in baseline and year 3 plasma from patients enrolled in CANVAS, investigating the effect of canagliflozin in participants with type 2 diabetes. The clinical outcomes investigated in this study were hospitalization for heart failure, cardiovascular death and all-cause mortality. RESULTS: Higher levels of PRO-C3 and C3M at baseline were associated with an increased incidence of all investigated outcomes, whereas levels of CTX-III at baseline were not associated with any of the investigated outcomes. Levels of PRO-C3 decreased and levels of CTX-III increased following canagliflozin treatment. An increase from baseline to year 3 in PRO-C3 in the placebo arm was associated with an increased incidence of cardiovascular outcomes, and in all participants was associated with an increased risk of all-cause mortality. CONCLUSIONS: The changes in PRO-C3 and CTX-III reflect a shift in the dynamics of COL3 turnover following treatment with canagliflozin. These biomarkers are promising pharmacodynamic tools that can be used to monitor the impact of canagliflozin treatment and possibly other sodium-glucose co-transporter-2 inhibitors on tissue remodelling in future interventional trials.

Biomarker-guided drug development provides value for patients, payers and drug developers: lessons learned from 25 years in the biomarker industry.

INTRODUCTION: There is an urgent, persistent, need for better biomarkers in clinical drug development. More informative biomarkers can increase the likelihood of drug advancement or approval, and implementing biomarkers increases the success rate in drug development. Biomarkers may guide decisions and allow resources to be directed to the projects most likely to succeed. However, biomarkers that are validated to high standards are needed, reflecting biological and pathological processes accurately. Such biomarkers are needed to develop treatments faster, and to improve and guide clinical trial design by selecting and de-selecting patients. METHODS: In this review based on the authors' previous published experience and interaction with pharmaceutical- and biomarker stakeholders, we highlight the use and value of biomarkers in clinical development according to the BEST guidelines. We highlight the value of 3 types of biomarkers that may provide optimal value to stakeholders: diagnostic, prognostic and pharmacodynamic biomarkers. RESULTS: A more appropriate clinical trial design, increasing the ratio between benefits and side effects, may come from a more tailored biomarker-approach identifying suitable molecular endotypes of patients to treat. DISCUSSION: Biomarkers may guide drug developers in selecting the optimal projects to progress, when designing clinical studies and development paths. Biomarkers may aid in the diagnosis and prognostic assessment of patients and assist in matching the molecular endotype to the selected treatment, which improves the success rate of clinical development progression. The aim of this paper is to provide a comprehensive ideation framework for how to utilize biomarkers in clinical development, with a focus on utility for patients, payers and drug developers.

Changes in type VI collagen degradation reflect clinical response to treatment in rheumatoid arthritis patients treated with tocilizumab.

OBJECTIVES: Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by inflammation in multiple articular joints, causing pain, joint damage, and loss of joint function. Despite the successful development of disease-modifying therapies, the heterogeneity of RA means that a significant proportion of patients respond poorly to treatment. This highlights the need for personalized medicine and predictive biomarkers to optimize treatment efficacy, safety, and cost. This study aimed to explore the relationship between type VI collagen (Col VI) remodeling and clinical response to anti-IL-6 receptor treatment. METHODS: Type VI collagen degradation was quantified using the C6M biomarker, a fragment of type VI collagen degraded by MMPs. Longitudinal differences in average biomarker levels between placebo and treatment groups were estimated using linear mixed models. The predictive capacity of the marker based on change from baseline to 4 weeks was analyzed using logistic regression. RESULTS: Both 4 mg and 8 mg doses of Tocilizumab (TCZ) reduced serum C6M concentrations compared to the placebo. Furthermore, C6M levels were more reduced in patients responding to treatment compared to early non-responders. A lower early reduction in C6M was associated with reduced odds of ACR treatment response and lowered disease activity. CONCLUSION: These findings suggest that quantifying type VI collagen turnover may aid in identifying patients less likely to respond to treatment, indicating a new path towards optimizing patient care. Further studies are needed to validate these findings and explore the underlying mechanisms driving the observed relationships.

The fibroid phenotype of biological naïve patients with rheumatoid arthritis are less likely to respond to anti-IL-6R treatment.

Type III collagen gene expression is upregulated in the synovium of patients with rheumatoid arthritis (RA) presenting the fibroid phenotype. The soluble type III collagen formation biomarker, PRO-C3, is known to measure fibrogenesis in fibrotic diseases. In this exploratory study, we aimed to investigate the association between fibrogenesis (PRO-C3) and the disease- and treatment response in patients with RA. We measured PRO-C3 in subsets of two clinical trials assessing the effect of the anti-interleukin-6 (IL-6) receptor treatment tocilizumab (TCZ) as monotherapy or polytherapy with methotrexate. PRO-C3 levels had weak or very weak correlations with the clinical parameters (Spearman's). However, when the patients were divided into Disease Activity Score-28 groups characterized by the erythrocyte sedimentation rate (DAS28-ESR), there was a statistical difference between the PRO-C3 levels of the different groups (p < 0.05). To determine the response in relation to PRO-C3, a cut-off based on PRO-C3 levels and patients in remission (DAS28-ESR ≤ 2.6) was identified. This showed that a reduction in PRO-C3 after treatment initiation was associated with decreased DAS28-ESR and a higher response rate in patients with low PRO-C3 levels than in those with high PRO-C3 levels. This indicates that a fibrotic component affects the responsiveness of patients.

Type XII collagen is elevated in serum from patients with solid tumors: a non-invasive biomarker of activated fibroblasts.

Understanding the tumor microenvironment (TME) and extracellular matrix (ECM) is crucial in cancer research due to their impact on tumor progression. Collagens, major ECM components, regulate cell signaling and behavior. Of the 28 reported collagens, type XII collagen is known to be vital for ECM organization. Over-produced by cancer-associated fibroblasts (CAFs), its upregulation correlates with poor survival in various cancers. This study aimed to develop an ELISA for quantifying circulating type XII collagen as a cancer biomarker. A specific ELISA targeting the C-terminal of type XII collagen was developed and used to analyze serum samples from cancer patients (n = 203) and healthy controls (n = 33). Additionally, type XII collagen expression was assessed in CAFs and normal fibroblasts (NFs) from different tissues, both under TGF-ß stimulated and non-stimulated conditions. The nordicPRO-C12 ELISA demonstrated robustness and specificity for type XII collagen. PRO-C12 levels were significantly elevated in patients with various cancers compared to healthy controls and effectively distinguished between cancer patients and controls. Findings were validated using gene expression data. Furthermore, Western blot analysis revealed increased type XII collagen expression in both CAFs and NFs upon TGF-ß1 stimulation, suggesting a potential role of TGF-ß1 in modulating the expression of type XII collagen in cancerous and normal tissue microenvironments. This study unveils a promising avenue for harnessing PRO-C12 as a non-invasive serum biomarker, enabling the quantification of type XII collagen fragments in cancer patients. Further investigations are warranted to explore the potential of PRO-C12 across different cancer types and disease stages, shedding light on its multifaceted role in cancer development.

Type IX Collagen Turnover Is Altered in Patients with Solid Tumors.

The fibrotic tumor microenvironment, characterized by its intricate extracellular matrix (ECM), consists of many collagens with diverse functions and unexplored biomarker potential. Type IX collagen is a member of the low-abundance collagen family known as the fibril-associated collagen with interrupted triple helices (FACITs) and is found mostly in cartilage. Its role in the tumor microenvironment remains unexplored. To investigate the biomarker potential of a type IX collagen in cancer, an immuno-assay was developed (PRO-C9) and technical assay performance was evaluated for the assessment of serum. PRO-C9 levels were measured in serum samples from 259 patients with various solid tumor types compared to serum levels from 73 healthy controls. PRO-C9 levels were significantly elevated in patients with solid tumors including bladder, breast, colorectal, gastric, head and neck, lung, melanoma, ovarian, pancreatic, and renal compared to levels in healthy controls (p < 0.05-p < 0.0001). PRO-C9 could discriminate between patients with cancer and healthy controls, with the area under the receiver operating characteristic values ranging from 0.58 to 0.86 (p < 0.3-p < 0.0001), indicating potential diagnostic utility. This study suggests that type IX collagen turnover is altered in patients with solid tumors and demonstrates the feasibility of using PRO-C9 as a non-invasive serum-based biomarker with relevance in multiple cancer types. Furthermore, these results underscore the potential utility of PRO-C9 to better elucidate the biology of FACITs in cancers.

Plasma levels of PRO-C3, a type III collagen synthesis marker, are associated with arterial stiffness and increased risk of cardiovascular death.

BACKGROUND AND AIMS: The N-terminal propeptide of type III collagen (PRO-C3) assay measures a pro-peptide released during type III collagen synthesis, an important feature of arterial stiffening and atherogenesis. There is a clinical need for improved non-invasive, cheap and easily accessible methods for evaluating individuals at risk of cardiovascular disease (CVD). In this study, we investigate the potential of using circulating levels of PRO-C3 to mark the degree of vascular stenosis and risk of cardiovascular events. METHODS: Baseline plasma levels of PRO-C3 were measured by ELISA in subjects belonging to the SUrrogate markers for Micro- and Macro-vascular hard endpoints for Innovative diabetes Tools (SUMMIT) cohort (N = 1354). Associations between PRO-C3 levels with vascular characteristics, namely stiffness and stenosis, and risk of future cardiovascular events were explored. Subjects were followed up after a median of 35 months (interquartile range 34-36 months), with recorded outcomes cardiovascular death and all-cause mortality. RESULTS: We found a correlation between PRO-C3 levels and pulse wave velocity (rho 0.13, p = 0.000009), a measurement of arterial stiffness. Higher PRO-C3 levels were also associated with elevated blood pressure (rho 0.07, p = 0.014), as well as risk of cardiovascular mortality over a three-year follow-up period (OR 1.56, confidence interval 1.008-2.43, p = 0.046). CONCLUSIONS: Elevated circulating PRO-C3 levels are associated with arterial stiffness and future cardiovascular death, in the SUMMIT cohort, suggesting a potential value of PRO-C3 as a novel marker for declining vascular health.

From biochemical markers to molecular endotypes of osteoarthritis: a review on validated biomarkers.

INTRODUCTION: Osteoarthritis (OA) affects over 500 million people worldwide. OA patients are symptomatically treated, and current therapies exhibit marginal efficacy and frequently carry safety-risks associated with chronic use. No disease-modifying therapies have been approved to date leaving surgical joint replacement as a last resort. To enable effective patient care and successful drug development there is an urgent need to uncover the pathobiological drivers of OA and how these translate into disease endotypes. Endotypes provide a more precise and mechanistic definition of disease subgroups than observable phenotypes, and a panel of tissue- and pathology-specific biochemical markers may uncover treatable endotypes of OA. AREAS COVERED: We have searched PubMed for full-text articles written in English to provide an in-depth narrative review of a panel of validated biochemical markers utilized for endotyping of OA and their association to key OA pathologies. EXPERT OPINION: As utilized in IMI-APPROACH and validated in OAI-FNIH, a panel of biochemical markers may uncover disease subgroups and facilitate the enrichment of treatable molecular endotypes for recruitment in therapeutic clinical trials. Understanding the link between biochemical markers and patient-reported outcomes and treatable endotypes that may respond to given therapies will pave the way for new drug development in OA.

Serologic extracellular matrix remodeling markers are related to fibrosis stage and prognosis in a phase 2b trial of simtuzumab in patients with primary sclerosing cholangitis.

BACKGROUND: Novel noninvasive predictors of disease severity and prognosis in primary sclerosing cholangitis (PSC) are needed. This study evaluated the ability of extracellular matrix remodeling markers to diagnose fibrosis stage and predict PSC-related fibrosis progression and clinical events. METHODS: Liver histology and serum markers of collagen formation (propeptide of type III collagen [Pro-C3], propeptide of type IV collagen, propeptide of type V collagen), collagen degradation (type III collagen matrix metalloproteinase degradation product and type IV collagen matrix metalloproteinase degradation product), and fibrosis (enhanced liver fibrosis [ELF] score and its components [metalloproteinase-1, type III procollagen, hyaluronic acid]) were assessed in samples from baseline to week 96 in patients with PSC enrolled in a study evaluating simtuzumab (NCT01672853). Diagnostic performance for advanced fibrosis (Ishak stages 3-6) and cirrhosis (Ishak stages 5-6) was evaluated by logistic regression and AUROC. Prognostic performance for PSC-related clinical events and fibrosis progression was assessed by AUROC and Wilcoxon rank-sum test. RESULTS: Among 234 patients, 51% had advanced fibrosis and 11% had cirrhosis at baseline. Baseline Pro-C3 and ELF score and its components provided moderate diagnostic ability for discrimination of advanced fibrosis (AUROC 0.73-0.78) and cirrhosis (AUROC 0.73-0.81). Baseline Pro-C3, ELF score, and type III procollagen provided a moderate prognosis for PSC-related clinical events (AUROC 0.70-0.71). Among patients without cirrhosis at baseline, median changes in Pro-C3 and ELF score to week 96 were higher in those with than without progression to cirrhosis (both p < 0.001). CONCLUSIONS: Pro-C3 correlated with fibrosis stage, and Pro-C3 and ELF score provided discrimination of advanced fibrosis and cirrhosis and predicted PSC-related events and fibrosis progression. The results support the clinical utility of Pro-C3 and ELF score for staging and as prognostic markers in PSC.

Extracellular matrix turnover proteins as risk markers in people with type 2 diabetes and microalbuminuria.

BACKGROUND: This post-hoc study investigated whether biomarkers reflecting extracellular matrix (ECM) turnover predicted cardiovascular disease (CVD), mortality, and progression of diabetic kidney disease (DKD) in individuals with type 2 diabetes (T2D) and microalbuminuria. METHODS: Serum levels of specific ECM turnover biomarkers were assessed in 192 participants with T2D and microalbuminuria from an observational study conducted at Steno Diabetes Center Copenhagen from 2007 to 2008. Endpoints included CVD events, mortality, and DKD progression, defined as decline in estimated glomerular filtration rate (eGFR) of >30 %. RESULTS: Participants had a mean age of 59 years, with 75 % males. Over a median follow-up of 4.9 to 6.3 years, the study recorded 38 CVD events, 24 deaths, and 40 DKD events. Elevated levels of a degradation fragment of collagen type I (C1M) were associated with an increased risk of >30 % eGFR decline, although this association was not independent of other risk factors. No significant associations were found between other ECM turnover biomarkers and DKD progression, mortality, or CVD risk. CONCLUSION: Elevated C1M levels were linked to DKD progression in individuals with T2D and microalbuminuria, but not independently of other risk factors. None of the ECM turnover biomarkers were associated with CVD or mortality.

Neutrophil-mediated type IV collagen degradation is elevated in patients with mild endoscopic ulcerative colitis reflecting early mucosal destruction.

Neutrophils play a significant role in sustaining chronic inflammation in Inflammatory Bowel Disease. The intestinal basement membrane acts as a barrier for immunological homeostasis, where the α3 and α4 chains of type IV collagen are expressed on the mucosal surface. We wanted to develop a biomarker reflecting early tissue injury, providing an opportunity for intervention. Two competitive enzyme-linked immunosorbent assays (ELISAs) quantifying human neutrophil elastase (HNE) degraded neo-epitopes of COL4A3 and COL4A4 were developed and investigated in two observational cohorts (n = 161, n = 100). A biomarker of MMP-mediated degradation of COL4A1 (C4M) was used for comparison. In Cohort 1, patients with mild endoscopic ulcerative colitis showed elevated levels of C4A3-HNE compared to those with severe disease. C4M had a strong positive correlation with disease activity. C4A3-HNE/C4M provided superior discrimination between mild and severe endoscopic disease and negatively correlated to disease activity. In Cohort 2, C4A4-HNE and C4A4-HNE/C4M showed similar trends. C4A3-HNE and C4A4-HNE possibly reflect early intestinal tissue injury. Combining the markers with a biomarker of another α-chain of the same collagen provides information on two distinct stages of mucosal damage. These biomarkers may be used to monitor disease flare-up in patients in remission, reducing the need for frequent endoscopic procedures.

Cluster analysis of blood biomarkers to identify molecular patterns in pulmonary fibrosis: assessment of a multicentre, prospective, observational cohort with independent validation.

BACKGROUND: Pulmonary fibrosis results from alveolar injury, leading to extracellular matrix remodelling and impaired lung function. This study aimed to classify patients with pulmonary fibrosis according to blood biomarkers to differentiate distinct disease patterns, known as endotypes. METHODS: In this cluster analysis, we first classified patients from the PROFILE study, a multicentre, prospective, observational cohort of individuals with incident idiopathic pulmonary fibrosis or non-specific interstitial pneumonia in the UK (Nottingham University Hospitals, Nottingham; and Royal Brompton Hospital, London). 13 blood biomarkers representing extracellular matrix remodelling, epithelial stress, and thrombosis were measured by ELISA in the PROFILE study. We classified patients by unsupervised consensus clustering. To evaluate generalisability, a machine learning classifier trained on biomarker signatures derived from consensus clustering was applied to a replication dataset from the Australian Idiopathic Pulmonary Fibrosis Registry (AIPFR). Biomarker associations with mortality and change in percentage of predicted forced vital capacity (FVC%) were assessed, adjusting for age, gender, baseline FVC%, and antifibrotic treatment and steroid treatment before and after baseline. Mortality risk associated with the clusters in the PROFILE cohort was evaluated with Cox proportional hazards models, and mixed-effects models were used to analyse how clustering was associated with longitudinal FVC% in the PROFILE and AIPFR cohorts. FINDINGS: 455 of 580 participants from the PROFILE study (348 [76%] men and 107 [24%] women; mean age 72·4 years [SD 8·3]) were included in the analysis. Within this group, three clusters were identified based on blood biomarkers. A basement membrane collagen (BM) cluster (n=248 [55%]) showed high concentrations of PRO-C4, PRO-C28, C3M, and C6M, whereas an epithelial injury (EI) cluster (n=109 [24%]) showed high concentrations of MMP-7, SP-D, CYFRA211, CA19-9, and CA-125. The third cluster (crosslinked fibrin [XF] cluster; n=98 [22%]) had high concentrations of X-FIB. In the replication dataset (117 of 833 patients from AIPFR; 87 [74%] men and 30 [26%] women; mean age 72·9 years [SD 7·9]), we identified the same three clusters (BM cluster, n=93 [79%]; EI cluster, n=8 [7%]; XF cluster, n=16 [14%]). These clusters showed similarities with clusters in the PROFILE dataset regarding blood biomarkers and phenotypic signatures. In the PROFILE dataset, the EI and XF clusters were associated with increased mortality risk compared with the BM cluster (EI vs BM: adjusted hazard ratio [HR] 1·88 [95% CI 1·42-2·49], p<0·0001; XF vs BM: adjusted HR 1·53 [1·13-2·06], p=0·0058). The EI cluster showed the greatest annual FVC% decline, followed by the BM and XF clusters. A similar FVC% decline pattern was observed in these clusters in the AIPFR replication dataset. INTERPRETATION: Blood biomarker clustering in pulmonary fibrosis identified three distinct blood biomarker signatures associated with lung function and prognosis, suggesting unique pulmonary fibrosis biomarker patterns. These findings support the presence of pulmonary fibrosis endotypes with the potential to guide targeted therapy development. FUNDING: None.

The fibroblast hormone Endotrophin is a biomarker of mortality in chronic diseases.

Fibrosis, driven by fibroblast activities, is an important contributor to morbidity and mortality in most chronic diseases. Endotrophin, a signaling molecule derived from processing of type VI collagen by highly activated fibroblasts, is involved in fibrotic tissue remodeling. Circulating levels of endotrophin have been associated with an increased risk of mortality in multiple chronic diseases. We conducted a systematic literature review collecting evidence from original papers published between 2012 and January 2023 that reported associations between circulating endotrophin (PROC6) and mortality. Cohorts with data available to the study authors were included in an Individual Patient Data (IPD) meta-analysis that evaluated the association of PROC6 with mortality (PROSPERO registration number: CRD42023340215) after adjustment for age, sex and BMI, where available. In the IPD meta-analysis including sixteen cohorts of patients with different non-communicable chronic diseases (NCCDs) (N = 15,205) the estimated summary hazard ratio for 3-years all-cause mortality was 2.10 (95 % CI 1.75-2.52) for a 2-fold increase in PROC6, with some heterogeneity observed between the studies (I2=70 %). This meta-analysis is the first study documenting that fibroblast activities, as quantified by circulating endotrophin, are independently associated with mortality across a broad range of NCCDs. This indicates that, irrespective of disease, interstitial tissue remodeling, and consequently fibroblast activities, has a central role in adverse clinical outcomes, and should be considered with urgency from drug developers as a target to treat.