Telomerase is essential for cardiac differentiation and sustained metabolism of human cardiomyocytes

Telomeres as the protective ends of linear chromosomes, are synthesized by the enzyme telomerase (TERT). Critically short telomeres essentially contribute to aging-related diseases and are associated with a broad spectrum of disorders known as telomeropathies. In cardiomyocytes, telomere length is strongly correlated with cardiomyopathies but it remains ambiguous whether short telomeres are the cause or the result of the disease. In this study, we employed an inducible CRISPRi human induced pluripotent stem cell (hiPSC) line to silence TERT expression enabling the generation of hiPSCs and hiPSC-derived cardiomyocytes with long and short telomeres. Reduced telomerase activity and shorter telomere lengths of hiPSCs induced global transcriptomic changes associated with cardiac developmental pathways. Consequently, the differentiation potential towards cardiomyocytes was strongly impaired and single cell RNA sequencing revealed a shift towards a more smooth muscle cell like identity in the cells with the shortest telomeres. Poor cardiomyocyte function and increased sensitivity to stress directly correlated with the extent of telomere shortening. Collectively our data demonstrates a TERT dependent cardiomyogenic differentiation defect, highlighting the CRISPRi TERT hiPSCs model as a powerful platform to study the mechanisms and consequences of short telomeres in the heart and also in the context of telomeropathies.

Circular RNA circZFPM2 regulates cardiomyocyte hypertrophy and survival

Hypertrophic cardiomyopathy (HCM) constitutes the most common genetic cardiac disorder. However, current pharmacotherapeutics are mainly symptomatic and only partially address underlying molecular mechanisms. Circular RNAs (circRNAs) are a recently discovered class of non-coding RNAs and emerged as specific and powerful regulators of cellular functions. By performing global circRNA-specific next generation sequencing in cardiac tissue of patients with hypertrophic cardiomyopathy compared to healthy donors, we identified circZFPM2 (hsa_circ_0003380). CircZFPM2, which derives from the ZFPM2 gene locus, is a highly conserved regulatory circRNA that is strongly induced in HCM tissue. In vitro loss-of-function experiments were performed in neonatal rat cardiomyocytes, human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs), and HCM-patient-derived hiPSC-CMs. A knockdown of circZFPM2 was found to induce cardiomyocyte hypertrophy and compromise mitochondrial respiration, leading to an increased production of reactive oxygen species and apoptosis. In contrast, delivery of recombinant circZFPM2, packaged in lipid-nanoparticles or using AAV-based overexpression, rescued cardiomyocyte hypertrophic gene expression and promoted cell survival. Additionally, HCM-derived cardiac organoids exhibited improved contractility upon CM-specific overexpression of circZFPM2. Multi-Omics analysis further promoted our hypothesis, showing beneficial effects of circZFPM2 on cardiac contractility and mitochondrial function. Collectively, our data highlight that circZFPM2 serves as a promising target for the treatment of cardiac hypertrophy including HCM.

Impact of individualized treatment on recovery from fatigue and return to work in survivors of advanced-stage Hodgkin's lymphoma: results from the randomized international GHSG HD18 trial

BACKGROUND

Persisting cancer-related fatigue impairs health-related quality of life (HRQoL) and social reintegration in patients with Hodgkin's lymphoma (HL). The GHSG HD18 trial established treatment de-escalation for advanced-stage HL guided by positron emission tomography after two cycles (PET-2) as new standard. Here, we investigate the impact of treatment de-escalation on long-term HRQoL, time to recovery from fatigue (TTR-F), and time to return to work (TTR-W).

PATIENTS AND METHODS

Patients received European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire C30 (EORTC QLQ-C30) and life situation questionnaires at baseline, interim, end of treatment, and yearly follow-up. TTR-F was defined as time from the end of chemotherapy until the first fatigue score <30. TTR-W was analyzed in previously working or studying patients and measured from the end of treatment until the first documented work or education. We compared duration of treatment on TTR-F and TTR-W using Cox proportional hazards regression adjusted for confounding variables.

RESULTS

HRQoL questionnaires at baseline were available in 1632 (83.9%) of all randomized patients. Overall, higher baseline fatigue and age were significantly associated with longer TTR-F and TTR-W and male sex with shorter TTR-W. Treatment reduction from eight to four chemotherapy cycles led to a significantly shorter TTR-F [hazard ratio (HR) 1.41, P = 0.008] and descriptively shorter TTR-W (HR 1.24, P = 0.084) in PET-2-negative patients. Reduction from six to four cycles led to non-significant but plausible intermediate accelerations. The addition of rituximab caused significantly slower TTR-F (HR 0.70, P = 0.0163) and TTR-W (HR 0.64, P = 0.0017) in PET-2-positive patients. HRQoL at baseline and age were the main determinants of 2-year HRQoL.

CONCLUSIONS

Individualized first-line treatment in patients with advanced-stage HL considerably shortens TTR-F and TTR-W in PET-2-negative patients. Our results support the use of response-adapted shortened treatment duration for patients with HL.

L-arginine metabolism inhibits arthritis and inflammatory bone loss

OBJECTIVES

To investigate the effect of the L-arginine metabolism on arthritis and inflammation-mediated bone loss.

METHODS

L-arginine was applied to three arthritis models (collagen-induced arthritis, serum-induced arthritis and human TNF transgenic mice). Inflammation was assessed clinically and histologically, while bone changes were quantified by μCT and histomorphometry. In vitro, effects of L-arginine on osteoclast differentiation were analysed by RNA-seq and mass spectrometry (MS). Seahorse, Single Cell ENergetIc metabolism by profilIng Translation inHibition and transmission electron microscopy were used for detecting metabolic changes in osteoclasts. Moreover, arginine-associated metabolites were measured in the serum of rheumatoid arthritis (RA) and pre-RA patients.

RESULTS

L-arginine inhibited arthritis and bone loss in all three models and directly blocked TNFα-induced murine and human osteoclastogenesis. RNA-seq and MS analyses indicated that L-arginine switched glycolysis to oxidative phosphorylation in inflammatory osteoclasts leading to increased ATP production, purine metabolism and elevated inosine and hypoxanthine levels. Adenosine deaminase inhibitors blocking inosine and hypoxanthine production abolished the inhibition of L-arginine on osteoclastogenesis in vitro and in vivo. Altered arginine levels were also found in RA and pre-RA patients.

CONCLUSION

Our study demonstrated that L-arginine ameliorates arthritis and bone erosion through metabolic reprogramming and perturbation of purine metabolism in osteoclasts.

Soluble CD83 modulates human-monocyte-derived macrophages toward alternative phenotype, function, and metabolism

Alterations in macrophage (Mφ) polarization, function, and metabolic signature can foster development of chronic diseases, such as autoimmunity or fibrotic tissue remodeling. Thus, identification of novel therapeutic agents that modulate human Mφ biology is crucial for treatment of such conditions. Herein, we demonstrate that the soluble CD83 (sCD83) protein induces pro-resolving features in human monocyte-derived Mφ biology. We show that sCD83 strikingly increases the expression of inhibitory molecules including ILT-2 (immunoglobulin-like transcript 2), ILT-4, ILT-5, and CD163, whereas activation markers, such as MHC-II and MSR-1, were significantly downregulated. This goes along with a decreased capacity to stimulate alloreactive T cells in mixed lymphocyte reaction (MLR) assays. Bulk RNA sequencing and pathway analyses revealed that sCD83 downregulates pathways associated with pro-inflammatory, classically activated Mφ (CAM) differentiation including HIF-1A, IL-6, and cytokine storm, whereas pathways related to alternative Mφ activation and liver X receptor were significantly induced. By using the LXR pathway antagonist GSK2033, we show that transcription of specific genes (e.g., PPARG, ABCA1, ABCG1, CD36) induced by sCD83 is dependent on LXR activation. In summary, we herein reveal for the first time mechanistic insights into the modulation of human Mφ biology by sCD83, which is a further crucial preclinical study for the establishment of sCD83 as a new therapeutical agent to treat inflammatory conditions.

Active and passive microrheology with large tracers in hard colloids

The dynamics of a tracer particle in a bath of quasi-hard colloidal spheres is studied by Langevin dynamics simulations and mode coupling theory (MCT); the tracer radius is varied from equal to up to seven times larger than the bath particles radius. In the simulations, two cases are considered: freely diffusing tracer (passive microrheology) and tracer pulled with a constant force (active microrheology). Both cases are connected by linear response theory for all tracer sizes. It links both the stationary and transient regimes of the pulled tracer (for low forces) with the equilibrium correlation functions; the velocity of the pulled tracer and its displacement are obtained from the velocity auto-correlation function and the mean squared displacement, respectively. The MCT calculations give insight into the physical mechanisms: At short times, the tracer rattles in its cage of neighbours, with the frequency increasing linearly with the tracer radius asymptotically. The long-time tracer diffusion coefficient from passive microrheology, which agrees with the inverse friction coefficient from the active case, arises from the transport of transverse momentum around the tracer. It can be described with the Brinkman equation for the transverse flow field obtained in extension of MCT, but cannot be recovered from the MCT kernel coupling to densities only. The dynamics of the bath particles is also studied; for the unforced tracer the dynamics is unaffected. When the tracer is pulled, the velocity field in the bath follows the prediction of the Brinkman model, but different from the case of a Newtonian fluid.

Advances in rectal cancer: Real-world evidence suggests limited gains in prognosis for elderly patients

BACKGROUND

Rectal cancer treatment has improved considerably due to the introduction of total meso-rectal excision, radio-chemotherapy, and high-resolution imaging. The aim of this observational cohort study was to quantify the effectiveness of these advances using high-quality data from a representative cohort of patients.

METHODS

20 281 non-metastasized cases retrieved from the Munich Cancer Registry database were divided into three time periods corresponding to before (1988-1997), partial (1998-2007), and full implementation (2008-2019) of clinical advances. Early-onset (<50 yrs.), middle-aged, elderly patient subgroups (> 70 yrs.) were compared. The overall effectiveness of evidence-based guideline adherence was also examined.

RESULTS

Median survival improved by 1.5 yrs. from the first to the last time period. Relative survival increased from 74.9% (5-yr 95%CI[73.3 - 76.6]) to 79.2% (95%CI[77.8 - 80.5]). The incidence of locoregional recurrences was reduced dramatically by more than half (5-yr 17.7% (95%CI[16.5 - 18.8]); 6.7% (95%CI[6.1 - 7.3])). Gains in 5-yr relative survival were limited to early-onset and middle-aged patients with no significant improvement seen in elderly patients (Female 68.6% [63.9 - 73.3] to 67.6% [64.0 - 71.2]; Male 71.7% [65.9 - 77.4] to 74.0% [70.8 - 77.2]).

CONCLUSIONS

Real-world evidence suggests that recent treatment advances have lead to an increase in prognosis for rectal cancer patients. However, more effort should be made to improve the implementation of new developments in elderly patients. Especially considering, that these cases represent a growing majority of diagnosed patients.

Quality Analysis of Radiation Therapy for Hodgkin Lymphoma in the HD 16/17 Trials: A Final Report By the Reference Radiation Oncology Panel of the German Hodgkin Study Group

PURPOSE/OBJECTIVE(S)

The HD 16 and 17 trials by the German Hodgkin Study Group (GHSG) have evaluated the use of consolidative radiotherapy (RT) in early-favorable and -unfavorable stage Hodgkin lymphoma (HL), respectively (1, 2). Quality of RT planning and execution is pivotal for treatment outcome in HL with protocol violations jeopardizing prognosis (3). Consequently, the present work aims at a decisive analysis of quality and dosimetry in the modern era.

MATERIALS/METHODS

Random samples of 100 involved-field RT (IFRT) plans in HD16 and 176 plans in HD17 (134 involved-node RT (INRT) and 42 IFRT) were selected for analysis. Evaluation was performed systematically by the reference radiation oncology panel using pre-chemotherapy imaging, recommendation by the reference radiation oncology and RT planning imaging and graded as "correct", "minor" or "major deviation", respectively. RT doses to the target volume and organs at risks (OAR) were analyzed using dose-volume histograms.

RESULTS

Median RT doses were 20 Gy (19.8 Gy-21.6 Gy) in HD16 and 30 Gy in HD17 (IFRT: 18-30.6 Gy, INRT: 14 Gy-40 Gy). Overall, 84.0%, 69.0%, and 76.1% of RT series in HD16, the IFRT-group of HD17 and the INRT-group of HD17, respectively, were planned correctly. The main reason for major deviation was an insufficient coverage of an involved region (11 %-14.3 %). There was no significant difference in quality between IFRT and INRT in HD17 (p = 0.418 for any deviations; p = 0.466 for major deviations). In comparison to previous GHSG studies in the respective stages, a significant increase in correct RT-series (p<0.001) and decrease in major deviations (p<0.001) occurred. However, doses to OAR varied individually with median values of 4.3 Gy (0.2 Gy-9.2 Gy), 4.7 Gy (0.2 Gy-15.2 Gy) and 3.8 Gy (0.0 Gy-16.0 Gy) for mean doses to the right lung, left lung and heart in HD16, respectively. Correspondingly, values were 9.8 Gy (0.3 Gy-20.0 Gy), 10.5 Gy (0.2 Gy-26.5 Gy) and 13.1 Gy (0.5 Gy-30.4 Gy) for mean doses to the right lung, left lung and heart in HD17, respectively. The size of the planning target volume decreased significantly with INRT compared to IFRT (median values: 1163.1 ml vs. 1464.3 ml; p = 0.043). However, only some OAR-parameters (V25 of the right and left lung, respectively, thyroid and spinal cord) showed significant differences between INRT and IFRT in HD17. The use of intensity-modulated techniques in HD 17 resulted in an increase in V5 and V10 of the lungs with a concomitant decrease in V20-V30.

CONCLUSION

Quality of RT in the planning and treatment of HL has improved significantly with the latest GHSG study generation. Future analyses will focus on a further individualization of treatment fields.

LITERATURE

Illuminating the inner workings of a natural protein switch: Blue-light sensing in LOV-activated diguanylate cyclases

Regulatory proteins play a crucial role in adaptation to environmental cues. Especially for lifestyle transitions, such as cell proliferation or apoptosis, switch-like characteristics are desirable. While nature frequently uses regulatory circuits to amplify or dampen signals, stand-alone protein switches are interesting for applications like biosensors, diagnostic tools, or optogenetics. However, such stand-alone systems frequently feature limited dynamic and operational ranges and suffer from slow response times. Here, we characterize a LOV-activated diguanylate cyclase (LadC) that offers precise temporal and spatial control of enzymatic activity with an exceptionally high dynamic range over four orders of magnitude. To establish this pronounced activation, the enzyme exhibits a two-stage activation process in which its activity is inhibited in the dark by caging its effector domains and stimulated upon illumination by the formation of an extended coiled-coil. These switch-like characteristics of the LadC system can be used to develop new optogenetic tools with tight regulation.

Abstract 4587: Vascular-derived signature imprinted by tumor microenvironment-dependent transcriptional memory predicts colon cancer prognosis

Background: Antiangiogenic therapy is part of the guideline therapy of colorectal cancer (CRC). Surprisingly, the impact of the tumor microenvironment (TME) on tumor vessel endothelial cells (TECs) is largely unclear. The aim of this study was to investigate the presence of a TME-dependent transcriptional memory in TECs isolated from patients and to exploit it to retrieve signatures that characterize TECs in different intratumoral TMEs with impact on patient outcome.

Methods: ECs from tumor and normal colon tissues, PBMCs and tumor cells were isolated from CRC patients with different prognostic TMEs. Cells were analyzed by qPCR, immunocytochemistry and multi-omics (transcriptomics, EPICmethylation chips, exome sequencing). Integrative bioinformatics was used to identify TME-dependent memory genes predicting prognosis and scRNASeq to validate endothelial gene expression in CRC tissues.

Results: Ultrapure TECs were isolated from CRC with different prognostic TMEs (Th1 vs. non-Th1) and systematically compared by multi-omics. A transcriptional memory differentiating the respective TEC groups was identified. This in vivo imprinted transcriptional memory was preferentially regulated by epigenetic DNA methylation but not by genomic alterations and was different from an in vitro primed transcriptional memory to IFN-γ. Moreover, it was specific for TECs and not observed in CAFs. With integrative bioinformatics a TME-dependent memory signature was extracted and its expression in TECs in CRC tissues was confirmed by scRNASeq. Notably, the identified signature predicted the prognosis of CRC patients.

Conclusion: We identified a tumor vessel-derived TME-dependent transcriptional memory signature that was manifested by epigenetic mechanisms and allowed tumor vessel-based prediction of CRC patients prognosis.

Citation Format: Elisabeth Naschberger, Maximilian Fuchs, Nicholas Dickel, Meik Kunz, Charles G. Anchang, Richard Demmler, Bernt Popp, Arif B. Ekici, Steffen Uebe, Carol I. Geppert, Claudia Günther, Susanne Merkel, Vera S. Schellerer, Michael Stürzl. Vascular-derived signature imprinted by tumor microenvironment-dependent transcriptional memory predicts colon cancer prognosis. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4587.

D-lactate is a promising biomarker for the diagnosis of periprosthetic joint infection

Introduction

Reliable biomarkers for the diagnosis of periprosthetic joint infection (PJI) are of paramount clinical value. To date, synovial fluid leukocyte count is the standard surrogate parameter indicating PJI. As D-lactate is almost solely produced by bacteria, it represents a promising molecule in the diagnostic workflow of PJI evaluation. Therefore, the purpose of this study was to assess the performance of synovial fluid D-lactate for diagnosing PJI of the hip and knee.

Materials and Methods

These are preliminary results of a prospective multicenter study from one academic center. Seventy-two consecutive patients after total hip arthroplasty (THA) or total knee arthroplasty (TKA) were prospectively included. All patients received a joint aspiration in order to rule out or confirm PJI, which was diagnosed according to previously published institutional criteria. Synovial fluid D-lactate was determined spectrophotometrically at 450 nm. Receiver operating characteristic (ROC) analysis was performed to assess the diagnostic performance.

Results

Eighteen patients (25%) were diagnosed with PJI and 54 patients (75%) were classified as aseptic. Synovial fluid D-lactate showed a sensitivity of 90.7% (95% CI: 79.7%-96.9%) and specificity of 83.3% (95% CI: 58.6%-96.4%) at a cut-off of 0.04 mmol/L. The median concentration of D-lactate was significantly higher in patients with PJI than in those with aseptic conditions (0.048 mmol/L, range, 0.026-0.076 mmol/L vs. 0.024 mmol/L, range, 0.003-0.058 mmol/L, p < 0.0001). The predominat microogranisms were staphylococci, followed by streptococci and gram-negative bacteria.

Conclusion

D-lactate bears a strong potential to act as a valuable biomarker for diagnosing PJI of the hip and knee. In our study, a cutoff of 0.04 mmol/L showed a comparable sensitivity to synovial fluid leukocyte count. However, its specificity was higher compared to conventional diagnostic tools. The additional advantages of D-lactate testing are requirement of low synovial fluid volume, short turnaround time and low cost.

Soluble CD83 improves and accelerates wound healing by the induction of pro-resolving macrophages

To facilitate the recovery process of chronic and hard-to-heal wounds novel pro-resolving treatment options are urgently needed. We investigated the pro-regenerative properties of soluble CD83 (sCD83) on cutaneous wound healing, where sCD83 accelerated wound healing not only after systemic but also after topical application, which is of high therapeutic interest. Cytokine profile analyses revealed an initial upregulation of inflammatory mediators such as TNFα and IL-1β, followed by a switch towards pro-resolving factors, including YM-1 and IL-10, both expressed by tissue repair macrophages. These cells are known to mediate resolution of inflammation and stimulate wound healing processes by secretion of growth factors such as epidermal growth factor (EGF) and vascular endothelial growth factor (VEGF), which promote vascularization as well as fibroblast and keratinocyte differentiation. In conclusion, we have found strong wound healing capacities of sCD83 beyond the previously described role in transplantation and autoimmunity. This makes sCD83 a promising candidate for the treatment of chronic- and hard-to-heal wounds.

Therapy of chronic extensor mechanism deficiency after total knee arthroplasty using a monofilament polypropylene mesh

Introduction

Lesions of the quadriceps or patellar tendon after total knee arthroplasty (TKA) are a rare but serious complication which, if left untreated, can lead to loss of function of the knee joint. While acute and subacute extensor mechanism disruptions may have several causes, chronic deficiencies are often related to multiple prior revision surgeries for joint infection or aseptic TKA failure. Up to date, biological allograft reconstruction showed unsatisfying results. The use of a monofilament polypropylene mesh is a promising approach for this pathological condition. The aim of the present study was to evaluate clinical, functional and patient reported outcomes of this procedure in patients with chronic extensor mechanism deficiency.

Materials and Methods

Twenty-eight patients with chronic extensor mechanism deficiency (quadriceps tendon rupture n = 9, patellar tendon rupture n = 19) after TKA were included in this retrospective study. None of the patients were lost to follow-up. Surgical reconstruction was performed at one institution between 2014 and 2020 with a monofilament polypropylene mesh (Marlex Mesh, Bard, Murray Hill, USA). The mean age at the time of surgery was 69 years. Patients presented with a mean BMI of 33 kg/m². The mean follow-up period was 23 months.

Results

The 2-year survivorship free of mesh revision was 89% [95% confidence interval (CI): 75% to 100%]. Three patients (11%) had to undergo revision because of mechanical mesh failure and received another polypropylene mesh. No further revisions were performed thereafter. Flexion was 87° (range, 30–120°) on average. The majority of patients (75%, 21/28) had a full active extension. The mean active extension lag after surgery was 4 degrees (range, 0–30°).

Discussion

We observed a substantial improvement of extensor mechanism function. The majority of patients had full extension and showed good clinical results. A failure rate of over 50% has been published for alternative procedures. Thus, the use of the described augmentation technique represents a reasonable treatment option for chronic extensor mechanism disruptions of the patellar tendon as well as the quadriceps tendon after total knee arthroplasty. However, there might be a potentially higher risk for infection persistence in periprosthetic joint infection cases due to the presence of a foreign material.

The soluble CD83 protein prevents bone destruction by inhibiting the formation of osteoclasts and inducing resolution of inflammation in arthritis

Here we show that soluble CD83 induces the resolution of inflammation in an antigen-induced arthritis (AIA) model. Joint swelling and the arthritis-related expression levels of IL-1β, IL-6, RANKL, MMP9, and OC-Stamp were strongly reduced, while Foxp3 was induced. In addition, we observed a significant inhibition of TRAP⁺ osteoclast formation, correlating with the reduced arthritic disease score. In contrast, cell-specific deletion of CD83 in human and murine precursor cells resulted in an enhanced formation of mature osteoclasts. RNA sequencing analyses, comparing sCD83- with mock treated cells, revealed a strong downregulation of osteoclastogenic factors, such as Oc-Stamp, Mmp9 and Nfatc1, Ctsk, and Trap. Concomitantly, transcripts typical for pro-resolving macrophages, e.g., Mrc1/2, Marco, Klf4, and Mertk, were upregulated. Interestingly, members of the metallothionein (MT) family, which have been associated with a reduced arthritic disease severity, were also highly induced by sCD83 in samples derived from RA patients. Finally, we elucidated the sCD83-induced signaling cascade downstream to its binding to the Toll-like receptor 4/(TLR4/MD2) receptor complex using CRISPR/Cas9-induced knockdowns of TLR4/MyD88/TRIF and MTs, revealing that sCD83 acts via the TRIF-signaling cascade. In conclusion, sCD83 represents a promising therapeutic approach to induce the resolution of inflammation and to prevent bone erosion in autoimmune arthritis.

Prognostic and predictive value of CA 19-9 in locally advanced pancreatic cancer treated with multiagent induction chemotherapy: results from a prospective, multicenter phase II trial (NEOLAP-AIO-PAK-0113)

BACKGROUND

The prognostic and predictive value of carbohydrate antigen 19-9 (CA 19-9) in locally advanced pancreatic cancer (LAPC) has not yet been defined from prospective randomized controlled trials (RCTs).

PATIENTS AND METHODS

A total of 165 LAPC patients were treated within the NEOLAP RCT for 16 weeks with multiagent induction chemotherapy [ICT; either nab-paclitaxel/gemcitabine alone or nab-paclitaxel/gemcitabine followed by FOLFIRINOX (combination of fluorouracil, leucovorin, irinotecan, and oxaliplatin)] followed by surgical exploration of all patients without evidence of disease progression. CA 19-9 was determined at baseline and after ICT and correlated with overall survival (OS) and secondary R0 resection rate.

RESULTS

From the NEOLAP study population (N = 165) 133 patients (81%) were evaluable for CA 19-9 at baseline and 81/88 patients (92%) for post-ICT CA 19-9 response. Median OS (mOS) in the CA 19-9 cohort (n = 133) was 16.2 months [95% confidence interval (CI) 13.0-19.4] and R0 resection (n = 31; 23%) was associated with a significant survival benefit [40.8 months (95% CI 21.7-59.8)], while R1 resected patients (n = 14; 11%) had no survival benefit [14.0 (95% CI 11.7-16.3) months, hazard ratio (HR) 0.27; P = 0.001]. After ICT most patients showed a CA 19-9 response (median change from baseline: -82%; relative decrease ≥55%: 83%; absolute decrease to ≤50 U/ml: 43%). Robust CA 19-9 response (decrease to ≤50U/ml) was significantly associated with mOS [27.8 (95% CI 18.4-37.2) versus 16.5 (95% CI 11.7-21.2) months, HR 0.49; P = 0.013], whereas CA 19-9 baseline levels were not prognostic for OS. Multivariate analysis demonstrated that a robust CA 19-9 response was an independent predictive factor for R0 resection. Using a CA 19-9 decrease to ≤61 U/ml as optimal cut-off (by receiver operating characteristic analysis) yielded 72% sensitivity and 62% specificity for successful R0 resection, whereas CA 19-9 nonresponders (<20% decrease or increase) had no chance for successful R0 resection.

CONCLUSIONS

CA 19-9 response after multiagent ICT provides relevant prognostic and predictive information and is useful in selecting LAPC patients for explorative surgery.

CLINICAL TRIAL NUMBER

ClinicalTrials.govNCT02125136; https://clinicaltrials.gov/ct2/show/NCT02125136; EudraCT 2013-004796-12; https://www.clinicaltrialsregister.eu/ctr-search/trial/2013-004796-12/results.

Study protocol of the FIRE-8 (AIO-KRK/YMO-0519) trial: a prospective, randomized, open-label, multicenter phase II trial investigating the efficacy of trifluridine/tipiracil plus panitumumab versus trifluridine/tipiracil plus bevacizumab as first-line treatment in patients with metastatic colorectal cancer

Background

Initial systemic therapy for patients with metastatic colorectal cancer (mCRC) is usually based on two- or three-drug chemotherapy regimens with fluoropyrimidine (5-fluorouracil (5-FU) or capecitabine), oxaliplatin and/or irinotecan, combined with either anti-VEGF (bevacizumab) or, for RAS wild-type (WT) tumors, anti-EGFR antibodies (panitumumab or cetuximab). Recommendations for patients who are not eligible for intensive combination therapies are limited and include fluoropyrimidine plus bevacizumab or single agent anti-EGFR antibody treatment. The use of a monochemotherapy concept of trifluridine/ tipiracil in combination with monoclonal antibodies is not approved for first-line therapy, yet. Results from the phase II TASCO trial evaluating trifluridine/ tipiracil plus bevacicumab in first-line treatment of mCRC patients and from the phase I/II APOLLON trial investigating trifluridine/ tipiracil plus panitumumab in pre-treated mCRC patients suggest favourable activity and tolerability of these new therapeutic approaches.

Methods

FIRE-8 (NCT05007132) is a prospective, randomized, open-label, multicenter phase II study which aims to evaluate the efficacy of first-line treatment with trifluridine/tipiracil (35 mg/m² body surface area (BSA), orally twice daily on days 1–5 and 8–12, q28 days) plus either the anti-EGFR antibody panitumumab (6 mg/kg body weight, intravenously on day 1 and 15, q28 days) [arm A] or (as control arm) the anti-VEGF antibody bevacizumab (5 mg/kg body weight, intravenously on day 1 and 15, q28 days) [arm B] in RAS WT mCRC patients. The primary objective is to demonstrate an improved objective response rate (ORR) according to RECIST 1.1 from 30% (control arm) to 55% with panitumumab. With a power of 80% and a two-sided significance level of 0.05, 138 evaluable patients are needed. Given an estimated drop-out rate of 10%, 153 patients will be enrolled.

Discussion

To the best of our knowledge, this is the first phase II trial to evaluate the efficacy of trifluridine/tipiracil plus panitumumab in first-line treatment of RAS WT mCRC patients. The administration of anti-EGFR antibodies rather than anti-VEGF antibodies in combination with trifluridine/tipiracil may result in an increased initial efficacy.

Trial registration

EU Clinical Trials Register (EudraCT) 2019-004223-20. Registered October 22, 2019, ClinicalTrials.govNCT05007132. Registered on August 12, 2021.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09892-8.

Deciphering Pro-angiogenic Transcription Factor Profiles in Hypoxic Human Endothelial Cells by Combined Bioinformatics and in vitro Modeling

Background

Constant supply of oxygen is crucial for multicellular tissue homeostasis and energy metabolism in cardiac tissue. As a first response to acute hypoxia, endothelial cells (ECs) promote recruitment and adherence of immune cells to the dysbalanced EC barrier by releasing inflammatory mediators and growth factors, whereas chronic hypoxia leads to the activation of a transcription factor (TF) battery, that potently induces expression of growth factors and cytokines including platelet-derived growth factor (PDGF) and vascular endothelial growth factor (VEGF). We report a hypoxia-minded, targeted bioinformatics approach aiming to identify and validate TFs that regulate angiogenic signaling.

Results

A comprehensive RNA-Seq dataset derived from human ECs subjected to normoxic or hypoxic conditions was selected to identify significantly regulated genes based on (i) fold change (normoxia vs. hypoxia) and (ii) relative abundancy. Transcriptional regulation of this gene set was confirmed via qPCR in validation experiments where HUVECs were subjected to hypoxic conditions for 24 h. Screening the promoter and upstream regulatory elements of these genes identified two TFs, KLF5 and SP1, both with a potential binding site within these regions of selected target genes. In vitro, siRNA experiments confirmed SP1- and KLF5-mediated regulation of identified hypoxia-sensitive endothelial genes. Next to angiogenic signaling, we also validated the impact of TFs on inflammatory signaling, both key events in hypoxic sensing. Both TFs impacted on inflammatory signaling since endogenous repression led to increased NF-κB signaling. Additionally, SP1 silencing eventuated decreased angiogenic properties in terms of proliferation and tube formation.

Conclusion

By detailed in silico analysis of promoter region and upstream regulatory elements for a list of hypoxia-sensitive genes, our bioinformatics approach identified putative binding sites for TFs of SP or KLF family in vitro. This strategy helped to identify TFs functionally involved in human angiogenic signaling and therefore serves as a base for identifying novel RNA-based drug entities in a therapeutic setting of vascularization.

Abstract 3802: Micromilieu-dependent transcriptional memory of tumor vessel endothelial cells in colorectal cancer

Purpose of the study: Tumor microenvironment (TME)-induced plasticity of fibroblasts and immune cells are known to contribute to cancer pathogenesis. In contrast, only little is known about the existence, stability, functions and prognostic potential of different plastic phenotypes of tumor vessel endothelial cells (TECs) in cancer. Recently, transcriptional memory effects have been observed in different cell lines after cytokine stimulation in vitro. From this we developed the hypothesis that isolated TEC may exhibit TME-dependent transcriptional memories, which may provide novel insights into the intratumoral effects on TEC plasticity in cancer. To investigate this, we isolated ultrapure TECs from colorectal cancer (CRC) with prognostically favorable (Th-1-like) or worse (non-Th1-like) immune-micro-environments and analyzed the prescence of TME-associated transcriptional memory patterns.

Methods: TECs and as controls normal colon endothelial cells (NECs), PBMCs and tumor cells (isolated by laser-microdissection) from the same CRC patients (n=75) were isolated by FACS-sorting. Ultra high purity (98%) of TECs and NECs was validated by qPCR and immunocytochemistry. Quality validated complete sample sets from 12 patients (Th-1-like, n=6, non-Th1-like, n=6) were compared using exome sequencing, Clariome S chips and EPICmethylation. Integrative bioinformatics was used to identify differential gene sets and to predict their association with prognosis.

Results: Differential transcriptional memory patterns were detected in TECs derived from CRC with different prognostic TMEs. Of note, the aggressiveness of the originating tumors was reflected by the functions of the vascular transcriptional memory genes. The transcriptional memory was imprinted by epigenetic DNA methylation and not due to acquired somatic variants in the genome. These results could be successfully confirmed by alternative methods. Most importantly, integrative bioinformatics analyses retrieved seven vascular memory genes (VMG), which were expressed in the TECs in a TME-dependent manner and predicted the outcome of patients in an independent cohort of CRC patients.

Conclusion: Our findings demonstrate for the first time a TME-dependent transcriptional memory of TECs, providing a clinically relevant indicator of intra-tumoral TME-dependent vascular plasticity with perspectives for patient stratification in vessel-directed tumor therapies.

Citation Format: Michael Stürzl, Maximilian Fuchs, Meik Kunz, Nicholas Dickel, Bernt Popp, Steffen Uebe, Arif B. Ekici, Carol I. Geppert, Susanne Merkel, Vera S. Schellerer, Elisabeth Naschberger. Micromilieu-dependent transcriptional memory of tumor vessel endothelial cells in colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3802.

OP0076 L-ARGININE REPROGRAMS OSTEOCLAST PURINE METABOLISM AMELIORATING BONE LOSS IN RHEUMATOID ARTHRITIS

Background

Bone erosion is a clinical feature of rheumatoid arthritis related to disease severity and poor functional prognosis. Excessive osteoclast differentiation and insufficient osteoblast function are the main reasons for the erosive process in RA. Our previous investigation indicated that L-arginine supplementation not only diminished arthritic inflammation in the serum-induced arthritis (K/BxN) model but also decreased inflammatory joints osteoclast numbers (1).

Objectives

In the present study, we aim to investigate the metabolic action of L-arginine supplementation in RA, especially on periarticular bone erosion and systemic bone loss. We plan to depict the metabolic features of TNFα induced inflammatory osteoclasts after in vitro L-arginine supplementation.

Methods

Three murine arthritis models (serum-induced arthritis (K/BxN) model, collagen-induced arthritis model, and hTNFtg mice model) were analysed in this study. L-arginine was supplemented within the drinking water after the onset of arthritis. Bone parameters for axial skeleton (spine) and peripheral skeleton (tibia) from the respective group were quantified by μCT. HE and TRAP staining were performed to address further the erosion area and osteoclast numbers in periarticular sites. In vitro osteoclast differentiation was conducted with or without L-arginine treatment, in the presence or not of TNFα activation. Seahorse and SCENITH analyses were adopted to delineate the metabolic features. JC-1 staining and transmission electron microscopy (TEM) were used to depict the mitochondria metabolism. RNA-seq and mass spectrometry (MS) were performed to investigate the underlying molecular mechanism.

Results

Inflammation was diminished in all three arthritis models after L-arginine supplementation with a significant reduction in arthritic score. Moreover, an amelioration of periarticular bone erosion, systemic bone loss, and decreased osteoclast numbers in periarticular sites were observed in arthritic mice after L-arginine treatment. L-arginine also inhibited osteoclastogenesis in vitro, particularly under TNFα activation. Seahorse and SCENITH analyses indicated TNFα promoted glycolysis while blocking mitochondria-driven oxidative phosphorylations (OXPHOS) in pre-osteoclasts. Meanwhile, JC-1 staining and TEM images also showed that TNFα decreased mitochondria membrane potential and prompted damage of mitochondria. Surprisingly, L-arginine rescued the TNFα inhibition of OXPHOS while promoting ATP production.

RNA-seq and MS data confirmed the boost of OXPHOS after L-arginine treatment under TNFα activation. To interfere with OXPHOS, L-arginine inhibited cJun thus altered arginase-1 and arginase-2 expression. Moreover, the increased ATP in L-arginine treated cells facilitated purine metabolism, especially the production of inosine and hypoxanthine, contributing to the inhibition of osteoclastogenesis. Increasing Adenosine deaminase (ADA) is essential for the production of inosine and hypoxanthine due to the decreased inhibitory regulation of the transcription factor c-Jun.

Conclusion

These data strongly demonstrated that L-arginine ameliorates bone erosion in RA through metabolic reprogramming and perturbation of purine metabolism in osteoclasts. L-arginine might therefore benefit RA therapy by reducing joint inflammation and also ameliorating bone destruction.

References

[1]Hannemann, Nicole, et al. “Transcription factor Fra-1 targets arginase-1 to enhance macrophage-mediated inflammation in arthritis.” The Journal of clinical investigation 129.7 (2019): 2669-2684.

Disclosure of Interests

Shan Cao: None declared, Rui Song: None declared, Xianyi Meng: None declared, Katerina Kachler: None declared, Maximilian Fuchs: None declared, Xinyu Meng: None declared, Yixuan Li: None declared, Verena Taudte: None declared, Meik Kunz: None declared, Ursula Schloetzer-Schrehardt: None declared, Ulrike Schleicher: None declared, Xiaoxiang Chen Speakers bureau: AbbVie, Roche and Novartis, Georg Schett Speakers bureau: AbbVie, BMS, Celgene, Janssen, Eli Lilly, Novartis, Roche and UCB, Aline Bozec: None declared.

IL-33-induced metabolic reprogramming controls the differentiation of alternatively activated macrophages and the resolution of inflammation

Alternatively activated macrophages (AAMs) contribute to the resolution of inflammation and tissue repair. However, molecular pathways that govern their differentiation have remained incompletely understood. Here, we show that uncoupling protein-2-mediated mitochondrial reprogramming and the transcription factor GATA3 specifically controlled the differentiation of pro-resolving AAMs in response to the alarmin IL-33. In macrophages, IL-33 sequentially triggered early expression of pro-inflammatory genes and subsequent differentiation into AAMs. Global analysis of underlying signaling events revealed that IL-33 induced a rapid metabolic rewiring of macrophages that involved uncoupling of the respiratory chain and increased production of the metabolite itaconate, which subsequently triggered a GATA3-mediated AAM polarization. Conditional deletion of GATA3 in mononuclear phagocytes accordingly abrogated IL-33-induced differentiation of AAMs and tissue repair upon muscle injury. Our data thus identify an IL-4-independent and GATA3-dependent pathway in mononuclear phagocytes that results from mitochondrial rewiring and controls macrophage plasticity and the resolution of inflammation.

A comprehensive method protocol for annotation and integrated functional understanding of lncRNAs

Long non-coding RNAs (lncRNAs) are of fundamental biological importance; however, their functional role is often unclear or loosely defined as experimental characterization is challenging and bioinformatic methods are limited. We developed a novel integrated method protocol for the annotation and detailed functional characterization of lncRNAs within the genome. It combines annotation, normalization and gene expression with sequence-structure conservation, functional interactome and promoter analysis. Our protocol allows an analysis based on the tissue and biological context, and is powerful in functional characterization of experimental and clinical RNA-Seq datasets including existing lncRNAs. This is demonstrated on the uncharacterized lncRNA GATA6-AS1 in dilated cardiomyopathy.

Engrailed 1 coordinates cytoskeletal reorganization to induce myofibroblast differentiation

Transforming growth factor-β (TGFβ) is a key mediator of fibroblast activation in fibrotic diseases, including systemic sclerosis. Here we show that Engrailed 1 (EN1) is reexpressed in multiple fibroblast subpopulations in the skin of SSc patients. We characterize EN1 as a molecular amplifier of TGFβ signaling in myofibroblast differentiation: TGFβ induces EN1 expression in a SMAD3-dependent manner, and in turn, EN1 mediates the profibrotic effects of TGFβ. RNA sequencing demonstrates that EN1 induces a profibrotic gene expression profile functionally related to cytoskeleton organization and ROCK activation. EN1 regulates gene expression by modulating the activity of SP1 and other SP transcription factors, as confirmed by ChIP-seq experiments for EN1 and SP1. Functional experiments confirm the coordinating role of EN1 on ROCK activity and the reorganization of cytoskeleton during myofibroblast differentiation, in both standard fibroblast culture systems and in vitro skin models. Consistently, mice with fibroblast-specific knockout of En1 demonstrate impaired fibroblast-to-myofibroblast transition and are partially protected from experimental skin fibrosis.

Direct Correlation Function of a Crystalline Solid

Direct correlation functions (DCFs), linked to the second functional derivative of the free energy with respect to the one-particle density, play a fundamental role in a statistical mechanics description of matter. This holds, in particular, for the ordered phases: DCFs contain information about the local structure including defects and encode the thermodynamic properties of crystalline solids; they open a route to the elastic constants beyond low temperature expansions. Via a demanding numerical approach, we have explicitly calculated for the first time the DCF of a solid: based on the fundamental measure concept, we provide results for the DCF of a hard sphere crystal. We demonstrate that this function differs at coexistence significantly from its liquid counterpart-both in shape as well as in its order of magnitude-because it is dominated by vacancies. We provide evidence that the traditional use of liquid DCFs in functional Taylor expansions of the free energy is conceptually wrong and show that the emergent elastic constants are in good agreement with simulation-based results.

Metagenomic analysis of nepoviruses: diversity, evolution and identification of a genome region in members of subgroup A that appears to be important for host range

Data mining and metagenomic analysis of 277 open reading frame sequences of bipartite RNA viruses of the genus Nepovirus, family Secoviridae, were performed, documenting how challenging it can be to unequivocally assign a virus to a particular species, especially those in subgroups A and C, based on some of the currently adopted taxonomic demarcation criteria. This work suggests a possible need for their amendment to accommodate pangenome information. In addition, we revealed a host-dependent structure of arabis mosaic virus (ArMV) populations at a cladistic level and confirmed a phylogeographic structure of grapevine fanleaf virus (GFLV) populations. We also identified new putative recombination events in members of subgroups A, B and C. The evolutionary specificity of some capsid regions of ArMV and GFLV that were described previously and biologically validated as determinants of nematode transmission was circumscribed in silico. Furthermore, a C-terminal segment of the RNA-dependent RNA polymerase of members of subgroup A was predicted to be a putative host range determinant based on statistically supported higher π (substitutions per site) values for GFLV and ArMV isolates infecting Vitis spp. compared with non-Vitis-infecting ArMV isolates. This study illustrates how sequence information obtained via high-throughput sequencing can increase our understanding of mechanisms that modulate virus diversity and evolution and create new opportunities for advancing studies on the biology of economically important plant viruses.

POS0423 NCOA3 AMPLIFIES PROFIBROTIC TRANSCRIPTIONAL PROGRAMS IN SYSTEMIC SCLEROSIS

Background:

Excessive activation of fibroblasts with a TGFβ-biased gene signature and deposition of extracellular matrix are key features of fibrotic diseases. The mechanisms underlying these transcriptional changes remain poorly understood. Deregulation, mutations and malfunctions of transcriptional co-regulators, which can interact with multiple transcription factors and enable a broad-spectrum regulation of transcriptional networks, have been implicated as driving factors in a large number of diseases and pathologies.

Objectives:

In the present study, we aimed to analyze the role of the co-regulator Nuclear Receptor Co-Activator 3 (NCOA3) in fibroblast activation and tissue fibrosis, and to evaluate a potential interaction of NCOA3 with fibrosis-relevant transcription factors.

Methods:

NCOA3 was inhibited genetically by siRNA transfection and pharmacologically by the SRC3 inhibitor-2 (SI-2). We performed bulk RNASeq of human dermal fibroblasts and in silico transcription factor binding site screening of differentially expressed genes (DEGs). The interaction of NCOA3 and TGFβ-SMAD signaling was analyzed by reporter and CoIP assays.

Results:

The expression of NCOA3 in skin biopsies of SSc patients compared to normal controls demonstrated that SSc fibroblasts express modestly, but significantly reduced levels of NCOA3, which persisted in cultured SSc fibroblasts. Stimulation of normal fibroblasts with chronically high levels of TGFβ as they also occur in fibrotic tissue remodeling strongly decreased NCOA3 expression to a similar extent as in SSc fibroblasts. Furthermore, NCOA3 expression is also deregulated in different murine models of skin fibrosis. To investigate the functional effects of decreased NCOA3 levels, we targeted the expression of NCOA3 in normal fibroblasts. SiRNA-mediated knockdown of NCOA3 ameliorated TGFβ-induced gene expression, collagen release, myofibroblast differentiation and cell proliferation. In contrast, knockdown of NCOA3 had no effects on collagen release, expression of contractile proteins or gene expression in unstimulated fibroblasts, suggesting that NCOA3 is not required for cellular homeostasis. To characterize the molecular mechanisms, we performed RNASeq upon NCOA3 knockdown. We identified 343 significant differentially expressed genes (220 downregulated and 123 upregulated with a Benjamini-Hochberg false discovery rate FDR < 0.25 and fold change > 1.5) between TGFβ-stimulated fibroblasts with and without NCOA3 knockdown (NCOA3-DEGs) including the fibrosis-relevant genes EDNRB, COL5A3, HES1, IL11 or IL33. Functional analysis of the NCOA3-DEGs showed enrichment of pathway terms such as collagen binding and extracellular matrix organization. In silico screening of the promoters of the NCOA3-DEGs for potential transcription factor binding motifs revealed binding motifs of core transcription factors of fibroblast activation and tissue fibrosis such as SMAD2/3/4, RBPJ, ZEB1, TCF4, REL, and SNAIL2 amongst the downregulated NCOA3-DEGs. Experimental validation of our biostatistical results using SMAD3 as example demonstrated a higher percentage of NCOA3-pSMAD3 double-positive fibroblasts in skin sections of SSc patients compared to healthy controls. In addition, knockdown of NCOA3 reduced TGFβ-induced SMAD-reporter activity. Furthermore, stimulation with TGFβ increased the interaction of NCOA3 with SMAD3 as analyzed by co-immunoprecipitation. Simultaneous knockdown of NCOA3 and SMAD3 showed no additional reductions compared to the single knockdowns, suggesting that NCOA3 controls SMAD3-dependent gene transcription under fibrotic conditions. Finally, inhibition of NCOA3 showed anti-fibrotic effects in different murine models of experimental skin and lung fibrosis.

Conclusion:

Our findings characterize NCOA3 as regulator of multiple pro-fibrotic transcription programs. Pharmaceutical inhibition of NCOA3 might be a strategy to interfere simultaneously with several core pro-fibrotic mediators in fibrotic diseases such as SSc.

Acknowledgements:

We thank Lena Summa, Vladyslav Fedorchenko, Wolfgang Espach and Regina Kleinlein for excellent technical assistance.

The study was funded by grants DI 1537/7-1, DI 1537/8-1, DI 1537/9-1 and -2, DI 1537/11-1, DI 1537/12-1, DI 1537/13-1, DI 1537/14-1, DI 1537/17-1, DE 2414/2-1, DE 2414/4-1, and RA 2506/3-1 of the German Research Foundation, SFB CRC1181 (project C01) and SFB TR221/ project number 324392634 (B04) of the German Research Foundation, grants J39, J40 and A64 of the IZKF in Erlangen, grant 2013.056.1 of the Wilhelm-Sander-Foundation, grants 2014_A47, 2014_A248 and 2014_A184 of the Else-Kröner-Fresenius-Foundation, grant 14-12-17-1-Bergmann of the ELAN-Foundation Erlangen, BMBF (Era-Net grant 01KT1801), MASCARA program, TP 2 and a Career Support Award of Medicine of the Ernst Jung Foundation.

Disclosure of Interests:

Clara Dees: None declared, Sebastian Poetter: None declared, Maximilian Fuchs: None declared, Christina Bergmann: None declared, Alexandru-Emil Matei: None declared, Andrea-Hermina Györfi: None declared, Alina Soare: None declared, Andreas Ramming: None declared, Paolo Ceppi: None declared, Georg Schett: None declared, Meik Kunz: None declared, Jörg H.W. Distler Consultant of: Actelion, Active Biotech, Anamar, ARXX, Bayer Pharma, Boehringer Ingelheim, Celgene, Galapagos, GSK, Inventiva, JB Therapeutics, Medac, Pfizer, RuiYi and UCB, Grant/research support from: Anamar, Active Biotech, Array Biopharma, ARXX, aTyr, BMS, Bayer Pharma, Boehringer Ingelheim, Celgene, Galapagos, GSK, Inventiva, Novartis, Sanofi-Aventis, RedX, UCB

POS0328 ENGRAILED 1 COORDINATES CYTOSKELETAL ORGANIZATION TO PROMOTE MYOFIBROBLAST DIFFERENTIATION AND FIBROTIC TISSUE REMODELING

Background:

Engrailed 1 (EN1) is a homeodomain-containing transcription factor with essential roles in embryonic development. In most cell types, the expression of EN1 is restricted to embryonic development. However, under pathological conditions, EN1 can be re-expressed to promote phenotypical adaptation. En1 is transiently expressed in the developing dermis of murine embryos in a distinct fibroblast lineage and silenced before birth (1). Former EN1-expressing cells give rise to a subpopulation of fibroblasts that has a high capacity for extracellular matrix production in adult murine skin. The role of EN1 in systemic sclerosis (SSc) was previously not explored.

Objectives:

To study the role of EN1 in the pathological activation of fibroblasts in tissue fibrosis.

Methods:

Bulk RNA-Seq and EN1 or SP1 ChIP-Seq were performed from cultured human dermal fibroblasts. The expression of EN1 was inhibited by siRNA. Cytoskeletal drugs paclitaxel, vinblastin and ROCK inhibitor (Y27632) were used to modulate the cytoskeleton in EN1 knockdown or overexpressing dermal fibroblasts. The role of EN1 in fibroblast activation was evaluated by functional experiments with EN1 knockdown or overexpression in standard 2D culture systems as well as in 3D skin equivalent models. The role of EN1 in skin fibrosis was further studied in En1fl/fl X Col6Cre mice, with fibroblast-specific knockout of En1 in three complementary mouse models: overexpression of a constitutively active TGFß-receptor I (TBRICA), bleomycin-induced skin fibrosis and TSK1 mice.

Results:

Pathologically activated dermal fibroblasts from SSc patients express higher levels of EN1 compared with age and sex matched healthy individuals in the skin and in vitro. TGFβ induces EN1 expression in fibroblasts in a SMAD3-dependent manner both in cultured fibroblasts and in murine skin. Knockdown of EN1 prevents TGFβ-induced fibroblast activation, whereas overexpression of EN1 fosters the pro-fibrotic effects of TGFβ with increased expression of αSMA, stress fibers and collagen. RNA sequencing demonstrates that EN1 induces a pro-fibrotic gene expression profile functionally related to cytoskeleton organization and ROCK activation. In silico analyses of the promoters of En1 target genes coupled with siRNA-mediated knockdown demonstrated that EN1 regulates these pro-fibrotic target genes by modulating the activity of regulatory modules that contain transcription factors of the specificity protein (SP) family. Functional experiments with selective modulators of ROCK and of microtubule polymerization confirm the coordinating role of EN1 on ROCK activity and the re-organization of cytoskeleton during myofibroblast differentiation in both conventional culture systems and 3D skin equivalents. Consistently, mice with fibroblast-specific knockout of En1 demonstrate impaired fibroblast-to-myofibroblast transition, reduced dermal thickening and impaired collagen deposition in the TBRICA, bleomycin-induced and TSK1 models.

Conclusion:

We characterize the homeodomain transcription factor EN1 as a molecular amplifier of TGFβ signaling in myofibroblast differentiation that coordinates cytoskeletal organization in a SP-dependent manner. EN1 might thus be a novel candidate for molecular targeted therapies to interfere with myofibroblast differentiation in fibrotic diseases.

References:

[1]Rinkevich Y, Walmsley GG, Hu MS, Maan ZN, Newman AM, Drukker M, et al. Skin fibrosis. Identification and isolation of a dermal lineage with intrinsic fibrogenic potential. Science. 2015;348(6232):aaa2151.

Disclosure of Interests:

Andrea-Hermina Györfi: None declared, Alexandru-Emil Matei: None declared, Maximilian Fuchs: None declared, Aleix Rius Rigau: None declared, Xuezhi Hong: None declared, ZHU Honglin: None declared, Markus Luber: None declared, Christina Bergmann: None declared, Clara Dees: None declared, Ingo Ludolph: None declared, Raymund Horch: None declared, Oliver Distler Consultant of: Actellion, AbbVie, Acceleron Pharma, Anamar, Amgen, Blade Therapeutics, CSL Behring, ChemomAb, Ergonex, Glenmark Pharma, GSK, Inventiva, Italfarmaco, iQvia, Medac, Medscape, Lilly, Sanofi, Target BioScience, UCB, Bayer, Boehringer Ingelheim, Catenion, iQone, Menarini, Mepha, Novartis, Mitsubishi, MSD, Roche, Pfizer, Georg Schett: None declared, Meik Kunz: None declared, Jörg H.W. Distler Consultant of: Actelion, Active Biotech, Anamar, ARXX, Bayer Pharma, Boehringer Ingelheim, Celgene, Galapagos, GSK, Inventiva, JB Therapeutics, Medac, Pfizer, RuiYi and UCB., Grant/research support from: Anamar, Active Biotech, Array Biopharma, aTyr, BMS, Bayer Pharma, Boehringer Ingelheim, Celgene, Galapagos, GSK, Inventiva, Novartis, Sanofi-Aventis, RedX, UCB

Protein kinase C-β-dependent changes in the glucose metabolism of bone marrow stromal cells of chronic lymphocytic leukemia

Survival of chronic lymphocytic leukemia (CLL) cells critically depends on the support of an adapted and therefore appropriate tumor microenvironment. Increasing evidence suggests that B-cell receptor-associated kinases such as protein kinase C-β (PKCβ) or Lyn kinase are essential for the formation of a microenvironment supporting leukemic growth. Here, we describe the impact of PKCβ on the glucose metabolism in bone marrow stromal cells (BMSC) upon CLL contact. BMSC get activated by CLL contact expressing stromal PKCβ that diminishes mitochondrial stress and apoptosis in CLL cells by stimulating glucose uptake. In BMSC, the upregulation of PKCβ results in increased mitochondrial depolarization and leads to a metabolic switch toward oxidative phosphorylation. In addition, PKCβ-deficient BMSC regulates the expression of Hnf1 promoting stromal insulin signaling after CLL contact. Our data suggest that targeting PKCβ and the glucose metabolism of the leukemic niche could be a potential therapeutic strategy to overcome stroma-mediated drug resistance.

Economic Studies Reinforce Efforts to Safeguard Specialty Crops in the United States

Pathogen-tested foundation plant stocks are the cornerstone of sustainable specialty crop production. They provide the propagative units that are used to produce clean planting materials, which are essential as the first-line management option of diseases caused by graft-transmissible pathogens such as viruses, viroids, bacteria, and phytoplasmas. In the United States, efforts to produce, maintain, and distribute pathogen-tested propagative material of specialty crops are spearheaded by centers of the National Clean Plant Network (NCPN). Agricultural economists collaborated with plant pathologists, extension educators, specialty crop growers, and regulators to investigate the impacts of select diseases caused by graft-transmissible pathogens and to estimate the return on investments in NCPN centers. Economic studies have proven valuable to the NCPN in (i) incentivizing the use of clean planting material derived from pathogen-tested foundation plant stocks; (ii) documenting benefits of clean plant centers, which can outweigh operating costs by 10:1 to 150:1; (iii) aiding the development of disease management solutions that are not only ecologically driven but also profit maximizing; and (iv) disseminating integrated disease management recommendations that resonate with growers. Together, economic studies have reinforced efforts to safeguard specialty crops in the United States through the production and use of clean planting material.

Modular micro-physiological human tumor/tissue models based on decellularized tissue for improved preclinical testing

High attrition rates associated with drug testing in 2D cell culture and animal models stress the need for improved modeling of human tumor tissues. In previous studies, our 3D models on a decellularized tissue matrix have shown better predictivity and higher chemoresistance. A single porcine intestine yields material for 150 3D models of breast, lung, colorectal cancer (CRC) or leukemia. The uniquely preserved structure of the basement membrane enables physiological anchorage of endothelial cells and epithelial-derived carcinoma cells. The matrix provides different niches for cell growth: on top as monolayer, in crypts as aggregates, and within deeper layers. Dynamic culture in bioreactors enhances cell growth. Comparing gene expression between 2D and 3D cultures, we observed changes related to proliferation, apoptosis and stemness. For drug target predictions, we utilize tumor-specific sequencing data in our in silico model, finding an additive effect of metformin and gefitinib treatment for lung cancer in silico, validated in vitro. To analyze mode-of-action, immune therapies such as trispecific T-cell engagers in leukemia or toxicity on non-cancer cells, the model can be modularly enriched with human endothelial cells (hECs), immune cells and fibroblasts. Upon addition of hECs, transmigration of immune cells through the endothelial barrier can be investigated. In an allogenic CRC model, we observe a lower basic apoptosis rate after applying PBMCs in 3D compared to 2D, which offers new options to mirror antigen-specific immunotherapies in vitro. In conclusion, we present modular human 3D tumor models with tissue-like features for preclinical testing to reduce animal experiments.

Integrative Bioinformatic Analyses of Global Transcriptome Data Decipher Novel Molecular Insights into Cardiac Anti-Fibrotic Therapies

Integrative bioinformatics is an emerging field in the big data era, offering a steadily increasing number of algorithms and analysis tools. However, for researchers in experimental life sciences it is often difficult to follow and properly apply the bioinformatical methods in order to unravel the complexity and systemic effects of omics data. Here, we present an integrative bioinformatics pipeline to decipher crucial biological insights from global transcriptome profiling data to validate innovative therapeutics. It is available as a web application for an interactive and simplified analysis without the need for programming skills or deep bioinformatics background. The approach was applied to an ex vivo cardiac model treated with natural anti-fibrotic compounds and we obtained new mechanistic insights into their anti-fibrotic action and molecular interplay with miRNAs in cardiac fibrosis. Several gene pathways associated with proliferation, extracellular matrix processes and wound healing were altered, and we could identify micro (mi) RNA-21-5p and miRNA-223-3p as key molecular components related to the anti-fibrotic treatment. Importantly, our pipeline is not restricted to a specific cell type or disease and can be broadly applied to better understand the unprecedented level of complexity in big data research.

G-POEM in patients with gastroparesis - gambling for healing or bigger armamentarium ? A case series and review of the literature

Approximately 30% of all affected patients suffering from gastroparesis do not respond to any available treatment modality. Gastric peroral endoscopic myotomiy (G-POEM, antropyloromyotomy) represents a new principle of therapy. In this single center study, G-POEM showed a high technical success rate with a very low procedural complication rate. However, the clinical response beyond a short-term post-interventional improvement did not succeed in a single patient. The heterogeneity of the clinical picture, which represents a spectrum of different pathophysiological, etiological and clinical characteristics, still requires a therapy tailored to the individual patient. G-POEM should be considered especially in patients with pylorus-dominant gastroparesis.

Thrombosis as a treatment complication in Hodgkin lymphoma patients: a comprehensive analysis of three prospective randomized German Hodgkin Study Group (GHSG) trials

BACKGROUND

The prognosis of Hodgkin lymphoma (HL) is excellent rendering research into treatment complications highly important. An important complication of cancer and its treatment is thrombosis. Thrombotic events are regularly observed in HL patients but precise information on incidence and risk factors is lacking and the value of prophylactic anticoagulation unclear.

PATIENTS AND METHODS

Thus, we comprehensively studied thrombotic events in 5773 patients from the German Hodgkin Study Group (GHSG) HD13-15 trials in early-favorable, intermediate and advanced HL. We estimated the incidence of and identified risk factors for thrombotic events. Additionally, we provide detailed data on the time course and characteristics of thrombotic events.

RESULTS

A total of 193 thrombotic events occurred for an incidence of 3.3%. Out of these, 175 (90.7%) were venous thromboses, 3 (1.5%) newly emerging post-thrombotic syndromes and 15 (7.8%) arterial thromboses. There were 11 (0.7%) events in early-favorable, 27 (1.3%) in early-unfavorable and 155 (7.3%) in advanced patients, the latter incidence being significantly higher (P < 0.001). The most common locations were deep vein thrombosis of the arm (46.3%) and leg (24.6%). Most venous thrombotic events occurred during chemotherapy (78.9%). We observed 59 (30.6%) catheter-associated events and a descriptively increased risk of venous thrombotic events in patients with oral contraception use during treatment (6.8% versus 3.9%). In advanced HL, the incidence of venous thrombotic events was increased upon treatment with BEACOPP-14 (9.4%, P = 0.0079) compared with 5.1% with 6×BEACOPPesc and 5.7% with 8×BEACOPPesc. Among commonly applied risk factors, including the Khorana score, only age and smoking were prognostic.

CONCLUSIONS

The incidence of thrombotic events in advanced stage HL is comparable to other high-risk cancer patients, especially if treated with dose-dense regimens. Additional risk factors are higher age and smoking. Selected HL patients could benefit from prophylactic anticoagulation, however, further interventional studies are needed before general recommendations can be made.

Comprehensive Bioinformatics Identifies Key microRNA Players in ATG7-Deficient Lung Fibroblasts

BACKGROUND

Deficient autophagy has been recently implicated as a driver of pulmonary fibrosis, yet bioinformatics approaches to study this cellular process are lacking. Autophagy-related 5 and 7 (ATG5/ATG7) are critical elements of macro-autophagy. However, an alternative ATG5/ATG7-independent macro-autophagy pathway was recently discovered, its regulation being unknown. Using a bioinformatics proteome profiling analysis of ATG7-deficient human fibroblasts, we aimed to identify key microRNA (miR) regulators in autophagy.

METHOD

We have generated ATG7-knockout MRC-5 fibroblasts and performed mass spectrometry to generate a large-scale proteomics dataset. We further quantified the interactions between various proteins combining bioinformatics molecular network reconstruction and functional enrichment analysis. The predicted key regulatory miRs were validated via quantitative polymerase chain reaction.

RESULTS

The functional enrichment analysis of the 26 deregulated proteins showed decreased cellular trafficking, increased mitophagy and senescence as the major overarching processes in ATG7-deficient lung fibroblasts. The 26 proteins reconstitute a protein interactome of 46 nodes and miR-regulated interactome of 834 nodes. The miR network shows three functional cluster modules around miR-16-5p, miR-17-5p and let-7a related to multiple deregulated proteins. Confirming these results in a biological setting, serially passaged wild-type and autophagy-deficient fibroblasts displayed senescence-dependent expression profiles of miR-16-5p and miR-17-5p.

CONCLUSIONS

We have developed a bioinformatics proteome profiling approach that successfully identifies biologically relevant miR regulators from a proteomics dataset of the ATG-7-deficient milieu in lung fibroblasts, and thus may be used to elucidate key molecular players in complex fibrotic pathological processes. The approach is not limited to a specific cell-type and disease, thus highlighting its high relevance in proteome and non-coding RNA research.

Inflammatory Drivers of Cardiovascular Disease: Molecular Characterization of Senescent Coronary Vascular Smooth Muscle Cells

The senescence of vascular smooth muscle cells (VSMCs) has been implicated as a causal pro-inflammatory mechanism for cardiovascular disease development and progression of atherosclerosis, the instigator of ischemic heart disease. Contemporary limitations related to studying this cellular population and senescence-related therapeutics are caused by a lack of specific markers enabling their detection. Therefore, we aimed to profile a phenotypical and molecular signature of senescent VSMCs to allow reliable identification. To achieve this goal, we have compared non-senescent and senescent VSMCs from two in vitro models of senescence, replicative senescence (RS) and DNA-damage induced senescence (DS), by analyzing the expressions of established senescence markers: cell cycle inhibitors- p16 INK4a, p14 ARF, p21 and p53; pro-inflammatory factors-Interleukin 1β (IL-1β), IL-6 and high mobility group box-1 (HMGB-1); contractile proteins-smooth muscle heavy chain- (MYH11), smoothelin and transgelin (TAGLN), as well as structural features (nuclear morphology and LMNB1 (Lamin B1) expression). The different senescence-inducing modalities resulted in a lack of the proliferative activity. Nucleomegaly was seen in senescent VSMC as compared to freshly isolated VSMC Phenotypically, senescent VSMC appeared with a significantly larger cell size and polygonal, non-spindle-shaped cell morphology. In line with the supposed switch to a pro-inflammatory phenotype known as the senescence associated secretory phenotype (SASP), we found that both RS and DS upregulated IL-1β and released HMGB-1 from the nucleus, while RS also showed IL-6 upregulation. In regard to cell cycle-regulating molecules, we detected modestly increased p16 levels in both RS and DS, but largely inconsistent p21, p14ARF, and p53 expressions in senescent VSMCs. Since these classical markers of senescence showed insufficient deregulation to warrant senescent VSMC detection, we have conducted a non-biased proteomics and in silico analysis of RS VSMC demonstrating altered RNA biology as the central molecular feature of senescence in this cell type. Therefore, key proteins involved with RNA functionality, HMGB-1 release, LMNB-1 downregulation, in junction with nuclear enlargement, can be used as markers of VSMC senescence, enabling the detection of these pathogenic pro-inflammatory cells in future therapeutic studies in ischemic heart disease and atherosclerosis.

Single-source dual-energy computed tomography for the detection of bone marrow lesions: impact of iterative reconstruction and algorithms

PURPOSE

To compare the diagnostic performance of different reconstruction algorithms of single-source dual-energy computed tomography (DECT) for the detection of bone marrow lesions (BML) in patients with vertebral compression fracture using MRI as the standard of reference.

MATERIAL AND METHODS

Seventeen patients with an age over 50 who underwent single-source DECT of the spine were included. The raw data (RD) were reconstructed using filtered back-projection (FBP) and iterative reconstruction (IR) with three iteration levels (IR1-IR3). Bone marrow images were generated using a three-material decomposition (3MD) and a two-material decomposition (2MD) algorithm and an RD-based approach. Three blinded readers scored the images for image quality and the presence of bone marrow lesions (BML). Only vertebrae with height loss were included. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. The different reconstructions were compared using Dunn's multiple comparison test.

RESULTS

Thirty-nine vertebrae were included. IR(1-3) showed superior sensitivity (87.5%) compared to FBP (75%) using 3MD but was comparable to RD (83.3%). All 2MD images were inferior (sensitivity < 38%). The image quality score was significantly higher for 3MD-IR(1-3) compared to 3MD-FBP (p < 0.0001) and all 2MD data sets (p < 0.03). This pattern was also supported by the SNR and CNR measurements. RD showed no significant improvement compared to IR.

CONCLUSION

The image quality of bone marrow images acquired with DECT can be improved by using IR compared with FBP. RD-based reconstruction does not offer significant improvement over image data-based reconstruction. 2MD algorithms are not suitable for BML detection.

Dynamics and friction of a large colloidal particle in a bath of hard spheres: Langevin dynamics simulations and hydrodynamic description

The analysis of the dynamics of tracer particles in a complex bath can provide valuable information about the microscopic behavior of the bath. In this work, we study the dynamics of a forced tracer in a colloidal bath by means of Langevin dynamics simulations and a theory model within continuum mechanics. In the simulations, the bath is comprised of quasihard spheres with a volume fraction of 50% immersed in a featureless quiescent solvent, and the tracer is pulled with a constant small force (within the linear regime). The theoretical analysis is based on the Navier-Stokes equation, where a term proportional to the velocity arises from coarse-graining the friction of the colloidal particles with the solvent. As a result, the final equation is similar to the Brinkman model, although the interpretation is different. A length scale appears in the model, k_{0}^{-1}, where the transverse momentum transport crosses over to friction with the solvent. The effective friction coefficient experienced by the tracer grows with the tracer size faster than the prediction from Stokes's law. Additionally, the velocity profiles in the bath decay faster than in a Newtonian fluid. The comparison between simulations and theory points to a boundary condition of effective partial slip at the tracer surface. We also study the fluctuations in the tracer position, showing that it reaches diffusion at long times, with a subdiffusive regime at intermediate times. The diffusion coefficient, obtained from the long-time slope of the mean-squared displacement, fulfills the Stokes-Einstein relation with the friction coefficient calculated from the steady tracer velocity, confirming the validity of the linear response formalism.

Critical force in active microrheology

Soft solids like colloidal glasses exhibit a yield stress, above which the system starts to flow. The microscopic analogon in microrheology is the untrapping or depinning of a tracer particle subject to an external force exceeding a threshold value in a glassy host. We characterize this delocalization transition based on a bifurcation analysis of the corresponding mode-coupling theory equations. A schematic model that allows analytical progress is presented first, and the full physical model is studied numerically next. This analysis yields a continuous dynamic transition with a critical power-law decay of the probe correlation functions with exponent -1/2. To compare with simulations with a limited duration, a finite-time analysis is performed, which yields reasonable results for not-too-small wave vectors. The theoretically predicted findings are verified by Langevin dynamics simulations. For small wave vectors we find anomalous behavior for the probe position correlation function, which can be traced back to a wave-vector divergence of the critical amplitude. In addition, we propose and test three methods to extract the critical force from experimental data, which provide the same value of the critical force when applied to the finite-time theory or simulations.

Value of bone marrow biopsy in Hodgkin lymphoma patients staged by FDG PET: results from the German Hodgkin Study Group trials HD16, HD17, and HD18

Background

Bone marrow (BM) involvement defines advanced-stage Hodgkin lymphoma and thus has impact on the assignment to treatment. Our aim was to evaluate whether the established BM biopsy may be omitted in patients if 18F-fluorodeoxyglucose positron emission tomography (PET) scanning is carried out during staging.

Patients and methods

Our analysis set consisted of 832 Hodgkin lymphoma patients from the German Hodgkin Study Group trials HD16, HD17, and HD18 who underwent both PET scanning and BM biopsy before treatment. All PET studies were centrally reviewed and BM was categorized as showing focal involvement or not.

Results

Taking BM biopsy as reference standard, baseline PET showed a negative predictive value of 99.9% [95% confidence interval (CI) 99.2% to 100%] with true-negative results in 702 of 703 cases. The sensitivity of PET for detecting BM involvement was 95.0% (95% CI 75.1% to 99.9%) as it could identify 19 out of 20 patients with positive BM biopsy. Moreover, PET found 110 additional subjects with focal BM lesions who would have been considered negative by biopsy.

Conclusions

When compared with BM biopsy, PET was able to detect focal BM lesions in a large number of additional patients. This indicates that conventional BM biopsy may substantially underestimate the actual incidence of BM involvement. Given the high negative predictive value, baseline PET scanning can safely be used to exclude BM involvement in Hodgkin lymphoma. BM biopsy should be considered only in such patients in whom PET-detected lesions lead to a change of treatment protocol.

Registered trials

The trials included in this analysis were registered at ClinicalTrials.gov: HD16-NCT00736320, HD17-NCT01356680, and HD18-NCT00515554.