Genetic variants in patients with multiple arterial aneurysms.

PURPOSE: The aim of this study was to identify causal genetic variants in patients with multiple arterial aneurysms. METHODS: From a total cohort of 3107 patients diagnosed with an arterial aneurysm from 2006 to 2016, patients with known hereditary connective tissue diseases, vasculitis, or other arterial pathologies (n = 918) were excluded. Of the remaining cohort (n = 2189), patients with at least 4 aneurysms at different arterial locations (n = 143) were included. Nine blood samples of respective patients were available and derived from the institutional vascular biomaterial bank, and analyzed by whole exome sequencing (WES). Possible candidate variants were selected based on in silico predictions: (I) Truncating variants or (II) Variants that were classified as likely pathogenic (SIFT score < 0.05 or PolyPhen score > 0.9) and with low (< 0.001) or unknown gnomAD allele frequency. The human genome databases GeneCards and MalaCards were used to correlate the variants with regard to possible associations with vascular diseases. RESULTS: A total of 24 variants in 23 different genes associated with vascular diseases were detected in the cohort. One patient with eight aneurysms was heterozygous for a variant in SMAD3, for which pathogenic variants are phenotypically associated with Loeys-Dietz syndrome 3. A heterozygous variant in TNXB was found in a patient with five aneurysms. Homozygous or compound heterozygous pathogenic variants in this gene are associated with Ehlers-Danlos syndrome (classical-like). Another patient with six aneurysms carried two heterozygous TET2 variants together with a heterozygous PPM1D variant. Pathogenic variants in these genes are associated with clonal hematopoiesis of indeterminate potential (CHIP), a known risk factor for cardiovascular disease. CONCLUSION: All nine patients in this study carried variants in genes associated with vascular diseases. Current knowledge of the specific variants is insufficient to classify them as pathogenic at the present time, underlining the need for a better understanding of the consequences of genetic variants. WES should be considered for patients with multiple arterial aneurysms to detect germline variants and to improve clinical management for the individual and family members.

"Mixed Reality" in patient education prior to abdominal aortic aneurysm repair.

Background: To investigate the usability of Mixed-Reality (MR) during patient education in patients scheduled for abdominal aortic aneurysm (AAA) repair. Patients and methods: Consecutive patients scheduled for elective AAA repair were block-randomized in either the Mixed-Reality group (MR group) or the conventional group (control group). Patients of both groups were educated about open and endovascular repair of their respective AAA. The MR group was educated using a head-mounted display (HMD) demonstrating a three-dimensional virtual reconstruction of the respective patient's vascular anatomy. The control group was educated using a conventional two-dimensional monitor to display the patient's vasculature. Outcomes were informational gain as well as patient satisfaction with the educational process. (DRKS-ID: DRKS00025174). Results: 50 patients were included with 25 patients in either group. Both groups demonstrated improvements in scores in the Informational Gain Questionnaire (IGQ) when comparing pre- and post-education scores. (MR group: 6.5 points (±1.8) versus 7.9 points (±1.5); Control group: 6.2 points (±1.8) versus 7.6 points (±1.6); p<0.01) There was no significant difference between the MR group and the control group either in informational gain (MR group: 1.4±1.8; Control group: 1.4±1.8; p=0.5) nor in patient satisfaction scores (MR group: mean 18.3 of maximum 21 points (±3.7); Control group: mean 17 of 21 points (±3.6); p=0.1) Multiple regression revealed no correlation between the use of MR and informational gain or patient satisfaction. Usability of the system was rated high, and patients' subjective assessment of MR was positive. Conclusions: The use of MR in patient education of AAA patients scheduled for elective repair is feasible. While patients reported positively on the use of MR in education, similar levels of informational gain and patient satisfaction can be achieved with MR and conventional methods.

Midterm single-center results after endovascular aneurysm sealing reveal a high rate of stent graft migration, secondary aneurysm ruptures, and device-related reinterventions.

OBJECTIVE: To report procedural results and mid-term follow-up outcomes of patients treated with endovascular aneurysm sealing (EVAS) for abdominal aortic disease. METHODS: In this retrospective observational study, all patients treated with EVAS between March 2013 and January 2018 for abdominal aortic aneurysm (AAA) or abdominal penetrating aortic ulcer were included. The datasets included demographics, aneurysm morphology, and procedural and clinical surveillance outcomes. Furthermore, patients treated within the original instructions for use (IFU-group) were compared with patients treated outside the IFU (non-IFU-group) with regard to survival, reintervention-free survival, freedom from type I endoleak, and freedom from stent graft migration. RESULTS: Seventy patients were included (67 male; median age, 72.5 years). Sixty-five patients were treated for AAA and 5 patients for abdominal penetrating aortic ulcer. Sixty-nine cases were treated electively (98.6%). Technical success was achieved in 68 cases (97.1%). The median clinical follow-up was 50.5 months (interquartile range, 29.3-62.7 months) with a median computed tomography angiographic follow-up of 38.5 months (interquartile range, 17.1-60.2 months). There were five deaths during the study period (7.1%), four of which were aneurysm related (5.7%). Five secondary AAA ruptures were detected (7.1%). Overall, 25 of 70 patients (35.7%) underwent 35 reinterventions, mostly owing to thrombotic complications (18.6%), stent graft migration (17.1%), and type I endoleak (12.9%). Fifteen patients were treated outside of the IFU (non-IFU-group) (21.4%). The estimated reintervention-free survival for the entire cohort at 30 days and 1, 3, and 5 years was 94.3%, 88.5%, 72%, and 56.9%, respectively. Freedom from stent graft migration at 1, 3, and 5 years was 98.6%, 82.0%, and 47.3%, respectively. The estimated freedom from type I endoleak at 30 days and 1, 3, and 5 years in the IFU-group was 100%, 100%, 94.9% and, 91.1% and significantly different when compared with the non-IFU-group with 79.5%, 72.2%, 72.2%, and 72.2% (P = .012). CONCLUSIONS: Although the technical and initial results were satisfying, the mid-term results were disappointing. The enforcement of a close follow-up protocol for all patients treated with EVAS, especially vigilant for stent graft migration to prevent secondary type I endoleak and rupture, is strongly recommended.

Isolated femoral artery revascularisation with or without iliac inflow improvement - a less invasive surgical option in critical limb ischemia.

Background: Isolated femoral artery revascularisation (iFAR) represents a well-established surgical method in the treatment of peripheral arterial disease (PAD) involving common femoral artery disease. Data for iFAR in multilevel PAD are inconsistent, particularly in patients with critical limb ischemia (CLI). The aim of the study was to evaluate the outcome of iFAR in CLI regarding major amputation and reintervention and to identify associated risk factors for this outcome. Patients and methods: The data used have been derived from the German Registry of Firstline Treatment in Critical Limb Ischemia (CRITISCH). A total of 1200 patients were enrolled in 27 vascular centres. This sub-analysis included patients, which were treated with iFAR with/without concomitant iliac intervention. For detection of risk factors for the combined endpoint of major amputation and/or reintervention, selection of variables for multiple regression was conducted using stepwise forward/backward selection by Akaike's information criterion. Results: 95 patients were included (mean age: 72 years ± 10.82; 64.2% male). Of those, 32 (33.7%) participants reached the combined endpoint. Risk factor analysis revealed continued tobacco use (odds ratio [OR] 2.316, confidence interval [CI] 0.832-6.674), TASC D-lesion (OR: 2.293, CI: 0.869-6.261) and previous vascular intervention in the trial leg (OR: 2.720, CI: 1.037-7.381) to be associated with reaching the combined endpoint. Conclusions: iFAR provides a reasonable, surgical option to treat CLI. Lesion length (TASC D) seems to have a negative impact on outcome. Further research is required to better define the future role of iFAR for combined femoro-popliteal lesions in CLI - best in terms of a randomised controlled trial.

Necrotic cell debris induces a NF-κB-driven inflammasome response in vascular smooth muscle cells derived from abdominal aortic aneurysms (AAA-SMC).

Abdominal aortic aneurysm (AAA) is a multi-factorial progressive vascular disease with life-threatening complications. Increasing evidence suggests that smooth muscle cell (SMC) dysfunction and cell death contribute to dilatation and rupture of the aorta by inducing an inflammatory response. The exact mechanism of this response however, is incompletely understood. We here investigated in vitro the capacity of autologous necrotic cell debris (CD) to induce inflammasome components and inflammatory mediators in aortic SMC (AAA-SMC) isolated from patients with AAA undergoing surgical repair. AAA-SMCs were additionally primed with Interferon- γ (IFN-γ) before treatment with CD in order to mimic the proinflammatory status caused by higher IFN-γ concentrations that have been demonstrated in the wall of AAAs. Real-time RT-PCR revealed that CD significantly increased NLRP3 and IL1B mRNA expression in different SMC cultures within 6 h of exposure. Priming of the AAA-SMC with IFN-γ significantly increased expression of NLRP3, AIM2, IFI16 and CASP1 mRNAs, whereas IL1B mRNA was reduced. Additional exposure of IFN-γ-primed AAA-SMC to CD for 6-24 h, further augmented expression of AIM2, NLRP3, and Caspase-1 protein levels. Analysis of the SMC supernatants by ELISA revealed CD-induced release of the senescence-associated cytokines IL-6 and MCP-1 in native and IFN-γ-primed SMC, whereas no secretion of Interleukin-(IL) 1α and IL-1ß secretion were observed. Our results implicate a role of necrotic cell debris derived from dead neighboring cells in SMC dysfunction and in inflammatory response of AAA tissue.

Vascular Biomaterial Banking in Academia.

BACKGROUND/PURPOSE: To establish a high-quality vascular biomaterial bank to serve vascular research teams and act as a basis for translational medicine. The aim was to collect and store material so that investigation into the pathogenesis of vascular disease would be possible employing methods based on histopathology and/or molecular biology. METHODS: The Vascular Biomaterialbank Heidelberg (VBBH) evolved as part of an established, partly accredited biobank complex at the University of Heidelberg (BioMaterialBank Heidelberg - BMBH). The BMBH provided infrastructure regarding legal and quality issues as well as safety, protocols for specimen collection, data management, and publication of results. Protocols were modified where necessary to accommodate specific needs of vascular tissue research. Correct identification of vascular biomaterial is controlled by certified vascular surgeons and pathologists at biobank entry and exit. Pseudonymized clinical data are attached to every specimen. RESULTS: The VBBH provides standardized operating procedures (SOP) regulating the request, processing, and delivery of material to researchers, as well as project tracking. Tissue samples for a research project are requested by filling out an online application form. Within 3-5 working days, a scientific board, including a member of the VBBH and a member of the BMBH, decide upon acceptance or rejection of the research project. Criteria determining acceptance include whether enough samples are available for the particular investigation and whether planned methods are judged adequate to successfully complete the research project. Through tracking of all ongoing studies involving specimens from the VBBH, methods for tissue conservation are continually being optimized. The VBBH platform has supported numerous high-ranking publications involving diverse medical departments and reflects a gain in translational medicine. CONCLUSIONS: SOPs and controls by certified specialists ensure the high quality of specimens obtained through the VBBH. Research performed by vascular surgeons can be facilitated by using the VBBH.

Effect of metformin treatment in patients with type 2 diabetes with respect to glyoxalase 1 activity in atherosclerotic lesions.

BACKGROUND: The enzyme glyoxalase1 (GLO1) is the main opponent in the degradation of the reactive metabolite methylglyoxal (MG), which by glycation of macromolecules is involved in atherogenesis. Reduced GLO1-activity in atherosclerotic tissue is known to be associated with diabetes. It has been shown that treatment of patients with type 2 diabetes with metformin leads to increased GLO1-activity in peripheral-blood-cells. The aim of this study was to evaluate whether metformin treatment increases GLO1-activity in atherosclerotic lesions of patients with type 2 diabetes. PATIENTS AND METHODS: Patients with type 2 diabetes and carotid artery disease were included into the study prospectively. Type of diabetes-medication was documented upon admission along with demographic and clinical history. Using shock frozen endarterectomy-derived carotid artery plaques, GLO1-activity as well as protein expression was measured by a spectophotometric assay and western-blotting respectively. RESULTS: 33 patients (76 % male, mean age 71 years) were included into the study and were divided according to treatment with metformin or not (15 vs. 18 patients). GLO1-activity was increased by the factor 1.36 when treated with metformin - however, not significantly (0.86 vs. 0.63 U/mg, p = 0.056). Normalisation of GLO1-activity onto GLO1-expression level lead to a significant increase by more than twofold (8.48 vs. 3.85, p = 0.044) while GLO1-protein levels did not differ significantly. GLO1-activity correlated positively with increasing HbA1c, especially under metformin treatment. CONCLUSIONS: Treatment with metformin in patients with type 2 diabetes is associated with enhanced GLO1-activity in atherosclerotic lesions. Regarding the macro- and microvascular complications in these patients further studies are needed to gain more insight into the effect of metformin on the GLO/MG system.

Reduced glyoxalase 1 activity in carotid artery plaques of nondiabetic patients with increased hemoglobin A1c level.

OBJECTIVE: Glyoxalase 1 (GLO1) is ubiquitously expressed in the cytosol of the cell and is the major opponent against the reactive metabolite methylglyoxal, which is involved in the development of atherosclerosis. Nondiabetic individuals with an increased hemoglobin A1c (HbA1c) level are at higher risk for development of cardiovascular diseases. As such, this study investigated whether there was an association between reduced GLO1 activity in atherosclerotic lesions of nondiabetic patients with an increased HbA1c level. METHODS: HbA1c level was determined in venous blood of patients with carotid artery disease. Protein level of GLO1 was measured in endarterectomy-derived carotid artery plaques by Western blotting. Activity was measured by spectrophotometric assay in the plaques as well as in the erythrocytes; GLO1 activity in erythrocytes was compared with that in a cohort of healthy individuals (n = 15; 33% men; average age, 60 years). RESULTS: There were 36 patients with carotid artery disease (69% men; average age, 69 years) included in this study and divided into two equal groups: group I, HbA1c < 5.7% (<39 mmol/mol); and group II, 5.7% ≤ HbA1c < 6.5% (39 mmol/mol ≤ HbA1c < 48 mmol/mol). GLO1 activity in carotid plaques was reduced by 29% in group II compared with group I (P = .048), whereas protein expression was unchanged (P = .25). Analysis of GLO1 activity in erythrocytes revealed no difference between the groups (P = .36) or in comparison to healthy controls (P = .15). Examination of clinical parameters showed an increased amount of patients with concomitant peripheral arterial disease in group II (44% vs 10%; P = .020). CONCLUSIONS: Reduction of GLO1 activity in atherosclerotic lesions of nondiabetic patients with increased HbA1c is associated with a functional involvement of this protective enzyme in atherogenesis. Systemic GLO1 activity seems to be independent of both HbA1c and localized atherosclerosis as it was unchanged between group I and group II as well as compared with healthy controls, respectively.

Current treatment strategies for ruptured abdominal aortic aneurysm.

BACKGROUND: Ruptured abdominal aortic aneurysm (rAAA) represents one of the most challenging emergencies in surgery. Open repair (OR) is associated with relevant morbidity and mortality and has not been reduced significantly over the last decade. The introduction of endovascular aneurysm repair (EVAR) and its meanwhile common use in the treatment of rAAA has raised the demand for randomised controlled trials (RCTs) in order to resolve a potential superiority of either OR or EVAR. PURPOSE: This review discusses the current treatment strategies in rAAA repair including diagnostics, peri-operative management and results of OR and EVAR, focussing on RCTs comparing both modalities. RESULTS: Thirty-day mortality after OR and EVAR shows no significant difference in published RCTs. In particular with respect to OR, 30-day mortality was much lower than anticipated throughout all RCTs ranging from 18 to 37 %. EVAR for rAAA resulted in reduced in-hospital stay. Limitations of all except one RCT are low patient recruitment and exclusion of haemodynamically unstable patients. CONCLUSIONS: OR and EVAR need to be provided for rAAA. Despite lacking evidence, EVAR is the first choice treatment in experienced high-volume vascular centres. Low mortality rates in all RCTs raise the question if aortic surgery should be centralised.

Xenopericardial self-made tube grafts in infectious vascular reconstructions: Preliminary results of an easy and ready to use surgical approach.

PURPOSE: Infections are a major setback of vascular reconstruction and associated with considerable morbidity and mortality. We evaluated retrospectively our results with self-made bovine pericardial grafts in infected vessel revascularization versus standard graft material. BASIC METHODS: Retrospective analysis of 9 patients with bovine reconstruction and 10 patients with miscellaneous grafts (vein, homograft) for vascular infections. PRINCIPAL FINDINGS: Infection-free rate of the pericardial group was 100% in 17 months. For patients after reconstructions with miscellaneous grafts, the infection-free rate was 82% in 45 months. Overall in-hospital mortality was 10.5%. There were no in-hospital deaths in the pericardial group. Graft patency of the whole cohort was 100%. The median follow up was 11.74 months. CONCLUSION: Self-made bovine pericardial tube grafts can be crafted to almost any size and adjusted to complex anatomic requirements. The use was feasible in various situations and was associated with good preliminary results concerning patency and reinfection.

Gender difference in glyoxalase 1 activity of atherosclerotic carotid artery lesions.

OBJECTIVE: Age and gender are two factors that determine the risk of atherosclerosis. The latter effect is only partly understood. Dicarbonyls, in particular methylglyoxal, participate in the development of atherosclerosis, and their major detoxification route is the enzyme glyoxalase 1 (GLO1), which is known to decrease during aging. METHODS: GLO1 expression and activity were studied in atherosclerotic carotid artery lesions of 71 patients with respect to demographic and clinical characteristics. RESULTS: GLO1 activity was nonsignificantly reduced by >50% in individuals with carotid artery disease compared with control individuals. There was no significant difference in GLO1 expression between the groups; however, the GLO1 activity-to-protein ratio showed a significant reduction for the carotid artery disease patients compared with the controls. The reduction in the GLO1 activity-to-protein ratio was more pronounced in men and was associated with increased inflammation shown by a significant elevation in the expression-level of interleukin-1ß. CONCLUSIONS: These data suggest that GLO1 is regulated on the post-translational level by factors such as gender as well as factors that affect the overall burden of atherosclerosis.

Type IIIb endoleak after thoracic endovascular aortic repair caused by endoanchor dislocation.

BACKGROUND: The aim of this study was to report the occurrence of a type IIIb endoleak after endovascular repair of a thoracic aortic aneurysm caused by endoanchor dislocation. CASE REPORT: An 84-year-old female patient underwent thoracic endovascular repair for aneurysmal disease of her thoracic aorta. The procedure included primary left subclavian artery revascularization and the placement of endoanchors to enhance fixation of the endograft within the aortic arch. Dislocation of one of the endoanchors resulted in a graft defect leading to a type IIIb endoleak and aortic diameter expansion. CONCLUSIONS: Endoanchors represent a promising adjunct in endovascular repair settings. However, their use requires careful procedure planning and special attention during follow-up.

Glyoxalase I (Glo1) and its metabolites in vascular disease.

Glo1 (glyxoalase I) is a cytosolic protein expressed in all mammalian cells. Its physiological function is the detoxification of MG (methylglyoxal), which is a potent precursor of AGEs (advanced glycation end-products). Although the impact of AGEs on different forms of vascular diseases has been intensively investigated, the evidence for the involvement of Glo1 and MG is still scarce. Recently, several studies have provided significant evidence for Glo1 having a protective effect on microvascular complications in diabetic patients, such as retinopathy and nephropathy. Regarding macrovascular complications, especially atherosclerotic lesions, the impact of Glo1 is even less clear. In the present article, we review the latest findings regarding the role of Glo1 and MG in vascular biology and the pathophysiology of micro- and macro-vascular disease.

Inflammation-related induction of absent in melanoma 2 (AIM2) in vascular cells and atherosclerotic lesions suggests a role in vascular pathogenesis.

BACKGROUND: Absent in melanoma (AIM2) was recently identified to act as a cytosolic DNA sensor in innate immunity. Considering the role of chronic inflammation in atherosclerosis, we hypothesized that AIM2 may act as a damage signal that is activated in response to cellular stress likewise in vascular cells of larger arteries. We thus addressed AIM2 expression in healthy arterial wall and in different vascular lesions. In addition, AIM2 expression was characterized in cultured human aortic endothelial cells (HAoECs), smooth muscle cells (HAoSMCs), and T/G-HA-vascular smooth muscle cells (VSMCs) in response to different stimuli. METHODS: Carotid and aortic lesions from patients who underwent surgery and normal arterial specimens were analyzed by immunohistochemistry for AIM2 expression. Cultured HAoECs, HAoSMCs, and T/G-HA-VSMCs were stimulated in vitro with proinflammatory cytokines (tumor necrosis factor-α, interferon-γ) or poly(dA:dT) and analyzed for AIM2 transcript and protein expression. RESULTS: AIM2 was detected in ECs of the intima and vasa vasorum of normal carotid artery and aorta. Moreover, AIM2 was moderately expressed in VSMCs of normal media and intima layers, as well as in VSMCs of atherosclerotic lesions. Increased AIM2 expression was detected around the necrotic core of atherosclerotic carotid lesions and in the vasa vasorum neovasculature of aortic aneurysms. Subsequent in vitro analysis identified an endogenous AIM2 expression in cultured HAoECs, HAoSMCs, and T/G-HA-VSMCs that was markedly increased upon treatment of the cells with tumor necrosis factor-α, interferon-γ, or cytosolic DNA. CONCLUSIONS: ECs and VSMC are able to respond to inflammatory signals by upregulation of AIM2 expression, indicating a role of AIM2 in vascular pathogenesis.

Mitochondrial Dysfunction and Increased DNA Damage in Vascular Smooth Muscle Cells of Abdominal Aortic Aneurysm (AAA-SMC).

There is increasing evidence for enhanced oxidative stress in the vascular wall of abdominal aortic aneurysms (AAA). Mitochondrial damage and dysfunction are hypothesized to be actors in altered production of reactive oxygen species (ROS) and oxidative stress. However, the role of mitochondria and oxidative stress in vascular remodelling and progression of AAA remains uncertain. We here addressed whether mitochondrial dysfunction is persistently increased in vascular smooth muscle cells (VSMCs) isolated from AAA compared to healthy VSMC. AAA-derived VSMC cultures (AAA-SMC, n = 10) and normal VSMC cultures derived from healthy donors (n = 7) were grown in vitro and analysed for four parameters, indicating mitochondrial dysfunction: (i) mitochondrial content and morphology, (ii) ROS production and antioxidative response, (iii) NADP+/NADPH content and ratio, and (iv) DNA damage, in the presence or absence of angiotensin II (AngII). AAA-SMC displayed increased mitochondrial circularity (rounded shape), reduced mitochondrial area, and reduced perimeter, indicating increased fragmentation and dysfunction compared to healthy controls. This was accompanied by significantly increased O2 - production, reduced NADP+/NADPH levels, a lower antioxidative response (indicated by antioxidative response element- (ARE-) driven luciferase reporter assays), more DNA damage (determined by percentage of γ-H2A.X-positive nuclei), and earlier growth arrest in AAA-SMC. Our data suggest that mitochondrial dysfunction and oxidative stress are persistently increased in AAA-SMC, emphasizing their implication in the pathophysiology of AAA.

Histopathological Characterization of Abdominal Aortic Aneurysms from Patients with Multiple Aneurysms Compared to Patients with a Single Abdominal Aortic Aneurysm.

The aim of this study was to investigate histopathological differences in abdominal aortic aneurysms (AAAs) between patients with multiple and single arterial aneurysms, as we suspect that there are different underlying mechanisms in aneurysm formation. Analysis was based on a previous retrospective study on patients with multiple arterial aneurysms (mult-AA; defined as at least four, n = 143) and a single AAA (sing-AAA, n = 972) who were admitted to our hospital for treatment between 2006 and 2016. Available paraffin-embedded AAA wall specimens were derived from the Vascular Biomaterial Bank Heidelberg (mult-AA, n = 12 vs. sing-AAA, n = 19). Sections were analyzed regarding structural damage of the fibrous connective tissue and inflammatory cell infiltration. Alterations to the collagen and elastin constitution were assessed by Masson-Goldner trichrome and Elastica van Gieson staining. Inflammatory cell infiltration, response and transformation were assessed by CD45 and IL-1ß immunohistochemistry and von Kossa staining. The extent of aneurysmal wall alterations was assessed by semiquantitative gradings and was compared between the groups using Fisher's exact test. IL-1ß was significantly more present in the tunica media in mult-AA compared to sing-AAA (p = 0.022). The increased expression of IL-1ß in mult-AA compared to sing-AAA indicates inflammatory processes play a role in aneurysm formation in patients with multiple arterial aneurysms.

Defective granulation tissue formation in mice with specific ablation of integrin-linked kinase in fibroblasts - role of TGFß1 levels and RhoA activity.

Wound healing crucially relies on the mechanical activity of fibroblasts responding to TGFß1 and to forces transmitted across focal adhesions. Integrin-linked kinase (ILK) is a central adapter recruited to integrin ß1 tails in focal adhesions mediating the communication between cells and extracellular matrix. Here, we show that fibroblast-restricted inactivation of ILK in mice leads to impaired healing due to a severe reduction in the number of myofibroblasts, whereas inflammatory infiltrate and vascularization of the granulation tissue are unaffected. Primary ILK-deficient fibroblasts exhibit severely reduced levels of extracellular TGFß1, α-smooth muscle actin (αSMA) production and myofibroblast conversion, which are rescued by exogenous TGFß1. They are further characterized by elevated RhoA and low Rac1 activities, resulting in abnormal shape and reduced directional migration. Interference with RhoA-ROCK signaling largely restores morphology, migration and TGFß1 levels. We conclude that, in fibroblasts, ILK is crucial for limiting RhoA activity, thus promoting TGFß1 production, which is essential for dermal repair following injury.

Cyclic mechanical stress downregulates endothelin-1 and its responsive genes independently of TGFß1 in dermal fibroblasts.

Mechanical forces are highly variable ranging from the ubiquitous gravity force to compression, fluid shear, torsion, tension and other forms. Mechanical forces act on cells and modulate their biological responses by regulating gene transcription, enzyme and growth factor activity. In soft connective tissues, formation of myofibroblasts strictly requires a mechanically loaded environment in addition to local transforming growth factor (TGF)-ß activity, which itself can be modulated by the mechanical status of the environment. The aim of this study was to monitor the adaptive responses of primary dermal fibroblasts towards cyclic mechanical stress under conditions of high force to better understand the regulation of gene expression in normal skin and mechanisms of gene regulation in mechanically altered fibrotic skin. Primary murine dermal fibroblasts were exposed to equi-biaxial tensile strain. Cyclic mechanical tension was applied at a frequency of 0.1 Hz (6× /min) for 24 h with a maximal increase in surface area of 15%. This treatment resulted in downregulation of alpha smooth muscle actin (αSMA) and connective tissue growth factor (CTGF) but not of TGFß1 expression. Cyclic strain also strongly reduced endothelin-1 (ET-1) expression and supplementing strained cultures with exogenous ET-1 rescued αSMA and CTGF levels. Of note, no biologically significant levels of TGFß1 activity were detected in strained cultures. We provide evidence for a novel, TGFß1-independent mechanism regulating ET-1 expression in dermal fibroblasts by biomechanical forces. Modulation of ET-1-dependent activities regulates downstream fibrotic marker genes; this pathway might therefore provide an approach to attenuate myofibroblast differentiation.

Thoracic Endovascular Aortic Repair (TEVAR) First in Patients with Lower Limb Ischemia in Complicated Type B Aortic Dissection: Clinical Outcome and Morphology.

Acute Type B aortic dissection (TBAD) can cause organ malperfusion, e.g., lower limb ischemia (LLI). Thoracic endovascular aortic repair (TEVAR) represents the standard treatment for complicated TBAD; however, with respect to LLI, data is scant. The aim of this study was to investigate clinical and morphological outcomes in patients with complicated TBAD and LLI managed with a "TEVAR-first" policy. Between March 1997 and December 2021, 731 TEVAR-procedures were performed, including 106 TBAD-cases. Cases with TBAD + LLI were included in this retrospective analysis. Study endpoints were morphological/clinical success of TEVAR, regarding aortic and extremity-related outcome, including extremity-related adjunct procedures (erAP) during a median FU of 28.68 months. A total of 20/106 TBAD-cases (18.8%, 32-82 years, 7 women) presented with acute LLI (12/20 Rutherford class IIb/III). In 15/20 cases, true lumen-collapse (TLC) was present below the aortic bifurcation. In 16/20 cases, TEVAR alone resolved LLI. In the remaining four cases, erAP was necessary. A morphological analysis showed a relation between lower starting point and lesser extent of TLC and TEVAR success. No extremity-related reinterventions and only one major amputation was needed. The data strongly suggest that aTEVAR-first-strategy for treating TBAD with LLI is reasonable. Morphological parameters might be of importance to anticipate the failure of TEVAR alone.

Gene Expression Profiling in Abdominal Aortic Aneurysms.

Gene expression profiling of abdominal aortic aneurysms (AAA) indicates that chronic inflammatory responses, active matrix metalloproteinases, and degradation of the extracellular matrix components are involved in disease development and progression. This study investigates intra- and interpersonal RNA genome-wide expression profiling differences (Illumina HumanHT-12, BeadCHIP expression) of 24 AAA biopsies from 12 patients using a single gene and pathway (GeneOntology, GO enrichment) analysis. Biopsies were collected during open surgical AAA repair and according to prior finite element analysis (FEA) from regions with the highest and lowest wall stress. Single gene analysis revealed a strong heterogeneity of RNA expression parameters within the same and different AAA biopsies. The pathway analysis of all samples showed significant enrichment of genes from three different signaling pathways (integrin signaling pathway: fold change FC 1.63, p = 0.001; cholecystokinin receptor pathway: FC 1.60, p = 0.011; inflammation mediated by chemokine signaling pathway: FC 1.45, p = 0.028). These results indicate heterogeneous gene expression patterns within the AAA vascular wall. Single biopsy investigations do not permit a comprehensive characterization of activated molecular processes in AAA disease.