Synthetic Antiangiogenic Vascular Endothelial Growth Factor-A Splice Variant Revascularizes Ischemic Muscle in Peripheral Artery Disease.

BACKGROUND: Alternative splicing in the eighth exon C-terminus of VEGF-A (vascular endothelial growth factor-A) results in the formation of proangiogenic VEGF165a and antiangiogenic VEGF165b isoforms. The only known difference between these 2 isoform families is a 6-amino acid switch from CDKPRR (in VEGF165a) to SLTRKD (in VEGF165b). We have recently shown that VEGF165b can induce VEGFR2-activation but fails to induce VEGFR1 (VEGF receptor 1)-activation. The molecular mechanisms that regulate VEGF165b's ability toward differential VEGFR2 versus VEGFR1 activation/inhibition are not yet clear. METHODS AND RESULTS: Hypoxia serum starvation was used as an in vitro peripheral artery disease model. Unilateral single ligation of the femoral artery was used as a preclinical peripheral artery disease model. VEGFR1 activating ligands have 2 arginine (RR) residues in their eighth exon C-terminus, that were replaced by lysine-aspartic acid (KD) in VEGF165b. A synthetic anti-angiogenic VEGF165b splice variant in which the KD residues were switched to RR (VEGF165bKD→RR) activated both VEGFR1- and VEGFR2-signaling pathways to induce ischemic-endothelial cell angiogenic capacity in vitro and enhance perfusion recovery in a severe experimental-peripheral artery disease model significantly higher than VEGF165a. Phosphoproteome arrays showed that the therapeutic efficacy of VEGF165bKD→RR over VEGF165a is due to its ability to induce P38-activation in ischemic endothelial cells. CONCLUSIONS: Our data shows that the KD residues regulate VEGF165b's VEGFR1 inhibitory property but not VEGFR2. Switching these KD residues to RR resulted in the formation of a synthetic/recombinant VEGF165bKD→RR isoform that has the ability to activate both VEGFR1- and VEGFR2-signaling and induce ischemic-endothelial cell angiogenic and proliferative capacity that matched the angiogenic requirement necessary to achieve perfusion recovery in a severe experimental-peripheral artery disease model.

Assessment of primary patency for femoropopliteal graft entrapment within the sartorius muscle.

PURPOSE: Blind tunneling of subfascial femoropopliteal bypass grafts may result in inadvertent graft passage through the sartorius. The purpose of this study was to determine whether intramuscular passage of femoropopliteal bypass grafts affects primary patency. METHODS: Patients undergoing femoropopliteal bypass at a Veterans Administration hospital and associated university medical center over a recent 13-year period who also had postoperative cross-sectional imaging adequate to determine graft location were examined. Five-year primary patency of grafts circumferentially enveloped by the muscle was compared with that of both extramuscular subfascial grafts and subcutaneous grafts. RESULTS: 370 femoropopliteal grafts were identified, among which 258 (70%) were subfascial. Vein grafts comprised 51% of the subfascial grafts, and 53% were inserted above the knee. Available postoperative imaging in 110 subfascial grafts demonstrated 74 (67%) to lie completely within the muscle at some point. Among imaged subfascial grafts, primary patency at five years for intramuscular grafts was not significantly worse than extramuscular grafts (P = 0.31). This remained true whether grafts were vein (P = 0.39) or prosthetic (P = 0.31) and whether grafts inserted to the above-knee (P = 0.43) or below-knee (P = 0.21) popliteal artery. Multivariable Cox regression revealed a significant relationship between use of vein grafts (P = 0.013), active smoking (P = 0.01), and hypertension (P = 0.041) and primary patency, but not intramuscular graft location (P = 0.31). CONCLUSION: This study failed to demonstrate significantly inferior primary patency among subfascial femoropopliteal grafts tunneled intramuscularly. Larger studies may be required to adequately detect any differences in patency by muscular entrapment, especially among subgroups.

Evaluation of the effects of ischemia-reperfusion injury in rat isogenic and allogeneic muscle and skin transplant models.

BACKGROUND: Ischemia-reperfusion injury (IRI) is a phenomenon that affects transplant survival. The aim of our study was to examine the effects of IRI in isogenic and allogeneic muscle and skin transplantation models exposed to prolonged warm ischemia. METHODS: Forty-eight Lewis rats and 16 Brown-Norway rats were used to create four groups: Isogenic Inguinal Flap Transplantation (IST), Isogenic Gastrocnemius Muscle Flap Transplantation (IMT), Allogeneic Inguinal Flap Transplantation (AST), and Allogeneic Gastrocnemius Muscle Flap Transplantation (AMT). Malonyldialdehyde (MDA) and superoxide dismutase (SOD) levels were measured on postoperative days 1, 7, 21, 35, 63, 100, and 120 in all groups. Donor-specific chimerism (DSC) in peripheral blood was evaluated in the allogeneic groups on postoperative days 7, 21, 35, 63, 100, and 120. The microRNA-21 and microRNA-205 levels were evaluated on postoperative days 1, 7, and 120 in all groups. At the end of the study, a histopathological examination was performed. RESULTS: A statistically significant difference was found between the groups in terms of MDA and SOD levels. DSC was detected in the AMT group. A significant increase in microRNA-205 was observed, especially in the AMT group. There was no significant difference in the number of functional muscle units between the muscle transplantation groups. CONCLUSION: The presence of DSC in the AMT group and the lack of a significant difference in the number of functional muscle units in the IMT and AMT groups are noteworthy findings.

Increased vascular deposition of oxidized LDL in untreated juvenile dermatomyositis.

BACKGROUND: Juvenile dermatomyositis (JDM) is a systemic vasculopathy associated with metabolic derangements and possible increased risk for premature atherosclerosis. Oxidation of low-density lipoprotein (LDL) in the endothelium is an early step in atherosclerotic plaque formation. It is not known if oxidized LDL is altered in children with untreated JDM. The deposition of oxidized LDL in the vasculature of muscle biopsies (MBx) from patients with untreated JDM and pediatric controls was assessed. FINDINGS: Frozen tissue sections of MRI-directed MBx from 20 female children with untreated JDM and 5 female controls were stained with DAPI and fluorescently labeled antibodies against von Willebrand factor (vWF) and LDL oxidized by copper (oxLDL). Blood vessels were identified by positive vWF staining, and total fluorescence of oxLDL within the vessel walls was measured. Children with untreated JDM had increased deposition of oxLDL in the walls of muscle vasculature compared to healthy children (difference in means ± SEM = 19.86 ± 8.195, p = 0.03). Within the JDM cohort, there was a trend towards increased oxLDL deposition with longer duration of untreated disease (r = 0.43, p = 0.06). There was no significant correlation found between oxLDL deposition and markers of acute JDM disease activity including disease activity scores or muscle enzymes. CONCLUSIONS: This study found increased deposition of oxLDL within blood vessels of children with untreated JDM supporting the concern that these children are at increased risk for premature atherosclerosis from chronic exposure to vascular oxLDL. This study highlights the importance of early diagnosis and treatment initiation to ameliorate cardiovascular damage.

Prophylactic Dose of Rivaroxaban Versus Warfarin for the Treatment of Isolated Calf Muscle Vein Thrombosis: A Retrospective Propensity Score-Matched Analysis.

BACKGROUND: Prophylactic dose of rivaroxaban is often used in treatment of isolated calf muscle vein thrombosis (ICMVT); nevertheless, its effect is less reported. This study aims to evaluate short-term outcomes in patients with ICMVT who received prophylactic dose of rivaroxaban or warfarin therapy. METHODS: A retrospective analysis of 472 ICMVT patients who received 2 different treatment regimens was undertaken. Propensity score matching method was used to balance the confounding effect of baseline clinical data. Chi-squared test and logistic regression analysis were used to compare outcomes (venous thromboembolism events, bleeding events, complete clot resolution) according to the type of treatment regimens before and after propensity score matching. Univariate and multivariable analysis were used to investigate risk factors for incomplete clot resolution of ICMVT after propensity score matching. RESULTS: 242 ICMVT patients received prophylactic dose of rivaroxaban (rivaroxaban group, RG), and 230 received warfarin (warfarin group, WG). After propensity score matching, 156 patients were included in each group; Venous thromboembolism (VTE) events occurred in 14 (9.0%) patients in the RG and 10 (6.4%) in the WG (P = 0.395); no major bleeding events occurred in each group, and clinically relevant nonmajor bleeding events occurred in 5 (3.2%) patients in the RG and 10 (6.4%) in the WG (P = 0.186); complete clot resolution at 3 months occurred in 80 (51.3%) patients in the RG and 100 (64.1%) in the WG (P = 0.022). Logistic regression analysis showed that there were no significant differences between RG and WG in VTE events (odds ratio 1.439, 95% confidence interval 0.619-3.347, P = 0.397) and clinically relevant nonmajor bleeding events (odds ratio 0.483, 95% confidence interval 0.161-1.449, P = 0.194); it revealed that complete clot resolution rate at 3 months was different in the 2 groups (odds ratio 0.589, 95% confidence interval 0.375-0.928, P = 0.022). Treatment regimens (prophylactic dose of rivaroxaban), thrombosis (maximum diameter >7 mm), and risk factors for VTE (nonsurgery risk factors, mainly referring to active malignancy) were risk factors for incomplete clot resolution of ICMVT (P < 0.05). CONCLUSIONS: In this retrospective study with a short-term follow-up, ICMVT patients who received prophylactic dose of rivaroxaban had no significant differences in VTE and bleeding events compared to those who received warfarin therapy (the overall INR >2.0 for >50% of the time); but it was not conducive to complete clot resolution.

Endurance Training Improves Leg Proton Release and Decreases Potassium Release During High-Intensity Exercise in Normoxia and Hypobaric Hypoxia.

AIM: To assess the impact of endurance training on skeletal muscle release of H+ and K+. METHODS: Nine participants performed one-legged knee extension endurance training at moderate and high intensities (70%-85% of Wpeak), three to four sessions·week-1 for 6 weeks. Post-training, the trained and untrained (control) leg performed two-legged knee extension at low, moderate, and high intensities (40%, 62%, and 83% of Wpeak) in normoxia and hypoxia (~4000 m). The legs were exercised simultaneously to ensure identical arterial inflow concentrations of ions and metabolites, and identical power output was controlled by visual feedback. Leg blood flow was measured (ultrasound Doppler), and acid-base variables, lactate- and K+ concentrations were assessed in arterial and femoral venous blood to study K+ and H+ release. Ion transporter abundances were assessed in muscle biopsies. RESULTS: Lactate-dependent H+ release was similar in hypoxia to normoxia (p = 0.168) and was lower in the trained than the control leg at low-moderate intensities (p = 0.060-0.006) but similar during high-intensity exercise. Lactate-independent and total H+ releases were higher in hypoxia (p < 0.05) and increased more with power output in the trained leg (leg-by-power output interactions: p = 0.02). K+ release was similar at low intensity but lower in the trained leg during high-intensity exercise in normoxia (p = 0.024) and hypoxia (p = 0.007). The trained leg had higher abundances of Na+/H+ exchanger 1 (p = 0.047) and Na+/K+ pump subunit α (p = 0.036). CONCLUSION: Moderate- to high-intensity endurance training increases lactate-independent H+ release and reduces K+ release during high-intensity exercise, coinciding with increased Na+/H+ exchanger 1 and Na+/K+ pump subunit α muscle abundances.

The Inhibition of γ-Aminobutyric Acid B1 Receptor Regulates Angiogenesis via the Hippo/YAP Signaling Pathway.

Promoting the establishment of collateral circulation is essential for chronic lower extremity ischemia. However, no effective therapeutic drugs have yet been developed. Recent studies discovered that in the peripheral arteries, there are γ-aminobutyric acid B1 (GABAB1) receptors expressed in endothelial cells and smooth muscle cells, these receptors may have some effects in regulating vascular functions, but the precise mechanism is not yet clear. This study explores the effect of GABAB1 receptor inhibition on angiogenesis and its regulatory mechanism. The expression of GABAB1 in human umbilical vein endothelial cells (HUVECs) was knocked down using shRNA transfection, and effects on HUVECs' proliferation, migration, and tube formation ability were detected. Western blot and RT-PCR were used to verify the signal pathway. The murine hind limb ischemia model was used to verify the effect of CGP35348, an antagonist of GABAB1R, on the recovery of blood flow perfusion and angiogenesis in ischemic tissues. Cell proliferation, migration, and tube formation ability were improved after GABAB1 receptor knockdown in HUVECs. The phosphorylation of the HIPPO/Yes-associated protein (YAP) pathway decreased, while the effect of promoting angiogenesis increased. After treating the ischemic hindlimbs of mice with GABAB1 receptor antagonists, the blood flow perfusion recovered and the angiogenesis increased. These findings demonstrate the effect of GABAB1 receptor inhibition on the HIPPO/YAP pathway in regulating angiogenesis, suggesting that inhibiting GABAB1 receptor levels might be a novel approach for chronic lower extremity ischemia diseases.

Daprodustat reduces skeletal muscle ischemia-reperfusion injury in mice.

PURPOSE: The purpose of the present work was to assess the specific effects and underlying mechanisms of Daprodustat (GSK1278863) on skeletal muscle injury induced by ischemia reperfusion (I/R). METHODS: C57BL/6 mice were randomized into the skeletal muscle I/R injury (I/R), Daprodustat (GSK1278863) pretreatment and I/R (I/R + GSK) and sham operation (Sham) groups. The skeletal muscle I/R injury model was established by placing an orthodontic rubber band at the left hip joint for 3 h and releasing it for 3 h. H&E staining, wet weight/dry weight ratio assessment, TUNEL assay, ELISA, qRT-PCR and immunoblot were utilized to assess the effects of Daprodustat. RESULTS: Daprodustat pretreatment significantly ameliorated apoptosis in skeletal muscle cells, reduced oxidative damage and suppressed inflammatory cytokines. Mechanistically, Daprodustat positively affected NF-κB signaling activation. CONCLUSION: These data demonstrated that Daprodustat may provide a potential clinical approach for preventing or treating skeletal muscle injury induced by I/R.

Trimodal wireless intramuscular device detects muscle pressure, flow, and oxygenation changes in porcine model of lower extremity compartment syndrome.

PURPOSE: Compartment syndrome remains difficult to diagnose early in its clinical course. Pressure transducer catheters have been used to directly measure intracompartmental pressure (ICP), but this method is unreliable, with a false positive rate of 35%. We have previously used intramuscular near infrared spectroscopy to detect changes in tissue oxygen saturation (StO2) in response to increasing ICP using a novel implantable probe. However, measuring StO2 may not be sufficient to identify CS in the clinical setting. The pathophysiology of CS consists of increased ICP, leading to decreased tissue perfusion, and resulting in reduced tissue oxygenation. More clinically useful information may come from the integration of multiple data streams to aid in the diagnosis of CS. In this study, we present a novel, intramuscular probe capable of simultaneous measurement of ICP, StO2, and microvascular blood flow in a porcine model of ACS. METHODS: Proof of concept for this device is demonstrated in a porcine lower extremity balloon compression model of ACS. Pressure was maintained for 20 min (short-term) or 3 h (long-term) before the balloon volume was removed. RESULTS: In both short- and long-term experiments, as ICP increased with increasing balloon volume, the novel multimodal sensor simultaneously and reliably detected pressure elevation and corresponding reversible reductions in microvascular flow rate and tissue oxygenation. CONCLUSION: This novel trimodal device simultaneously measured the elevated ICP, decreased perfusion, and tissue ischemia of evolving ACS, substantiating our basic understanding of CS pathophysiology.

Exercise training alters skeletal muscle microvascular endothelial cell properties in recent postmenopausal females.

The present study examined and compared the impact of exercise training on redox and molecular properties of human microvascular endothelial cells derived from skeletal muscle biopsies from sedentary recent (RPF, ≤ 5 years as postmenopausal) and late (LPF, ≥ 10 years as postmenopausal) postmenopausal females. Resting skeletal muscle biopsies were obtained before and after 8 weeks of intense aerobic exercise training for isolation of microvascular endothelial cells and determination of skeletal muscle angiogenic proteins and capillarisation. The microvascular endothelial cells were analysed for mitochondrial respiration and production of reactive oxygen species (ROS), glycolysis and proteins related to vascular function, redox balance and oestrogen receptors. Exercise training led to a reduced endothelial cell ROS formation (∼50%; P = 0.009 and P = 0.020 for intact and permeabilized cells (state 3), respectively) in RPF only, with no effect on endothelial mitochondrial capacity in either group. Basal endothelial cell lactate formation was higher (7%; P = 0.028), indicating increased glycolysis, after compared to before the exercise training period in RPF only. Baseline endothelial G protein-coupled oestrogen receptor (P = 0.028) and muscle capillarisation (P = 0.028) was lower in LPF than in RPF. Muscle vascular endothelial growth factor protein was higher (32%; P = 0.002) following exercise training in LPF only. Exercise training did not influence endothelial cell proliferation or skeletal muscle capillarisation in either group, but the CD31 level in the muscle tissue, indicating endothelial cell content, was higher (>50%; P < 0.05) in both groups. In conclusion, 8 weeks of intense aerobic exercise training reduces ROS formation and enhances glycolysis in microvascular endothelial cells from RPF but does not induce skeletal muscle angiogenesis. KEY POINTS: Late postmenopausal females have been reported to achieve limited vascular adaptations to exercise training. There is a paucity of data on the effect of exercise training on isolated skeletal muscle microvascular endothelial cells (MMECs). In this study the formation of reactive oxygen species in MMECs was reduced and glycolysis increased after 8 weeks of aerobic exercise training in recent but not late postmenopausal females. Late postmenopausal females had lower levels of G protein-coupled oestrogen receptor in MMECs and lower skeletal muscle capillary density at baseline. Eight weeks of intense exercise training altered MMEC properties but did not induce skeletal muscle angiogenesis in postmenopausal females.

Anti-oxidative and anti-inflammatory effects of Ginkgo biloba extract (EGb761) on hindlimb skeletal muscle ischemia-reperfusion injury in rats.

In posterior spine surgery, retractors exert pressure on paraspinal muscles, elevating intramuscular pressure and compromising blood flow, potentially causing muscle injury during ischemia-reperfusion. Ginkgo biloba extract (EGb 761), known for its antioxidant and free radical scavenging properties and its role in treating cerebrovascular diseases, is investigated for its protective effects against muscle ischemia-reperfusion injury in vitro and in vivo. Animals were randomly divided into the control group, receiving normal saline, and experimental groups, receiving varying doses of EGb761 (25/50/100/200 mg/kg). A 2-h hind limb tourniquet-induced ischemia was followed by reperfusion. Blood samples collected pre-ischemia and 24 h post-reperfusion, along with muscle tissue samples after 24 h, demonstrated that EGb761 at 1000 µg/mL effectively inhibited IL-6 and TNF-α secretion in RAW 264.7 cells without cytotoxicity. EGb761 significantly reduced nitric oxide (NO) and malondialdehyde (MDA) levels, myeloperoxidase (MPO) activity, and increased glutathione (GSH) levels compared to the control after 24 h. Muscle tissue sections revealed more severe damage in the control group, indicating EGb761's potential in mitigating inflammatory responses and oxidative stress during ischemia-reperfusion injury, effectively protecting against muscle damage.

Staged bilateral release of the popliteus muscle using a posterior surgical approach to the popliteal fossa to treat type 4 popliteal artery entrapment.

Popliteal artery entrapment syndrome (PAES) is a rare cause of intermittent claudication in the young. Aberrant embryological development results in entrapment of the popliteal artery by myofascial structures of the popliteal fossa. Type 4 PAES is due to aberrant development of the popliteus muscle superficial to the popliteal artery. We present a case of bilateral type 4 PAES, along with intraoperative photography highlighting the anatomical cause for this pathology. Both limbs in this patient were treated successfully with surgical release of the entrapping popliteus muscle via a posterior surgical approach to the popliteal fossa. This report emphasises the importance of determining popliteal artery integrity and entrapment subtype to guide the management of this condition.

Evaluation of the effect of enriched hydrogen saline solution on distant organ (lung) damage in skeletal muscle ischemia reperfusion in rats.

INTRODUCTION: Ischemia-reperfusion (IR) injury is a major concern that frequently occurs during vascular surgeries. Hydrogen-rich saline (HRS) solution exhibits antioxidant and anti-inflammatory properties. This study aimed to examine the effects of HRS applied before ischemia in the lungs of rats using a lower extremity IR model. MATERIAL AND METHODS: After approval was obtained from the ethics committee, 18 male Wistar albino rats weighing 250-280 g were randomly divided into three groups: control (C), IR and IR-HRS. In the IR and IR-HRS groups, an atraumatic microvascular clamp was used to clamp the infrarenal abdominal aorta, and skeletal muscle ischemia was induced. After 120 min, the clamp was removed, and reperfusion was achieved for 120 min. In the IR-HRS group, HRS was administered intraperitoneally 30 min before the procedure. Lung tissue samples were examined under a light microscope and stained with hematoxylin-eosin (H&E). Malondialdehyde (MDA) levels, total sulfhydryl (SH) levels, and histopathological parameters were evaluated in the tissue samples. RESULTS: MDA and total SH levels were significantly higher in the IR group than in the control group (p < 0.0001 and p = 0.001, respectively). MDA and total SH levels were significantly lower in the IR-HRS group than in the IR group (p < 0.0001 and p = 0.013, respectively). A histopathological examination revealed that neutrophil infiltration/aggregation, alveolar wall thickness, and total lung injury score were significantly higher in the IR group than in the control group (p < 0.0001, p = 0.001, and p < 0.0001, respectively). Similarly, alveolar wall thickness and total lung injury scores were significantly higher in the IR-HRS group than in the control group (p = 0.009 and p = 0.004, respectively). A statistically significant decrease was observed in neutrophil infiltration/aggregation and total lung injury scores in the IR-HRS group compared to those in the IR group (p = 0.023 and p = 0.022, respectively). CONCLUSION: HRS at a dose of 20 mg/kg, administered intraperitoneally 30 min before ischemia in rats, reduced lipid peroxidation and oxidative stress, while also reducing IR damage in lung histopathology. We believe that HRS administered to rats prior to IR exerts a lung-protective effect.

Estrogen stimulates fetal vascular endothelial growth factor expression and microvascularization.

We recently showed that the ratio of capillaries to myofibers in skeletal muscle, which accounts for 80% of insulin-directed glucose uptake and metabolism, was reduced in baboon fetuses in which estrogen was suppressed by maternal letrozole administration. Since vascular endothelial growth factor (VEGF) promotes angiogenesis, the present study determined the impact of estrogen deprivation on fetal skeletal muscle VEGF expression, capillary development, and long-term vascular and metabolic function in 4- to 8-year-old adult offspring. Maternal baboons were untreated or treated with letrozole or letrozole plus estradiol on days 100-164 of gestation (term = 184 days). Skeletal muscle VEGF protein expression was suppressed by 45% (P < 0.05) and correlated (P = 0.01) with a 47% reduction (P < 0.05) in the number of capillaries per myofiber area in fetuses of baboons in which serum estradiol levels were suppressed 95% (P < 0.01) by letrozole administration. The reduction in fetal skeletal muscle microvascularization was associated with a 52% decline (P = 0.02) in acetylcholine-induced brachial artery dilation and a 23% increase (P = 0.01) in mean arterial blood pressure in adult progeny of letrozole-treated baboons, which was restored to normal by letrozole plus estradiol. The present study indicates that estrogen upregulates skeletal muscle VEGF expression and systemic microvessel development within the fetus as an essential programming event critical for ontogenesis of systemic vascular function and insulin sensitivity/glucose homeostasis after birth in primate offspring.

Aerobic exercise training combined with local strength exercise restores muscle blood flow and maximal aerobic capacity in long-term Hodgkin lymphoma survivors.

It is unclear whether muscle blood flow (MBF) is altered in long-term Hodgkin lymphoma (HL) survivors. We tested the hypothesis that 1) MBF response during mental stress (MS) is impaired in long-term HL survivors and 2) aerobic exercise training combined with local strength exercise (ET) restores MBF responses during MS in these survivors. Eighteen 5-year HL survivors and 10 aged-paired healthy subjects (HC) were studied. Twenty HL survivors were randomly divided into two groups: exercise-trained (HLT, n = 10) and untrained (HLUT, n = 10). Maximal aerobic capacity was evaluated by a cardiopulmonary exercise test and forearm blood flow (FBF) by venous occlusion plethysmography. MS was elicited by Stroop color and word test. ET was conducted for 4 mo, 3/wk for 60 min each session. The aerobic exercise intensity corresponded to anaerobic threshold up to 10% below the respiratory compensation point. The strength exercises consisted of two to three sets of chest press, pulley and squat exercises, 12-15 repetitions each exercise at 30-50% of the maximal voluntary contraction. Baseline was similar in HL survivors and HC, except peak oxygen consumption (peak V̇o2, P = 0.013) and FBF (P = 0.006) that were lower in the HL survivors. FBF responses during MS were lower in HL survivors (P < 0.001). ET increased peak V̇o2 (11.59 ± 3.07%, P = 0.002) and FBF at rest (33.74 ± 5.13%, P < 0.001) and during MS (24 ± 5.31%, P = 0.001). Further analysis showed correlation between the changes in peak V̇o2 and the changes in FBF during MS (r = 0.711, P = 0.001). In conclusion, long-term HL survivors have impaired MBF responses during MS. ET restores MBF responses during MS.NEW & NOTEWORTHY Long-term Hodgkin lymphoma (HL) survivors have impaired muscle blood flow responses during mental stress and decreased maximal aerobic capacity. Supervised aerobic exercise training combined with local strength exercises restores muscle blood flow responses during mental stress and maximal aerobic capacity in these survivors. These findings provide evidence of safety and effectiveness of exercise training in HL survivors. Moreover, they highlight the importance of exercise training in the treatment of this set of patients.

Reduced Muscle Mass and Muscle Quality in Patients with Intermittent Claudication due to Peripheral Artery Disease.

BACKGROUND: Peripheral arterial disease (PAD) is associated with reduced muscle mass and quality, but the effects of leg ischemia caused by PAD on muscle quality remain poorly understood. The purpose of this study was to evaluate leg muscle mass and muscle quality in patients with intermittent claudication due to PAD using bioelectrical impedance analysis (BIA). METHODS: One hundred forty-one patients with intermittent claudication due to PAD who visited Tokyo Medical University Hospital from April 2019 to April 2020 were retrospectively analyzed. Leg ischemia was assessed using ankle-brachial pressure index (ABI). The skeletal muscle mass (SMM) assessed leg muscle mass, while the phase angle (PhA) assessed leg muscle quality using BIA. RESULTS: A total of 282 legs in 141 patients were included in the analysis. Leg PhA and SMM showed a decreasing trend according to the severity of leg ischemia (borderline/no ischemia: 2.80 ± 0.50 kg/m2, 4.38 ± 0.94°; mild ischemia: 2.83 ± 0.49 kg/m2, 4.33 ± 1.03°; moderate/severe ischemia: 2.50 ± 0.40 kg/m2, 3.89 ± 0. 88°; P < 0.001 and P = 0.020, respectively). The ABI was moderately correlated with leg SMM (B = 0.347, ß = 0.134, P < 0.001) and leg PhA (B = 0.577, ß = 0.111, P = 0.013) after adjustment for all significant covariates. Leg PhA was moderately correlated with leg SMM (r = 0.318, P < 0.001). CONCLUSIONS: Leg ischemia, especially when moderate or severe, has an adverse effect on both muscle mass and quality in the lower extremities and is associated with skeletal muscle myopathy.

Prophylactic Transversely Hemisected Sartorius Flap for High-Risk Groin Dissections in Vascular Surgery-A Case Series.

Groin wound dehiscence and infection are a common complication of femoral artery exposure. In patients with prosthetic conduits placed in the groin, these complications can lead to graft infection or anastomotic dehiscence with hemorrhage. Sartorius flaps can be useful in preventing graft infections or anastomotic breakdown in the setting of wound infections. Prophylactic sartorius flaps have been suggested to be a useful adjunct in patients who are at high risk for groin complications. Standard sartorius flaps can be difficult to perform and increase the operative time. We present our experience with a modified sartorius flap, a Transversely Hemisected Sartorius (THT), which avoids dissection to the anterior superior iliac spine. Patients who received femoral artery exposure and a modified prophylactic sartorius flap were included in this case series. The Penn Groin Assessment Scale (PGAS) was calculated for each patient and our primary outcome was the rate of deep space wound infections. Fifteen patients received a THT muscle flap. The average age of the cohort was 67.5 (35-86) years. Eight (50%) were male. The mean PGAS was 2.5 (0-6). Eight (50%) groins had a prosthetic conduit underlying the flap. Four (25%) patients had infrainguinal bypass, 3 (18.8%) for femoral-femoral bypass, and 1 (6.3%) patient received aortic-bifemoral bypass. Eight (50%) patients received sartorius flap after femoral artery exposure for thromboembolectomy, endarterectomy, or access complications. Six (37.5%) patients developed superficial surgical site infections however no deep space infections or prosthetic graft excisions resulted. This procedure was effective in preventing graft infections in all patients with high-risk features for groin infection in our retrospective case series. The segmental blood supply is maintained while providing good coverage of the femoral vessels with this rotational flap.

Alginate-Encapsulated Mesenchymal Stromal Cells Improve Hind Limb Ischemia in a Translational Swine Model.

BACKGROUND: Cellular therapies have been investigated to improve blood flow and prevent amputation in peripheral artery disease with limited efficacy in clinical trials. Alginate-encapsulated mesenchymal stromal cells (eMSCs) demonstrated improved retention and survival and promoted vascular generation in murine hind limb ischemia through their secretome, but large animal evaluation is necessary for human applicability. We sought to determine the efficacy of eMSCs for peripheral artery disease-induced limb ischemia through assessment in our durable swine hind limb ischemia model. METHODS AND RESULTS: Autologous bone marrow eMSCs or empty alginate capsules were intramuscularly injected 2 weeks post-hind limb ischemia establishment (N=4/group). Improvements were quantified for 4 weeks through walkway gait analysis, contrast angiography, blood pressures, fluorescent microsphere perfusion, and muscle morphology and histology. Capsules remained intact with mesenchymal stromal cells retained for 4 weeks. Adenosine-induced perfusion deficits and muscle atrophy in ischemic limbs were significantly improved by eMSCs versus empty capsules (mean±SD, 1.07±0.19 versus 0.41±0.16, P=0.002 for perfusion ratios and 2.79±0.12 versus 1.90±0.62 g/kg, P=0.029 for ischemic muscle mass). Force- and temporal-associated walkway parameters normalized (ratio, 0.63±0.35 at week 3 versus 1.02±0.19 preligation; P=0.17), and compensatory footfall patterning was diminished in eMSC-administered swine (12.58±8.46% versus 34.85±15.26%; P=0.043). Delivery of eMSCs was associated with trending benefits in collateralization, local neovascularization, and muscle fibrosis. Hypoxia-cultured porcine mesenchymal stromal cells secreted vascular endothelial growth factor and tissue inhibitor of metalloproteinase 2. CONCLUSIONS: This study demonstrates the promise of the mesenchymal stromal cell secretome at improving peripheral artery disease outcomes and the potential for this novel swine model to serve as a component of the preclinical pipeline for advanced therapies.

Novel Angiogenesis Role of GLP-1(32-36) to Rescue Diabetic Ischemic Lower Limbs via GLP-1R-Dependent Glycolysis in Mice.

BACKGROUND: Restoring the capacity of endothelial progenitor cells (EPCs) to promote angiogenesis is the major therapeutic strategy of diabetic peripheral artery disease. The aim of this study was to investigate the effects of GLP-1 (glucagon-like peptide 1; 32-36)-an end product of GLP-1-on angiogenesis of EPCs and T1DM (type 1 diabetes) mice, as well as its interaction with the classical GLP-1R (GLP-1 receptor) pathway and its effect on mitochondrial metabolism. METHODS: In in vivo experiments, we conducted streptozocin-induced type 1 diabetic mice as a murine model of unilateral hind limb ischemia to examine the therapeutic potential of GLP-1(32-36) on angiogenesis. We also generated Glp1r-/- mice to detect whether GLP-1R is required for angiogenic function of GLP-1(32-36). In in vitro experiments, EPCs isolated from the mouse bone marrow and human umbilical cord blood samples were used to detect GLP-1(32-36)-mediated angiogenic capability under high glucose treatment. RESULTS: We demonstrated that GLP-1(32-36) did not affect insulin secretion but could significantly rescue angiogenic function and blood perfusion in ischemic limb of streptozocin-induced T1DM mice, a function similar to its parental GLP-1. We also found that GLP-1(32-36) promotes angiogenesis in EPCs exposed to high glucose. Specifically, GLP-1(32-36) has a causal role in improving fragile mitochondrial function and metabolism via the GLP-1R-mediated pathway. We further demonstrated that GLP-1(32-36) rescued diabetic ischemic lower limbs by activating the GLP-1R-dependent eNOS (endothelial NO synthase)/cGMP/PKG (protein kinase G) pathway. CONCLUSIONS: Our study provides a novel mechanism with which GLP-1(32-36) acts in modulating metabolic reprogramming toward glycolytic flux in partnership with GLP-1R for improved angiogenesis in high glucose-exposed EPCs and T1DM murine models. We propose that GLP-1(32-36) could be used as a monotherapy or add-on therapy with existing treatments for peripheral artery disease. REGISTRATION: URL: www.ebi.ac.uk/metabolights/; Unique identifier: MTBLS9543.