Angiopoietin-2-induced lymphatic endothelial cell migration drives lymphangiogenesis via the β1 integrin-RhoA-formin axis

Lymphangiogenesis is an essential physiological process but also a determining factor in vascular-related pathological conditions. Angiopoietin-2 (Ang2) plays an important role in lymphatic vascular development and function and its upregulation has been reported in several vascular-related diseases, including cancer. Given the established role of the small GTPase RhoA on cytoskeleton-dependent endothelial functions, we investigated the relationship between RhoA and Ang2-induced cellular activities. This study shows that Ang2-driven human dermal lymphatic endothelial cell migration depends on RhoA. We demonstrate that Ang2-induced migration is independent of the Tie receptors, but dependent on β1 integrin-mediated RhoA activation with knockdown, pharmacological approaches, and protein sequencing experiments. Although the key proteins downstream of RhoA, Rho kinase (ROCK) and myosin light chain, were activated, blockade of ROCK did not abrogate the Ang2-driven migratory effect. However, formins, an alternative target of RhoA, were identified as key players, and especially FHOD1. The Ang2-RhoA relationship was explored in vivo, where lymphatic endothelial RhoA deficiency blocked Ang2-induced lymphangiogenesis, highlighting RhoA as an important target for anti-lymphangiogenic treatments.

     

A novel heterozygous mutation in the NOTCH3 gene causing CADASIL

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an identifiable cause of inherited stroke among young adults, characterised by diffuse leukoencephalopathy with prominent involvement of the temporal poles and external capsule. The disease is caused by mutations in the NOTCH3 gene encoding a NOTCH3 receptor protein. The clinical course is relentlessly progressive with early transient ischaemic attacks (TIA) or strokes, dementia and finally death in the mid-60s. We describe a 40-year-old patient with clinical features of CADASIL and a positive family history who was a carrier of a new mutation at the exon 4 of the NOTCH3 gene: C162R. Regardless of the distinctive clinical and neuroimaging features one of his siblings had been mistakenly diagnosed as suffering from multiple sclerosis (MS), suggesting that the disease can occasionally be misdiagnosed as MS.     

Putative contribution of prostaglandin and bradykinin to muscle reflex hyperactivity in patients on Ace-inhibitor therapy for chronic heart failure.

AIMS: In patients with chronic heart failure (CHF), an overactive muscle ergoreceptor reflex (chemo-afferents sensitive to the products of muscle work) is thought to play an important role in the origin of dyspnoea. We sought to investigate whether raised intra-muscular prostaglandins (PG) and bradykinin, as estimated by levels within the venous effluent from exercising skeletal muscle may be involved in symptom generation through the stimulation of the ergoreflex. METHODS AND RESULTS: In 19 stable CHF patients and 12 normal controls, cardiopulmonary exercise capacity (peak O2 consumption [peak VO2]) and the ergoreflex contribution to ventilation (post-handgrip regional circulatory occlusion method) were measured. Venous resting and exercise plasma PGE2, PGF1alpha and bradykinin concentrations were assessed. Eleven patients on angiotensin converting enzyme inhibitors and 10 controls were challenged with ketoprofen infusion (to inhibit PG synthesis and bradykinin activity). Patients vs. controls presented lower exercise tolerance (peak VO2 15.9+/-0.7 vs. 33.0+/-1.3 mL/kg/min), an increased ventilatory response to exercise (VE/VCO2 slope 43+/-2 vs. 27+/-0.9) (p<0.0001 for all comparisons). The overactive ergoreflex of CHF (5.1+/-1.3 vs. 0.1+/-0.3 L/min) was significantly related to the increase in PGF1alpha (adjusted R2=0.34, p<0.005) but not PGE2 (adjusted R2=0.16, p>0.05). The increased PG and bradykinin productions both at rest and during exercise in CHF were attenuated after ketoprofen infusion, associated with ergoreflex reduction (-5.1+/-2.2 L/min, p<0.05 vs. saline). CONCLUSION: In CHF, overactive muscle ergoreflex is associated with elevated blood concentration of PG and bradykinin. Modulation of these metabolite concentrations acutely reduces the muscle ergoreflex activity, which suggests a causative role in triggering and/or mediating the ergoreflex response.     

Subclinical peritonitis due to perforated sigmoid diverticulitis 14 years after heart-lung transplantation

Acute complicated diverticulitis, particularly with colon perforation, is a rare but serious condition in transplant recipients with high morbidity and mortality. Neither acute diverticulitis nor colon perforation has been reported in young heart-lung grafted patients. A case of subclinical peritonitis due to perforated acute sigmoid diverticulitis 14 years after heart-lung transplantation is reported. A 26-year-old woman, who received heart-lung transplantation 14 years ago, presented with vague abdominal pain. Physical examination was normal. Blood tests revealed leukocytosis. Abdominal X-ray showed air-fluid levels while CT demonstrated peritonitis due to perforated sigmoid diverticulitis. Sigmoidectomy and end-colostomy （Hartmann＇s procedure） were performed. Histopathology confirmed perforated acute sigmoid diverticulitis. The patient was discharged on the 8th postoperative day after an uneventful postoperative course. This is the first report of acute diverticulitis resulting in colon perforation in a young heart-lung transplanted patient. Clinical presentation, even in peritonitis, may be atypical due to the masking effects of immunosuppression. A high index of suspicion, urgent aggressive diagnostic investigation of even vague abdominal symptoms, adjustment of immunosuppression, broad-spectrum antibiotics, and immediate surgical treatment are critical. Moreover, strategies to reduce the risk of this complication should be implemented. Pretransplantation colon screening, prophylactic pretransplantation sigmoid resection in patients with diverticulosis, and elective surgical intervention in patients with nonoperatively treated acute diverticulitis after transplantation deserve consideration and further studies.     

Regulation of intercellular biomolecule transfer–driven tumor angiogenesis and responses to anticancer therapies

Intercellular biomolecule transfer (ICBT) between malignant and benign cells is a major driver of tumor growth, resistance to anticancer therapies, and therapy-triggered metastatic disease. Here we characterized cholesterol 25-hydroxylase (CH25H) as a key genetic suppressor of ICBT between malignant and endothelial cells (ECs) and of ICBT-driven angiopoietin-2–dependent activation of ECs, stimulation of intratumoral angiogenesis, and tumor growth. Human CH25H was downregulated in the ECs from patients with colorectal cancer and the low levels of stromal CH25H were associated with a poor disease outcome. Knockout of endothelial CH25H stimulated angiogenesis and tumor growth in mice. Pharmacologic inhibition of ICBT by reserpine compensated for CH25H loss, elicited angiostatic effects (alone or combined with sunitinib), augmented the therapeutic effect of radio-/chemotherapy, and prevented metastatic disease induced by these regimens. We propose inhibiting ICBT to improve the overall efficacy of anticancer therapies and limit their prometastatic side effects.     

Radiotherapy for SMAD4-negative musculoskeletal lesions from pancreatic cancer

Background

Pancreatic cancer (PC) predominantly metastasizes to liver, lung, and peritoneum. Metastatic disease correlates with SMAD4 status. Musculoskeletal metastases (MSM) are rare in pancreatic cancer. The role of radiation therapy (RT) in patients with musculoskeletal metastases is not clear.

Methods

We present a case of a woman with musculoskeletal metastases of PC evolving 4 years after Whipple’s procedure and adjuvant therapy. She was treated with RT for 7 MSM. Radiation dose was 15–45 Gy, delivered in doses of 2.5–5 Gy per fraction. SMAD4 status was examined by immunohistochemistry. Furthermore we undertook a review of the literature to examine the value of RT in musculoskeletal metastasis of PC.

Results

In the presented patient we treated 7 MSM of SMAD4-mutant PC with RT. RT achieved local control in 4 of the 7 MSM. At the resection margin of one MSM recurrent tumor was observed after RT. The status of one MSM was unknown and one MSM showed local progression. Follow-up revealed progression of pain in 1 of the 7 MSM. Except of hyperpigmentation no side effects occurred. There was no dose–correlation effect on tumor control observed. A review of the literature showed that a musculoskeletotrophic phenotype of metastases is rare in PC. MSM of PC are rapidly increasing soft tissue masses causing pain and loss of anatomical function. RT as a treatment option for musculoskeletal metastasis is described in the current literature in only 2 cases. Radiotherapy aims to achieve local control, pain relief, and to maintain anatomical function.

Conclusion

Radiotherapy is an effective and well-tolerated approach for multiple musculoskeletal metastases of PC.