Rabbit Anti-Human COL3A1 (Cleaved-Gly1221) polyclonal antibody

A 31-year-old woman presented at the emergency room after experiencing colic pain in the right iliac fossa for 5 days. She had previously consulted another center, where deterioration of renal function had been identified and abdominal computed tomography (CT) angiography had shown a dissection of the right renal artery, with areas suggestive of infarction in the right kidney, as well as an aneurysm in the left renal artery and a smaller left kidney. The patient had no relevant family or personal history except posttraumatic carotid-cavernous fistula in 2014, which had been treated with embolization. In our hospital, the patient was hypertensive and acute renal failure was confirmed, accompanied by an increase in lactate dehydrogenase and isomorphic microhematuria. After a new CT Scan, in addition to the lesions described in the renal arteries, another aneurysm in the splenic artery and an aneurysm of the right femoral artery were identified. Antihypertensive treatment was initiated with calcium antagonists and anticoagulation. Subsequent renal arteriography confirmed the dissection of the right renal artery, which could not be repaired, and a coated stent was placed in the left renal artery to exclude the aneurysm. The splenic artery lesion was treated 2 months later. The etiological diagnosis in this young woman was challenging. The presence of visceral aneurysms suggested a differential diagnosis comprising fibromuscular dysplasia, vasculitis, and collagenopathies. Using a multidisciplinary approach and directed anamnesis, the presence of frequent sprains, joint hypermobility, and skin fragility was confirmed. Blood immunology and CT angiography including the thoracic and cervical territories were normal. Echocardiography revealed tricuspid insufficiency. All these data suggested the presence of a collagen-like Ehlers-Danlos syndrome (vascular form). The diagnosis was confirmed by the genetic study, which showed a pathogenic mutation in the COL3A1 gene. Currently, the patient is asymptomatic with recovered renal function following treatment with a beta-blocker and antiplatelet therapy.

It is well established that hypoxia induces epithelial-mesenchymal transition in vitro and in vivo. However, the role of hypoxia in endothelial-mesenchymal transition (EndMT), an important process in the pathogenesis of pulmonary hypertension, is not well-characterized. The present study demonstrated a significant downregulation of the endothelial marker CD31 and its co-localization with a mesenchymal marker, -smooth muscle actin (-SMA), in the intimal layer of small pulmonary arteries of rats exposed to chronic hypoxia. These results suggest a possible role of hypoxia in inducing EndMT in vivo. Consistent with these observations, pulmonary microvascular endothelial cells (PMVECs) cultured under hypoxic conditions exhibited a significant decrease in CD31 expression, alongside a marked increase in the expression of -SMA and two other mesenchymal markers, collagen (Col) 1A1 and Col3A1. In addition, hypoxia promoted the proliferation and migration of -SMA-expressing mesenchymal-like cells, but not of PMVECs. Of note, knockdown of hypoxia-inducible factor 1 (HIF-1) effectively inhibited hypoxic induction of -SMA, Col1A1 and the transcription factor Twist1, while rescuing hypoxic suppression of CD31; these results suggest that HIF-1 is essential for hypoxia-induced EndMT and that it serves as an upstream regulator of Twist1. Mechanistically, HIF-1 was identified to bind to the promoter of the Twist1 gene, thus activating Twist1 transcription and regulating EndMT. Collectively, the present results indicate that the HIF-1/Twist1 pathway has a critical role in mediating the effect of hypoxia-induced EndMT in pulmonary arterial remodeling.