Pulmonary veno-occlusive disease in Sjogren's syndrome: a case report.

BACKGROUND: Pulmonary arterial hypertension (PAH) associated with connective tissue disease (CTD) belongs to Group 1 pulmonary hypertension. Pulmonary veno-occlusive disease (PVOD), which is characterized by venous system aberrations, has been previously reported in CTD-PAH; however, it has rarely been observed in Sjogren's syndrome (SS). CASE PRESENTATION: Our 28-year-old female patient was admitted to the hospital with recurrent shortness of breath even after minimal physical activity. Her chest high-resolution CT scan demonstrated pulmonary artery dilatation and bilateral ground-glass nodules. A subsequent right heart catheterization confirmed pulmonary hypertension because her mean pulmonary arterial pressure was 62 mmHg. Our inquisitive genomic assessment identified a novel EIF2AK4 mutation at c.1021 C > T (p. Gln341*), the dominant causal gene of PVOD. Histological examination demonstrated stenosis and occlusions in the pulmonary veins. Because she presented with features such as dry eyes and Raynaud's phenomenon, we performed a biopsy on the labial salivary gland, which confirmed SS. Her treatment regimen included PAH-targeted therapies (tadalafil and macitentan) in combination with hydroxychloroquine. Although she was hospitalized several times due to acute exacerbation of PAH, her disease progression was under control, and she did not demonstrate any signs of pulmonary edema even after a three-year treatment period. CONCLUSION: Here, we report the case of an SS-PAH patient with PVOD who carried a novel biallelic EIF2AK4 mutation, and PAH-targeted therapies were well tolerated by our patient.

Thromboxane-Prostanoid Receptor Signaling Drives Persistent Fibroblast Activation in Pulmonary Fibrosis.

Rationale: Although persistent fibroblast activation is a hallmark of idiopathic pulmonary fibrosis (IPF), mechanisms regulating persistent fibroblast activation in the lungs have not been fully elucidated. Objectives: On the basis of our observation that lung fibroblasts express TBXA2R (thromboxane-prostanoid receptor) during fibrosis, we investigated the role of TBXA2R signaling in fibrotic remodeling. Methods: We identified TBXA2R expression in lungs of patients with IPF and mice and studied primary mouse and human lung fibroblasts to determine the impact of TBXA2R signaling on fibroblast activation. We used TBXA2R-deficient mice and small-molecule inhibitors to investigate TBXA2R signaling in preclinical lung fibrosis models. Measurements and Main Results: TBXA2R expression was upregulated in fibroblasts in the lungs of patients with IPF and in mouse lungs during experimental lung fibrosis. Genetic deletion of TBXA2R, but not inhibition of thromboxane synthase, protected mice from bleomycin-induced lung fibrosis, thereby suggesting that an alternative ligand activates profibrotic TBXA2R signaling. In contrast to thromboxane, F2-isoprostanes, which are nonenzymatic products of arachidonic acid induced by reactive oxygen species, were persistently elevated during fibrosis. F2-isoprostanes induced TBXA2R signaling in fibroblasts and mediated a myofibroblast activation profile due, at least in part, to potentiation of TGF-ß (transforming growth factor-ß) signaling. In vivo treatment with the TBXA2R antagonist ifetroban reduced profibrotic signaling in the lungs, protected mice from lung fibrosis in three preclinical models (bleomycin, Hermansky-Pudlak mice, and radiation-induced fibrosis), and markedly enhanced fibrotic resolution after bleomycin treatment. Conclusions: TBXA2R links oxidative stress to fibroblast activation during lung fibrosis. TBXA2R antagonists could have utility in treating pulmonary fibrosis.

Rapid disease progress in a PVOD patient carrying a novel EIF2AK4 mutation: a case report.

BACKGROUND: Pulmonary veno-occlusive disease (PVOD) and pulmonary arterial hypertension (PAH) share an overlapping disease phenotype. Hence it is necessary to distinguish them. CASE PRESENTATION: Our 14-year-old female patient admitted with progressive shortness of breath, dizziness, and fatigue even after minimal physical activity was clinically suspected for PAH, based on her previous history. Her chest computed tomography artery reported the presence of PVOD triad features - subpleural thickened septal lines, ground-glass nodules/opacities and mediastinal lymphadenopathy. Because of her weak physical stature, a lung biopsy was not performed; however, the genetic testing identified a novel heterozygous EIF2AK4 mutation at c.4833_4836dup (p.Q1613Kfs*10) - the dominant susceptible factor driving PVOD. Combination of genetic testing and computed tomography artery facilitated us to distinguish PVOD from PAH. Her disease symptoms advanced aggressively so that she died even before the lung transplantation, which was less than 6 months from the onset of disease symptoms. CONCLUSION: This case report highlights that novel EIF2AK4 mutation at [c.4833_4836dup (p.Q1613Kfs*10)] would predict an aggressive phenotype of PVOD. Hence, we conclude that a genetic test identifying EIF2AK4 mutation would serve as a tool for the early diagnosis of PVOD, circumventing lung biopsy.

A potential therapeutic role for angiotensin-converting enzyme 2 in human pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) is a deadly disease with no cure. Alternate conversion of angiotensin II (AngII) to angiotensin-(1-7) (Ang-(1-7)) by angiotensin-converting enzyme 2 (ACE2) resulting in Mas receptor (Mas1) activation improves rodent models of PAH. Effects of recombinant human (rh) ACE2 in human PAH are unknown. Our objective was to determine the effects of rhACE2 in PAH.We defined the molecular effects of Mas1 activation using porcine pulmonary arteries, measured AngII/Ang-(1-7) levels in human PAH and conducted a phase IIa, open-label pilot study of a single infusion of rhACE2 (GSK2586881, 0.2 or 0.4 mg·kg-1 intravenously).Superoxide dismutase 2 (SOD2) and inflammatory gene expression were identified as markers of Mas1 activation. After confirming reduced plasma ACE2 activity in human PAH, five patients were enrolled in the trial. GSK2586881 was well tolerated with significant improvement in cardiac output and pulmonary vascular resistance. GSK2586881 infusion was associated with reduced plasma markers of inflammation within 2-4 h and increased SOD2 plasma protein at 2 weeks.PAH is characterised by reduced ACE2 activity. Augmentation of ACE2 in a pilot study was well tolerated, associated with improved pulmonary haemodynamics and reduced markers of oxidant and inflammatory mediators. Targeting this pathway may be beneficial in human PAH.

Involvement of Neuroinflammation in the Pathogenesis of Monocrotaline-Induced Pulmonary Hypertension.

Pulmonary hypertension (PH) is a devastating disease and its successful treatment remains to be accomplished despite recent advances in pharmacotherapy. It has been proposed that PH be considered as a systemic disease, rather than primarily a disease of the pulmonary vasculature. Consequently, an investigation of the intricate interplay between multiple organs such as brain, vasculature, and lung in PH could lead to the identification of new targets for its therapy. However, little is known about this interplay. This study was undertaken to examine the concept that altered autonomic-pulmonary communication is important in PH pathophysiology. Therefore, we hypothesize that activation of microglial cells in the paraventricular nucleus of hypothalamus and neuroinflammation is associated with increased sympathetic drive and pulmonary pathophysiology contributing to PH. We utilized the monocrotaline rat model for PH and intracerebroventricular administration of minocycline for inhibition of microglial cells activation to investigate this hypothesis. Hemodynamic, echocardiographic, histological, immunohistochemical, and confocal microscopic techniques assessed cardiac and pulmonary function and microglial cells. Monocrotaline treatment caused cardiac and pulmonary pathophysiology associated with PH. There were also increased activated microglial cells and mRNA for proinflammatory cytokines (IL [interleukin]-1ß, IL-6, and TNF [tumor necrosis factor]-α) in the paraventricular nucleus. Furthermore, increased sympathetic drive and plasma norepinephrine were observed in rats with PH. Intracerebroventricular infusion of minocycline inhibited all these parameters and significantly attenuated PH. These observations implicate a dysfunctional autonomic-lung communication in the development and progression of PH providing new therapeutic targets, such as neuroinflammation, for PH therapy.

Stem cell therapy restores viscoelastic properties of myocardium in rat model of hypertension.

Extensive remodeling of the myocardium is seen in a variety of cardiovascular diseases, including systemic hypertension. Stem cell therapy has been proposed to improve the clinical outcomes of hypertension, and we hypothesized that changes in mechanical properties of the myocardium would accompany the progression of disease and the results of treatment conditions. Using spontaneously hypertensive rats (SHR) as a model of hypertension, we treated 13-week-old hypertensive rats with a single injection of adipose-derived stem cells (ADSC) isolated from a normotensive control. We indented the isolated ventricles of control, untreated sham-injected SHR, and ADSC-treated SHR hearts with a custom cantilever-based system and fit the resulting data to a standard linear solid model. SHR animals had higher blood pressure (198.4±25.9mmHg) and lower ejection fraction (69.9±4.2%) than age-matched control animals (109.0±1.6mmHg, 88.2±1.3%), and increased viscoelastic properties accompanied these clinical changes (right ventricle effective stiffness, SHR: 21.97±5.10kPa, Control: 13.14±3.48kPa). ADSC-treated animals saw improvement in clinical parameters compared to the untreated SHR group, which was also accompanied by a significant restoration of viscoelastic properties of the myocardium (ACSD-treated SHR: 9.77±6.96kPa).