Transient Left Ventricular Dysfunction in Loeys-Dietz Syndrome With Loss-of-Function TGFBR1 Variants

Figures

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  Figure 1. Clinical Course of 2 Patients With Loeys-Dietz Syndrome With TGFBR1 Variants Exhibiting Left Ventricular Dysfunction (A) Pedigrees of the probands. Individuals affected with Loeys-Dietz syndrome indicated by filled circles (females) or filled squares (males). In patient 1, a TGFBR1 variant (TGFBR1-Asp400Gly) was identified in the proband indicated by an arrow (II-2). In patient 2, a TGFBR1 variant (TGFBR1-Leu196Pro) was identified in the proband indicated by an arrow (I-2) and her daughter (II-2). (B) Results of Sanger sequencing analysis of TGFBR1 after polymerase chain reaction amplification using genomic DNA extracted from the peripheral blood of the patient 1 proband. (C) Mitral regurgitation detected by transthoracic echocardiography in patient 1 at 27 years of age (apical 4-chamber view with Doppler imaging). (D) Longitudinal changes in LVEF and clinical course in patient 1. The x-axis indicates the patient's age (in years). Between the ages of 26 and 27, medication compliance in patient 1 was inadequate. (E) Longitudinal changes in LVEF and clinical course in patient 2. The x-axis indicates the patient's age (in years). ARB = angiotensin receptor blocker; ARNI =…

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  Figure 2. Histopathologic Analysis Revealed Minimal Fibrosis in the Right Ventricular Myocardium of 2 Patients With Loeys-Dietz Syndrome With TGFBR1 Variants (A) Patient 1: hematoxylin and eosin staining, scale bar: 100 μm. Masson's trichrome staining was not available because of limited clinical material. (B) Patient 2: hematoxylin and eosin staining (top) and Masson's trichrome staining (bottom), scale bar: 200 μm.

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  Figure 3. TGFBR1-Asp400Gly and Leu196Pro Reduced TGF-β Signaling Activities (A) HEK293T cells were co-transfected with SBE4-Luc and expression vectors encoding WT or variant TGFBR1. Twenty-four hours after vehicle or TGF-β1(10, 50, 100 ng/mL) stimulation, cells were collected and luciferase activity was measured. Data are presented as relative luciferase activity normalized to the activity of vehicle control, which was set to 1. Data are shown as mean ± SD. Statistical significance was assessed by 2-way analysis of variance followed by Dunnett's multiple comparisons test. ∗P < 0.0001. (B) HEK293T cells were transfected with expression vectors encoding WT or variant TGFBR1, and protein expression was evaluated by Western blotting. Representative Western blots (left) and quantitative analysis shown as bar graphs (right) are presented. TGFBR1 protein levels were quantified by densitometric analysis of Western blot bands and normalized to GAPDH. Relative TGFBR1 protein expressions are expressed relative to WT, which was set to 1. Data are presented as mean ± SD (n = 4). Statistical analysis was performed using 1-way analysis of variance followed by Dunnett's multiple comparisons test with WT…