Elisabetta Morini

Preliminary data suggest that mutations in the CgRP pathway are not involved in human sporadic cryptorchidism

In testicular descent to the scrotum, a multistep process, many anatomical and hormonal factors play a role. Cryptorchidism occurs in about 1–2% of males and may cause secondary degeneration of the testes. Animal models have shown that abnormalities, in the calcitonin generelated peptide (CgRP) activity, could be relevant in the pathogenesis of cryptorchidism. We performed a mutation screening by PCR exon amplification, single-strand conformation polymorphism (SSCP) and sequencing in four candidate genes, CgRPs (αCgRP, βCgRP), their receptor (CgRPR) and the receptor component protein (CgRP-RCP), in 90 selected cases of idiopathic unilateral or bilateral cryptorchidism. Mutation screening of the coding regions and intron-exon boundaries revealed some polymorphic variants but no pathogenic sequence changes. These preliminary data suggest that these genes are not major factors for cryptorchidism in humans.

Sensory and autonomic deficits in a new humanized mouse model of familial dysautonomia

Familial dysautonomia (FD) is an autosomal recessive neurodegenerative disease that affects the development and survival of sensory and autonomic neurons. FD is caused by an mRNA splicing mutation in intron 20 of the IKBKAP gene that results in a tissue-specific skipping of exon 20 and a corresponding reduction of the inhibitor of kappaB kinase complex-associated protein (IKAP), also known as Elongator complex protein 1. To date, several promising therapeutic candidates for FD have been identified that target the underlying mRNA splicing defect, and increase functional IKAP protein. Despite these remarkable advances in drug discovery for FD, we lacked a phenotypic mouse model in which we could manipulate IKBKAP mRNA splicing to evaluate potential efficacy. We have, therefore, engineered a new mouse model that, for the first time, will permit to evaluate the phenotypic effects of splicing modulators and provide a crucial platform for preclinical testing of new therapies. This new mouse model, TgFD9; Ikbkap(Δ20/flox) was created by introducing the complete human IKBKAP transgene with the major FD splice mutation (TgFD9) into a mouse that expresses extremely low levels of endogenous Ikbkap (Ikbkap(Δ20/flox)). The TgFD9; Ikbkap(Δ20/flox) mouse recapitulates many phenotypic features of the human disease, including reduced growth rate, reduced number of fungiform papillae, spinal abnormalities, and sensory and sympathetic impairments, and recreates the same tissue-specific mis-splicing defect seen in FD patients. This is the first mouse model that can be used to evaluate in vivo the therapeutic effect of increasing IKAP levels by correcting the underlying FD splicing defect.

Altered Tnnt3 characterizes selective weakness of fast fibers in mice overexpressing FSHD region gene 1 (FRG1)

Facioscapulohumeral muscular dystrophy (FSHD), a common hereditary myopathy, is characterized by atrophy and weakness of selective muscle groups. FSHD is considered an autosomal dominant disease with incomplete penetrance and unpredictable variability of clinical expression within families. Mice overexpressing FRG1 (FSHD region gene 1), a candidate gene for this disease, develop a progressive myopathy with features of the human disorder. Here, we show that in FRG1-overexpressing mice, fast muscles, which are the most affected by the dystrophic process, display anomalous fast skeletal troponin T (fTnT) isoform, resulting from the aberrant splicing of the Tnnt3 mRNA that precedes the appearance of dystrophic signs. We determine that muscles of FRG1 mice develop less strength due to impaired contractile properties of fast-twitch fibers associated with an anomalous MyHC-actin ratio and a reduced sensitivity to Ca(2+). We demonstrate that the decrease of Ca(2+) sensitivity of fast-twitch fibers depends on the anomalous troponin complex and can be rescued by the substitution with the wild-type proteins. Finally, we find that the presence of aberrant splicing isoforms of TNNT3 characterizes dystrophic muscles in FSHD patients. Collectively, our results suggest that anomalous TNNT3 profile correlates with the muscle impairment in both humans and mice. On the basis of these results, we propose that aberrant fTnT represents a biological marker of muscle phenotype severity and disease progression.

Long-term hemostatic effects of cholesterol-lowering therapy with atorvastatin.

This study assessed hemostatic effects of an HMC-CoA reductase inhibitor, atorvastatin, on different parameters in 32 hypercholesterolemic patients of both sexes. In the patients and in 25 control subjects, plasma levels of tissue-type plasminogen activator, plasminogen activator inhibitor (PAI-1), D-dimer, prothrombin fragment 1 + 2 (F1 + 2), total cholesterol, triglycerides and fibrinogen had been measured. All these parameters were evaluated in patients after 6 and 12 months of treatment with atorvastatin at a dosage of 20 mg/day. This treatment significantly lowered the total cholesterol level in all patients. Moreover, after 6 months of atorvastatin treatment, PAI-1 and F1 + 2, which were both increased at baseline, were significantly reduced. This reduction continued after 12 months. The present results show that a reduction of hemostatic abnormalities, which exist in hypercholesterolemia, may be another important effect of the atorvastatin therapy.

Bone health assessment by quantitative ultrasound and dual-energy x-ray absorptiometry in postmenopausal women with breast cancer receiving aromatase inhibitors.

Objective: Phalangeal quantitative ultrasound (QUS) measurements provide surrogate information on bone quality. The aim of the present study was to assess bone status by phalangeal QUS and by dual-energy x-ray absorptiometry (DXA), and to evaluate bone turnover in breast cancer (BC) women receiving aromatase inhibitors (AIs). Methods: Sixty postmenopausal BC women and 42 matched controls were recruited (mean age 61.64 ± 8.33 y). Amplitude-dependent speed of sound (AD-SoS), bone transmission time (BTT), Ultrasound Bone Profile Index, as QUS parameters, L1-L4 and femoral neck BMD by DXA were assessed at baseline and after 18 months; serum bone-specific alkaline phosphatase (BSAP) and C-telopeptide of type 1 collagen were measured at baseline, 9 and 18 months. Results: FRAX (without BMD) derived 10-years probability of major fractures and hip fractures were significantly associated with AD-SoS (r = −0.381, P = < 0.001 and r = −0.370, P < 0.001, respectively), Ultrasound Bone Profile Index (r = −0.434, P ⩽ 0.001 and r = −0.409, P = < 0.001, respectively), BTT (r = −0.309, P = 0.002 and r = −0.340, P = 0.001, respectively). The median percent changes of AD-SoS (−3.71 [−5.38 to 0.11] vs −0.7 [−4.15 to 0.83], P = 0.02 respectively), BTT (−8.4 [−14.91 to −3.53] vs −1 [−5.72 to 3.75], P < 0.001 respectively) were significantly different between AIs users and controls. The same trend was observed for DXA measurements. BSAP and C-telopeptide of type 1 collagen significantly changed in AIs users. AD-SoS was associated with change of BMD at lumbar spine (&bgr;, 0.16; SE, 0.08; P = 0.04) and change of BSAP (&bgr;, −0.04; SE, 0.02; P = 0.04). Conclusions: Phalangeal QUS appeared a useful tool to evaluate bone quality in BC women on AIs.

Development of a Screening Platform to Identify Small Molecules That Modify ELP1 Pre-mRNA Splicing in Familial Dysautonomia

Familial dysautonomia (FD) is an autonomic and sensory neuropathy caused by a mutation in the splice donor site of intron 20 of the ELP1 gene. Variable skipping of exon 20 leads to a tissue-specific reduction in the level of ELP1 protein. We have shown that the plant cytokinin kinetin is able to increase cellular ELP1 protein levels in vivo and in vitro through correction of ELP1 splicing. Studies in FD patients determined that kinetin is not a practical therapy due to low potency and rapid elimination. To identify molecules with improved potency and efficacy, we developed a cell-based luciferase splicing assay by inserting renilla (Rluc) and firefly (Fluc) luciferase reporters into our previously well-characterized ELP1 minigene construct. Evaluation of the Fluc/Rluc signal ratio enables a fast and accurate way to measure exon 20 inclusion. Further, we developed a secondary assay that measures ELP1 splicing in FD patient-derived fibroblasts. Here we demonstrate the quality and reproducibility of our screening method. Development and implementation of this screening platform has allowed us to efficiently screen for new compounds that robustly and specifically enhance ELP1 pre-mRNA splicing.

Exon-specific U1 snRNAs improve ELP1 exon 20 definition and rescue ELP1 protein expression in a familial dysautonomia mouse model

Abstract Familial dysautonomia (FD) is a rare genetic disease with no treatment, caused by an intronic point mutation (c.2204+6T>C) that negatively affects the definition of exon 20 in the elongator complex protein 1 gene (ELP1 also known as IKBKAP). This substitution modifies the 5′ splice site and, in combination with regulatory splicing factors, induces different levels of exon 20 skipping, in various tissues. Here, we evaluated the therapeutic potential of a novel class of U1 snRNA molecules, exon-specific U1s (ExSpeU1s), in correcting ELP1 exon 20 recognition. Lentivirus-mediated expression of ELP1-ExSpeU1 in FD fibroblasts improved ELP1 splicing and protein levels. We next focused on a transgenic mouse model that recapitulates the same tissue-specific mis-splicing seen in FD patients. Intraperitoneal delivery of ELP1-ExSpeU1s-adeno-associated virus particles successfully increased the production of full-length human ELP1 transcript and protein. This splice-switching class of molecules is the first to specifically correct the ELP1 exon 20 splicing defect. Our data provide proof of principle of ExSpeU1s-adeno-associated virus particles as a novel therapeutic strategy for FD.

l-thyroxine malabsorption due to calcium carbonate impairs blood pressure, total cholesterolemia, and fasting glycemia

PurposeCalcium carbonate was previously shown to interfere with l-thyroxine absorption. To estimate the magnitude of tablet l-thyroxine malabsorption caused by calcium carbonate, with resulting increase in serum thyrotropin (TSH), we performed a cohort study in a referral care center.MethodsFifty postmenopausal hypothyroid l-thyroxine-treated women (age 71.7 ± 5.1 years) who added calcium supplementation (600–1000 mg/day) were considered. They were taking l-thyroxine 45–60 min before breakfast (setting 1). After 4.4 ± 2.0 years from initiation of l-thyroxine therapy, they took calcium supplemaentation within 2 h after l-thyroxine taking (setting 2) for 2.3 ± 1.1 years. Hence, we recommended postponing calcium intake 6–8 h after l-thyroxine (setting 3). We evaluated TSH levels, the prevalence of women with elevated TSH (>4.12 mU/L), total cholesterolemia, fasting glycemia, blood pressure, and the prevalence of hypercholesterolemia, hyperglycemia, and hypertension.ResultsTSH levels were 3.33 ± 1.93 mU/L versus 1.93 ± 0.51 or 2.16 ± 0.54 comparing setting 2 with setting 1 or 3 (P < 0.001, both). In setting 2, 18% women had elevated TSH versus none in setting 1 or 3 (P < 0.01). Total cholesterolemia, fasting glycemia, systolic, and diastolic blood pressure were also significantly higher in setting 2 compared to settings 1 and 3. For every 1.0 mU/L increase within the TSH range of 0.85–6.9 mU/L, total cholesterolemia, glycemia, systolic, and diastolic blood pressure increased by 12.1, 3.12 mg/dL, 2.31, and 2.0 mmHg, respectively.ConclusionsMonitoring of hypothyroid patients who ingest medications that decrease l-thyroxine absorption should not be restricted to solely measuring serum TSH.