Cobalt chloride supplementation differently affects human mesenchymal stem cells isolated from dental pulp, umbilical cord and adipose tissues in their chondrogenic potential

Articular cartilage is an avascular tissue without innervations, characterized by low cell density and abundant extracellular matrix (ECM). These characteristics leave articular cartilage with very limited capacity of repair and regeneration. Multipotent stem/stromal cells (MSC) are considered promising for cartilage tissue engineering. Stem cells are resided in a special microenvironment known as the stem-cell niche, characterized by the presence of low oxygen concentration. Previous studies have reported that hypoxic conditions could enhance the chondrogenic differentiation of mesenchymal stem cells in the presence of an inductive medium. Cobalt chloride (CoCl2) imitates hypoxia in vitro by preventing hypoxia-inducible factor-alpha (HIF-a) from being destroyed by oxygen. However, the long-term hypoxic culture of stem cells is difficult and requires special attention to avoid cell death due to cobalt treatment. In this study we investigated if CoCl2 affected MSCs isolated from dental pulp, umbilical cord and adipose tissue in their potential to differentiate toward the chondrogenic phenotype. Cells were treated with concentrations of CoCl2 ranging from 50 to 400 uM. Cell proliferation, mRNA expression of stem-cell marker and chondrogenic associated genes were analyzed by RT-PCR and Real-time PCR. The results showed that the CoCl2 supplementation had no effect on the proliferation of all the three type of cells analyzed, while the up-regulation of chondrogenic markers such as aggrecan, sox9, and type II collagen, was dependent on the cellular source. This study shows that hypoxia induced by CoCl2 treatment can differently influence the behavior of MSCs of different sources in their chondrogenic potential. These findings should be taken into consideration in the treatment of cartilage repair and regeneration based on stem cell therapies

Cell Line and DNA Biobank From Patients Affected by Genetic Diseases

The Bioresource, presently storing 10,279 biospecimens, was initially established in 1976 as a private laboratory-collection to maintain rare mutant cell lines from genetic-metabolic diseases. Shortly afterwards, however, data from the sample collection was organised in a database and the sample collection was released to the scientific community. The Biobank has received Telethon grants since 1993, as individual facility, and from 2008 as part of the Telethon Network of Genetic Biobanks (www.biobanknetwork.org).In 2010, the Biobank has obtained official recognition from Regione Liguria. The Biobank has always provided essential services by establishing, analysing, maintaining, and distributing biospecimens from patients affected by rare genetic diseases. Up to now, the contribution of the Biobank to the scientific community has been expressed in acknowledgement notes in 145 scientific manuscripts

Rapid SARS-CoV-2 intra-host and within-household emergence of novel haplotypes

In February 2020, the municipality of Vo’, a small town near Padua (Italy) was quarantined due to the first coronavirus disease 19 (COVID-19)-related death detected in Italy. To investigate the viral prevalence and clinical features, the entire population was swab tested in two sequential surveys. Here we report the analysis of 87 viral genomes, which revealed that the unique ancestor haplotype introduced in Vo’ belongs to lineage B, carrying the mutations G11083T and G26144T. The viral sequences allowed us to investigate the viral evolution while being transmitted within and across households and the effectiveness of the non-pharmaceutical interventions implemented in Vo’. We report, for the first time, evidence that novel viral haplotypes can naturally arise intra-host within an interval as short as two weeks, in approximately 30% of the infected individuals, regardless of symptom severity or immune system deficiencies. Moreover, both phylogenetic and minimum spanning network analyses converge on the hypothesis that the viral sequences evolved from a unique common ancestor haplotype that was carried by an index case. The lockdown extinguished both the viral spread and the emergence of new variant

Follow-Up with Exercise Test of Effort-Induced Ventricular Arrhythmias Linked to Ryanodine Receptor Type 2 Gene Mutations

The aim of this study was to assess exercise test results and efficacy of therapy with a β blocker (acebutolol) in ryanodine receptor type 2 (RyR2) mutation carriers with documented ventricular arrhythmias (VAs) and long-term follow-up. Twenty RyR2 mutation carriers belonging to 8 families and regularly followed at our center were analyzed using a study protocol involving electrocardiography, exercise tests off and on β-blocker therapy, 2-dimensional echocardiography, and signal-averaged electrocardiography. Off-therapy exercise testing triggered the onset of VAs at different heart rates (mean 132 ± 13 beats/min) with various patterns that worsened while exercising and disappeared immediately after stopping. The most severe VAs detected were nonsustained ventricular tachycardia in 35% and ventricular couplets in 35%. In the remaining subjects single ventricular premature beats were recorded. In 15% of patients single monomorphic ventricular premature beats were detected and identified to be linked to RyR2 mutations owing to the presence of sudden deaths of their family members and subsequent family screening. Acebutolol made the VAs disappear completely in 20% of subjects and decreased their complexity in 50%, whereas it did not change VAs appreciably in 30% of patients with less complex VAs. After 11 ± 8 years of follow-up 2 patients developed syncope. In conclusion, exercise testing was a fundamental tool for assessing the clinical phenotype and efficacy of therapy in RyR2 mutation carriers and therapy with acebutolol led in most subjects to a decreased complexity of the arrhythmic pattern or to complete suppression

Multiple mutations in desmosomal proteins encoding genes in arrhythmogenic right ventricular cardiomyopathy/dysplasia

BACKGROUND: Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is a progressive cardiomyopathy showing a wide clinical spectrum in terms of clinical expressions and prognoses. OBJECTIVE: This study sought to estimate the occurrence of compound and double heterozygotes for mutations in desmosomal proteins encoding genes in a cohort of ARVC/D Italian index cases, and to assess the clinical phenotype of mutations carriers. METHODS: Fourty-two consecutive ARVC/D index cases who fulfilled the International Task Force diagnostic criteria were screened for mutations in PKP2, DSP, DSG2, DSC2, and JUP genes by denaturing high-performance liquid chromatography (DHPLC) and direct sequencing. RESULTS: Three probands (7.1%) showing a family history of sudden death carried multiple mutations. Family screening identified an additional 7 multiple-mutation carriers. Among the 7 double heterozygotes for mutations in different genes, 2 were clinically unaffected, 2 were affected, and 3 showed some clinical signs of ARVC/D even if they did not fulfill the diagnostic criteria. Two compound heterozygotes for mutations in the same gene and 1 subject carrying 3 different mutations showed a severe form of the disease with heart failure onset at a young age. Moreover, multiple-mutation carriers showed a higher prevalence of left ventricular involvement (P = .025) than single-mutation carriers. CONCLUSION: Occurrence of compound and double heterozygotes in ARVC/D index cases is particularly relevant to mutation screening strategy and to genetic counseling. Even if multiple-mutation carriers show a wide variability in clinical expression, the extent of the disease is higher compared to that in single-mutation carrier

Clinical phenotype and diagnosis of arrhythmogenic right ventricular cardiomyopathy in pediatric patients carrying desmosomal gene mutations.

BACKGROUND: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited heart muscle disease carrying a risk of sudden death. Information about the clinical features during childhood and the age at disease onset is scanty. OBJECTIVE: The aim of the study was to describe the ARVC phenotype as its initial clinical manifestation in a pediatric population (<18 years) with desmosomal gene mutations. METHODS: Fifty-three ARVC desmosomal gene mutation carriers (mean age 12.3 ± 3.9 years) were investigated by electrocardiogram (ECG), signal-averaged ECG, 24-hour Holter, echocardiogram, and contrast-enhanced cardiac magnetic resonance (CMR). RESULTS: None of the children ≤10 years old fulfilled the 1994 criteria, as opposed to six (33%) aged 11-14 years and eight aged >14 years (42%). At the end of follow-up (9 ± 7 years), 21 (40%) fulfilled the 1994 diagnostic criteria (mean age 16 ± 4 years). By using the 2010 criteria in subjects aged ≤18 years, 53% were unaffected, versus 62% by using the traditional criteria. More than two-thirds of affected subjects had moderate-severe forms of the disease. Contrast-enhanced CMR was performed in 21 (40%); of 13 unaffected gene mutation carriers, six showed ARVC morphological and/or tissue abnormalities. CONCLUSION: In pediatric ARVC mutation carriers, a diagnosis was achieved in 40% of cases, confirming that the disease usually develops during adolescence and young adulthood. The 2010 modified criteria seem to be more sensitive than the 1994 ones in identifying familial pediatric cases. Contrast-enhanced CMR can provide diagnostic information on gene mutation carriers not fulfilling either traditional or modified criteria. Management of asymptomatic gene mutation carriers remains the main clinical challenge

Identification of a PKP2 gene deletion in a family with arrhythmogenic right ventricular cardiomyopathy.

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a primary heart muscle disease characterized by progressive myocardial loss, with fibro-fatty replacement, and high frequency of ventricular arrhythmias that can lead to sudden cardiac death. ARVC is a genetically determined disorder, usually caused by point mutations in components of the cardiac desmosome. Conventional mutation screening of ARVC genes fails to detect causative mutations in about 50% of index cases, suggesting a further genetic heterogeneity. We performed a genome-wide linkage study and a copy number variations (CNVs) analysis, using high-density SNP arrays, in an ARVC family showing no mutations in any of the desmosomal genes. The CNVs analysis identified a heterozygous deletion of about 122\u2009kb on chromosome 12p11.21, including the entire plakophilin-2 gene and shared by all affected family members. It was not listed on any of available public CNVs databases and was confirmed by quantitative real-time PCR. This is the first SNP array-based genome-wide study leading to the identification of a CNV segregating with the disease phenotype in an ARVC family. This result underscores the importance of performing additional analysis for possible genomic deletions/duplications in ARVC patients without point mutations in known disease genes

Mutations in the area composita protein T-catenin are associated with arrhythmogenic right ventricular cardiomyopathy

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a major cause of juvenile sudden death and is characterized by fibro-fatty replacement of the right ventricle. Mutations in several genes encoding desmosomal proteins have been identified in ARVC. We speculated that T-catenin, encoded by CTNNA3, might also carry mutations in ARVC patients. Alpha-T-catenin binds plakophilins and this binding contributes to the formation of the area composita, which strengthens cellcell adhesion in contractile cardiomyocytes. We used denaturing high-performance liquid chromatography and direct sequencing to screen CTNNA3 in 76 ARVC patients who did not carry any mutations in the desmosomal genes commonly mutated in ARVC. Mutations c.281T A (p.V94D) and c.2293_2295delTTG (p.del765L) were identified in two probands. They are located in important domains of T-catenin. Yeast two-hybrid and cell transfection studies showed that the interaction between the p.V94D mutant protein and -catenin was affected, whereas the p.del765L mutant protein showed a much stronger dimerization potential and formed aggresomes in HEK293T cells. These findings might point to a causal relationship between CTNNA3 mutations and ARVC. This first report on the involvement of an area composita gene in ARVC shows that the pathogenesis of this disease extends beyond desmosomes. Since the frequency of CTNNA3 mutations in ARVC patients is not rare, systematic screening for this gene should be considered to improve the clinical management of ARVC families

Wharton’s Jelly Derived Mesenchymal Stem Cells: Comparing Human and Horse

Wharton's jelly (WJ) is an important source of mesenchymal stem cells (MSCs) both in human and other animals. The aim of this study was to compare human and equine WJMSCs. Human and equine WJMSCs were isolated and cultured using the same protocols and culture media. Cells were characterized by analysing morphology, growth rate, migration and adhesion capability, immunophenotype, differentiation potential and ultrastructure. Results showed that human and equine WJMSCs have similar ultrastructural details connected with intense synthetic and metabolic activity, but differ in growth, migration, adhesion capability and differentiation potential. In fact, at the scratch assay and transwell migration assay, the migration ability of human WJMSCs was higher (P &lt; 0.05) than that of equine cells, while the volume of spheroids obtained after 48 h of culture in hanging drop was larger than the volume of equine ones (P &lt; 0.05), demonstrating a lower cell adhesion ability. This can also revealed in the lower doubling time of equine cells (3.5 +/- 2.4 days) as compared to human (6.5 +/- 4.3 days) (P &lt; 0.05), and subsequently in the higher number of cell doubling after 44 days of culture observed for the equine (20.3 +/- 1.7) as compared to human cells (8.7 +/- 2.4) (P &lt; 0.05), and to the higher (P &lt; 0.05) ability to form fibroblast colonies at P3. Even if in both species tri-lineage differentiation was achieved, equine cells showed an higher chondrogenic and osteogenic differentiation ability (P &lt; 0.05). Our findings indicate that, although the ultrastructure demonstrated a staminal phenotype in human and equine WJMSCs, they showed different properties reflecting the different sources of MSCs