Novel pathogenic TGFBR1 and SMAD3 variants identified after cerebrovascular events in adult patients with Loeys-dietz syndrome

Differentially expressed miRNA profiles of serum derived extracellular vesicles from patients with acute ischemic stroke

BACKGROUND

MicroRNAs (miRNAs) participate in diverse cellular changes following acute ischemic stroke (AIS). Circulating miRNAs, stabilized and delivered to target cells via extracellular vesicles (EVs), are potential biomarkers to facilitate diagnosis, prognosis, and therapeutic modulation. We aimed to identify distinctive expression patterns of circulating EV-miRNAs in AIS patients.

METHODS

miRNA profiles from EVs, isolated from plasma samples collected within 24 h following AIS diagnosis, were examined between a dataset of 10 age-, gender- and existing comorbidities-matched subjects (5 AIS and 5 healthy controls, HC). We measured 2578 miRNAs and identified differentially expressed miRNAs between AIS and HC. An enrichment analysis was conducted to delineate the networks and biological pathways implicated by differentially expressed microRNAs. An enrichment analysis was conducted to delineate the networks and biological pathways implicated by differentially expressed microRNAs.

RESULTS

Five miRNAs were differentially expressed between stroke (AIS) versus control (HC). hsa-let-7b-5p, hsa-miR-16-5p, and hsa-miR-320c were upregulated, whereas hsa-miR-548a-3p and hsa-miR-6808-3p, with no previously reported changes in stroke were downregulated. The target genes of these miRNAs affect various cellular pathways including, RNA transport, autophagy, cell cycle progression, cellular senescence, and signaling pathways like mTOR, PI3K-Akt, and p53. Key hub genes within these networks include TP53, BCL2, Akt, CCND1, and NF-κB. These pathways are crucial for cellular function and stress response, and their dysregulation can have significant implications for the disease processes.

CONCLUSION

Our findings reveal distinct circulating EV-miRNA expression patterns in AIS patients from Qatar, highlighting potential biomarkers that could aid in stroke diagnosis and therapeutic strategies. The identified miRNAs are involved in critical cellular pathways, offering novel insights into the molecular mechanisms underlying stroke pathology. Circulating EV-miRNAs differentially expressed in AIS may have a pathophysiological role and may guide further research to elucidate their precise mechanisms.

Dysregulation of the immune response in TGF-β signalopathies

The transforming growth factor-β (TGF-β) family of cytokines exerts pleiotropic functions during embryonic development, tissue homeostasis and repair as well as within the immune system. Single gene defects in individual component of this signaling machinery cause defined Mendelian diseases associated with aberrant activation of TGF-β signaling, ultimately leading to impaired development, immune responses or both. Gene defects that affect members of the TGF-β cytokine family result in more restricted phenotypes, while those affecting downstream components of the signaling machinery induce broader defects. These rare disorders, also known as TGF-β signalopathies, provide the unique opportunity to improve our understanding of the role and the relevance of the TGF-β signaling in the human immune system. Here, we summarize this elaborate signaling pathway, review the diverse clinical presentations and immunological phenotypes observed in these patients and discuss the phenotypic overlap between humans and mice genetically deficient for individual components of the TGF-β signaling cascade.

Infant with Loeys-Dietz syndrome treated for febrile status epilepticus with COVID-19 infection: first reported case of febrile status epilepticus and focal seizures in a patient with Loeys-Dietz syndrome and review of literature

Loeys-Dietz syndrome (LDS) is a rare, autosomal dominant multisystem disorder that is caused by mutations of transforming growth factor-β receptors. Mutations inSMAD3andTGFB3have been recently reported.

LDS is characterised by the triad of arterial tortuosity, hypertelorism and a bifid uvula or cleft palate among other cardiovascular, craniofacial and orthopaedic manifestations. Patients with LDS show clinical and genetic variability and there is a significant risk of reduced life expectancy due to widespread arterial involvement, aortic root dilation, aneurysms and an aggressive vascular course. Thus early genetic testing is warranted if clinical signs and history are suggestive of this potentially catastrophic disorder.

LDS predisposes patients to aortic aneurysms and early death due to vascular malformations, but neurological emergencies, such as seizures and febrile status epilepticus, have not been reported.

Febrile status epilepticus is the most common neurological emergency in childhood. Neurological manifestations of COVID-19 in the paediatric population are not as well described in medical literature.

To the best of our knowledge, this is the first reported case of febrile status epilepticus with COVID-19 infection in an infant with LDS. Our patient had focal epileptiform activity emanating over the left posterior hemisphere, which evolved into an electrographic seizure on video EEG. Such patients have a heightened risk of epilepsy in the future, and this occurrence is consistent with a diagnosis of focal epilepsy. Neurological complications such as epilepsy and status epilepticus in a patient with LDS have never been reported before.

A brief review of literature is also given here.

Tracking an Elusive Killer: State of the Art of Molecular-Genetic Knowledge and Laboratory Role in Diagnosis and Risk Stratification of Thoracic Aortic Aneurysm and Dissection

The main challenge in diagnosing and managing thoracic aortic aneurysm and dissection (TAA/D) is represented by the early detection of a disease that is both deadly and “elusive”, as it generally grows asymptomatically prior to rupture, leading to death in the majority of cases. Gender differences exist in aortic dissection in terms of incidence and treatment options. Efforts have been made to identify biomarkers that may help in early diagnosis and in detecting those patients at a higher risk of developing life-threatening complications. As soon as the hereditability of the TAA/D was demonstrated, several genetic factors were found to be associated with both the syndromic and non-syndromic forms of the disease, and they currently play a role in patient diagnosis/prognosis and management-guidance purposes. Likewise, circulating biomarker could represent a valuable resource in assisting the diagnosis, and several studies have attempted to identify specific molecules that may help with risk stratification outside the emergency department. Even if promising, those data lack specificity/sensitivity, and, in most cases, they need more testing before entering the “clinical arena”. This review summarizes the state of the art of the laboratory in TAA/D diagnostics, with particular reference to the current and future role of molecular-genetic testing.

Audiologic and Otologic Clinical Manifestations of Loeys-Dietz Syndrome: A Heritable Connective Tissue Disorder

OBJECTIVE

Loeys-Dietz syndrome (LDS) is a rare genetic connective tissue disorder resulting from TGF-ß signaling pathway defects and characterized by a wide spectrum of aortic aneurysm, arterial tortuosity, and various extravascular abnormalities. This study describes the audiologic, otologic, and craniofacial manifestations of LDS.

STUDY DESIGN

Consecutive cross-sectional study.

SETTING

Tertiary medical research institute.

METHODS

Audiologic and clinical evaluations were conducted among 36 patients (mean ± SD age, 24 ± 17 years; 54% female) with genetically confirmed LDS. Cases were categorized into genetically based LDS types 1 to 4 (TGFBR1, TGFBR2, SMAD3, TGFB2, respectively). Audiometric characteristics included degree and type of hearing loss: subclinical, conductive, mixed, and sensorineural.

RESULTS

LDS types 1 to 4 included 11, 13, 5, and 7 patients, respectively. In LDS-1, 27% had bilateral conductive hearing loss; 9%, unilateral mixed; and 36%, subclinical. In LDS-2, 38% had conductive hearing loss and 38% subclinical. In LDS-3 and LDS-4, 40% and 43% had bilateral sensorineural hearing loss, respectively. Degree of hearing loss ranged from mild to moderate. Bifid uvula was observed only in LDS-1 (55%) and LDS-2 (62%). Submucosal/hard cleft palates were primarily in LDS-1 and LDS-2. Posttympanostomy tympanic membrane perforations occurred in 45% (10/22 ears) of LDS-1 and LDS-2. There were 4 cases of cholesteatoma: 3 middle ear (LDS-1 and LDS-2) and 1 external ear canal (LDS-3).

CONCLUSION

Conductive hearing loss, bifid uvula/cleft palate, and posttympanostomy tympanic membrane perforation are more common in LDS-1 and LDS-2 than LDS-3 and LDS-4, while sensorineural hearing loss was present only in LDS-3 and LDS-4. These LDS-associated key clinical presentations may facilitate an early diagnosis of LDS and thus prompt intervention to prevent related detrimental outcomes.

Novel Mutation of the TGF-β 3 Protein (Loeys-Dietz Type 5) Associated With Aortic and Carotid Dissections: Case Report

Objectives

Loeys-Dietz syndrome (LDS) is a rare genetic cause of stroke associated with connective tissue disorders but is not well known among stroke physicians.¹ The main objectives of this case report are to increase awareness of this condition and to improve stroke prevention at follow-up visits.

Methods

A patient with aortic and carotid artery dissection who had undergone 2 major aortic surgeries with mechanical composite graft and treated with full-dose anticoagulation was reevaluated by neurologists due to retinal hypoperfusion symptoms. After musculoskeletal examination, cervical ultrasonography, and computerized tomography angiography, he was referred for whole-genome sequencing.

Results

We found joint hypermobility, skin hyperelasticity, bifid uvula, and combined cervical artery dissections that caused intermittently decreased blood flow in the left ophthalmic artery and an acute asymptomatic embolic stroke. A novel pathogenic variant of LDS type 5 consisting of a heterogeneous nonsense variant c.1044C>A, p.(Cys384*) was found in the TGF-β 3 (TGFB3) gene. Consequently, anticoagulation was intensified, and at 1-year follow-up, the patient's symptoms improved.

Discussion

This novel genetic variant coupled to the patient's phenotype contributes to the knowledge of genetic causes of stroke. Patients with multiple arterial dissections and musculoskeletal features should be offered genetic testing and be carefully evaluated to avoid further cerebrovascular ischemic lesions.

The Roles of TGF-β Signaling in Cerebrovascular Diseases

Cerebrovascular diseases are one of the leading causes of death worldwide, however, little progress has been made in preventing or treating these diseases to date. The transforming growth factor-β (TGF-β) signaling pathway plays crucial and highly complicated roles in cerebrovascular development and homeostasis, and dysregulated TGF-β signaling contributes to cerebrovascular diseases. In this review, we provide an updated overview of the functional role of TGF-β signaling in the cerebrovascular system under physiological and pathological conditions. We discuss the current understanding of TGF-β signaling in cerebral angiogenesis and the maintenance of brain vessel homeostasis. We also review the mechanisms by which disruption of TGF-β signaling triggers or promotes the progression of cerebrovascular diseases. Finally, we briefly discuss the potential of targeting TGF-β signaling to treat cerebrovascular diseases.