👤 Regina M Carney

Wound healing is a complex physiological process fundamentally dependent on angiogenesis for effective tissue repair. Endothelial progenitor cells (EPCs) have shown significant potential in promoting angiogenesis, primarily through their secretome, rich in proteins and extracellular vesicles (EVs) essential for cell signaling and tissue regeneration. This study investigates the effect of a collagen-bound proteoglycan mimetic (LXW7-DS-SILY or LDS), that binds to the αvβ3 integrin receptor, on the EPC secretome, with a dual focus on the proteomic content and the functional properties of EVs. Utilizing high-resolution two-dimensional liquid chromatography-tandem mass spectrometry (LC-MS/MS) alongside bioinformatic analysis, we identified significant alterations in protein expression profiles, particularly in angiogenesis and wound healing pathways. The functional impact of these changes was validated through biological assays, where the whole secretome and the EV fraction from EPCs seeded on collagen-bound LDS markedly enhanced vascular network formation, driven by the increase of growth factors and angiogenic regulators such as FGFR1, NRP1, and ANGPT2 within the EV fraction. Gene Ontology (GO) enrichment analysis further highlighted the enrichment of proteins within the EVs driving biological processes, including 'response to wounding' and 'positive regulation of cell motility'. These results underscore that LDS modulates the EPC secretome and significantly enhances its angiogenic potential, offering a promising therapeutic strategy for non-healing and ischemic wounds and suggesting that biomaterials can be modified to control the EV secretome to enhance tissue repair. Functional assays validating the omics data highlight the robustness of LDS as a targeted therapeutic for enhancing angiogenesis and tissue repair in clinical settings. Moreover, the pivotal role of EVs in mediating pro-angiogenic effects offers insights into developing biomaterial therapies that exploit key regulators within the EPC secretome for wound healing. STATEMENT OF SIGNIFICANCE: This manuscript explores how a proteoglycan mimetic that binds to both collagen and the α Show less

This study was undertaken to analyze phenotypic features of a cohort of patients with protracted CLN3 disease to improve recognition of the disorder. We analyzed phenotypic data of 10 patients from six families with protracted CLN3 disease. Haplotype analysis was performed in three reportedly unrelated families. Visual impairment was the initial symptom, with onset at 5-9 years, similar to classic CLN3 disease. Mean time from onset of visual impairment to seizures was 12 years (range = 6-41 years). Various seizure types were reported, most commonly generalized tonic-clonic seizures; focal seizures were present in four patients. Progressive myoclonus epilepsy was not seen. Interictal electroencephalogram revealed mild background slowing and 2.5-3.5-Hz spontaneous generalized spike-wave discharges. Additional interictal focal epileptiform discharges were noted in some patients. Age at death for the three deceased patients was 31, 31, and 52 years. Molecular testing revealed five individuals were homozygous for c.461-280₆₇₇ + 382del966, the "common 1-kb" CLN3 deletion. The remaining individuals were compound heterozygous for various combinations of recurrent pathogenic CLN3 variants. Haplotype analysis demonstrated evidence of a common founder for the common 1-kb deletion. Dating analysis suggested the deletion arose approximately 1500 years ago and thus did not represent cryptic familial relationship in this Australian cohort. We highlight the protracted phenotype of a disease generally associated with death in adolescence, which is a combined focal and generalized epilepsy syndrome with progressive neurological deterioration. The disorder should be suspected in an adolescent or adult patient presenting with generalized or focal seizures preceded by progressive visual loss. The common 1-kb deletion has been typically associated with classic CLN3 disease, and the protracted phenotype has not previously been reported with this genotype. This suggests that modifying genetic factors may be important in determining this somewhat milder phenotype and identification of these factors should be the subject of future research. Show less

The MAST family of microtubule-associated serine-threonine kinases (STKs) have distinct expression patterns in the developing and mature human and mouse brain. To date, only MAST1 has been conclusively associated with neurological disease, with de novo variants in individuals with a neurodevelopmental disorder, including a mega corpus callosum. Using exome sequencing, we identify MAST3 missense variants in individuals with epilepsy. We also assess the effect of these variants on the ability of MAST3 to phosphorylate the target gene product ARPP-16 in HEK293T cells. We identify de novo missense variants in the STK domain in 11 individuals, including 2 recurrent variants p.G510S (n = 5) and p.G515S (n = 3). All 11 individuals had developmental and epileptic encephalopathy, with 8 having normal development prior to seizure onset at <2 years of age. All patients developed multiple seizure types, 9 of 11 patients had seizures triggered by fever and 9 of 11 patients had drug-resistant seizures. In vitro analysis of HEK293T cells transfected with MAST3 cDNA carrying a subset of these patient-specific missense variants demonstrated variable but generally lower expression, with concomitant increased phosphorylation of the MAST3 target, ARPP-16, compared to wild-type. These findings suggest the patient-specific variants may confer MAST3 gain-of-function. Moreover, single-nuclei RNA sequencing and immunohistochemistry shows that MAST3 expression is restricted to excitatory neurons in the cortex late in prenatal development and postnatally. In summary, we describe MAST3 as a novel epilepsy-associated gene with a potential gain-of-function pathogenic mechanism that may be primarily restricted to excitatory neurons in the cortex. ANN NEUROL 2021;90:274-284. Show less