Lapinskaitė, Patricija

Aim: To determine whether pharmacological modulation with the transglutaminase-2 inhibitor LDN-27219 alters endothelial adaptation to high-glucose stress. Methods: EA.hy926 endothelial cells were cultured under normoglycaemic (5.5 mM) or high-glucose (25 mM) conditions and treated for 24 h with vehicle or LDN-27219 (20 µg/mL; 48.9 µM). Cellular reducing capacity, total protein content, mitochondrial respiration, extracellular acidification rate, MitoSOX Red fluorescence, and selected cytokine and adhesion-marker secretion were assessed. Results: High glucose shifted cells toward a more glycolytic basal phenotype, increased MitoSOX Red fluorescence, and reduced glycolytic stress responsiveness. LDN-27219 had limited effects under normoglycaemic conditions but, under high glucose, reduced basal respiration, maximal respiration, ATP-linked oxygen consumption, and spare respiratory capacity, while partially restoring stressed extracellular acidification. LDN-27219 also reduced high-glucose-induced MitoSOX Red fluorescence. No statistically significant changes were detected in selected inflammatory or adhesion markers. Conclusions: LDN-27219 modifies endothelial bioenergetic and oxidant-associated fluorescence responses under high-glucose conditions. Because mitochondrial membrane potential and direct transglutaminase-2 target engagement were not assessed, these findings should be interpreted as LDN-27219-associated effects requiring further mechanistic validation.

Background: Endothelial dysfunction is a key feature of diabetic vascular disease and is associated with high-glucose-induced changes in endothelial energy metabolism and redox balance. Transglutaminase-2 has been implicated in vascular stress responses, but its contribution to endothelial adaptation to high glucose remains incompletely defined. Methods: EA.hy926 endothelial cells were cultured under normoglycaemic (NG) or high-glucose conditions and treated with LDN-27219 at 20 µg/mL (48.9 µM). Cellular reducing capacity, total protein content, mitochondrial respiration, MitoSOX Red fluorescence, and selected cytokine and adhesion-marker secretion were assessed. Results: High glucose shifted cells toward a more glycolytic basal phenotype, increased MitoSOX Red fluorescence, and reduced glycolytic stress responsiveness compared with NG conditions. LDN-27219 had limited effects under NG conditions but, under high-glucose conditions, reduced basal respiration, maximal respiration, ATP-linked oxygen consumption, and spare respiratory capacity, while partially restoring stressed extracellular acidification. LDN-27219 also reduced high-glucose-induced MitoSOX Red fluorescence, although this cannot be interpreted as definitive evidence of reduced mitochondrial superoxide production because mitochondrial membrane potential was not measured. No statistically significant changes were detected in the selected inflammatory or adhesion markers. Conclusions: LDN-27219 modifies endothelial bioenergetic and oxidant-associated fluorescence responses under high-glucose conditions.

Congenital Long QT Syndrome (LQTS) is a hereditary cardiac channelopathy defined by delayed ventricular repolarization and an elevated risk of life-threatening ventricular arrhythmias. Recent echocardiographic studies using speckle-tracking and strain imaging have identified subtle abnormalities in ventricular and atrial mechanics among LQTS patients, including reduced global longitudinal strain, impaired diastolic function, enlarged left atrial volumes and a consistently negative electromechanical window. These findings challenge the traditional concept of LQTS as solely an electrical disease and support evolving evidence of a subclinical cardiomyopathic phenotype. Left atrial remodeling, although less studied, may represent an underrecognized component of LQTS with potential implications for arrhythmia vulnerability and diastolic dysfunction. This review summarizes current evidence on electromechanical and structural cardiac involvement in congenital LQTS, highlights its diagnostic and clinical implications, and outlines future directions for research in this evolving field.

This case examines the precarious stability of the HFimpEF phenotype, in which symptomatic remission obscured subclinical cardiac deterioration. It highlights the synergistic impact of patient non-adherence and clinical inertia. Findings necessitate lifelong 2023 ESC GDMT to mitigate reciprocal pathophysiological exacerbation of HFrEF and arrhythmias. A 48-year-old physically active male presented with decompensated HFrEF (LVEF ~30%, NT-proBNP 4040 pmol/l) and tachysystolic AF (HR 145 bpm). Because the arrhythmia duration was unknown, electrical cardioversion was deferred. The patient was first stabilized for heart failure and maintained on continuous anticoagulation for 21 days before successful restoration of sinus rhythm. He was initiated on full GDMT (ARNI, SGLT2 inhibitor, MRA, and beta-blocker), leading to an improvement in LVEF to 35-40% (HFimpEF) within 3 months. Two years later, the patient was readmitted with an AF paroxysm, peripheral edema, and exertional dyspnea (NT-proBNP 358 pmol/l). It was revealed that the patient had selfdiscontinued his therapy due to a false sense of recovery. Critically, following this second stabilization, the patient was discharged on a suboptimal regimen (switching from ARNI to ACEi and omitting SGLT2i and beta-blockers), reflecting the healthcare provider's clinical inertia despite the availability of evidence-based therapy. This case illustrates the reciprocal pathophysiological exacerbation between AF and HFrEF, in which rhythm stability is highly dependent on neurohormonal blockade [3]. Recurrent symptoms were triggered by a dual failure: patient-driven noncompliance and provider-driven clinical inertia. Research indicates that a substantial proportion of HFrEF patients do not receive quadruple therapy, regardless of a country's economic status [1, 4]. According to the 2023 ESC Focused Update, maintaining GDMT is mandatory even in asymptomatic patients with improved LVEF. This case emphasizes that achieving long-term stability requires not only patient education but also strict adherence by physicians to the "four pillars" to prevent recurrence of tachycardia-induced cardiomyopathy. Management of HFrEF remains suboptimal when clinical guidelines are not strictly followed by both the patient and the physician. To disrupt the cycle of heart failure progression, it is essential to overcome clinical inertia and ensure sustained use of quadruple therapy, regardless of subjective symptom resolution.

Įvadas. Širdies ir kraujagyslių ligos yra viena pagrindinių mirtingumo priežasčių visame pasaulyje, o cukrinis diabetas reikšmingai padidina kraujagyslių disfunkcijos riziką. Diabetas yra lėtinė metabolinė liga, kuriai būdinga hiperglikemija – padidėjusi gliukozės koncentracija kraujyje. Hiperglikemija sukelia oksidacinį stresą, pažeidžiantį endotelio ląsteles ir trikdantį jų gebėjimą reguliuoti kraujagyslių tonusą. Dėl to vystosi uždegiminiai procesai, sutrikdoma kraujotaka ir progresuoja aterosklerozė [1]. Mitochondrijų disfunkcija, susijusi su padidėjusia reaktyviųjų deguonies junginių gamyba, kuri dar labiau pablogina endotelio pažeidimus. Transglutaminazė 2 (TG2) – daugiafunkcis fermentas, aktyvuojamas oksidacinio streso metu, kuris dalyvauja endotelio ląstelių išlikime, metabolizme ir mitochondrijų funkcijos palaikyme. Vis dėlto, per didelis TG2 aktyvumas sergant diabetu gali sustiprinti oksidacinį stresą ir endotelio disfunkciją. TG2 inhibicija gali pagerinti kraujagyslių funkciją, tačiau tikslus TG2 vaidmuo hiperglikemijos sąlygomis vis dar nėra iki galo aiškus. Tyrimo tikslas. Įvertinti TG2 poveikį endotelio ląstelių metabolizmui ir oksidaciniam stresui hiperglikemijos sąlygomis. Metodai. Tyrimui naudota komercinė endotelio ląstelių linija EAhy926, kuri auginta normalios gliukozės (NG, 5.5 mM) ir aukštos gliukozės (HG, 25 mM) DMEM terpėje, papildytoje 10 % FBS, 1 % P/S antibiotiko. Ląsteles užsėjus eksperimentui jos buvo augintos 24 val. iki suformuojant monosluoksnį. Norint įvertinti TG2 vaidmenį, ląstelės 24 val. buvo inkubuotos su specifiniu alosteriniu inhibitoriumi LDN27219 (LDN). Optimali inhibitoriaus koncentracija buvo parinkta atlikus PrestoBlue ląstelių gyvybingumo testą, paremta ląstelių gebėjimu redukuoti rezazuriną į fluorescuojantį rezorufiną, ir leidžiantį įvertinti ląstelių metabolinį aktyvumą. Ląstelių proliferacija įvertinta pagal bendro baltymo kiekį nustatytą Bradfordo metodu. Oksidacinio streso pokyčiai vertinti nustatant mitochondrijų superoksido kiekį, naudojant fluorescencinį MitoSOX žymenį ir išmatuojant fluorescencijos intensyvumą iš Olympus APEXVIEW APX100 gautų vaizdų, analizuojant juos ImageJ programa. Fluorescencijos signalo intensyvumas yra tiesiogiai proporcingas mitochondrijų superoksido kiekiui. Gauti duomenys buvo analizuojami MS ,,Excel” programoje, o statistinis vertinimas atliktas IBM SPSS programa. Rezultatai. Gauti rezultatai parodė, kad hiperglikemijos sąlygomis sumažėja endodelio ląstelių proliferacija, tačiau metabolinis aktyvumas išlieka nepakitęs. Slopinant TG2 aktyvumą naudotos skirtingos LDN inhibitoriaus koncentracijos ir pastebėta, kad po poveikio LDN – ląstelių metabolinis aktyvumas normoglikemijos sąlygomis yra didesnis nei hiperglikemijos. Nustatyta, kad 20 µg/ml LDN koncentracija yra didžiausia, kuri atstato hiperglikemijos sukeltą endotelio ląstelių proliferacijos sumažėjimą nesukeliant citotoksiško poveikio. Ši LDN koncentracija taip pat padidina metabolinį aktyvumą tiek normoglikemijos, tiek hiperglikemijos sąlygomis, todėl buvo pasirinkta tolimesniems tyrimams. Mitochondrijų superoksido kiekis hiperglikemijos sąlygomis reikšmingai padidėjo 35% lyginant su normoglikemija. LDN neturėjo įtakos mitochondrijų superoksido kiekiui normoglikemijos sąlygomis, bet reikšmingai atstatė hiperglikemijos sukeltą oksidacinį stresą iki normoglikemijos lygio. Išvados. Specifinis TG2 inhibitorius LDN27219 efektyviai apsaugo endotelio ląsteles nuo hiperglikemijos sukelto poveikio – atstato ląstelių proliferaciją, sumažina mitochondrijų superoksido gamybą, grąžindamas ją į normoglikelimį lygį bei padidina ląstelių metabolinį aktyvumą.

Long QT syndrome (LQTS) is a genetic condition, defined as a channelopathy that causes prolonged ventricular repolarization, manifesting as a prolonged QT interval on the electrocardiogram (ECG) [1]. While commonly associated with ventricular arrhythmias and an increased risk of sudden cardiac death, emerging scientific studies suggest that some LQTS patients may develop both subclinical or overt structural cardiac changes [2]. We present a case of a young female with congenital LQTS who developed left atrial cardiomyopathy in absence of any known conditions that lead to atrial remodeling. A 33-year-old female patient, diagnosed with a LQTS type 1 due to a mutation in the KCNQ1 gene, presented with frequent palpitations, fatigue and dyspnea. Serial ECGs revealed prolonged QTc interval with sinus bradycardia and firstdegree atrioventricular (AV) block. Echocardiographic findings included mildly reduced left ventricular systolic function (LVEF) and a significantly dilated left atrium (LA) with impaired LA reservoir and conduit strain, as well as reduced contractile function. Cardiac magnetic resonance (CMR) scan confirmed LA enlargement with no evidence of myocardial fibrosis, excluding any other underlying structural myocardial diseases. The patient was started on propranolol for symptomatic control, with recommendations for an echocardiographic follow-up and genetic re-evaluation for additional cardiomyopathyrelated mutation. LQTS is most associated with inherited mutations in ion channel genes and clinical arrhythmic manifestations [3]. While typically considered to be an electrophysiological disorder, a growing number of reported cases suggest that patients may develop structural heart changes, particularly in the atria and the right ventricular region [4]. While LA remodeling is often linked to hemodynamic overload, atrial fibrillation, or mitral valve disease, our patient presented with atrial dysfunction in the absence of these conditions This clinical case suggests previously unrecognized associations between LQTS and left atrial cardiomyopathy. It highlights the importance of echocardiographic evaluation, including LA strain analysis, in LQTS patients. Further research is warranted to determine whether LQTS-related atrial remodeling represents a new phenotypic variant or an early indicator of another underlying genetic cardiomyopathy.

Įvadas Paprastoji pūslinė (PP) – reta, IgG autoantikūnų sukelta odos liga, kurios metu atsiranda negyjančios pūslės ir erozijos odoje bei gleivinėse. Histologiškai stebimas ryšių tarp keratinocitų nutrūkimas ir intraepiderminių pūslių susidarymas [1]. Yra duomenų, jog ligos metu paveikiamos keratinocitų mitochondrijos ir sutrikdomos kvėpavimo grandinės funkcijos, todėl mažėja mitochondrijų membranos potencialas, didėja aktyvių deguonies junginių (ROS) gamyba ir įvyksta keratinocitų apoptozė. Todėl suprantant šios ligos eigą, simptomus ir jų poveikį pacientams, galima geriau pritaikyti gydymo planus, suteikti reikiamų žinių pacientams bei jų šeimoms. In vitro modeliai, kurie atitinka paprastąją pūslinę, gali padėti tyrėjams geriau suprasti ligos patogenezę ir rasti naujus būdus jos gydymui. Tyrimo tikslas Sukurti PP modelį, naudojant kultivuojamus odos keratinocitus ir įvertinti mitochondrijų funkciją, ląstelių gyvybingumą. [...].