Therapeutic potential of mesenchymal stem cell-derived extracellular vesicles in SARS-CoV-2 and H1N1 influenza-induced acute lung injury.

Mesenchymal stem cell (MSC)-derived extracellular vesicles (EVs) have shown anti-inflammatory potential in multiple inflammatory diseases. In the March 2022 issue of the Journal of Extracellular Vesicles, it was shown that EVs from human MSCs can suppress severe acute respiratory distress syndrome, coronavirus 2 (SARS-CoV-2) replication and can mitigate the production and release of infectious virions. We therefore hypothesized that MSC-EVs have an anti-viral effect in SARS-CoV-2 infection in vivo. We extended this question to ask whether also other respiratory viral infections could be treated by MSC-EVs. Adipose stem cell-derived EVs (ASC-EVs) were isolated using tangential flow filtration from conditioned media obtained from a multi-flask cell culture system. The effects of the ASC-EVs were tested  in Vero E6 cells in vitro. ASC-EVs were also given i.v. to SARS-CoV-2 infected Syrian Hamsters, and H1N1 influenza virus infected mice. The ASC-EVs attenuated SARS-CoV-2 virus replication in Vero E6 cells and reduced body weight and signs of lung injury in infected Syrian hamsters. Furthermore, ASC-EVs increased the survival rate of influenza A-infected mice and attenuated signs of lung injury. In summary, this study suggests that ASC-EVs can have beneficial therapeutic effects in models of virus-infection-associated acute lung injury and may potentially be developed to treat lung injury in humans.

Impact of the Grade and Jet-flow Direction of Residual Aortic Regurgitation after Valve-Sparing Root Replacement.

OBJECTIVES: The current study aimed to investigate the impact of the grade and jet direction of residual aortic regurgitation (rAR) after valve-sparing root replacement (VSRR). METHODS: The study enrolled 248 adult patients who underwent VSRR from 1995 to 2021. The patients were divided into groups based on the postoperative rAR. Patients with rAR were further categorized per the rAR grade and jet direction. The primary endpoint was the development of aortic regurgitation ≥ moderate and/or the need for valve replacement during the follow-up, analyzed by a multivariable competing risk analysis. The secondary endpoints included the occurrence of rAR and overall survival. RESULTS: The median age of the patients was 36.5 years, and 79.8% were diagnosed with connective tissue disease. After VSRR, 146 patients did not present with rAR. However, 102 had rAR (77 with minimal central, 18 with minimal eccentric, and 7 with mild). The 5- and 8-year incidence rates of the primary endpoint were 14.6% and 17.9%, respectively. The rAR was a significant risk factor (P=0.001), and eccentricity and mild rAR seemed to play an important role. The risk factors of rAR included dilated root, preoperative moderate regurgitation, and redo sternotomy. The overall survival was influenced only by age. CONCLUSION: rAR after VSRR operation could be a risk factor for AR progression. Minimal central rAR generally has a tolerable clinical course. However, patients with even minimal eccentric AR may develop AR progression, so active surveillance and timely management might be required. Further, early VSRR can help reduce the rAR.

Impact of early diagnosis on surgical outcomes in patients with Loeys-Dietz syndrome.

Background: This study aimed to investigate the influence of early diagnosis (ED) on surgical outcomes in patients definitively diagnosed with Loeys-Dietz syndrome (LDS). Methods: A retrospective review was conducted on 38 patients with LDS who underwent aortic surgery at our institution between January 1995 and June 2022. The primary endpoint was freedom from aortic reoperation. Results: Among the patients, the median age at the initial surgery was 33 (range: 39-44) years, and 23 (60.5%) patients were male. Twenty-one (55.3%; aortic dissection or rupture (n = 2) and aneurysm (n = 19)) patients were diagnosed with LDS before the initial surgery (ED group). Meanwhile, the remaining 17 (44.7%; aortic dissection or rupture (n = 13) and aneurysm (n = 4)) patients were after surgery [delayed diagnosis (DD) group]. The ED group had significantly lower rates of emergency surgery and concomitant arch procedure (P < .001, respectively) but a higher rate of valve-sparing root surgery (P = .018) compared to the DD group. No in-hospital mortality was observed in either group. Nevertheless, the ED group had a shorter postoperative hospital stay (median difference: 3 days, P = .032) and a lower rate of aortic reoperation (P = .013). Conclusion: Early detection of LDS may help in preventing acute aortic syndrome, reducing the risk of aortic reoperation, and potentially shortening hospital stay. Careful medical management before surgery could contribute to better clinical outcomes and an improved quality of life for patients with LDS.

Efficacy of biologics for eosinophilic otitis media.

BACKGROUND: Eosinophilic otitis media (EOM) is an intractable condition primarily treated with steroids. Recently, biologics targeting IgE or IL-5 have been introduced. OBJECTIVES: This study aimed to evaluate the efficacy of biologics for EOM. MATERIALS AND METHODS: We retrospectively collected data on EOM patients treated from January 2008 to December 2020 from electronic medical records. Patients were classified into the steroid group, treated with systemic or local steroids, and the biologics group, treated with biologics with or without steroids. RESULTS: The otorrhea remission rate was 63.33% in the steroid group, comparable to 58.82% in the biologics group (p = 0.760). Before treatment, the steroid group showed better bone-conduction (BC) thresholds at 0.5 kHz and 1 kHz than the biologics group. Post-treatment, the steroid group improved in air-conduction (AC) threshold and air-bone gap (ABG) at 1 kHz and 2 kHz. The biologics group exhibited stable audiological results. No significant differences were observed post-treatment between the groups, except for the BC threshold at 0.5 kHz, which remained as pre-treatment. CONCLUSIONS AND SIGNIFICANCE: Biologics demonstrated similar efficacy in otorrhea remission as steroids and might help maintain hearing levels. Biologics can be considered for controlling EOM with active otorrhea and reducing systemic steroid use.

Prediction model for intraoperative implant volume using the 3D surface imaging system (VECTRA XT 3D) in direct-to-implant breast reconstructions.

Background: In direct-to-implant breast reconstruction, accurate preoperative breast volume estimation is crucial for surgeons to select the appropriate implant volume, considering the cosmetic outcomes during surgery. We proposed the prediction model for intraoperative implant volume based on the preoperative estimated volume of the contralateral breast obtained through a three-dimensional surface imaging system (3DSI) as surgeons usually choose the implant volume on the breast which should be reconstructed considering symmetricity with the contralateral breast. Methods: We enrolled 97 patients from our single institution who underwent unilateral mastectomy with immediate breast reconstruction using smooth silicone implants between October 2021 and January 2023. Preoperatively, plastic surgeons measured the volume of the contralateral breast using the VECTRA XT 3D imaging system. Data on implant volume and the types of acellular dermal matrix used during surgery, determined by a single surgeon to ensure symmetry, were also collected. Linear regression analysis was utilized to construct the predictive model. Results: In the multiple linear regression analysis with preoperative contralateral breast volume, age, and body mass index as variables, the coefficient of determination of the model expressed as R squared (R2) was 0.554, and except for age, the other variables were statistically significant. When replaced by mastectomy volume instead of age, R2 increased to 0.723 and all variables were significant. Conclusions: 3DSI can be helpful for preoperative surgical planning and postoperative outcome simulation. With our multiple linear regression model, we can predict the intraoperative implant volume using preoperative contralateral breast volume measured by the 3D scans.

Functional pathogenicity of ESRRB variant of uncertain significance contributes to hearing loss (DFNB35).

Advances in next-generation sequencing technologies have led to elucidation of sensorineural hearing loss genetics and associated clinical impacts. However, studies on the functional pathogenicity of variants of uncertain significance (VUS), despite their close association with clinical phenotypes, are lacking. Here we identified compound heterozygous variants in ESRRB transcription factor gene linked to DFNB35, specifically a novel splicing variant (NM_004452.4(ESRRB): c.397 + 2T>G) in trans with a missense variant (NM_004452.4(ESRRB): c.1144C>T p.(Arg382Cys)) whose pathogenicity remains unclear. The splicing variant (c.397 + 2T>G) caused exon 4 skipping, leading to premature stop codon formation and nonsense-mediated decay. The p.(Arg382Cys) variant was classified as a VUS due to its particularly higher allele frequency among East Asian population despite disease-causing in-silico predictions. However, functional assays showed that p.(Arg382Cys) variant disrupted key intramolecular interactions, leading to protein instability. This variant also reduced transcriptional activity and altered expression of downstream target genes essential for inner ear function, suggesting genetic contribution to disease phenotype. This study expanded the phenotypic and genotypic spectrum of ESRRB in DFNB35 and revealed molecular mechanisms underlying ESRRB-associated DFNB35. These findings suggest that variants with high allele frequencies can also possess functional pathogenicity, providing a breakthrough for cases where VUS, previously unexplored, could be reinterpreted by elucidating their functional roles and disease-causing characteristics.

TGF-ß and RAS jointly unmask primed enhancers to drive metastasis.

Epithelial-to-mesenchymal transitions (EMTs) and extracellular matrix (ECM) remodeling are distinct yet important processes during carcinoma invasion and metastasis. Transforming growth factor ß (TGF-ß) and RAS, signaling through SMAD and RAS-responsive element-binding protein 1 (RREB1), jointly trigger expression of EMT and fibrogenic factors as two discrete arms of a common transcriptional response in carcinoma cells. Here, we demonstrate that both arms come together to form a program for lung adenocarcinoma metastasis and identify chromatin determinants tying the expression of the constituent genes to TGF-ß and RAS inputs. RREB1 localizes to H4K16acK20ac marks in histone H2A.Z-loaded nucleosomes at enhancers in the fibrogenic genes interleukin-11 (IL11), platelet-derived growth factor-B (PDGFB), and hyaluronan synthase 2 (HAS2), as well as the EMT transcription factor SNAI1, priming these enhancers for activation by a SMAD4-INO80 nucleosome remodeling complex in response to TGF-ß. These regulatory properties segregate the fibrogenic EMT program from RAS-independent TGF-ß gene responses and illuminate the operation and vulnerabilities of a bifunctional program that promotes metastatic outgrowth.

Risk Factors for Abdominal Aortic Aneurysm in Patients With Diabetes.

OBJECTIVE: Although diabetes has been shown to be negatively associated with development of abdominal aortic aneurysm (AAA), patients with diabetes may still develop aneurysms. In this study we examined risk factors for development of AAA in patients with diabetes. METHODS: Adults over 50 years with diabetes who underwent health screening between 2009 and 2012 were followed for incident AAA until December 31, 2019. Cox proportional hazard regression models were used to calculate multivariate hazard ratios (HR) and 95% confidence intervals (CI) for risk factors associated with AAA. RESULTS: Among 1,913,066 participants (55.3% men), 6,996 AAA cases were identified during a mean follow-up of 7.7 years. Increased AAA risk was observed for age ≥ 65 years (HR 2.69, 95% CI 2.55-2.83), men (HR 1.81, 95% CI 1.69-1.94), smoking (ex-smoker ≥ 20 pack-years, HR 1.75, 95% CI 1.61-1.89; current smoker < 20 pack-years, HR 1.76, 95% CI 1.59-1.94; current smoker ≥ 20 pack-years, HR 2.40, 95% CI 2.23-2.59), abdominal obesity (HR 1.30, 95% CI 1.23-1.38), and comorbidities: hypertension (HR 1.63, 95% CI 1.53-1.73), dyslipidemia (HR 1.35, 95% CI 1.29-1.42), chronic kidney disease (HR 1.52, 95% CI 1.44-1.61), cardiovascular disease (HR 1.71, 95% CI 1.58-1.86). Heavy (HR 0.67, 95% CI 0.61-0.74) and mild alcohol consumption (HR 0.78, 95% CI 0.74-0.83), overweight (HR 0.87, 95% CI 0.81-0.93) and obesity (HR 0.81, 95% CI 0.75-0.87), longer diabetes duration (≥ 5 years: HR 0.74, 95% CI 0.70-0.78), and using ≥ 3 oral hypoglycemic agents (HR 0.84, 95% CI 0.79-0.90) were associated with decreased AAA risk, while insulin use was associated with a marginally increased risk (HR 1.09, 95% CI 1.00-1.18). Among the oral hypoglycemic agents, metformin (HR 0.95, 95% CI 0.90-1.00), thiazolidinedione (HR 0.87, 95% CI 0.79-0.97), and sulfonylurea (HR 0.88, 95% CI 0.83-0.93) were associated with decreased risk of AAA. CONCLUSIONS: Although diabetes is associated with decreased AAA risk, those with comorbid cardiometabolic diseases, abdominal obesity, and smoking history should be aware of increased AAA risk. Further studies are warranted to verify the potential use of oral hypoglycemic agents for reducing AAA risk.

Discovery of novel disease-causing mutation in SSBP1 and its correction using adenine base editor to improve mitochondrial function.

Mutations in nuclear genes regulating mitochondrial DNA (mtDNA) replication are associated with mtDNA depletion syndromes. Using whole-genome sequencing, we identified a heterozygous mutation (c.272G>A:p.Arg91Gln) in single-stranded DNA-binding protein 1 (SSBP1), a crucial protein involved in mtDNA replisome. The proband manifested symptoms including sensorineural deafness, congenital cataract, optic atrophy, macular dystrophy, and myopathy. This mutation impeded multimer formation and DNA-binding affinity, leading to reduced efficiency of mtDNA replication, altered mitochondria dynamics, and compromised mitochondrial function. To correct this mutation, we tested two adenine base editor (ABE) variants on patient-derived fibroblasts. One variant, NG-Cas9-based ABE8e (NG-ABE8e), showed higher editing efficacy (≤30%) and enhanced mitochondrial replication and function, despite off-target editing frequencies; however, risks from bystander editing were limited due to silent mutations and off-target sites in non-translated regions. The other variant, NG-Cas9-based ABE8eWQ (NG-ABE8eWQ), had a safer therapeutic profile with very few off-target effects, but this came at the cost of lower editing efficacy (≤10% editing). Despite this, NG-ABE8eWQ-edited cells still restored replication and improved mtDNA copy number, which in turn recovery of compromised mitochondrial function. Taken together, base editing-based gene therapies may be a promising treatment for mitochondrial diseases, including those associated with SSBP1 mutations.

Severe acquired hemophilia A associated with COVID-19 vaccination: A case report and literature review.

RATIONALE: Acquired hemophilia A (AHA) is a rare autoimmune disease caused by an antibody that inhibits coagulation factor VIII activity. More than half of patients with AHA cannot identify underlying disorders. The remaining patients are associated with malignancies, autoimmune diseases, skin diseases, infections, and medications. Here, we present a case of 56-year-old Korean man with underlying hypertension, dyslipidemia, and diabetes mellitus who developed AHA following the second dose of BNT162b2 COVID-19 vaccination. PATIENT CONCERNS: He presented with a large 20 × 30 cm-sized hematoma along the psoas muscle and intracranial hemorrhage, necessitating intensive care with mechanical ventilation and continuous renal replacement therapy. Laboratory testing demonstrated that activated partial thromboplastin time and prothrombin times were 74.7 seconds (normal range 29-43 seconds) and 17.2 seconds (normal range 12.5-14.7 seconds), respectively. DIAGNOSES: Laboratory tests confirmed AHA with undetectable factor VIII activity (<1.5%) and a positive factor VIII antibody with a titer of 8.49 Bethesda units/mL. INTERVENTIONS: Recombinant factor VIIa (NovoSeven®) was administered every 2 hours to control the bleeding, alongside immunosuppression with methylprednisolone 1 mg/kg daily and cyclophosphamide 2 mg/kg daily to eliminate the autoantibody. OUTCOMES: Despite the treatments, the patient developed sepsis and succumbed 14 weeks after admission. LESSONS: This rare case underscores the importance of monitoring for AHA following COVID-19 vaccination. Although the benefits outweigh the risks of vaccination, AHA should be considered in the differential diagnosis of unusual bleeding following the vaccinations. Early diagnosis and management before severe bleeding are critical for successfully controlling life-threatening bleeding.