Experimental evolution for the recovery of growth loss due to genome reduction.

As the genome encodes the information crucial for cell growth, a sizeable genomic deficiency often causes a significant decrease in growth fitness. Whether and how the decreased growth fitness caused by genome reduction could be compensated by evolution was investigated here. Experimental evolution with an Escherichia coli strain carrying a reduced genome was conducted in multiple lineages for approximately 1000 generations. The growth rate, which largely declined due to genome reduction, was considerably recovered, associated with the improved carrying capacity. Genome mutations accumulated during evolution were significantly varied across the evolutionary lineages and were randomly localized on the reduced genome. Transcriptome reorganization showed a common evolutionary direction and conserved the chromosomal periodicity, regardless of highly diversified gene categories, regulons, and pathways enriched in the differentially expressed genes. Genome mutations and transcriptome reorganization caused by evolution, which were found to be dissimilar to those caused by genome reduction, must have followed divergent mechanisms in individual evolutionary lineages. Gene network reconstruction successfully identified three gene modules functionally differentiated, which were responsible for the evolutionary changes of the reduced genome in growth fitness, genome mutation, and gene expression, respectively. The diversity in evolutionary approaches improved the growth fitness associated with the homeostatic transcriptome architecture as if the evolutionary compensation for genome reduction was like all roads leading to Rome.

Impaired Relaxation in Induced Pluripotent Stem Cell-Derived Cardiomyocytes with Pathogenic TNNI3 Mutation of Pediatric Restrictive Cardiomyopathy.

BACKGROUND: Restrictive cardiomyopathy (RCM) is characterized by impaired diastolic function with preserved ventricular contraction. Several pathogenic variants in sarcomere genes, including TNNI3, are reported to cause Ca2+ hypersensitivity in cardiomyocytes in overexpression models; however, the pathophysiology of induced pluripotent stem cell (iPSC)-derived cardiomyocytes specific to a patient with RCM remains unknown. METHODS AND RESULTS: We established an iPSC line from a pediatric patient with RCM and a heterozygous TNNI3 missense variant, c.508C>T (p.Arg170Trp; R170W). We conducted genome editing via CRISPR/Cas9 technology to establish an isogenic correction line harboring wild type TNNI3 as well as a homozygous TNNI3-R170W. iPSCs were then differentiated to cardiomyocytes to compare their cellular physiological, structural, and transcriptomic features. Cardiomyocytes differentiated from heterozygous and homozygous TNNI3-R170W iPSC lines demonstrated impaired diastolic function in cell motion analyses as compared with that in cardiomyocytes derived from isogenic-corrected iPSCs and 3 independent healthy iPSC lines. The intracellular Ca2+ oscillation and immunocytochemistry of troponin I were not significantly affected in RCM-cardiomyocytes with either heterozygous or homozygous TNNI3-R170W. Electron microscopy showed that the myofibril and mitochondrial structures appeared to be unaffected. RNA sequencing revealed that pathways associated with cardiac muscle development and contraction, extracellular matrix-receptor interaction, and transforming growth factor-ß were altered in RCM-iPSC-derived cardiomyocytes. CONCLUSIONS: Patient-specific iPSC-derived cardiomyocytes could effectively represent the diastolic dysfunction of RCM. Myofibril structures including troponin I remained unaffected in the monolayer culture system, although gene expression profiles associated with cardiac muscle functions were altered.

Utility of the Angle between the Right Aortic Arch and First Branch for Detecting Double Aortic Arch via Fetal Echocardiography.

INTRODUCTION: The presence of a double aortic arch (DAA) is manifested by compressive symptoms, requiring surgery. DAA cases are classified as either complete or incomplete type. DAA and a right aortic arch with mirror image branching (mRAA) have a similar configuration to the first branch artery. The first branch of the mRAA is the left brachiocephalic artery, which appears to be the same as that of an incomplete DAA due to blood flow interruption. The present retrospective study aimed to evaluate the differences between DAA and mRAA by fetal echocardiography. METHODS: This single retrospective cohort study included all patients diagnosed with complete DAA, incomplete DAA, or mRAA at our facility between 2010 and 2022. The patients were diagnosed with complete DAA, incomplete DAA, or mRAA after birth and remaining fetal echocardiograms. The patients were divided into the DAA (complete DAA: n = 4, incomplete DAA: n = 3) and mRAA (n = 4) groups. The following three outcomes were compared: (1) angle between the right aortic arch and first branch (RF angle), (2) ratio of height to width of the region bounded by the aortic arch, first branch of the aortic arch, and descending aorta, and (3) maximum tracheal diameter on a three-vessel trachea view. RESULTS: The incomplete DAA cases were difficult to diagnose via fetal echocardiography. On fetal echocardiography, the RF angle was significantly steeper in the DAA group than in the mRAA group (median 57° [36°-69°] vs. 75° [62°-94°]; p < 0.05). The DAA and RAA groups showed no significant differences in the ratio of height to width of the region bounded by the aortic arch, first branch of the aortic arch, and descending aorta (median 0.57 [0.17-0.68] vs. 0.73 [0.56-1.0]) and maximum tracheal diameter (median 2.5 [1.4-3.3] vs. 3.2 [2.8-3.5] mm). The cut-off value for the presence of DAA was an RF angle <71°. CONCLUSION: The DAA group (complete and incomplete DAA) had a significantly steeper RF angle than the mRAA group. Therefore, RF angle measurement could improve the fetal diagnosis and postnatal prognosis of DAA.

Isogenic pairs of induced-pluripotent stem-derived endothelial cells identify DYRK1A/PPARG/EGR1 pathway is responsible for Down syndrome-associated pulmonary hypertension.

Down syndrome (DS) is the most prevalent chromosomal disorder associated with a higher incidence of pulmonary arterial hypertension (PAH). The dysfunction of vascular endothelial cells (ECs) is known to cause pulmonary arterial remodeling in PAH, although the physiological characteristics of ECs harboring trisomy 21 (T21) are still unknown. In this study, we analyzed the human vascular ECs by utilizing the isogenic pairs of T21-induced pluripotent stem cells (iPSCs) and corrected disomy 21 (cDi21)-iPSCs. In T21-iPSC-derived ECs, apoptosis and mitochondrial reactive oxygen species (mROS) were significantly increased, and angiogenesis and oxygen consumption rate (OCR) were significantly impaired as compared with cDi21-iPSC-derived ECs. The RNA-sequencing identified that EGR1 on chromosome 5 was significantly upregulated in T21-ECs. Both EGR1 suppression by siRNA and pharmacological inhibitor could recover the apoptosis, mROS, angiogenesis, and OCR in T21-ECs. Alternately, the study also revealed that DYRK1A was responsible to increase EGR1 expression via PPARG suppression, and that chemical inhibition of DYRK1A could restore the apoptosis, mROS, angiogenesis, and OCR in T21-ECs. Finally, we demonstrated that EGR1 was significantly upregulated in the pulmonary arterial ECs from lung specimens of a patient with DS and PAH. In conclusion, DYRK1A/PPARG/EGR1 pathway could play a central role for the pulmonary EC functions and thus be associated with the pathogenesis of PAH in DS.

Pathogenic Roles of Cardiac Fibroblasts in Pediatric Dilated Cardiomyopathy.

Background Dilated cardiomyopathy (DCM) is a major cause of heart failure in children. Despite intensive genetic analyses, pathogenic gene variants have not been identified in most patients with DCM, which suggests that cardiomyocytes are not solely responsible for DCM. Cardiac fibroblasts (CFs) are the most abundant cell type in the heart. They have several roles in maintaining cardiac function; however, the pathological role of CFs in DCM remains unknown. Methods and Results Four primary cultured CF cell lines were established from pediatric patients with DCM and compared with 3 CF lines from healthy controls. There were no significant differences in cellular proliferation, adhesion, migration, apoptosis, or myofibroblast activation between DCM CFs compared with healthy CFs. Atomic force microscopy revealed that cellular stiffness, fluidity, and viscosity were not significantly changed in DCM CFs. However, when DCM CFs were cocultured with healthy cardiomyocytes, they deteriorated the contractile and diastolic functions of cardiomyocytes. RNA sequencing revealed markedly different comprehensive gene expression profiles in DCM CFs compared with healthy CFs. Several humoral factors and the extracellular matrix were significantly upregulated or downregulated in DCM CFs. The pathway analysis revealed that extracellular matrix receptor interactions, focal adhesion signaling, Hippo signaling, and transforming growth factor-ß signaling pathways were significantly affected in DCM CFs. In contrast, single-cell RNA sequencing revealed that there was no specific subpopulation in the DCM CFs that contributed to the alterations in gene expression. Conclusions Although cellular physiological behavior was not altered in DCM CFs, they deteriorated the contractile and diastolic functions of healthy cardiomyocytes through humoral factors and direct cell-cell contact.

Utility of novel echocardiographic measurements to improve prenatal diagnosis of coarctation of the aorta.

Prenatal recognition of coarctation of the aorta (CoA) may improve neonatal survival and reduce morbidity. However, prenatal diagnosis of CoA remains challenging, with relatively high false-positive and false-negative rates. This study aimed to identify a novel formula based on fetal echocardiographic measures to predict prenatal identification of CoA. A retrospective comparison on the echocardiographic evaluation of 30 patients with suspected CoA between May 2016 and April 2021 was performed. The patients were divided into a postnatal surgical intervention group (n = 13) and a non-intervention group (n = 17). The measurements that showed significant differences were aortic isthmus diameter Z-score (p < 0.001), ductus arteriosus diameter/aortic isthmus diameter (p < 0.001), and distal aortic arch (DA) index (p < 0.001). In the receiver operating characteristic curves analysis, the DA index was the largest with an area under the curve of 0.941 and a cutoff value of 1.28, with a sensitivity of 85% and a specificity of 94%. Measurement of the DA index improved the diagnostic rate of fetal CoA and a DA index ≧ 1.28 indicated fetal CoA cases requiring surgical intervention.

Cardiac Fibroblasts Play Pathogenic Roles in Idiopathic Restrictive Cardiomyopathy.

BACKGROUND: Restrictive cardiomyopathy (RCM) is characterized by impaired ventricular relaxation. Although several mutations were reported in some patients, no mutations were identified in cardiomyocyte expressing genes of other patients, indicating that pathological mechanisms underlying RCM could not be determined by cardiomyocytes only. Cardiac fibroblasts (CFs) are a major cell population in the heart; however, the pathological roles of CFs in cardiomyopathy are not fully understood.Methods and Results:This study established 4 primary culture lines of CFs from RCM patients and analyzed their cellular physiology, the effects on the contraction and relaxation ability of healthy cardiomyocytes under co-culture with CFs, and RNA sequencing. Three of four patients hadTNNI3mutations. There were no significant alterations in cell proliferation, apoptosis, migration, activation, and attachment. However, when CFs from RCM patients were co-cultured with healthy cardiomyocytes, the relaxation velocity of cardiomyocytes was significantly impaired both under direct and indirect co-culture conditions. RNA sequencing revealed that gene expression profiles of CFs in RCM were clearly distinct from healthy CFs. The differential expression gene analysis identified that several extracellular matrix components and cytokine expressions were dysregulated in CFs from RCM patients. CONCLUSIONS: The comprehensive gene expression patterns were altered in RCM-derived CFs, which deteriorated the relaxation ability of cardiomyocytes. The specific changes in extracellular matrix composition and cytokine secretion from CFs might affect pathological behavior of cardiomyocytes in RCM.

Tri-substituted organotin compounds, but not retinoic acid, are potent ligands of complement component 8 γ.

Complement component 8 γ (C8γ) is a subunit of complement protein 8 (C8), which itself is a subunit of the complement cytolytic membrane attack complex. However, C8γ is also suggested to be a carrier protein for the general clearance of endogenous and exogenous compounds because it belongs to the lipocalin family of small secreted proteins that have the common ability to bind small hydrophobic ligands. Although retinoic acid, a metabolite of vitamin A, has been suggested as a potential ligand of C8γ, it remains unclear which other substances are able to bind to C8γ as ligands. Here, we evaluated the binding affinity of several organotin compounds that are ligands of a receptor of retinoic acid, retinoid X receptor, by using radioligand binding assays. The amount of [14C]triphenyltin (TPT), a tri-substituted organotin, that bound to purified recombinant C8γ was increased with increasing protein concentration, whereas that of [3H]all-trans retinoic acid and [3H]9-cis retinoic acid was unchanged. Scatchard analysis revealed that [14C]TPT bound to C8γ with an equilibrium dissociation constant (Kd) of 56.2 ± 16.2 nM. Non-radiolabeled tributyltin (TBT), another tri-substituted organotin, blocked the binding of [14C]TPT to C8γ in a competitive manner, but non-radiolabeled mono- or di-substituted organotin compounds did not. Together, our present observations indicate that TBT and TPT, but not retinoic acid or mono- or di-substituted organotin compounds, are potent ligands of C8γ, suggesting that C8γ may be involved in the toxicities of these organotin compounds.

The Evaluation of Fetal Cardiac Remote Screening in the Second Trimester of Pregnancy Using the Spatio-Temporal Image Correlation Method.

We prospectively performed remote fetal cardiac screening using the spatio-temporal image correlation (STIC), and examined the usefulness and problems of remote screening. We performed heart screening for all pregnant women at four obstetrics clinics over the three years from 2009 to 2014. The STIC data from 15,404 examinations in normal pregnancies (16-27 weeks, median 25 weeks) were analyzed. Obstetricians and sonographer collected STIC data from four-chamber view images. Eight pediatric cardiologists analyzed the images offline. A normal heart was diagnosed in 14,002 cases (90.9%), an abnormal heart was diagnosed in 457 cases (3.0%), and poor images were obtained in 945 cases (6.1%). 138 cases had congenital heart disease (CHD) after birth, and severe CHD necessitating hospitalization occurred in 36 cases. We were not able to detect CHD by screening in 12 cases. The sensitivity and specificity of STIC in CHD screening was 50% and 99.5%, respectively. The sensitivity and specificity of STIC in screening for severe CHD was 82% and 99.9%, respectively. The STIC method was useful in fetal remote screening for CHD. However, the fact that > 10% of images that could not be analyzed by this method was a problem.

Evolutionary Exploitation of Vertebrate Peroxisome Proliferator-Activated Receptor γ by Organotins.

Globally persistent man-made chemicals display ever-growing ecosystemic consequences, a hallmark of the Anthropocene epoch. In this context, the assessment of how lineage-specific gene repertoires influence organism sensitivity toward endocrine disruptors is a central question in toxicology. A striking example highlights the role of a group of compounds known as obesogens. In mammals, most examples involve the modulation of the nuclear receptor peroxisome proliferator-activated receptor γ (PPARγ). To address the structural and biological determinants of PPARγ exploitation by a model obesogen, tributyltin (TBT), in chordates, we employed comparative genomics, transactivation and ligand binding assays, homology modeling, and site-directed-mutagenesis. We show that the emergence of multiple PPARs (α, ß and γ) in vertebrate ancestry coincides with the acquisition of TBT agonist affinity, as can be deduced from the conserved transactivation and binding affinity of the chondrichthyan and mammalian PPARγ. The amphioxus single-copy PPAR is irresponsive to TBT; as well as the investigated teleosts, this is a probable consequence of a specific mutational remodeling of the ligand binding pocket. Our findings endorse the modulatory ability of man-made chemicals and suggest an evolutionarily diverse setting, with impacts for environmental risk assessment.

Abnormal cardiac axis as a prenatal marker of left pulmonary artery sling.

Left pulmonary artery sling (LPAS) is a rare vascular anomaly. The left pulmonary artery arises distally from the right pulmonary artery on the right side of the trachea and passes between the trachea and esophagus towards the left lung, compressing the lower trachea. LPAS is associated with congenital tracheal stenosis, which frequently requires early surgical intervention and has a poor prognosis due to severe airway obstruction after birth. Therefore, LPAS should be prenatally diagnosed to prepare for surgical intervention for tracheal stenosis. To the best of our knowledge, there are few reports on prenatal echocardiographic findings in LPAS. We report three prenatal cases of LPAS, which resulted in respiratory symptoms. We discuss fetal ultrasound findings and highlight the abnormal rotation of the fetal cardiac axis to the right as a useful sign in the prenatal screening of LPAS.

Efficacy of the circulatory management of an antenatally diagnosed congenital diaphragmatic hernia: outcomes of the proposed strategy.

OBJECT: The purpose of this study is to evaluate the outcome of our therapeutic strategy for antenatally diagnosed congenital diaphragmatic hernia (ADCDH). METHODS: We treated 61 cases of ADCDH according to our strategy. Prostaglandin E1 was required to be maintained the patency of the ductus arteriosus (PDA) in 39 cases (Group I) while it was not administered in 22 cases (Group II). Left ventricular end-diastolic dimension (LVDD) and Tei index were measured with echocardiography on days 0, 2, and 7 after birth. Radical surgery was performed on all cases by day 2. RESULTS: On day 0, Group I showed smaller LVDD and Tei index than those in Group II. Between day 0 and day 2, these parameters increased significantly in Group I, but not in Group II. On day 7, no significant difference in these parameters was observed between the two groups. Five patients died of cardiac and respiratory failure, resulting in a survival rate of 92 %. CONCLUSION: Our therapeutic strategy improves the clinical outcome of ADCDH. This can be attributed to two factors: earlier surgery resulting in improved LV function. The latter attenuates pulmonary hypertension and maintains PDA with a consequent decrease in right ventricular afterload to compensate for the low cardiac output resulting from PDA.

Evaluation of bilateral pulmonary artery banding for initial palliation in single-ventricle neonates and infants: risk factors for mortality before the bidirectional Glenn procedure.

OBJECTIVES: Bilateral pulmonary artery banding is considered as 'first-stage' palliation for neonates who have hypoplastic left heart syndrome. This study aimed to identify risk factors that influence outcome before the bidirectional Glenn operation. METHODS: This retrospective evaluation involved 30 consecutive patients with hypoplastic left heart syndrome, or a variant, who underwent bilateral pulmonary artery banding between August 2005 and December 2011 at our institution. Clinical echocardiographic, operative and catheter examination data were reviewed. RESULTS: This study included 9 patients with hypoplastic left heart syndrome and 21 patients with variants. Bilateral pulmonary artery banding was performed at a median age of 7 days. Finally, 19 patients had the bidirectional Glenn operation performed (Group A), and the remaining 11 patients died before the bidirectional Glenn procedure (Group NA). Catheter evaluations before the bidirectional Glenn procedure were carried out at 97 ± 34 days. The mean pulmonary venous wedge pressure was significantly lower (Group A: 13.1 ± 3.1 mmHg vs Group NA: 22.9 ± 3.7 mmHg, P <0.01), systemic ventricular ejection fraction was higher (54.4 ± 10.7 vs 41.7 ± 9.9%, P <0.05), systemic ventricular end-diastolic pressure was lower (6.1 ± 2.4 vs 10.5 ± 3.6 mmHg, P <0.05) and the rate of patients with more than mild systemic atrioventricular valve regurgitation was lower in Group A than in Group NA (15.7 vs 62.5%, P <0.05). Multivariate logistic regression analysis showed that mean pulmonary venous wedge pressure was the most significant predictor of attaining the bidirectional Glenn anastomosis (odds ratio: 2.35, P <0.01). CONCLUSIONS: Postoperative atrioventricular valve regurgitation, cardiac function and mean pulmonary venous wedge pressure are closely correlated with mortality after bilateral pulmonary artery banding. Additional treatments, including operations, are considered to maintain cardiac function and not to raise pulmonary venous wedge pressure before the bidirectional Glenn procedure.

Efficacy of intravenous immunoglobulin combined with prednisolone following resistance to initial intravenous immunoglobulin treatment of acute Kawasaki disease.

OBJECTIVES: To determine the most effective first-line rescue therapy for intravenous immunoglobulin (IVIG) nonresponders, using IVIG, prednisolone, or both, to prevent coronary artery abnormalities (CAAs). STUDY DESIGN: We retrospectively reviewed the clinical records of 359 consecutive patients with Kawasaki disease who failed to respond to initial IVIG. RESULTS: CAAs up to 1 month after treatment were less common in the IVIG+prednisolone group (15.9%) than in the IVIG group (28.7%, P = .005) and the prednisolone group (30.6%, P = .01). The IVIG+prednisolone group had significantly lower risks of failing to respond to first-line rescue therapy (aOR 0.16, 95% CI 0.09-0.31), CAAs up to 1 month (aOR 0.46, 95% CI 0.27-0.90), and CAAs at 1 month (aOR 0.40, 95% CI 0.18-0.91) than the IVIG group. In the prednisolone and IVIG+prednisolone groups, risk score, day of illness at first-line rescue therapy, prednisolone monotherapy, and resistance to first-line rescue therapy were independent risk factors for CAA. Sex and resistance to first-line rescue therapy were independent risk factors in the IVIG group. CONCLUSIONS: IVIG+prednisolone may be superior to IVIG or prednisolone as first-line rescue therapy in the treatment of IVIG nonresponders. To establish the efficacy of rescue therapy with IVIG+prednisolone following nonresponse to initial IVIG, a prospective randomized trial is warranted.

Zero mortality of continuous veno-venous hemodiafiltration with PMMA hemofilter after pediatric cardiac surgery.

OBJECTIVE: Continuous veno-venous hemodiafiltration (CVVH) is used as one of the modalities of continuous renal replacement therapy (CRRT) in pediatric intensive units. The aim of our study was to investigate the use of CVVH in small children with acute renal failure (ARF) after cardiac surgery. PATIENT AND METHODS: Between June 2005 and June 2008, 7 patients who required dialysis after pediatric cardiac surgery without ECMO underwent CVVH with polymethylmethacrylate membrane (PMMA) treatment. The definition of ARF was based on a 100% rise in serum creatinine (Cr) concentration, oliguria. On the other hand, PMMA-CVVH was weaned in patients with satisfactory urine output, stable biochemical markers of renal function and adequate fluid balance. RESULTS: All patients treated with PMMA-CVVH alone (4 boys, 3 girls) had a median age of 36 months and a median body weight of 11 kg. The averaged established time from cardiac operation to CVVH was 2.6 days. There was a significant decrease in the post-filter compared with pre-filter levels of BUN, Cr, potassium concentration. There were no significant changes in systolic blood pressure, lactate level and CRP; however, it was unnecessary for all patients to use epinephrine. CONCLUSIONS: Continuous veno-venous hemodiafiltration with PMMA-CVVH without ECMO achieved a surprisingly Zero mortality.

Isolated unilateral agenesis of the pulmonary artery: surgical repair with an artificial graft.

This report describes a 3-month-old Japanese boy with a diagnosis of isolated unilateral agenesis of the proximal right pulmonary artery with severe pulmonary hypertension. One-stage reconstruction of the right pulmonary artery was performed without cardiopulmonary bypass. The hilar right pulmonary artery and the distal main pulmonary artery were joined by anastomosis to an artificial ring graft. The boy's postoperative course was uneventful, and the pressure in the pulmonary artery was within the normal range. Although mild right pulmonary artery stenosis remained, the authors' therapeutic strategy may provide a clinically important option for isolated unilateral agenesis of the pulmonary artery.

External validation of a risk score to predict intravenous immunoglobulin resistance in patients with kawasaki disease.

BACKGROUND: we previously developed a new risk score to predict intravenous immunoglobulin (IVIG) resistance in Kawasaki disease. However, the IVIG dosage used in that study (1 g/kg/d for 2 consecutive days) differs from the single infusion of 2 g/kg recommended in the United States and elsewhere. Our aim was to assess the validity and applicability of our risk score in patients treated with a single infusion. METHODS: we used a database of 1626 patients with Kawasaki disease given initial IVIG treatment at a dose of 1 g/kg/d for 2 consecutive days (n = 990; IVIG- 1 g/kg × 2) or 2 g/kg/d for 1 day (n = 636; IVIG- 2 g/kg × 1) across 17 hospitals in Japan. Patients received the total IVIG dose within 36 hours in IVIG- 1 g/kg × 2 and 24 hours in IVIG- 2 g/kg × 1. We stratified the patients according to a risk scoring system developed to predict IVIG unresponsiveness, based on scores of ≥ 5 points. We compared the accuracy of prediction between the 2 groups using receiver operating characteristic analysis. RESULTS: baseline characteristics and clinical outcomes were similar between both groups. The areas under the receiver operating characteristic curve in IVIG- 2 g/kg × 1 were similar to those of IVIG- 1 g/kg × 2. Using a cut-off risk score of ≥ 5 points, we could identify IVIG resistance in terms of coronary artery abnormalities within 1 month and coronary artery abnormalities at 1 month with equivalent sensitivity and specificity in both groups. CONCLUSION: our risk score can be used to predict IVIG unresponsiveness to a regimen based on a single infusion of 2 g/kg IVIG.