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In today's changing health care landscape, it has become necessary that providers have a fundamental understanding of practice management as pertinent to the care they provide. The reproductive endocrinology and infertility (REI) practice is a uniquely complex setting with many component parts, necessitating frequent assessment and collaboration to provide safe, quality, and cost-effective care. In this review, we aim to describe the basics of medical practice management, divided into six sections: practice models; operations; patient safety; patient experience; employee recruitment; development, and satisfaction; and technology. These topics will be presented with a focus on the application of these principles to the REI practice.

Background: Pathogenic variants in MYBPC3 , encoding cardiac MyBP-C (myosin binding protein C), are the most common cause of familial hypertrophic cardiomyopathy. A large number of unique MYBPC3 variants and relatively small genotyped hypertrophic cardiomyopathy cohorts have precluded detailed genotype-phenotype correlations. Methods: Patients with hypertrophic cardiomyopathy and MYBPC3 variants were identified from the Sarcomeric Human Cardiomyopathy Registry. Variant types and locations were analyzed, morphological severity was assessed, and time-event analysis was performed (composite clinical outcome of sudden death, class III/IV heart failure, left ventricular assist device/transplant, atrial fibrillation). For selected missense variants falling in enriched domains, myofilament localization and degradation rates were measured in vitro. Results: Among 4756 genotyped patients with hypertrophic cardiomyopathy in Sarcomeric Human Cardiomyopathy Registry, 1316 patients were identified with adjudicated pathogenic truncating (N=234 unique variants, 1047 patients) or nontruncating (N=22 unique variants, 191 patients) variants in MYBPC3 . Truncating variants were evenly dispersed throughout the gene, and hypertrophy severity and outcomes were not associated with variant location (grouped by 5′–3′ quartiles or by founder variant subgroup). Nontruncating pathogenic variants clustered in the C3, C6, and C10 domains (18 of 22, 82%, P Conclusions: Truncating variants account for 91% of MYBPC3 pathogenic variants and cause similar clinical severity and outcomes regardless of location, consistent with locus-independent loss-of-function. Nontruncating MYBPC3 pathogenic variants are regionally clustered, and a subset also cause loss of function through failure of myofilament incorporation and rapid degradation. Cardiac morphology and clinical outcomes are similar in patients with truncating versus nontruncating variants.

Introduction: Pulmonary arterial hypertension (PAH) is a progressive disease characterized by increased pulmonary arterial pressure and vascular resistance. This vascular injury promotes immune dysregulation, further worsening the vasculopathy. A genome-wide association study identified a single nucleotide polymorphism (SNP) associated with PAH risk (rs2856830) at Human Leukocyte Antigen DPA1 (HLA-DPA1) locus, a gene known to be involved in adaptive immunity. However, little is known about the mechanism underlying this clinical association. Hypothesis: Allele-specific binding of transcription factors to a disease-associated functional SNP (fSNP) controls HLA-DPA1 expression, driving pulmonary vascular cell dysfunction and PAH. Methods: Oligonucleotides containing alleles of rs2856830 and eight SNPs in linkage disequilibrium (LD) were subjected to electrophoretic mobility shift assays (EMSA) to identify fSNPs characterized by allele-imbalanced binding to human pulmonary arterial endothelial cells (PAEC) nuclear proteins. SNP genotyping was done using blood from PAH (n=134) and control patients (n=131) at UPMC. Transcriptomics, angiogenesis, and migration were assessed in siRNA mediated HLA-DPA1 and Alpha Actinin 4 (ACTN4) knockdown (KD) in PAECs. Results: Through EMSA, rs9277336 (LD r 2 =0.87) was identified as a fSNP in HLA-DPA1 locus. SNP pulldown and immunoblotting confirmed allele-specific binding of nuclear ACTN4 protein to rs9277336 risk allele A (3.26 ± 0.49, p=0.001). SNP genotyping revealed a 2.04 ± 0.67 fold enrichment of risk allele A in PAH patients (χ 2 test, p=0.025). ACTN4 KD in cultured human PAECs decreased HLA-DPA1 transcript (0.30 ± 0.10, p. Transcriptomics revealed overlap of several cell structure and immune system-related pathways by HLA-DPA1 and ACTN4 KD. HLA-DPA1 and ACTN4 KD affected PAH associated pathophenotypes, including angiogenesis and migration. Conclusions: Our functional analysis identified ACTN4 as a novel regulator to disease-associated gene HLA-DPA1, affecting the endothelial pathophenotypes in PAH. The allele-specific binding to fSNP rs9277336 provides a mechanistic explanation for the clinical association between HLA-DPA1 locus and PAH outcomes.

International audience; Pulmonary arterial hypertension (PAH) refers to a set of heterogeneous vascular diseases defined by elevation of pulmonary arterial pressure (PAP) and pulmonary vascular resistance (PVR), leading to right ventricular (RV) remodeling and often death. Early increases in pulmonary artery stiffness in PAH drive pathogenic alterations of pulmonary arterial endothelial cells (PAECs), leading to vascular remodeling. Dysregulation of microRNAs can drive PAEC dysfunction. However, the role of vascular stiffness in regulating pathogenic microRNAs in PAH is incompletely understood. Here, we demonstrated that extracellular matrix (ECM) stiffening downregulated miR-7 levels in PAECs. The RNA-binding protein quaking (QKI) has been implicated in the biogenesis of miR-7. Correspondingly, we found that ECM stiffness upregulated QKI, and QKI knockdown led to increased miR-7. Downstream of the QKI-miR-7 axis, the serine and arginine-rich splicing factor 1 (SRSF1) was identified as a direct target of miR-7. Correspondingly, SRSF1 was reciprocally upregulated in PAECs exposed to stiff ECM and was negatively correlated with miR-7. Decreased miR-7 and increased QKI and SRSF1 were observed in lungs from patients with PAH and PAH rats exposed to SU5416/hypoxia. Lastly, miR-7 upregulation inhibited human PAEC migration, whereas forced SRSF1 expression reversed this phenotype, proving that miR-7 depended upon SRSF1 to control migration. In aggregate, these results define the QKI-miR-7-SRSF1 axis as a mechanosensitive mechanism linking pulmonary arterial vascular stiffness to pathogenic endothelial function. These findings emphasize implications relevant to PAH and suggest the potential benefit of developing therapies that target this miRNA-dependent axis in PAH.

Introduction: Early increases in pulmonary artery stiffness drive pathogenic alterations of pulmonary arterial endothelial cells (PAECs), leading to vascular remodeling, a prominent feature of pulmonary hypertension (PH). However, the molecular mechanisms by which PAECs respond to altered extracellular matrix (ECM) mechanics remain unclear. Recent RNA sequencing study of PAECs exposed to stiff versus soft matrices has identified miRNA-7 (miR-7) as a mechanosensitive downregulated miRNA. The biogenesis of miR-7 is inhibited by the RNA binding protein quaking (QKI), which is shown to be correspondingly upregulated in ECM stiffness. Moreover, subsequent RNA sequencing and computational analyses have identified serine and arginine rich splicing factor 1 (SRSF1) as a miR-7 target in PAECs with ECM stiffening. Hypothesis: The QKI-miR-7-SRSF1 axis is a pivotal ECM stiffening-mediated pathogenic signal in PAECs. Methods: Human PAECs were cultured on soft (0.5 or 1 kPa) or stiff (50 kPa) matrices. Lungs from PH patients and rats (SU5416/Hypoxia- and MCT-exposed models) were used to evaluate genes and miRNA expression. Boyden chamber migration analysis examined PAEC mobility. Results: In human and rat PH lungs, miRNA-7 (miR-7) was down-regulated ( P < 0.05). To validate RNA sequencing data by RT-qPCR, QKI level was increased (2.13 ± 0.19, P P P P Conclusions: Our data demonstrate that mechanoactivation of a QKI-miR-7-SRSF1 signal axis promotes PAEC pathophenotypes driven by ECM stiffness. These insights broaden our understanding of RNA pathobiology in vascular stiffening and carry important therapeutic implications in PH.

Supplemental Digital Content is available in the text., Background: Pathogenic variants in MYBPC3, encoding cardiac MyBP-C (myosin binding protein C), are the most common cause of familial hypertrophic cardiomyopathy. A large number of unique MYBPC3 variants and relatively small genotyped hypertrophic cardiomyopathy cohorts have precluded detailed genotype-phenotype correlations. Methods: Patients with hypertrophic cardiomyopathy and MYBPC3 variants were identified from the Sarcomeric Human Cardiomyopathy Registry. Variant types and locations were analyzed, morphological severity was assessed, and time-event analysis was performed (composite clinical outcome of sudden death, class III/IV heart failure, left ventricular assist device/transplant, atrial fibrillation). For selected missense variants falling in enriched domains, myofilament localization and degradation rates were measured in vitro. Results: Among 4756 genotyped patients with hypertrophic cardiomyopathy in Sarcomeric Human Cardiomyopathy Registry, 1316 patients were identified with adjudicated pathogenic truncating (N=234 unique variants, 1047 patients) or nontruncating (N=22 unique variants, 191 patients) variants in MYBPC3. Truncating variants were evenly dispersed throughout the gene, and hypertrophy severity and outcomes were not associated with variant location (grouped by 5′–3′ quartiles or by founder variant subgroup). Nontruncating pathogenic variants clustered in the C3, C6, and C10 domains (18 of 22, 82%, P

Nitric oxide regulates BP by binding the reduced heme iron (Fe(2+)) in soluble guanylyl cyclase (sGC) and relaxing vascular smooth muscle cells (SMCs). We previously showed that sGC heme iron reduction (Fe(3+) → Fe(2+)) is modulated by cytochrome b5 reductase 3 (CYB5R3). However, the in vivo role of SMC CYB5R3 in BP regulation remains elusive. Here, we generated conditional smooth muscle cell–specific Cyb5r3 KO mice (SMC CYB5R3–KO) to test if SMC CYB5R3 loss affects systemic BP in normotension and hypertension via regulation of the sGC redox state. SMC CYB5R3–KO mice exhibited a 5.84-mmHg increase in BP and impaired acetylcholine-induced vasodilation in mesenteric arteries compared with controls. To drive sGC oxidation and elevate BP, we infused mice with angiotensin II. We found that SMC CYB5R3–KO mice exhibited a 14.75-mmHg BP increase, and mesenteric arteries had diminished nitric oxide–dependent vasodilation but increased responsiveness to sGC heme-independent activator BAY 58-2667 over controls. Furthermore, acute injection of BAY 58-2667 in angiotensin II–treated SMC CYB5R3–KO mice showed greater BP reduction compared with controls. Together, these data provide the first in vivo evidence to our knowledge that SMC CYB5R3 is an sGC heme reductase in resistance arteries and provides resilience against systemic hypertension development.

Cardiac myosin binding protein C (MYBPC3) is the most commonly mutated gene associated with hypertrophic cardiomyopathy (HCM). Haploinsufficiency of full-length MYBPC3 and disruption of proteostasis have both been proposed as central to HCM disease pathogenesis. Discriminating the relative contributions of these 2 mechanisms requires fundamental knowledge of how turnover of WT and mutant MYBPC3 proteins is regulated. We expressed several disease-causing mutations in MYBPC3 in primary neonatal rat ventricular cardiomyocytes. In contrast to WT MYBPC3, mutant proteins showed reduced expression and failed to localize to the sarcomere. In an unbiased coimmunoprecipitation/mass spectrometry screen, we identified HSP70-family chaperones as interactors of both WT and mutant MYBPC3. Heat shock cognate 70 kDa (HSC70) was the most abundant chaperone interactor. Knockdown of HSC70 significantly slowed degradation of both WT and mutant MYBPC3, while pharmacologic activation of HSC70 and HSP70 accelerated degradation. HSC70 was expressed in discrete striations in the sarcomere. Expression of mutant MYBPC3 did not affect HSC70 localization, nor did it induce a protein folding stress response or ubiquitin proteasome dysfunction. Together these data suggest that WT and mutant MYBPC3 proteins are clients for HSC70, and that the HSC70 chaperone system plays a major role in regulating MYBPC3 protein turnover.

The most commonly mutated gene in hypertrophic cardiomyopathy (HCM) is cardiac myosin binding protein C (MYBPC3). Over 90% of MYBPC3 mutations are nonsense, but whether these mutations manifest in loss- or gain-of-function is unresolved. Evidence suggests MYBPC3 mutants impact protein quality control mechanisms. The objective of this study was to evaluate interactions of MYBPC3 with proteostatic systems and test the hypothesis that these interactions affect protein homeostasis in cardiomyocytes. WT and mutant MYBPC3 constructs were expressed in neonatal rat ventricular myocytes (NRVMs) via adenovirus. Mutant MYBPC3 induced ubiquitin proteasome system reporter GFPu accumulation (fold increase in GFPu-positive cells vs control: WT 138±14.0%, mutant 198±27.2%, mean±SEM, p½ =5.47±0.70 hr, WT Hsc70 knockdown t ½ =13.5±1.62 hr; mutant control t ½ =3.42±0.61 hr, mutant Hsc70 knockdown t ½ =9.87±0.95 hr), while YM-1 treatment accelerated degradation (WT DMSO t ½ =10.2±3.28 hr, WT YM-1 t ½ =3.16±0.61 hr; mutant DMSO t ½ =11.7±2.67 hr, mutant YM-1 t ½ =1.37±0.16 hr). We then evaluated whether transferrin uptake via clathrin mediated endocytosis, a critical Hsc70-dependent activity, was affected by mutant MYBPC3. Transferrin uptake was significantly decreased in NRVMs expressing mutant MYBPC3 compared to WT and untreated controls (transferrin-positive cells: control 22.93±3.34%, WT 17.47±0.70%, mutant 9.30±1.63%, mean±SEM, p In conclusion, we have demonstrated that Hsp70 chaperones interact with MYBPC3 in cardiomyocytes and affect MYBPC3 degradation, suggesting MYBPC3 is a client of Hsp70 and Hsc70. Additionally, expression of mutant MYBPC3 causes ubiquitin proteasome impairment and interferes with normal Hsc70 function. These results support our hypothesis that mutant MYBPC3 affects protein homeostasis in HCM.