Duration of Simultaneous Exposure to High-Risk and Lower-Risk Nephrotoxic Antimicrobials in the Neonatal Intensive Care Unit (NICU) and Future Adolescent Kidney Health.

OBJECTIVE: To determine whether greater duration of simultaneous exposure to antimicrobials with high nephrotoxicity risk combined with lower-risk antimicrobials (simultaneous exposure) in the neonatal intensive care unit (NICU) is associated with worse later kidney health in adolescents born preterm with very low birth weight (VLBW). STUDY DESIGN: Prospective cohort study of participants born preterm with VLBW (<1500 g) as singletons between January 1, 1992, and June 30, 1996. We defined simultaneous exposure as a high-risk antimicrobial, such as vancomycin, administered with a lower-risk antimicrobial on the same date in the NICU. Outcomes were serum creatinine, estimated glomerular filtration rate (eGFR), and first-morning urine albumin-creatinine ratio (ACR) at age 14 years. We fit multivariable linear regression models with days of simultaneous exposure and days of nonsimultaneous exposure as main effects, adjusting for gestational age, birth weight, and birth weight z-score. RESULTS: Of the 147 out of 177 participants who had exposure data, 97% received simultaneous antimicrobials for mean duration 7.2 days (SD 5.6). No participant had eGFR <90 ml/min/1.73 m2. The mean ACR was 15.2 mg/g (SD 38.7) and 7% had albuminuria (ACR >30 mg/g). Each day of simultaneous exposure was associated only with a 1.04-mg/g higher ACR (95% CI 1.01 to 1.06). CONCLUSIONS: Despite frequent simultaneous exposure to high-risk combined with lower-risk nephrotoxic antimicrobials in the NICU, there were no clinically relevant associations with worse kidney health identified in adolescence. Although future studies are needed, these findings may provide reassurance in a population thought to be at increased risk of chronic kidney disease.

Maintenance of chronicity signatures in fibroblasts isolated from recessive dystrophic epidermolysis bullosa chronic wound dressings under culture conditions.

BACKGROUND: Recessive Dystrophic Epidermolysis Bullosa (RDEB) is a rare inherited skin disease caused by variants in the COL7A1 gene, coding for type VII collagen (C7), an important component of anchoring fibrils in the basement membrane of the epidermis. RDEB patients suffer from skin fragility starting with blister formation and evolving into chronic wounds, inflammation and skin fibrosis, with a high risk of developing aggressive skin carcinomas. Restricted therapeutic options are limited by the lack of in vitro models of defective wound healing in RDEB patients. RESULTS: In order to explore a more efficient, non-invasive in vitro model for RDEB studies, we obtained patient fibroblasts derived from discarded dressings) and examined their phenotypic features compared with fibroblasts derived from non-injured skin of RDEB and healthy-donor skin biopsies. Our results demonstrate that fibroblasts derived from RDEB chronic wounds (RDEB-CW) displayed characteristics of senescent cells, increased myofibroblast differentiation, and augmented levels of TGF-ß1 signaling components compared to fibroblasts derived from RDEB acute wounds and unaffected RDEB skin as well as skin from healthy-donors. Furthermore, RDEB-CW fibroblasts exhibited an increased pattern of inflammatory cytokine secretion (IL-1ß and IL-6) when compared with RDEB and control fibroblasts. Interestingly, these aberrant patterns were found specifically in RDEB-CW fibroblasts independent of the culturing method, since fibroblasts obtained from dressing of acute wounds displayed a phenotype more similar to fibroblasts obtained from RDEB normal skin biopsies. CONCLUSIONS: Our results show that in vitro cultured RDEB-CW fibroblasts maintain distinctive cellular and molecular characteristics resembling the inflammatory and fibrotic microenvironment observed in RDEB patients' chronic wounds. This work describes a novel, non-invasive and painless strategy to obtain human fibroblasts chronically subjected to an inflammatory and fibrotic environment, supporting their use as an accessible model for in vitro studies of RDEB wound healing pathogenesis. As such, this approach is well suited to testing new therapeutic strategies under controlled laboratory conditions.

Growth During Infancy After Extremely Preterm Birth: Associations with Later Neurodevelopmental and Health Outcomes.

OBJECTIVE: To evaluate associations between changes in weight, length, and weight/length ratio during infancy and outcomes later in life among individuals born extremely preterm. STUDY DESIGN: Among participants in the Extremely Low Gestational Age Newborn (ELGAN) study, we measured weight and length at discharge from the neonatal intensive care unit (NICU) and at age 2 years and evaluated neurocognitive, psychiatric, and health outcomes at age 10 years and 15 years. Using multivariable logistic regression, we estimated associations between gains in weight, length, and weight/length ratio z-scores between discharge and 2 years and outcomes at 10 and 15 years. High gain was defined as the top quintile of change; low gain, as the bottom quintile of change. RESULTS: High gains in weight and weight/length were associated with greater odds of obesity at 10 years, but not at 15 years. These associations were found only for females. High gain in length z-score was associated with lower odds of obesity at 15 years. The only association found between high gains in growth measures and more favorable neurocognitive or psychiatric outcomes was between high gain in weight/length and lower odds of cognitive impairment at age 10 years. CONCLUSIONS: During the 2 years after NICU discharge, females born extremely preterm with high gains in weight/length or weight have greater odds of obesity at 10 years, but not at 15 years. Infants with high growth gains in the 2 years after NICU discharge have neurocognitive and psychiatric outcomes in middle childhood and adolescence similar to those of infants with lower gains in weight and weight/length.

Maintenance of chronicity signatures in fibroblasts isolated from recessive dystrophic epidermolysis bullosa chronic wound dressings under culture conditions

BACKGROUND: Recessive Dystrophic Epidermolysis Bullosa (RDEB) is a rare inherited skin disease caused by variants in the COL7A1 gene, coding for type VII collagen (C7), an important component of anchoring fibrils in the basement membrane of the epidermis. RDEB patients suffer from skin fragility starting with blister formation and evolving into chronic wounds, inflammation and skin fibrosis, with a high risk of developing aggressive skin carcinomas. Restricted therapeutic options are limited by the lack of in vitro models of defective wound healing in RDEB patients. RESULTS: In order to explore a more efficient, non-invasive in vitro model for RDEB studies, we obtained patient fibroblasts derived from discarded dressings) and examined their phenotypic features compared with fibroblasts derived from non-injured skin of RDEB and healthy-donor skin biopsies. Our results demonstrate that fibroblasts derived from RDEB chronic wounds (RDEB-CW) displayed characteristics of senescent cells, increased myofibroblast differentiation, and augmented levels of TGF-ß1 signaling components compared to fibroblasts derived from RDEB acute wounds and unaffected RDEB skin as well as skin from healthy-donors. Furthermore, RDEB-CW fibroblasts exhibited an increased pattern of inflammatory cytokine secretion (IL-1ß and IL-6) when compared with RDEB and control fibroblasts. Interestingly, these aberrant patterns were found specifically in RDEB-CW fibroblasts independent of the culturing method, since fibroblasts obtained from dressing of acute wounds displayed a phenotype more similar to fibroblasts obtained from RDEB normal skin biopsies. CONCLUSIONS: Our results show that in vitro cultured RDEB-CW fibroblasts maintain distinctive cellular and molecular characteristics resembling the inflammatory and fibrotic microenvironment observed in RDEB patients' chronic wounds. This work describes a novel, non-invasive and painless strategy to obtain human fibroblasts chronically subjected to an inflammatory and fibrotic environment, supporting their use as an accessible model for in vitro studies of RDEB wound healing pathogenesis. As such, this approach is well suited to testing new therapeutic strategies under controlled laboratory conditions.

Collagen VII maintains proteostasis in dermal fibroblasts by scaffolding TANGO1 cargo.

Lack of type VII collagen (C7) disrupts cellular proteostasis yet the mechanism remains undescribed. By studying the relationship between C7 and the extracellular matrix (ECM)-associated proteins thrombospondin-1 (TSP1), type XII collagen (C12) and tissue transglutaminase (TGM2) in primary human dermal fibroblasts from multiple donors with or without the genetic disease recessive dystrophic epidermolysis bullosa (RDEB) (n=31), we demonstrate that secretion of each of these proteins is increased in the presence of C7. In dermal fibroblasts isolated from patients with RDEB, where C7 is absent or defective, association with the COPII outer coat protein SEC31 and ultimately secretion of each of these ECM-associated proteins is reduced and intracellular levels are increased. In RDEB fibroblasts, overall collagen secretion (as determined by the levels of hydroxyproline in the media) is unchanged while traffic from the ER to Golgi of TSP1, C12 and TGM2 occurs in a type I collagen (C1) dependent manner. In normal fibroblasts association of TSP1, C12 and TGM2 with the ER exit site transmembrane protein Transport ANd Golgi Organization-1 (TANGO1) as determined by proximity ligation assays, requires C7. In the absence of wild-type C7, or when ECM-associated proteins are overexpressed, C1 proximity and intracellular levels increase resulting in elevated cellular stress responses and elevated TGFß signaling. Collectively, these data demonstrate a role for C7 in loading COPII vesicle cargo and provides a mechanism for disrupted proteostasis, elevated cellular stress and increased TGFß signaling in patients with RDEB. Furthermore, our data point to a threshold of cargo loading that can be exceeded with increased protein levels leading to pathological outcomes in otherwise normal cells.

White Coat Hypertension Persistence in Children and Adolescents: The Pediatric Nephrology Research Consortium Study.

OBJECTIVES: To determine whether youth with white coat hypertension on initial ambulatory blood pressure monitoring (ABPM) continue to demonstrate the same pattern on repeat ABPM. STUDY DESIGN: Retrospective longitudinal cohort study of patients referred for high blood pressure (BP) and diagnosed with white coat hypertension by ABPM who had follow-up ABPM 0.5-4.6 years later at 11 centers in the Pediatric Nephrology Research Consortium. We classified ABPM phenotype using the American Heart Association guidelines. At baseline, we classified those with hypertensive BP in the clinic as "stable white coat hypertension," and those with normal BP as "intermittent white coat hypertension." We used multivariable generalized linear mixed effect models to estimate the association of baseline characteristics with abnormal ABPM phenotype progression. RESULTS: Eighty-nine patients met the inclusion criteria (median age, 13.9 years; 78% male). Median interval time between ABPM measurements was 14 months. On follow-up ABPM, 61% progressed to an abnormal ABPM phenotype (23% ambulatory hypertension, 38% ambulatory prehypertension). Individuals age 12-17 years and those with stable white coat hypertension had greater proportions progressing to either prehypertension or ambulatory hypertension. In the multivariable models, baseline wake systolic BP index ≥0.9 was significantly associated with higher odds of progressing to ambulatory hypertension (OR 3.07, 95% CI 1.02-9.23). CONCLUSIONS: The majority of the patients with white coat hypertension progressed to an abnormal ABPM phenotype. This study supports the 2017 American Academy of Pediatrics Clinical Practice Guideline's recommendation for follow-up of ABPM in patients with white coat hypertension.

Sex Differences in MicroRNA Expression and Cardiometabolic Risk Factors in Hispanic Adolescents with Obesity.

OBJECTIVE: To evaluate sex differences in microRNA (miRNA) expression, anthropometric measures, and cardiometabolic risk factors in Hispanic adolescents with obesity. STUDY DESIGN: Cross-sectional study of 68 (60% male) Hispanic adolescents with obesity, aged 13-17 years, recruited from a pediatric weight management clinic. We used small RNA sequencing to identify differentially expressed circulating miRNAs. We used ingenuity pathway analysis and David bioinformatic resource tools to identify target genes for these miRNAs and enriched pathways. We used standard procedures to measure anthropometric and cardiometabolic factors. RESULTS: We identified 5 miRNAs (miR-24-3p, miR-361-3p, miR-3605-5p, miR-486-5p, and miR-199b-3p) that differed between females and males. miRNA targets-enriched pathways included phosphatidylinositol 3-kinase-protein, 5' AMP-activated protein kinase, insulin resistance, sphingolipid, transforming growth factor-ß, adipocyte lipolysis regulation, and oxytocin signaling pathways. In addition, there were sex differences in blood pressure, skeletal muscle mass, lean body mass, and percent body fat. CONCLUSIONS: We have identified sex differences in miRNA expression in Hispanic adolescents relevant to cardiometabolic health. Future studies should focus on sex-specific mechanistic roles of miRNAs on gene pathways associated with obesity pathophysiology to support development of precision cardiometabolic interventions.

Cells from discarded dressings differentiate chronic from acute wounds in patients with Epidermolysis Bullosa.

Impaired wound healing complicates a wide range of diseases and represents a major cost to healthcare systems. Here we describe the use of discarded wound dressings as a novel, cost effective, accessible, and non-invasive method of isolating viable human cells present at the site of skin wounds. By analyzing 133 discarded wound dressings from 51 patients with the inherited skin-blistering disease epidermolysis bullosa (EB), we show that large numbers of cells, often in excess of 100 million per day, continually infiltrate wound dressings. We show, that the method is able to differentiate chronic from acute wounds, identifying significant increases in granulocytes in chronic wounds, and we show that patients with the junctional form of EB have significantly more cells infiltrating their wounds compared with patients with recessive dystrophic EB. Finally, we identify subsets of granulocytes and T lymphocytes present in all wounds paving the way for single cell profiling of innate and adaptive immune cells with relevance to wound pathologies. In summary, our study delineates findings in EB that have potential relevance for all chronic wounds, and presents a method of cellular isolation that has wide reaching clinical application.

Antenatal Steroid Exposure, Aerobic Fitness, and Physical Activity in Adolescents Born Preterm with Very Low Birth Weight.

OBJECTIVE: To determine whether antenatal corticosteroid exposure is associated with aerobic fitness or physical activity participation in adolescents born preterm with very low birth weight (VLBW). STUDY DESIGN: Observational cohort study of 14-year-old adolescents (n = 173) born with VLBW between 1992 and 1996 at a regional perinatal center with 91 exposed to antenatal corticosteroids. Aerobic fitness was determined from peak oxygen uptake (V˙O2peak) obtained via maximal exercise testing on a cycle ergometer. Physical activity levels for the past year and past 2 months were estimated from a questionnaire. Between-group comparisons for continuous variables were evaluated using independent t tests or Mann-Whitney U tests. Generalized linear models were used to compare differences in fitness and physical activity between those exposed to antenatal corticosteroids and not exposed to antenatal corticosteroids, with race and sex in models. RESULTS: Regression analysis revealed an antenatal corticosteroids × sex × race interaction for V˙O2peak (P ≤ .001). Nonblack male adolescents exposed to antenatal corticosteroids had significantly greater V˙O2peak than nonblack male adolescents not exposed to antenatal corticosteroids expressed relative to body mass (mean difference [95% CI]; 8.5 [2.1-15.0] mL·kg-1·min-1) and lean body mass (9.0 [1.1-16.9] mL·kglean body mass-1·min-1). No antenatal corticosteroid group differences in V˙O2peak were evident in black male adolescents, or black and nonblack female adolescents. Male adolescents exposed to antenatal corticosteroids reported participating in significantly more total physical activity (medians: 14.6 vs 8.5) and vigorous physical activity (3.0 vs 0.95) per week for the past 2 months than male adolescents not exposed to antenatal corticosteroids. CONCLUSIONS: Exposure to antenatal corticosteroids was associated with greater physical activity participation and aerobic fitness in adolescents with VLBW, particularly in nonblack male adolescents, which may confer health benefits in this at-risk population.

Obesity is Associated with Higher Blood Pressure and Higher Levels of Angiotensin II but Lower Angiotensin-(1-7) in Adolescents Born Preterm.

OBJECTIVES: To evaluate if obesity is associated with increased angiotensin II (Ang II) and decreased angiotensin-(1-7) or Ang-(1-7) in the circulation and urine among adolescents born prematurely. STUDY DESIGN: In a cross-sectional analysis of 175 14-year-olds born preterm with very low birth weight, we quantified plasma and urinary Ang II and Ang-(1-7) and compared their levels between subjects with overweight/obesity (body mass index ≥85th percentile, n = 61) and those with body mass index <85th percentile (n = 114) using generalized linear models, adjusted for race and antenatal corticosteroid exposure. RESULTS: Overweight/obesity was associated with higher systolic blood pressure and a greater proportion with high blood pressure. After adjustment for confounders, overweight/obesity was associated with an elevated ratio of plasma Ang II to Ang-(1-7) (ß: 0.57, 95% CI 0.23-0.91) and higher Ang II (ß: 0.21 pmol/L, 95% CI 0.03-0.39) but lower Ang-(1-7) (ß: -0.37 pmol/L, 95% CI -0.7 to -0.04). Overweight/obesity was associated with a higher ratio of urinary Ang II to Ang-(1-7) (ß: 0.21, 95% CI -0.02 to 0.44), an effect that approached statistical significance. CONCLUSIONS: Among preterm-born adolescents, overweight/obesity was associated with increased Ang II but reduced Ang-(1-7) in the circulation and the kidney as well as higher blood pressure. Obesity may compound the increased risk of hypertension and cardiovascular disease in individuals born prematurely by further augmenting the prematurity-associated imbalance in the renin-angiotensin system.

An investigation into the MMP1 gene promoter region polymorphism--1607 2G with recessive dystrophic epidermolysis bullosa disease severity in northeastern Mexican patients.

BACKGROUND: Recessive dystrophic epidermolysis bullosa (RDEB) is a severe genetic skin blistering disorder caused by mutations in the gene COL7A1 encoding type VII collagen. Most of the patients' clinical severity depends in part on the nature and location of the mutations, ranging from the mild form described as RDEBother-generalized (RDEB-O) to the more aggressive phenotype described as RDEBsevere-generalized (RDEB-sev gen). However, interfamilial and interindividual differences in subjects with identical COL7A1 mutations suggest the presence of modifier elements, which may influence severity. There is a single nucleotide polymorphism (SNP) at the promoter of the MMP1 gene-encoding matrix metalloproteinase type 1, which has been studied as a genetic disease modifier in different patient cohorts with different findings. METHODS: We tested the SNP in 30 patients with RDEB and 130 controls whose four grandparents were born in northeastern Mexico. Patients were clinically classified as RDEB-sev gen and RDEB-O by three dermatologists. The SNPStats, RXC, and SPSS software were used to perform statistical testing. RESULTS: The allele frequencies for 2G were 0.607, 0.562, and 0.642 for RDEB-O, RDEB-sev gen, and the control group, respectively. When the genotype frequencies were compared, there was no significant difference between RDEB-sev gen (OR = 0.38, CI 95% 0.12-1.21), RDEB-O (OR = 1.03, CI 95% 0.21-4.96), and the control group. CONCLUSION: We found no significant association in relation to the severity of the study subjects and the SNP at the promoter of the MMP1 gene.

Oncostatin M receptor-beta mutations underlie familial primary localized cutaneous amyloidosis.

Familial primary localized cutaneous amyloidosis (FPLCA) is an autosomal-dominant disorder associated with chronic skin itching and deposition of epidermal keratin filament-associated amyloid material in the dermis. FPLCA has been mapped to 5p13.1-q11.2, and by candidate gene analysis, we identified missense mutations in the OSMR gene, encoding oncostatin M-specific receptor beta (OSMRbeta), in three families. OSMRbeta is a component of the oncostatin M (OSM) type II receptor and the interleukin (IL)-31 receptor, and cultured FPLCA keratinocytes showed reduced activation of Jak/STAT, MAPK, and PI3K/Akt pathways after OSM or IL-31 cytokine stimulation. The pathogenic amino acid substitutions are located within the extracellular fibronectin type III-like (FNIII) domains, regions critical for receptor dimerization and function. OSM and IL-31 signaling have been implicated in keratinocyte cell proliferation, differentiation, apoptosis, and inflammation, but our OSMR data in individuals with FPLCA represent the first human germline mutations in this cytokine receptor complex and provide new insight into mechanisms of skin itching.

Variation in childhood asthma among former preterm infants.

OBJECTIVES: The role of in utero and perinatal exposures in modifying asthma risk among children born prematurely was assessed. Study design Former preterm children (n=251) were identified from a birth cohort. Examinations, including lung function testing, were performed at ages 8 to 11 years. Perinatal exposures were ascertained from neonatal medical records. RESULTS: Univariate predictors of asthma included male gender, African American ethnicity, maternal asthma, and birth weight. Asthmatics were less likely to have been small for gestational age (SGA) than nonasthmatics (12.4% vs 22.7%, P=.04) and had more neonatal pulmonary disease. After adjusting for maternal asthma and demographic factors, asthma was associated with chronic lung disease of infancy, neonatal mechanical ventilation and corticosteroid use, and a higher childhood body mass index. Children who were septic postbirth and girls who were SGA were less likely to have asthma (OR for sepsis, 0.2; 95% CI, 0.1-0.6; OR for girls who were SGA compared with girls who were not SGA, 0.05; CI, 0.01-0.34). CONCLUSIONS: Among premature children, female SGA status and neonatal sepsis appear protective relative to the development of childhood asthma. Differential susceptibility to asthma among preterm children may relate to exposures that operate in the in utero and early postnatal environment to accelerate lung development, alter innate immunity, or both.