Melissa Van Arsdall

Linking Gene Expression to Function: Metabolic Flexibility in the Normal and Diseased Heart

Abstract: Metabolism transfers energy from substrates to ATP. As a “metabolic omnivore,” the normal heart adapts to changes in the environment by switching from one substrate to another. We propose that this flexibility is lost in the maladapted, diseased heart. Both adaptation and maladaptation are the results of metabolic signals that regulate transcription of key cardiac regulatory genes. We propose that metabolic remodeling precedes, initiates, and sustains functional and structural remodeling. The process of metabolic remodeling then becomes a target for pharmacological intervention restoring metabolic flexibility and normal contractile function of the heart.

Stat1 negatively regulates angiogenesis, tumorigenicity and metastasis of tumor cells

Stat1 is deficient or inactive in many types of human tumors whereas some tumors have activated Stat1. Whether Stat1 affects tumor growth and metastasis is unclear. In the present study, we used Stat1 knockout tumor cells to determine (1) whether Stat1 can regulate angiogenesis, growth, and metastasis of tumor cells; and (2) whether Stat1 is required for the inhibitory effect of IFN-β on the expression of angiogenic factor bFGF. Highly tumorigenic and metastatic RAD-105 tumor cells derived from a fibrosarcoma of a Stat1 knockout mouse were reconstituted with a Stat1 expression vector. The reconstitution of Stat1 suppressed the tumorigenicity and metastasis of RAD-105 cells in nude mice which correlated with a decreased microvessel density and decreased expression of proangiogenic molecules bFGF, MMP-2, and MMP-9 in vivo. Moreover, noncytotoxic concentrations of IFN-β significantly inhibited the in vitro expression of bFGF in the Stat1-reconstituted cells but not in the Stat1-deficient cells, which was consistent with decreased bFGF expression of Stat1-reconstituted tumors in vivo. Therefore, Stat1 is essential for IFN-mediated inhibition of bFGF production, suggesting that tumor-intrinsic Stat1 is an important mediator for antiangiogenic signals, such as IFN. Collectively, these data demonstrate that Stat1 expressed by tumor cells is a negative regulator of tumor angiogenesis and, hence, tumor growth and metastasis.

Safety and Tolerability of Lactobacillus reuteri DSM 17938 and Effects on Biomarkers in Healthy Adults: Results from a Randomized Masked Trial

Background There are few carefully-designed studies investigating the safety of individual probiotics approved under Investigational New Drug policies. Objectives The primary aim of this prospective, double-blind placebo-controlled trial was to investigate if daily treatment of adults with Lactobacillus reuteri DSM 17938 (LR) for 2 months is safe and well-tolerated. Our secondary aim was to determine if LR treatment has immune effects as determined by regulatory T cell percentages, expression of toll-like receptors (TLR)-2 and −4 on circulating peripheral blood mononuclear cells (PMBCs), cytokine expression by stimulated PBMC, and intestinal inflammation as measured by fecal calprotectin. Methods Forty healthy adults were randomized to a daily dose of 5×108 CFUs of LR (nu200a=u200a30) or placebo (nu200a=u200a10) for 2 months. Participants completed a daily diary card and had 7 clinic visits during treatment and observation. Results There were no severe adverse events (SAEs) and no significant differences in adverse events (AEs). There were no differences in PBMC subclasses, TLRs, or cytokine expression after treatment. The probiotic-treated group had a significantly higher fecal calprotectin level than the placebo group after 2 months of treatment: 50 µg/g (IQR 24–127 µg/g) vs. 17 µg/g (IQR 11–26 µg/g), pu200a=u200a0.03, although values remained in the normal clinical range (0–162.9 µg/g). LR vials retained >108 CFUs viable organisms/ml. Conclusions LR is safe and well tolerated in adults, without significant changes in immunologic markers. There was a small but significant increase in fecal calprotectin, perhaps indicating some element of immune recognition at the intestinal level. Trial Registration Clinical Trials.gov NCT00922727

Hypoallergenic formula with Lactobacillus rhamnosus GG for babies with colic: A pilot study of recruitment, retention, and fecal biomarkers

AIMnTo investigate recruitment, retention, and estimates for effects of formula supplementation with Lactobacillus rhamnosus GG (LGG) on inflammatory biomarkers and fecal microbial community in infants with colic.nnnMETHODSnA prospective, double-blind, placebo-controlled trial was conducted in otherwise healthy infants with colic. We screened 74 infants and randomized and analyzed results in 20 infants [9 receiving LGG (LGG+) and 11 not receiving LGG (LGG-)]. LGG was incorporated in the formula (Nutramigen(®)) (minimum of 3 × 10(7) CFU/d) in the LGG+ group. Fecal microbiota and inflammatory biomarkers, including fecal calprotectin (FC), plasma cytokines, circulating regulatory T cells (Tregs), and crying + fussing time were analyzed to determine optimal time points and effect sizes for a larger trial.nnnRESULTSnRecruitment in this population was slow, with about 66% of eligible infants willing to enroll; subject retention was better (75%). These rates were influenced by parents reluctance to volunteer their infant for a clinical trial and by their tendency to change formulas. The maximal difference of crying + fussing time was observed at day 14, comparing the 2 groups, with a mean difference of -91 (95%CI: -76, 259) min (P = NS). FC showed no significant difference, but the optimal time to determine a potential effect was at day 90 [with a mean difference of 121 (95%CI: -48, 291) μg/g stool], observing a lower level of FC in the LGG+ group. The fecal microbial communities were chaotic, as determined by Shannons diversity index and not apparently influenced by the probiotic. No significant change was observed in plasma inflammatory cytokines or Tregs, comparing LGG+ to LGG- groups.nnnCONCLUSIONnDesigning future colic trials involving a probiotic-supplemented formula for infants in the United States will require consideration for difficult enrollment. Infants with colic have major variations in feal microbiota and calprotectin, both of which improve with time, with optimal time points for measurement at days 14 and 90 after treatment.

Is There a Role for the Enteral Administration of Serum-Derived Immunoglobulins in Human Gastrointestinal Disease and Pediatric Critical Care Nutrition?

Twenty years ago, there was profound, international interest in developing oral human, bovine, or chicken egg-derived immunoglobulin (Ig) for the prevention and nutritional treatment of childhood malnutrition and gastrointestinal disease, including acute diarrhea and necrotizing enterocolitis. Although such Ig products were shown to be effective, with both nutritional and antidiarrheal benefits, interest waned because of their cost and because of the perceived risk of bovine serum encephalitis (BSE). BSE is no longer considered a barrier to use of oral Ig, because the WHO has declared the United States to be BSE-free since the early 2000s. Low-cost bovine-derived products with high Ig content have been developed and are regulated as medical foods. These new products, called serum bovine Igs (SBIs), facilitate the management of chronic or severe gastrointestinal disturbances in both children and adults and are regulated by the US Food and Drug Administration. Well-established applications for use of SBIs include human immunodeficiency virus (HIV)-associated enteropathy and diarrhea-predominant irritable bowel syndrome. However, SBIs and other similar products could potentially become important components of the treatment regimen for other conditions, such as inflammatory bowel disease, by aiding in disease control without immunosuppressive side effects. In addition, SBIs may be helpful in conditions associated with the depletion of circulating and luminal Igs and could potentially play an important role in critical care nutrition. The rationale for their use is to facilitate intraluminal microbial antibody coating, an essential process in immune recognition in the gut which is disturbed in these conditions, thereby leading to intestinal inflammation. Thus, oral Ig may emerge as an important add-on therapy for a variety of gastrointestinal and nutritional problems during the next decade.

Infant Colic Represents Gut Inflammation and Dysbiosis

Objective To dissect potential confounding effects of breast milk and formula feeding on crying + fussing, fecal calprotectin, and gut microbiota in babies with colic. We hypothesized that infant colic is associated with gut inflammation linked to intestinal dysbiosis. Study design A nested case‐control design of 3 of our studies was used to analyze clinical and laboratory data at presentation, comparing babies with colic with controls. All investigators other than the biostatistician were blinded during data analysis. Subjects were recruited based on their age and crying + fussy time. We screened 65 infants, 37 with colic, as defined by Barr diary (crying + fussing time >3 hours daily), who were compared with 28 noncolicky infants. Results Fecal calprotectin was elevated in babies with colic. For each mode of infant feeding (breast milk, formula, or breast + formula), infants fecal calprotectin was higher in babies with colic. Infants with colic had similar levels of fecal alpha diversity (richness) when compared with controls, and alpha diversity was lower in breast‐fed babies. Beta diversity at the phylum level revealed significant differences in microbial population. A phylum difference resulted from reduced Actinobacteria (95% of which are Bifidobacilli) in babies with colic. Species significantly associated with colic were Acinetobacter and Lactobacillus iners. Conclusions Colic is linked with gut inflammation (as determined by fecal calprotectin) and dysbiosis, independent of mode of feeding, with fewer Bifidobacilli. Trial registration Clinicaltrials.gov: NCT01279265 and NCT01849991.

Elevated Lipase during Initial Presentation of Ulcerative Colitis in a Pediatric Patient: Do We Check for It.

There are very few reports of elevated lipase in pediatric inflammatory bowel disease (IBD). Symptoms of pancreatitis may be masked by abdominal pain in pediatric IBD. During the initial presentation of IBD in our patient, lipase was elevated to more than 3 times the upper limit of normal. Normalization of values coincided with remission of IBD. This may be due to extraintestinal involvement of the pancreas as part of the inflammatory process or due to leakage of pancreatic enzymes from an inflamed gut or mediated by inflammatory cytokines. Checking pancreatic enzymes during initial presentation of IBD may, therefore, be important to determine if pancreatic involvement has resulted from the inflammation in IBD or as an adverse effect of therapy. If unchecked, recurrent subclinical pancreatitis may be masked by IBD symptoms and missed prior to starting IBD therapy. This may result in chronic pancreatic insufficiency as reported in 50% of adults with IBD. Early detection of elevated pancreatic enzymes in IBD may help direct the management strategy, as treatment of the underlying inflammation in IBD may be the most important management for resolution of pancreatitis instead of cessation of therapy for fear of iatrogenic medication-induced pancreatitis.

Sa2051 Safety and Tolerability of a 2-Month Course of Lactobacillus Reuteri and Effect on Circulating and Fecal Biomarkers in Healthy Adults

Introduction: Obesity and metabolic disorders are linked to inflammation via gut flora and/ or gut permeability. Gut derived endotoxin triggers inflammation leading to metabolic syndrome (MetS) and contributing to oxidative stress. Aim: To investigate the effect of Lactobacillus casei Shirota on gut permeability, presence of endotoxin and neutrophil function in MetS. Patients and Methods: Patients with MetS were randomized to receive 3 x 6.5x109 CFU Lactobacillus casei Shirota (probiotic group) or not for 3 months. Gut permeability was assessed by a differential sugar absorption method, endotoxin by an adapted limulus amoebocyte lysate assay, neutrophil function and toll-like receptor (TLR) expression by flow cytometry and ELISA was used to detect lipopolysaccharide binding protein (LBP) and sCD14 levels. Results: Twenty-eight patients and 10 healthy controls were included. Gut permeability was significantly increased in MetS compared to controls but did not differ between patient groups. None of the patients were positive for endotoxin. LBP and sCD14 levels were not significantly different from healthy controls. C-reactive protein and LBP levels slightly but significantly increased after 3 months within the probiotics group. Neutrophil function and TLR expression did not differ from healthy controls or within the patient groups. Discussion: Gut permeability of MetS patients was increased before markers of low grade inflammation were measurable, most likely because only a minority of patients had morbid obesity normally leading to inflammation. Lactobacillus casei Shirota did not have any influence on any parameter tested possibly due to too short study duration or underdosing of Lactobacillus casei Shirota.