Stiffness Restricts the Stemness of the Intestinal Stem Cells and Skews Their Differentiation Toward Goblet Cells.

BACKGROUND & AIMS: Fibrosis and tissue stiffening are hallmarks of inflammatory bowel disease (IBD). We have hypothesized that the increased stiffness directly contributes to the dysregulation of the epithelial cell homeostasis in IBD. Here, we aim to determine the impact of tissue stiffening on the fate and function of the intestinal stem cells (ISCs). METHODS: We developed a long-term culture system consisting of 2.5-dimensional intestinal organoids grown on a hydrogel matrix with tunable stiffness. Single-cell RNA sequencing provided stiffness-regulated transcriptional signatures of the ISCs and their differentiated progeny. YAP-knockout and YAP-overexpression mice were used to manipulate YAP expression. In addition, we analyzed colon samples from murine colitis models and human IBD samples to assess the impact of stiffness on ISCs in vivo. RESULTS: We demonstrated that increasing the stiffness potently reduced the population of LGR5+ ISCs and KI-67+-proliferating cells. Conversely, cells expressing the stem cell marker, olfactomedin-4, became dominant in the crypt-like compartments and pervaded the villus-like regions. Concomitantly, stiffening prompted the ISCs to preferentially differentiate toward goblet cells. Mechanistically, stiffening increased the expression of cytosolic YAP, driving the extension of olfactomedin-4+ cells into the villus-like regions, while it induced the nuclear translocation of YAP, leading to preferential differentiation of ISCs toward goblet cells. Furthermore, analysis of colon samples from murine colitis models and patients with IBD demonstrated cellular and molecular remodeling reminiscent of those observed in vitro. CONCLUSIONS: Collectively, our findings highlight that matrix stiffness potently regulates the stemness of ISCs and their differentiation trajectory, supporting the hypothesis that fibrosis-induced gut stiffening plays a direct role in epithelial remodeling in IBD.

Survival After Adrenalectomy for Metastatic Lung Cancer.

BACKGROUND: Adrenal metastasectomy is associated with increased survival in non-small cell lung cancer (NSCLC) with isolated adrenal metastases. Although clinical use of adrenal metastasectomy has expanded, indications remain poorly defined. The aim of this study was to evaluate the clinical benefit of adrenal metastasectomy for all lung cancer subtypes. PATIENTS AND METHODS: We performed a retrospective cohort study of patients who underwent adrenal metastasectomy for metastatic lung cancer at six institutions between 2001 and 2015. The primary outcomes were disease-free survival (DFS) and overall survival (OS). Cox proportional hazards regressions and Kaplan-Meier survival analysis were performed. RESULTS: For 122 patients, the mean age was 60.5 years and 49.2% were female. Median time to detection of the metastasis was 11 months, and 41.8% were ipsilateral to the primary lung cancer. Median DFS was 40 months (1 year: 64.8%; 5 year: 42.9%). Factors associated with longer DFS included primary tumor resection [hazard ratio (HR): 0.001; p = 0.005], longer time to adrenal metastasis (HR: 0.94; p = 0.005), and ipsilateral metastases (HR: 0.13; p = 0.004). Shorter DFS corresponded with older age (HR: 1.11; p = 0.01), R1 resection (HR: 8.94; p = 0.01), adjuvant radiation (HR: 9.45; p = 0.02), and open adrenal metastasectomy (HR: 10.0; p = 0.03). Median OS was 47 months (1 year: 80.2%; 5 year: 35.2%). Longer OS was associated with ipsilateral metastasis (HR: 0.55; p = 0.02) and adjuvant chemotherapy (HR: 0.35; p = 0.02). Shorter OS was associated with extra-adrenal metastases at adrenalectomy (HR: 3.52; p = 0.007), small cell histology (HR: 15.0; p = 0.04), and lung radiation (HR: 3.37; p = 0.002). DISCUSSION: Durable survival was observed in patients undergoing adrenal metastasectomy and should be considered for isolated adrenal metastases of NSCLC. Small cell histology and extra-adrenal metastases are relative contraindications to adrenal metastasectomy.

Adrenalectomy for Secondary Malignancy: Patients, Outcomes, and Indications.

OBJECTIVE: The goal of this study was to examine a multi-institutional experience with adrenal metastases to describe survival outcomes and identify subpopulations who benefit from adrenal metastasectomy. BACKGROUND: Adrenalectomy for metastatic disease is well-described, although indications and outcomes are incompletely defined. METHODS: A retrospective cohort study was performed of patients undergoing adrenalectomy for secondary malignancy (2002-2015) at 6 institutions. The primary outcomes were disease free survival (DFS) and overall survival (OS). Analysis methods included Kaplan-Meier and Cox proportional hazards. RESULTS: Of 269 patients, mean age was 60.1 years; 50% were male. The most common primary malignancies were lung (n = 125, 47%), renal cell (n = 38, 14%), melanoma (n = 33, 12%), sarcoma (n = 18, 7%), and colorectal (n = 12, 5%). The median time to detection of adrenal metastasis after initial diagnosis of the primary tumor was 17 months (interquartile range: 6-41). Post-adrenalectomy, the median DFS was 18 months (1-year DFS: 54%, 5-year DFS: 31%). On multivariable analysis, lung primary was associated with longer DFS [hazard ratio (HR): 0.49, P = 0.008). Extra-adrenal oligometastatic disease at initial presentation (HR: 1.84, P = 0.016), larger tumor size (HR: 1.07, P = 0.013), chemotherapy as treatment of the primary tumor (HR: 2.07 P = 0.027) and adjuvant chemotherapy (HR: 1.95, P = 0.009) were associated with shorter DFS. Median OS was 53 months (1-year OS: 83%, 5-year OS: 43%). On multivariable analysis, extra-adrenal oligometastatic disease at adrenalectomy (HR: 1.74, P = 0.031), and incomplete resection of adrenal metastasis (R1 margins; HR: 1.62, P = 0.034; R2 margins; HR: 5.45, P = 0.002) were associated with shorter OS. CONCLUSIONS: Durable survival is observed in patients undergoing adrenal metastasectomy and should be considered for subjects with isolated adrenal metastases.

Bowel Function After J-Pouch May Be More Complex Than Previously Appreciated: A Comprehensive Analysis to Highlight Existing Knowledge Gaps.

BACKGROUND: Functional outcomes following J-pouch for ulcerative colitis have been studied, but lack standardization in which symptoms are reported. Furthermore, the selection of symptoms studied has not been patient centered. OBJECTIVE: This study aimed to utilize a validated bowel function survey to determine which symptoms are present after J-pouch creation, and whether patients display a functional profile similar to low anterior resection syndrome. DESIGN: This study is a retrospective analysis of a prospectively maintained single-center database. SETTINGS: This study was conducted at the colorectal surgery center of a tertiary care academic hospital PATIENTS:: Included were 159 patients with J-pouch, ≥6 months after ileostomy reversal. MAIN OUTCOME MEASURES: The primary outcomes were individual answers to the Memorial Sloan Kettering Cancer Center Bowel Function Instrument. The original Bowel Function Instrument validation cohort was used as an historical comparison (n = 127). RESULTS: The mean total Bowel Function Instrument score for the J-pouch cohort was 59.9 ± 9.7 compared with a reported average score of 63.7 ± 11.6 for patients with low anterior resection in the validation cohort (p < 0.001), indicating worse bowel function in patients with J-pouch. When evaluating the Bowel Function Instrument subscales, patients with J-pouch reported frequency subscale scores of 18.2 ± 3.8, diet scores of 12.2 ± 3.8, and urgency scores of 15.9 ± 3.7, compared with 21.7 ± 4.5 (p < 0.001), 14.1 ± 3.7 (p < 0.001), and 15.0 ± 3.9 (p = 0.04) for patients undergoing rectal resection. Furthermore, 90.4% of patients with J-pouch state that they are sometimes, rarely, or never able to wait 15 minutes to get to the toilet. In addition, 56.4% of patients report having another bowel movement within 15 minutes of the last bowel movement, sometimes, always, or most of the time, and 50.6% of patients say that they sometimes, rarely, or never feel like their bowels have been totally emptied after a bowel movement. LIMITATIONS: This study is limited because it took place at a single center and the Bowel Function Instrument was only validated for patients undergoing rectal resection. CONCLUSIONS: Patients that undergo J-pouch surgery exhibit a constellation of bowel function symptoms that is more complex than fecal incontinence and frequency alone, despite the focus on these functional outcomes in the literature. See Video Abstract at http://links.lww.com/DCR/B73. LA FUNCIÓN INTESTINAL DESPUÉS DE LA BOLSA EN J PUEDE SER MÁS COMPLEJA DE LO QUE SE APRECIABA ANTERIORMENTE: UN ANÁLISIS EXHAUSTIVO PARA RESALTAR LAS BRECHAS DE CONOCIMIENTO EXISTENTES: Se han estudiado los resultados funcionales después de la bolsa en J para la colitis ulcerosa, pero carecen de estandarización en la que se informen los síntomas. Además, la selección de los síntomas estudiados no se ha centrado en el paciente.Utilizar una encuesta validada de la función intestinal para determinar qué síntomas están presentes después de la bolsa en J y si los pacientes muestran un perfil funcional similar al síndrome de resección anterior baja.Análisis retrospectivo de una base de datos de un solo centro mantenida prospectivamente.Centro de cirugía colorrectal de un hospital académico de atención terciaria.159 pacientes con bolsa en J, ≥6 meses después de la reversión de ileostomía.Instrumento para la función intestinal del "Memorial Sloan Kettering Cancer Center"; cohorte de validación original de instrumentos de función intestinal utilizada como comparación histórica (n = 127).La puntuación media total del instrumento de función intestinal para la cohorte de bolsa J fue 59.9 ± 9.7 en comparación con un puntaje promedio reportado de 63.7 ± 11.6 para pacientes con resección anterior baja en la cohorte de validación (p < 0.001), lo que indica peor función intestinal en pacientes con bolsa en J. Al evaluar las subescalas del instrumento de función intestinal, los pacientes con bolsa en J informaron puntuaciones de subescala de frecuencia de 18.2 ± 3.8, puntuaciones de dieta de 12.2 ± 3.8 y puntuaciones de urgencia de 15.9 ± 3.7, en comparación con 21.7 ± 4.5 (p < 0.001), 14.1 ± 3.7 (p < 0.001) y 15.0 ± 3.9 (p = 0.04) respectivamente para pacientes con resección rectal. Además, el 90.4% de los pacientes con bolsa en J afirman que a veces, rara vez o nunca pueden esperar 15 minutos para llegar al baño. Además, el 56.4% de los pacientes reportan haber tenido otra evacuación intestinal dentro de los 15 minutos posteriores a la última evacuación intestinal, a veces, siempre o la mayor parte del tiempo, y el 50.6% de los pacientes dicen que a veces, rara vez o nunca sienten que sus intestinos han sido vaciados totalmente después de una evacuación intestinal.Estudio en un solo centro, instrumento de función intestinal validado solo para pacientes con resección rectalLos pacientes que se someten a una bolsa en J exhiben una constelación de síntomas de la función intestinal que es más compleja que la incontinencia fecal y la frecuencia sola, a pesar del enfoque en estos resultados funcionales en la literatura.Consulte Video Resumen en http://links.lww.com/DCR/B73. (Traducción-Dr. Gonzalo Federico Hagerman).

Comparable perioperative outcomes, long-term outcomes, and quality of life in a retrospective analysis of ulcerative colitis patients following 2-stage versus 3-stage proctocolectomy with ileal pouch-anal anastomosis.

PURPOSE: Many surgeons assume 3-stage ileal pouch-anal anastomosis (IPAA) is safer than 2-stage IPAA in patients with active ulcerative colitis (UC), although recent data suggest outcomes are comparable. This study aimed to compare perioperative complications, late complications, and functional outcomes after 2- versus 3-stage IPAA in patients with active UC. METHODS: A retrospective review was conducted of patients who underwent 2- or 3-stage IPAA for active UC from 2000 to 2015 in a high-volume institution. Patients completed quality-of-life surveys 6 months following ileostomy reversal. Perioperative and late complications were recorded. Outcomes were compared with the Fisher exact test, and multivariable logistic regression was used to adjust for potential confounders. RESULTS: We identified 212 patients who underwent 2- or 3-stage IPAA for active UC, of whom 157 patients (74.1%) underwent 2-stage procedures and 55 (25.9%) underwent 3-stage procedures. More patients undergoing 2-stage procedures were taking immunomodulators preoperatively (46.3% vs. 23.1%, p = 0.01), but there was no difference in use of steroids (p = 0.09) or biologic agents (p = 0.85). Three-stage procedures were more likely to be urgent (78.6% vs. 30.2%, p < 0.001). There were no differences in perioperative complications (p = 0.50), anastomotic leak (p = 0.94), pouchitis (p = 0.45), pouch failure (p = 0.46), perceived quality of life (p = 0.68), number of bowel movements per day (p = 0.27), or sexual satisfaction (p = 0.21) between the 2- and 3-stage groups. CONCLUSIONS: Patients undergoing 2-stage compared to 3-stage IPAA for active ulcerative colitis have comparable outcomes and quality of life following ileostomy reversal. Two-stage IPAA appears to be safe and appropriate, even in high-risk patients.

Applying Enhanced Recovery Pathways to Unique Patient Populations.

Enhanced Recovery after Surgery (ERAS) pathways have become popular in colorectal surgery due to their associated decrease in length of stay (LOS), complications, and readmission rate. However, it is unclear if these pathways are safe, feasible, or effective in unique patient populations such as elderly patients, urgent/emergent surgeries, patients with specific comorbidities, inflammatory bowel disease, or pediatric patients. Enhanced recovery pathways appear safe in elderly patients, associated with decreased complications, though with slightly lower rates of adherence and increased LOS and readmission rates. Modified ERAS pathways have been applied to urgent and emergent surgeries, resulting in decreased morbidity and LOS. There have been no studies that performed subgroup analyses of ERAS pathways in patients with specific comorbidities. Studies investigating patients with inflammatory bowel disease on enhanced recovery pathways are extremely limited, but suggest that they are safe and feasible. Data on ERAS pathways in pediatric patients are still emerging. Therefore, though data are sparse, enhanced recovery pathways appear to be safe in unique patient populations, with similar efficacy in decreasing LOS and complications. There is an urgent need for more studies investigating these specific patient groups to aid perioperative decision making by colorectal surgeons.

Loss of Intestinal Alkaline Phosphatase Leads to Distinct Chronic Changes in Bone Phenotype.

BACKGROUND: The gut is becoming increasingly recognized as the source of various systemic diseases, and recently, it has been linked to bone metabolism via the so-called gut-bone axis. The microbiome and gut-derived mediators are thought to impact upon bone metabolism, and administration of probiotics has been shown to have beneficial effects in bone. The gut brush border enzyme intestinal alkaline phosphatase (IAP) plays an important role in controlling calcium absorption, inhibiting lipopolysaccharides, and other inflammatory mediators responsible for endotoxemia and appears to preserve the normal gut microbiota. Interestingly, IAP-deficient mice (AKP3-/-) also display a significant decrease in fecal Lactobacillus, the genus shown to be beneficial to bone. MATERIALS AND METHODS: IAP mRNA levels in mouse bone were measured using quantitative real-time polymerase chain reaction. Femurs of IAP-knockout (KO) and wild-type (WT) mice were analyzed by microcomputed tomography and histopathology. Serum levels of alkaline phosphatase, calcium, and phosphorus were measured. Target cell response upon exposure to serum from IAP-KO and WT mice was quantified using primary bone marrow macrophages. RESULTS: IAP was not significantly expressed in bones of WT or KO animals. IAP (alkaline phosphatase 3) expression in bone was vanishingly low compared to the duodenum (bone versus duodenum, 56.9 ± 17.7 versus 25,430.3 ± 10,884.5 relative expression, P = 0.01). Bone histology of younger IAP-KO and WT animals was indistinguishable, whereas older IAP-deficient mice showed a distinctly altered phenotype on histology and computed tomography scan. Younger KO mice did not display any abnormal levels in blood chemistry. Older IAP-KO animals showed an isolated increase in serum alkaline phosphatase levels reflecting an environment of active bone formation (IAP-WT versus IAP-KO, 80 ± 27.4 U/I versus 453 ± 107.5 U/I, P = 0.004). There was no significant difference in serum calcium or phosphorus levels between KO and WT mice. Serum from IAP-KO mice induced a significantly higher inflammatory target cell response. CONCLUSIONS: Through its multiple functions, IAP seems to play a crucial role in connecting the gut to the bone. IAP deficiency leads to chronic changes in bone formation, most likely through dysbiosis and systemic dissemination of proinflammatory mediators.

Intestinal alkaline phosphatase decreases intraperitoneal adhesion formation.

BACKGROUND: Damage to the peritoneum initiates an inflammatory response leading to the formation of adhesions, which subsequently cause significant morbidity in some patients. Intestinal alkaline phosphatase (IAP) is a gut enzyme capable of detoxifying various inflammatory mediators such as lipopolysaccharide, lipoteichoic acid, CpG DNA, and adenosine triphosphate. In this study, we aimed to examine the anti-inflammatory effects of IAP on postoperative adhesions in mice. METHODS: C57BL/6 mice were subjected to a midline laparotomy and then six musculoperitoneal buttons (MPBs) were created by pinching and ligating the peritoneum and underlying muscle. The buttons were half-excised and E-cauterized, and then cecal abrasion was performed. Five hundred microliters of vehicle with IAP 5000 U or vehicle alone were applied over the peritoneal cavity. In some experiments, the mice were euthanized on the first and second postoperative day (POD), and cytokines analysis was done on the MPB, peritoneal tissue, and peritoneal fluid. In separate experiments, the mice were sacrificed on the 21st POD, and adhesion to each button was scored based on type and tenacity. RESULTS: IAP group mice had significantly lower adhesion scores compared with controls (21.5 ± 1.7 versus 13.2 ± 1.3; P = 0.0014, n = 15). MPB from IAP group mice had significantly lower interleukin-1ß and tumor necrosis factor-α protein level compared to control mice (105.66 ± 4.5 versus 69.8 ± 4.8 versus pg/mg, P = 0.0001; 45.25 ± 2.8 pg/mg versus 24.88 ± 4.1 pg/mg; P = 0.0007, n = 10). IAP treatment significantly decreased interleukin-1ß and tumor necrosis factor-α mRNA expression in MPB in the first POD (1.14 ± 0.25 versus 0.33 ± 0.07; P = 0.0068; 1.33 ± 0.31 versus 0.33 ± 0.08; P = 0.0064, n = 10). CONCLUSIONS: Application of IAP during laparotomy could represent a novel approach to prevent postoperative adhesions.

Intestinal Alkaline Phosphatase Attenuates Alcohol-Induced Hepatosteatosis in Mice.

BACKGROUND AND AIMS: Bacterially derived factors from the gut play a major role in the activation of inflammatory pathways in the liver and in the pathogenesis of alcoholic liver disease. The intestinal brush-border enzyme intestinal alkaline phosphatase (IAP) detoxifies a variety of bacterial pro-inflammatory factors and also functions to preserve gut barrier function. The aim of this study was to investigate whether oral IAP supplementation could protect against alcohol-induced liver disease. METHODS: Mice underwent acute binge or chronic ethanol exposure to induce alcoholic liver injury and steatosis ± IAP supplementation. Liver tissue was assessed for biochemical, inflammatory, and histopathological changes. An ex vivo co-culture system was used to examine the effects of alcohol and IAP treatment in regard to the activation of hepatic stellate cells and their role in the development of alcoholic liver disease. RESULTS: Pretreatment with IAP resulted in significantly lower serum alanine aminotransferase compared to the ethanol alone group in the acute binge model. IAP treatment attenuated the development of alcohol-induced fatty liver, lowered hepatic pro-inflammatory cytokine and serum LPS levels, and prevented alcohol-induced gut barrier dysfunction. Finally, IAP ameliorated the activation of hepatic stellate cells and prevented their lipogenic effect on hepatocytes. CONCLUSIONS: IAP treatment protected mice from alcohol-induced hepatotoxicity and steatosis. Oral IAP supplementation could represent a novel therapy to prevent alcoholic-related liver disease in humans.

Development and initial results of a mandatory department of surgery faculty mentoring pilot program.

BACKGROUND: Mentoring of junior faculty by senior faculty is an important part of promotion and/or tenure and enhanced job satisfaction. This study reports the development and results to date of a faculty mentorship program in surgery. METHODS: We implemented a departmental faculty mentoring program in July 2014 that consisted of both structured and informal meetings between junior faculty mentees and assigned senior faculty mentors. All senior faculty mentors attended a brief mentor training session. We then developed an evidence-based mentorship instrument that featured standardized metrics of academic success. This instrument was completed by each mentee, and then reviewed at the junior faculty's annual career conference with their division chief. A survey was distributed in July 2015 to assess junior faculty satisfaction with the new mentorship program. RESULTS: Junior or senior faculty consisted of six of three women and 16 of 11 men, respectively. Junior faculty members were aged 40 ± 3 y and had been an attending for 4 ± 2 y. Mentorship meetings occurred approximately three times during the year (range = 0-10). Total meeting time with senior mentors per meeting was a mean of 40 min (range = 0-300 min). Over 75% of junior faculty members were very or somewhat satisfied with the mentorship program and would like to continue in the program. The best aspect of the program was the opportunity to meet with an accomplished surgeon outside their division. Opportunities to improve the program included better matching of mentor to mentee by disease or research focus. Interestingly, almost the entire junior faculty members tended to have at least two other mentors besides the mentor assigned to them in this program. In terms of program outcomes, junior faculty members agreed that the mentorship program improved their overall career plans and enhanced their involvement in professional organizations but has not yet helped with academic productivity, home and/or work balance, and overall job satisfaction. CONCLUSIONS: A mandatory, structured mentorship program with senior surgeons benefits most junior faculty members in terms of academic career planning and becoming more involved with surgical organizations. More research is required to understand the best method to pair mentors and mentees and more objective measurements of academic surgery success.

PATIENTS' PERCEPTION ON CLINICAL OUTCOME AND QUALITY OF LIFE AFTER A DIAGNOSIS OF CUSHING SYNDROME.

OBJECTIVE: Excess cortisol production (Cushing syndrome, CS) is a chronic disease affecting many organ systems and impacting quality of life (QoL). This study analyzed factors associated with self-reported QoL, including aspects related to the diagnosis and treatment modalities of CS. METHODS: In collaboration with the Cushing's Support and Research Foundation (CSRF), surveys using a validated QoL instrument were sent to CSRF members. Data were analyzed for associations between QoL and demographic, treatment, and disease factors. RESULTS: A total of 269 patients completed the survey. Respondents were 89.9% female, and the mean age was 48 years (SD 12, range 16-76). Respondents visited a median of 4 physicians (range 1-40) prior to the diagnosis of CS, with a median of 5 years (mean 7, SD 5, range 1-30) to obtain a diagnosis, showing a statistically significant negative correlation (P<.001). In one-quarter of cases, someone other than a physician suggested the diagnosis. Multiple regression analysis demonstrated that remission status, time to diagnosis, radiation therapy, and hypopituitarism were significant predictors of QoL. There was no association between QoL and patient's sex, age, replacement steroid use, having follow-up with an endocrinologist, or surgical approach. CONCLUSION: This is one of the largest QoL studies of CS patients and provides information for treatment and education goals. It is notable that early diagnosis and treatment was the major predictor of better QoL after achieving remission from disease, highlighting the need for awareness about the disorder. Patients in remission had better QoL, emphasizing the importance of disease control.

Intestinal alkaline phosphatase prevents metabolic syndrome in mice.

Metabolic syndrome comprises a cluster of related disorders that includes obesity, glucose intolerance, insulin resistance, dyslipidemia, and fatty liver. Recently, gut-derived chronic endotoxemia has been identified as a primary mediator for triggering the low-grade inflammation responsible for the development of metabolic syndrome. In the present study we examined the role of the small intestinal brush-border enzyme, intestinal alkaline phosphatase (IAP), in preventing a high-fat-diet-induced metabolic syndrome in mice. We found that both endogenous and orally supplemented IAP inhibits absorption of endotoxin (lipopolysaccharides) that occurs with dietary fat, and oral IAP supplementation prevents as well as reverses metabolic syndrome. Furthermore, IAP supplementation improves the lipid profile in mice fed a standard, low-fat chow diet. These results point to a potentially unique therapy against metabolic syndrome in at-risk humans.

The intestinal epithelial cell differentiation marker intestinal alkaline phosphatase (ALPi) is selectively induced by histone deacetylase inhibitors (HDACi) in colon cancer cells in a Kruppel-like factor 5 (KLF5)-dependent manner.

The histone deacetylase inhibitor (HDACi) sodium butyrate promotes differentiation of colon cancer cells as evidenced by induced expression and enzyme activity of the differentiation marker intestinal alkaline phosphatase (ALPi). Screening of a panel of 33 colon cancer cell lines identified cell lines sensitive (42%) and resistant (58%) to butyrate induction of ALP activity. This differential sensitivity was similarly evident following treatment with the structurally distinct HDACi, MS-275. Resistant cell lines were significantly enriched for those harboring the CpG island methylator phenotype (p = 0.036, Chi square test), and resistant cell lines harbored methylation of the ALPi promoter, particularly of a CpG site within a critical KLF/Sp regulatory element required for butyrate induction of ALPi promoter activity. However, butyrate induction of an exogenous ALPi promoter-reporter paralleled up-regulation of endogenous ALPi expression across the cell lines, suggesting the presence or absence of a key transcriptional regulator is the major determinant of ALPi induction. Through microarray profiling of sensitive and resistant cell lines, we identified KLF5 to be both basally more highly expressed as well as preferentially induced by butyrate in sensitive cell lines. KLF5 overexpression induced ALPi promoter-reporter activity in resistant cell lines, KLF5 knockdown attenuated butyrate induction of ALPi expression in sensitive lines, and butyrate selectively enhanced KLF5 binding to the ALPi promoter in sensitive cells. These findings demonstrate that butyrate induction of the cell differentiation marker ALPi is mediated through KLF5 and identifies subsets of colon cancer cell lines responsive and refractory to this effect.

Intestinal alkaline phosphatase promotes gut bacterial growth by reducing the concentration of luminal nucleotide triphosphates.

The intestinal microbiota plays a pivotal role in maintaining human health and well-being. Previously, we have shown that mice deficient in the brush-border enzyme intestinal alkaline phosphatase (IAP) suffer from dysbiosis and that oral IAP supplementation normalizes the gut flora. Here we aimed to decipher the molecular mechanism by which IAP promotes bacterial growth. We used an isolated mouse intestinal loop model to directly examine the effect of exogenous IAP on the growth of specific intestinal bacterial species. We studied the effects of various IAP targets on the growth of stool aerobic and anaerobic bacteria as well as on a few specific gut organisms. We determined the effects of ATP and other nucleotides on bacterial growth. Furthermore, we examined the effects of IAP on reversing the inhibitory effects of nucleotides on bacterial growth. We have confirmed that local IAP bioactivity creates a luminal environment that promotes the growth of a wide range of commensal organisms. IAP promotes the growth of stool aerobic and anaerobic bacteria and appears to exert its growth promoting effects by inactivating (dephosphorylating) luminal ATP and other luminal nucleotide triphosphates. We observed that compared with wild-type mice, IAP-knockout mice have more ATP in their luminal contents, and exogenous IAP can reverse the ATP-mediated inhibition of bacterial growth in the isolated intestinal loop. In conclusion, IAP appears to promote the growth of intestinal commensal bacteria by inhibiting the concentration of luminal nucleotide triphosphates.

Intestinal alkaline phosphatase prevents antibiotic-induced susceptibility to enteric pathogens.

OBJECTIVE: To determine the efficacy of oral supplementation of the gut enzyme intestinal alkaline phosphatase (IAP) in preventing antibiotic-associated infections from Salmonella enterica serovar Typhimurium (S. Typhimurium) and Clostridium difficile. BACKGROUND: The intestinal microbiota plays a pivotal role in human health and well-being. Antibiotics inherently cause dysbiosis, an imbalance in the number and composition of intestinal commensal bacteria, which leads to susceptibility to opportunistic bacterial infections. Previously, we have shown that IAP preserves the normal homeostasis of intestinal microbiota and that oral supplementation with calf IAP (cIAP) rapidly restores the normal gut flora. We hypothesized that oral IAP supplementation would protect against antibiotic-associated bacterial infections. METHODS: C57BL/6 mice were treated with antibiotic(s) ± cIAP in the drinking water, followed by oral gavage of S. Typhimurium or C. difficile. Mice were observed for clinical conditions and mortality. After a defined period of time, mice were killed and investigated for hematological, inflammatory, and histological changes. RESULTS: We observed that oral supplementation with cIAP during antibiotic treatment protects mice from infections with S. Typhimurium as well as with C. difficile. Animals given IAP maintained their weight, had reduced clinical severity and gut inflammation, and showed improved survival. CONCLUSIONS: Oral IAP supplementation protected mice from antibiotic-associated bacterial infections. We postulate that oral IAP supplementation could represent a novel therapy to protect against antibiotic-associated diarrhea (AAD), C. difficile-associated disease (CDAD), and other enteric infections in humans.

A novel approach to maintain gut mucosal integrity using an oral enzyme supplement.

OBJECTIVE: To determine the role of intestinal alkaline phosphatase (IAP) in enteral starvation-induced gut barrier dysfunction and to study its therapeutic effect as a supplement to prevent gut-derived sepsis. BACKGROUND: Critically ill patients are at increased risk for systemic sepsis and, in some cases, multiorgan failure leading to death. Years ago, the gut was identified as a major source for this systemic sepsis syndrome. Previously, we have shown that IAP detoxifies bacterial toxins, prevents endotoxemia, and preserves intestinal microbiotal homeostasis. METHODS: WT and IAP-KO mice were used to examine gut barrier function and tight junction protein levels during 48-hour starvation and fed states. Human ileal fluid samples were collected from 20 patients postileostomy and IAP levels were compared between fasted and fed states. To study the effect of IAP supplementation on starvation-induced gut barrier dysfunction, WT mice were fasted for 48 hours +/- IAP supplementation in the drinking water. RESULTS: The loss of IAP expression is associated with decreased expression of intestinal junctional proteins and impaired barrier function. For the first time, we demonstrate that IAP expression is also decreased in humans who are deprived of enteral feeding. Finally, our data demonstrate that IAP supplementation reverses the gut barrier dysfunction and tight junction protein losses due to a lack of enteral feeding. CONCLUSIONS: IAP is a major regulator of gut mucosal permeability and is able to ameliorate starvation-induced gut barrier dysfunction. Enteral IAP supplementation may represent a novel approach to maintain bowel integrity in critically ill patients.

Effect of Surgery on Postoperative Levels of the Gut Homeostasis-Regulating Enzyme Intestinal Alkaline Phosphatase.

BACKGROUND: Intestinal homeostasis is a crucial factor for complication-free short- and long-term postoperative recovery. The brush border enzyme intestinal alkaline phosphatase (IAP) is an important regulator of gut barrier function and intestinal homeostasis and prevents endotoxemia by detoxifying lipopolysaccharides (LPSs). As IAP is predominantly secreted by enterocytes in the duodenum, we hypothesized that pancreaticoduodenectomy (PD) leads to a significantly stronger decrease in IAP than other major abdominal surgery. STUDY DESIGN: Pre- and postoperative blood, stool, and intestinal samples were collected from patients undergoing PD, as well as other major surgical procedures without duodenectomy. The samples were analyzed using enzyme histochemistry, the para -nitrophenyl phosphate method for IAP, and the limulus amebocyte lysate assay for LPS. RESULTS: Overall, 88 patients were prospectively enrolled in the study. Fecal IAP activity negatively correlated with serum LPS (r = -0.3603, p = 0.0006). PD led to a significant decline in IAP compared to preoperative baseline levels (p < 0.0001). The decline in IAP correlated with the length of proximal small intestinal resection (r = 0.4271, p = 0.0034). Compared to controls, PD was associated with a much more pronounced reduction in IAP-also after adjusting for surgical trauma (operative time, blood loss; r = 0.4598, p = 0.0086). Simultaneously, PD triggered a clearly more prominent increase in serum LPS compared to controls (p = 0.0001). Increased postoperative LPS was associated with an elongated hospitalization (r = 0.7534, p = 0.0062) and more prominent in pancreatic cancer (p = 0.0009). CONCLUSIONS: Based upon the functional roles for IAP, supplementation with exogenous IAP might be a new treatment option to improve short- and long-term outcome after PD.

Intestinal alkaline phosphatase inhibits the proinflammatory nucleotide uridine diphosphate.

Uridine diphosphate (UDP) is a proinflammatory nucleotide implicated in inflammatory bowel disease. Intestinal alkaline phosphatase (IAP) is a gut mucosal defense factor capable of inhibiting intestinal inflammation. We used the malachite green assay to show that IAP dephosphorylates UDP. To study the anti-inflammatory effect of IAP, UDP or other proinflammatory ligands (LPS, flagellin, Pam3Cys, or TNF-α) in the presence or absence of IAP were applied to cell cultures, and IL-8 was measured. UDP caused dose-dependent increase in IL-8 release by immune cells and two gut epithelial cell lines, and IAP treatment abrogated IL-8 release. Costimulation with UDP and other inflammatory ligands resulted in a synergistic increase in IL-8 release, which was prevented by IAP treatment. In vivo, UDP in the presence or absence of IAP was instilled into a small intestinal loop model in wild-type and IAP-knockout mice. Luminal contents were applied to cell culture, and cytokine levels were measured in culture supernatant and intestinal tissue. UDP-treated luminal contents induced more inflammation on target cells, with a greater inflammatory response to contents from IAP-KO mice treated with UDP than from WT mice. Additionally, UDP treatment increased TNF-α levels in intestinal tissue of IAP-KO mice, and cotreatment with IAP reduced inflammation to control levels. Taken together, these studies show that IAP prevents inflammation caused by UDP alone and in combination with other ligands, and the anti-inflammatory effect of IAP against UDP persists in mouse small intestine. The benefits of IAP in intestinal disease may be partly due to inhibition of the proinflammatory activity of UDP.

Management of thyroid nodules with atypical cytology on fine-needle aspiration biopsy.

BACKGROUND: Fine-needle aspiration biopsy (FNAB) of the thyroid categorized as atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) is a newly defined category according to the recent Bethesda guidelines. We sought to assess the characteristics and treatment of patients with an AUS/FLUS FNAB at our institution. Additionally, we evaluated the utility of the recommended 3-month timing of repeat FNAB. METHODS: A retrospective study of all patients with an FNAB categorized as AUS/FLUS at an academic tertiary-care center. Clinical, cytological, and ultrasound variables were compared among management groups. Differences in patients receiving repeat FNAB before or after a 3-month interval were compared. RESULTS: A total of 203 patients of the 5,391 FNABs performed at our institution met the Bethesda criteria for AUS/FLUS; 62% were sent directly to surgery, 25% had a repeat FNAB, and 13% were observed. Younger (p=0.006) and male patients (p=0.04) were more likely to go directly to surgery. Microcalcifications, irregular margins, and marked hypoechogenicity on ultrasound did not appear to influence the decision to repeat the FNAB, observe the patient, or refer the patient for surgery. Timing of repeat FNAB (<3 months or ≥3 months) did not alter the diagnostic results of the second FNAB (p=0.73). The overall rate of malignancy in patients undergoing surgery was 15.7%. CONCLUSIONS: Gender and age, not ultrasound characteristics, appear to influence the decision for surgery in AUS/FLUS patients. Timing of repeat biopsy did not alter management, repeat FNAB diagnosis, or rate of malignancy in our cohort.