Modifiable factors related to 7-year renal outcomes in subjects with type 2 diabetes and chronic kidney disease stage 3.

BACKGROUND AND AIMS: Subjects with diabetes are prone to a rapid decline in renal function and major adverse cardiovascular events when they reach chronic kidney disease (CKD) stage 3. This study aimed to identify modifiable risk factors associated with the progression of CKD in this population. SETTINGS AND DESIGN: An observational cohort study. METHODS AND MATERIALS: A total of 320 type 2 diabetic patients with CKD stage 3 registered in the shared-care-system in our hospital in 2010 were regularly followed up for 7 years. Demographic, laboratory, medication, and fundus examination data of these subjects were collected and analyzed. STATISTICAL ANALYSIS USED: Cox regression was used to identify factors associated with changes in CKD stage. RESULTS: During the 7-year follow-up period, 204 cases (63.7%) remained at CKD stage 3 while 79 cases (24.7%) progressed to stage 4 or 5 and 37 cases (11.6%) improved to stage 1 or 2. The change in estimated glomerular filtration rate (eGFR) in the first 2 years and variations in glycated hemoglobin (HbA1c) over 7 years were independent factors of both progression (hazard ratio (HR) 1.098 and 1.710, respectively) and improvement (HR 0.919 and 0.231, respectively) of CKD stage. Variations in systolic blood pressure (SBP) was also found as an independent factor for progression of renal function (HR 1.052). CONCLUSIONS: Our results demonstrated that fluctuations in HbA1c and SBP, and changes in eGFR during the first 2 years of treatment were associated with the long-term renal outcomes in type 2 diabetic patients with CKD stage 3.

Higher risk of incident ankylosing spondylitis in patients with uveitis: a secondary cohort analysis of a nationwide, population-based health claims database.

OBJECTIVES: Ankylosing spondylitis (AS) is a progressive, systemic, inflammatory autoimmune disease that typically affects young adults. Uveitis is a common extra-articular manifestation of AS. Nevertheless, the magnitude of the risk of AS among patients with uveitis is not clear. The aim of this secondary retrospective cohort study was to investigate the risk of incident AS in patients with uveitis using data from a nationwide, population-based health claims research database. METHOD: Using Taiwan's National Health Insurance Research Database, we identified 6637 patients with uveitis between 2000 and 2012. A comparison cohort was assembled, which consisted of five patients without uveitis, based on frequency matching for gender, 10 year age interval, and index year, for each patient with uveitis. Both groups were followed until diagnosis of AS or the end of the follow-up period. A Poisson regression model was used to calculate the incidence rate ratio for AS between the uveitis cohort and the comparison cohort. RESULTS: Patients with uveitis exhibited a significantly higher incidence of AS than the comparison cohort (adjusted incidence rate ratio = 2.57, p < 0.001). Subgroup analysis with stratification by the interval between the diagnosis of uveitis and AS indicated that the adjusted incidence rates were significantly higher in the uveitis cohort with an interval of up to 7.9 years. CONCLUSION: A significant increased risk in AS among patients with uveitis was observed, with a time lag of up to 7.9 years between the diagnosis of uveitis and subsequent diagnosis of AS.

Occurrence and distribution of Naegleria species from thermal spring environments in Taiwan.

UNLABELLED: Naegleria spp. is a free-living amoeba that can be found in the natural environment. A number of Naegleria spp. can cause fatal infections in the central nervous system in humans and animals, and the most important source of infection is through direct water contact. In this study, water samples from various thermal springs were taken from four thermal spring areas. Naegleria spp. was detected via culture confirmation and molecular taxonomic identification. Among the 60 samples obtained, Naegleria spp. was identified in 26 (43·3%) samples. The identified species included Naegleria australiensis, Naegleria gruberi, Naegleria lovaniensis and Naegleria mexicana. The presence of living Naegleria spp. was significantly associated with elevated pH value in the water sample. SIGNIFICANCE AND IMPACT OF STUDY: In this study, we examined the presence of living Naegleria spp. in thermal spring waters in south-eastern Taiwan. Naegleria spp. was isolated and culture-confirmed from thermal spring water. Naegleria fowleri was not found in all water samples, and Naegleria australiensis was the most common Naegleria genotype.

Gelanxinning capsule improves coronary microvascular dysfunction by inhibiting inflammation and restoring endothelial function.

OBJECTIVE: Gelanxinning capsule (GXSC) is a Chinese medicine to cure coronary artery disease (CAD) and a compound of Pueraria lobata, hawthorn extract, and gypenosides. However, whether GXSC could improve coronary microvascular dysfunction (CMD) is unknown. We aimed to demonstrate the therapeutic effect of GXSC on CMD and its underlying mechanisms in CAD patients. PATIENTS AND METHODS: This was a single-center, randomized control trial. A total of 78 patients diagnosed by selective coronary angiography (CAG) participated in this study. Patients' demographics, medical history, medications, and results of laboratory testing were collected. The index of microcirculatory resistance (IMR) and coronary flow reserve (CFR) were obtained by CAG and single-photon emission computed tomography (SPECT) separately. Fasting blood samples were obtained on the morning following the admission day. Concentrations of several molecules of inflammation, endothelial function, and coronary microvascular function were measured by ELISA. Patients were followed-up two months after discharge and fasting blood samples were also acquired. RESULTS: All patients were randomly divided into 2 groups: GXSC, 38 (48.7%), and control, 40 (51.3%). The intergroup comparison revealed no significant differences with respect to all baseline variables. As for inflammation biomarkers, proinflammatory NOD-like receptor thermal protein domain associated protein 3 (NLRP3) and interleukin (IL)-1 were significantly decreased in GXSC compared with the control group (0.71±0.08 vs. 1.04±0.07, p<0.01 and 7.16±0.59 vs. 10.93±1.04, p<0.01). Anti-inflammatory adropin was increased in the GXSC group (7.75±0.59 vs. 5.71±0.68, p=0.03). As for indexes of endothelial function, the concentrations of syndecan (SDC) 1, SDC4 and heparan sulphates (HS) were significantly downregulated in 2 months GXSC treatment (3.31±0.28 vs. 4.85±0.43, p<0.01, 3.79±0.56 vs. 5.69±0.68, p=0.03 and 21.31±2.79 vs. 35.18±4.11 p<0.01). In addition, the level of SIRTUIN 1 (SIRT1), which is a vascular protective protein, was upregulated in GXSC group (5.63±0.30 vs. 4.22±0.37, p<0.01). As for molecules of coronary microvascular function, endocan, soluble urokinase plasminogen activator receptor (suPAR), and growth differentiation factor (GDF)-15 were significantly decreased consistently in GXSC compared with the control group (0.09±0.01 vs. 0.19±0.03, p<0.01, 4.44±0.40 vs. 5.73±0.40, p=0.03 and 2.08±0.17 vs. 2.69±0.18, p=0.02). CONCLUSIONS: In conclusion, GXSC could improve CMD by inhibiting inflammation and restoring endothelial function. GXSC might be an effective drug in CAD patients without obstructive epicardial coronary arteries but suffering from angina.

Modulation of T cell development by an endogenous altered peptide ligand.

T cells potentially encounter numerous endogenous peptides during selection in the thymus and in the periphery. We examined the impact of an endogenous peptide on in vivo T cell development, using a TCR transgenic mouse model based on a hemoglobin-specific T cell clone. In these mice, the transgenic beta chains paired with endogenous alpha chains. This led to a serendipitous primary reactivity to Ser69 peptide, an altered peptide ligand of the Hbd (64-76) epitope of the parent clone. Two Ser69-reactive T cell populations were identified. A smaller population of the Ser69-reactive T cells responded both to Ser69 and Hbd (64-76). A majority reacted only to Ser69, and not to Hbd(64-76); in fact, Hbd(64-76) was a specific TCR antagonist for these Ser69-only-reactive T cells. Thus, in this unique experimental system, Ser69 became an agonist, and Hbd (64-76) was an antagonist. Endogenous presentation of the antagonist ligand in the thymus selectively eliminated the high-avidity cells, while sparing low-avidity cells in the Ser69-reactive T cell repertoire. These results highlight how specificity guides developing T cells through a network of ligands and indicate that the endogenous peptide pool has a profound effect on T cell development and repertoire.

Endogenous altered peptide ligands can affect peripheral T cell responses.

T cells potentially encounter a large number of endogenous self-peptide/MHC ligands in the thymus and the periphery. These endogenous ligands are critical to both positive and negative selection in the thymus; however, their effect on peripheral T cells has not been directly ascertained. Using the murine allelic Hbd (64-76)/I-Ek self-antigen model, we have previously identified altered peptide ligands (APLs) which are able to stimulate some but not all TCR-mediated effector functions. To determine directly the effect of endogenously synthesized APL/MHC complexes on peripheral T cells, we used a TCR transgenic mouse which had reversed our normal antigen system, with Ser69 peptide now being the agonist and Hbd(64-76) being the APL. In this report, we show that the constitutive level of endogenous Hbd(64-76)/I-Ek complexes presented by APCs in vivo is too low to affect the response of Ser69 reactive T cells. However, by increasing the number of Hbd(64-76)/I-Ek complexes expressed by the APCs, TCR antagonism is observed for both primary T cells and T cell hybridomas. In addition, the level of the CD4 coreceptor expressed on T cells and T cell hybridomas. In addition, the level of the CD4 coreceptor expressed on T cells changes the response pattern to endogenously presented Hbd(64-76)/I-Ek ligand. These findings demonstrate that T cells are selected to ignore the constitutive levels of endogenous complexes they encounter in the periphery. T cell responses can be affected by endogenous APLs in the periphery under limited but attainable circumstances which change the efficacy of the TCR/ligand interaction. Thus, endogenous APLs play a role in both the selection of T cells in the thymus and the responses of peripheral T cells.

Isolation and identification of Acanthamoeba species related to amoebic encephalitis and nonpathogenic free-living amoeba species from the rice field.

AIMS: Isolation and characterization of the clinically relevant amphizoic amoebas in vegetated farmlands, which may present a risk to farmers' health. METHODS AND RESULTS: Acanthamoeba species was isolated and characterized via morphological and molecular means in the rice field where the patient was exposed to rice paddy water which most probably was the point of infection. An Acanthamoeba sp. abundant in the rice field was identified. Genotyping showed the strain to be genotype T4, which was identical to the amoebic parasite found in patient's cerebrospinal fluid. During the course of the study, three nonpathogenic free-living amoeba species were also isolated and characterized for the first time in Taiwan. CONCLUSIONS: This study successfully located a possible source of granulomatous amoebic encephalitis in a patient and provided the first evidence that Acanthamoeba genotype T4 may be a potential pathogen in Taiwan. SIGNIFICANCE AND IMPACT OF THE STUDY: The integration of field survey, clinical data and morphological and genetic examination represents a sound strategy for investigation of the possible role of free-living amoebae in causing human diseases. Future work should include investigating the potential contributory role of other nonpathogenic free-living protozoa in disease of livestock or even human.

Population pharmacokinetics of golimumab in patients with ankylosing spondylitis: impact of body weight and immunogenicity.

AIMS: To develop a population pharmacokinetic (PK) model of subcutaneously administered golimumab, a human anti-tumor necrosis factor monoclonal antibody, in patients with ankylosing spondylitis (AS), estimate typical fixed and random population PK parameters, and identify significant covariates on golimumab pharmacokinetics. METHODS: Serum concentration data through Week 24 of a randomized, double-blind, placebo-controlled Phase III trial of golimumab (50 or 100 mg every 4 weeks) were analyzed using a nonlinear mixed-effects modeling approach. The effects of potential covariates on golimumab were evaluated. RESULTS: A one-compartment PK model with first-order absorption and elimination was chosen to describe the observed golimumab concentration-time data in patients with AS. Population estimates obtained from the final model for a typical 70-kg patient were: apparent systemic clearance (CL/F), 1.41 l/day (95% confidence interval (CI): 1.31 - 1.51) and apparent volume of distribution (V/F), 22.6 L (95% CI: 20.7 - 24.4). The first-order absorption rate constant (Ka) was estimated to be 1.01 day-1 (95% CI: 0.760 - 1.46). The between-subject variabilities for CL/F, V/F, and Ka were 35.2%, 38.6%, and 78.6%, respectively. Body weight was the most significant covariate, affecting both CL/F and V/F. Antibody-to-golimumab status, baseline C-reactive protein level, and sex were also identified as significant covariates on CL/F. CONCLUSIONS: A one-compartment model with first-order absorption and elimination adequately described the PK of golimumab following subcutaneous administrations in patients with AS. Body weight and anti-golimumab antibody status were found to significantly influence golimumab clearance. When a patient does not respond to the prescribed golimumab therapy, the possibility of the development of antibodies to golimumab has to be considered.

Frailty and Cause-Specific Hospitalizations in Community-Dwelling Older Men.

OBJECTIVES: The types of medical conditions leading to hospitalization in frail older people have not been investigated. The objectives were to evaluate associations between frailty and (a) risk of all-cause and cause-specific hospitalization, and (b) rate of all-cause and cause-specific hospitalizations. DESIGN, SETTING AND PARTICIPANTS: Community-dwelling men aged 70+ years in the Concord Health and Ageing in Men Project (CHAMP) were assessed for frailty at baseline (2005-2007, n=1705). MEASUREMENTS: Frailty was determined by both the Fried frailty phenotype (FP) and the Rockwood frailty index (FI). Non-elective and elective hospitalization data were accessed from the New South Wales (NSW) Admitted Patient Data Collection and mortality from the NSW Deaths Registry for the period 2005-2017. Causes of hospitalization were categorized using ICD-10 classification of principal diagnoses based on organ system involved into 14 major categories. RESULTS: Nearly 80% of CHAMP men had at least one non-elective hospitalization and 63% had an elective hospitalization over a 9-year follow-up. Men with FP frailty were twice as likely to have a non-elective hospitalization (HR: 1.98, 95%CI: 1.61-2.44) and a greater number of non-elective hospitalizations (IRR: 1.44, 95%CI: 1.22-1.70). Similar relationships were found between FI frailty and non-elective hospitalizations. Men with frailty (either FP or FI) were more likely to have at least one non-elective hospitalization for 13 of the 14 cause-related admissions. In contrast, frailty was only associated with 3 cause-related elective hospitalizations. Men with frailty were also more likely to have an increased number of non-elective hospitalizations for all 14 causes, but only for 6 causes of elective hospitalizations. CONCLUSIONS: Our findings suggest frailty increases the risk and number of non-elective hospitalizations in older men for a wide range of cause. Strategies on early identification of frailty, followed by appropriate preventative strategies to lower the risk of non-elective hospital admissions are warranted.

Effect of metabolic inhibitors on nuclear pore formation during the HeLa S3 cell cycle.

The effect of various antimetabolites on nuclear pore formation was studied in synchronized HeLa S(3) cells. The nuclear size was determined by light microscopy and the pore number per unit area of nuclear surface by the freeze-etching technique and electron microscopy. It was found that the inhibition of DNA replication or ribosomal RNA synthesis has no effect on nuclear size increase or pore formation. However, the inhibition of ATP synthesis effectively stops nuclear pore formation. Cycloheximide blocks nuclear pore formation at the same time during G(1) phase of the cell cycle when nuclear size increase is blocked by high concentrations of actinomycin D. This suggests that certain proteins or other factors leading to pore formation and nuclear size increase are transcribed and synthesized at about 3-4 h after mitosis, i.e., about 1-2 h before S phase begins.

Time sequence of nuclear pore formation in phytohemagglutinin-stimulated lymphocytes and in HeLa cells during the cell cycle.

The time sequence of nuclear pore frequency changes was determined for phytohemagglutinin (PHA)-stimulated human lymphocytes and for HeLa S-3 cells during the cell cycle. The number of nuclear pores/nucleus was calculated from the experimentally determined values of nuclear pores/micro(2) and the nuclear surface. In the lymphocyte system the number of pores/nucleus approximately doubles during the 48 hr after PHA stimulation. The increase in pore frequency is biphasic and the first increase seems to be related to an increase in the rate of protein synthesis. The second increase in pores/nucleus appears to be correlated with the onset of DNA synthesis. In the HeLa cell system, we could also observe a biphasic change in pore formation. Nuclear pores are formed at the highest rate during the first hour after mitosis. A second increase in the rate of pore formation corresponds in time with an increase in the rate of nuclear acidic protein synthesis shortly before S phase. The total number of nuclear pores in HeLa cells doubles from approximately 2000 in G(1) to approximately 4000 at the end of the cell cycle. The doubling of the nuclear volume and the number of nuclear pores might be correlated to the doubling of DNA content. Another correspondence with the nuclear pore number in S phase is found in the number of simultaneously replicating replication sites. This number may be fortuitous but leads to the rather speculative possibility that the nuclear pore might be the site of initiation and/or replication of DNA as well as the site of nucleocytoplasmic exchange. That is, the nuclear pore complex may have multiple functions.

Three-dimensional structures of acidic and basic fibroblast growth factors.

Members of the fibroblast growth factor (FGF) family of proteins stimulate the proliferation and differentiation of a variety of cell types through receptor-mediated pathways. The three-dimensional structures of two members of this family, bovine acidic FGF and human basic FGF, have been crystallographically determined. These structures contain 12 antiparallel beta strands organized into a folding pattern with approximate threefold internal symmetry. Topologically equivalent folds have been previously observed for soybean trypsin inhibitor and interleukins-1 beta and -1 alpha. The locations of sequences implicated in receptor and heparin binding by FGF are presented. These sites include beta-sheet strand 10, which is adjacent to the site of an extended sequence insertion in several oncogene proteins of the FGF family, and which shows sequence conservation among the FGF family and interleukin-1 beta.

Hyperglycemia in vitro up-regulates growth-related cell cycle proteins of adult mouse pancreatic islets.

To study effects of glucose on growth-related proteins of adult islets, we cultured mice islets in medium containing either 5.5 mmol/L (LG) or 20 mmol/L (HG) glucose. Total islet proteins were processed for sodium dodecyl sulfate polyacrylamide gel and Western blotting using antibodies against beta-actin (housekeeping), p27kip1 (G1/G0 checkpoint), cyclin D1 (G1/S), cyclin B1 (G2/M), and FoxM1. At day 1, protein levels p27, B1, D1, and FoxM1 of islets on LG and HG were 0.48- and 0.63-fold; 7.09- and 11.58-fold; 1.25- and 1.38-fold; and 1.75- and 1.75-folds, the value of day 0, determinations respectively. At day 3, the proteins of p27, B1, D1, and FoxM1 of islets in LG and HG were 0.84- and 0.84-fold; 3.08- and 17.17-fold; 1.41- and 1.54-fold; and 0.83- and 1.17-fold of those on day 0, respectively. On day 7 the values were 1.19- and 1.09-fold; 3.15- and 14.81-fold; 0.86- and 1.44-fold; and 2.75- and 3.42-fold that of day 0, respectively. At day 1, the ratios of protein in islets after HG verse LG were 1.25, 2.38, 0.94, and 1.00 for p27, B1, D1, and FoxM1, respectively. At days 3 and 7, the protein ratios of HG/LG were 0.81 and 0.82, 5.47 and 2.64, 0.81 and 1.51, and 1.11 and 1.24 for p27, B1, D1, and FoxM1, respectively. In conclusion, adult mouse islets rapidly respond to cultivation by reducing p27 and increasing B1; HG attenuates p27 elevation but enhances B1 and D1 elevations, which favor islet entry into the cell cycle.

Legionella prevalence in wastewater treatment plants of Taiwan.

Legionella is a bacterium that is ubiquitous in natural and artificial aquatic environments. Some species of Legionella are recognized as opportunistic potential human pathogens. We investigated the distribution of Legionella at seventeen WWTPs throughout Taiwan. Legionella were detected in 10 of the 17 WWTPs (58.8%) and 25 of 41 samples (61.0%). In the integrated, hospital, industrial and domestic wastewater systems were 13/18 (72.2%), 7/12 (58.3%), 2/7 (28.6%) and 3/4 (75.0%) of the samples were positive for Legionella, respectively. The most frequently encountered species were L. donaldsonii and uncultured L. spp., which were both found in 10 samples (24.4% of all samples), then followed by L. lytica (4.9%) and L. pneumophila (4.9%). L. anisa was detected in one sample (2.4%). The results of this survey confirm that Legionella are ubiquitous in WWTPs in Taiwan. Therefore, long-term investigations should be conducted to evaluate the overall occurrence of Legionella in WWTPs in Taiwan.

Molecular detection and prevalence of enterovirus within environmental water in Taiwan.

AIMS: To investigate the presence of enterovirus RNA in various samples of environmental water collected in Taiwan during 2004-2005, and to characterize the genotypes and distribution of the viruses identified in Taiwan. METHODS AND RESULTS: Total 131 environmental samples were screened using the reverse transcription polymerase chain reaction (RT-PCR) for the highly conserved 5'-nontranslated regions (5'-NTR). Among these enterovirus RNA-positive samples, 32, 15 and 6 of the samples were recovered from surface water, ground water and sewage water respectively. However, the total positive detection rate increased to 40.5% with the application of seminested PCR. Sequencing revealed that the majority of isolates belonged to the following genotypes: coxsackie A2 (35.8%), coxsackie A6 (13.2%) and enterovirus (EV)71 (11.3%); echovirus 11, porcine EV9 and coxsackie A16 isolates were also observed. CONCLUSIONS: This study confirms that the major epidemic genotypes of enterovirus are prevalent in the surface and ground water of Taiwan. SIGNIFICANCE AND IMPACT OF THE STUDY: This study is helpful in understanding the significance and epidemiology of the virus within and beyond the study area. Moreover, it was possible to predict the enterovirus genotype and evaluate possible correlations between water contamination and viral sequences found among clinical samples.

Inverse Association of N-terminal Pro‒B-type Natriuretic Peptide Level With Metabolic Syndrome in Kidney Transplant Patients.

BACKGROUND: Low levels of natriuretic peptide may activate the renin-angiotensin-aldosterone system, which may contribute to the development of obesity. Therefore, in study we aim to evaluate the relationship between metabolic syndrome (MetS) and serum N-terminal pro‒B-type natriuretic peptide (NT-proBNP) concentration in kidney transplant recipients. METHODS: Fasting blood samples were obtained from 66 kidney transplant recipients. MetS and its components were defined using the diagnostic criteria of the International Diabetes Federation. RESULTS: A total of 20 patients (30.3%) had MetS. Hypertension, prevalence of diabetes, use of statin or fibrate, body weight, body mass index, waist circumference, body fat mass, and levels of systolic blood pressure, total cholesterol, triglyceride, blood urea nitrogen, insulin, and HOMA-IR were higher, whereas the levels of high-density lipoprotein cholesterol and NT-proBNP were lower in patients with MetS. Logarithmically transformed creatinine and log-HOMA-IR were associated with NT-proBNP levels in a multivariable linear regression analysis. Multivariate logistic regression analysis revealed that NT-proBNP was an independent predictor of MetS in kidney transplant recipients. CONCLUSION: Our study has revealed that fasting level of NT-proBNP was negatively associated with MetS and that serum creatinine and HOMA-IR were independent predictors of serum NT-proBNP level in kidney transplant recipients.

Oral health of community-dwelling older Australian men: the Concord Health and Ageing in Men Project (CHAMP).

BACKGROUND: The Concord Health and Ageing in Men Project (CHAMP) is a cohort study of the health of a representative sample of Australian men aged 70 years and older. The aim of this report is to describe the oral health of these men. METHODS: Oral health was assessed when the men were all aged 78 years or older. Two calibrated examiners conducted a standardized intraoral assessment. Descriptive data were analysed by statistical association tests. Participants were excluded from the collection of some periodontal assessments if they had a medical contraindication. RESULTS: Dental assessments of 614 participants revealed 90 (14.6%) were edentate. Men had a mean of 13.8 missing teeth and 10.3 filled teeth. Dentate participants had a mean of 1.1 teeth with active coronal decay. Those in the low-income group had a higher rate of decayed teeth and lower rate of filled teeth. Thirty-four participants (5.5%) had one or more dental implants, and 66.3% relied on substitute natural teeth for functional occlusion. Of those with full periodontal assessments; 90.9% had sites with pocket depths of 3 mm or more, 96.6% had sites with CAL of 5 mm or more, and 79.7% had three or more sites with GI scores of 2 or more. CONCLUSIONS: There was a high prevalence of periodontal diseases and restorative burden of dentitions, which suggests that greater attention needs to be given to prevention and health maintenance in older Australian men.

LKB1 deficiency in T cells promotes the development of gastrointestinal polyposis.

Germline mutations in STK11, which encodes the tumor suppressor liver kinase B1 (LKB1), promote Peutz-Jeghers syndrome (PJS), a cancer predisposition syndrome characterized by the development of gastrointestinal (GI) polyps. Here, we report that heterozygous deletion of Stk11 in T cells (LThet mice) is sufficient to promote GI polyposis. Polyps from LThet mice, Stk11+/- mice, and human PJS patients display hallmarks of chronic inflammation, marked by inflammatory immune-cell infiltration, signal transducer and activator of transcription 3 (STAT3) activation, and increased expression of inflammatory factors associated with cancer progression [interleukin 6 (IL-6), IL-11, and CXCL2]. Targeting either T cells, IL-6, or STAT3 signaling reduced polyp growth in Stk11+/- animals. Our results identify LKB1-mediated inflammation as a tissue-extrinsic regulator of intestinal polyposis in PJS, suggesting possible therapeutic approaches by targeting deregulated inflammation in this disease.

Identification of a novel receptor for B lymphocyte stimulator that is mutated in a mouse strain with severe B cell deficiency.

BLyS (also called BAFF, TALL-1, THANK, and zTNF4), a TNF superfamily member, binds two receptors, TACI and BCMA, and regulates humoral immune responses [1-7]. These two receptors also bind APRIL [7-10], another TNF superfamily member. The results from TACI(-/-) and BCMA(-/-) mice suggest the existence of additional receptor(s) for BLyS. The TACI knockout gives the paradoxical result of B cells being hyperresponsive, suggesting an inhibitory role for this receptor [11, 12], while BCMA null mice have no discernable phenotype [13]. Here we report the identification of a third BLyS receptor (BR3; BLyS receptor 3). This receptor is unique in that, in contrast to TACI and BCMA, BR3 only binds BLyS. Treatment of antigen-challenged mice with BR3-Fc inhibited antibody production, indicating an essential role for BLyS, but not APRIL, in this response. A critical role for BR3 in B cell ontogeny is underscored by our data showing that the BR3 gene had been inactivated by a discrete, approximately 4.7 kb gene insertion event that disrupted the 3' end of the BR3 gene in A/WySnJ mice, which lack peripheral B cells.

Competition for BLyS-mediated signaling through Bcmd/BR3 regulates peripheral B lymphocyte numbers.

Striking cell losses occur during late B lymphocyte maturation, reflecting BcR-mediated selection coupled with requisites for viability promoting signals. How selection and survival cues are integrated remains unclear, but a key role for B lymphocyte stimulator (BLyS(TM); trademark of Human Genome Sciences, Inc.) is suggested by its marked effects on B cell numbers and autoantibody formation as well as the B lineage-specific expression of BLyS receptors. Our analyses of the B cell-deficient A/WySnJ mouse have established Bcmd as a gene controlling follicular B cell life span, and recent reports show Bcmd encodes a novel BLyS receptor. Here we show that A/WySnJ B cells are unresponsive to BLyS, affording interrogation of how Bcmd influences B cell homeostasis. Mixed marrow chimeras indicate A/WySnJ peripheral B cells compete poorly for peripheral survival. Moreover, in vivo BrdU labeling shows that (A/WySnJ x BALB/c)F(1) B cells have an intermediate but uniform life span, indicating viability requires continuous signaling via this pathway. Together, these findings establish the BLyS/Bcmd pathway as a dominant mediator of B cell survival, suggesting competition for BLyS/Bcmd signals regulates follicular B cell numbers.