A Unique Multiplex ELISA to Profile Growth Factors and Cytokines in Cerebrospinal Fluid

Multiplex arrays designed for enzyme-linked immunosorbent assays (ELISAs) are robust and cost-effective for profiling biomarkers. Identification of relevant biomarkers in biological matrices or fluids helps in the understanding of disease pathogenesis. Here, we describe a sandwich ELISA-based multiplex assay to assess growth factor and cytokine levels in cerebrospinal fluid (CSF) samples derived from multiple sclerosis patients, amyotrophic lateral sclerosis patients, and control subjects without any neurological disorder. Results indicate that multiplex assay designed for the sandwich ELISA method is a unique, robust, and cost-effective method for profiling growth factors and cytokines present in CSF samples.

POS0253 PERSONALIZED RISK EVALUATION FOR OUTCOME PREDICTION IN ANCA ASSOCIATED VASCULITIS (AAV) USING LATENT CLASS ANALYSIS AND MACHINE LEARNING

Background

ANCA associated vasculitides (AAV) are a heterogeneous group of rare diseases with unknown etiology. In the most severe cases AAV can lead to end stage kidney disease or death. Since etiology and detailed pathogenesis of AAV is not known, the prediction of disease outcome at the time of diagnosis is challenging. Thus, there is an unmet need for tools to identify patients with the highest risk of organ dysfunction and death and apply effective personalized therapy.

Objectives

The aim of this work was to search for tools allowing outcome prediction at the time of AAV diagnosis. Early identification of patients, who are likely to develop severe organ dysfunction and death is crucial for appropriate disease management. Induction therapy in AAV relays on immunosuppressive drugs characterized by a high risk of severe side effects. Thus, their administration in high doses should be limited only to individual patients with an especially high risk of poor outcome.

Methods

We applied here two methods of identification of AAV patients at risk to develop severe organ dysfunction and death. First method (latent class analysis [LCA] followed by logistic regression) was meant to subcategorize patients and identify a subgroup at subjects at risk to develop chronic renal replacement therapy (CRRT) and death [1]. Second, served to assess individual poor outcome risk and was based on two machine learning (ML) classifiers, which by analyzing clinical information allow assigning computed risk for CRRT and death in an individual patient allowing to identify subjects with high risk of chronic replacement therapy (CRRT) and death. We have evaluated a number of different approaches to build the ML models (including logistic regression, support vector machines, random forests), and obtained the best results for the gradient boosting algorithm implementation called LightGBM [2]. It works as a sequential ensemble of so-called weak learners (decision trees) finally combined in a one prediction model. Both analyses were based on retrospective data from Polish national AAV registry (POLVAS) [3] including presently 565 GPA and 135 MPA patients. The parameters used were: demographic data and laboratory parameters, specific organ involvement, ANCA specificity and time between selected stages of the disease.

Results

LCA used on our AAV cohort identified four subphenotypes – three already previously proposed - and revealing a fourth clinically relevant subphenotype. This new subphenotype includes only GPA patients, usually diagnosed at a younger age as compared to other groups, and characterized by multiorgan involvement, high relapse rate, relatively high risk of death, but no end-stage kidney disease. Logistic regression analysis revealed significant differences in the risk of CRRT and death between those subphenotypes – the worst prognosis was found for severe MPO AAV. On the other hand, using ML approach we obtained an individual prediction model with potentially relevant clinical performance (ROC AUC of 0.85 for CRRT and 0.82 for death).

Conclusion

We consider results obtained encouraging. They may offer a new insight into AAV course based on data available at diagnosis, and create a solid foundation for potential clinical decision support system.

References

[1]Wójcik K et al. Subphenotypes of ANCA-associated vasculitis identified by latent class analysis. Clin Exp Rheumatol. 2021 Mar-Apr;39 Suppl 129(2):62-68.

[2]Ke G, at al. Light GBM: A Highly Efficient Gradient Boosting Decision Tree. Advances in Neural Information Processing Systems 30 (NIPS 2017), pp. 3149-3157.

[3]Wójcik K et al. Clinical characteristics of Polish patients with ANCA-associated vasculitides-retrospective analysis of POLVAS registry. Clin Rheumatol. 2019 Sep;38(9):2553-2563.

Acknowledgements

This work was supported by a grant from Polish National Science Center UMO-2018/31/B/NZ6/03898

Disclosure of Interests

None declared

A unique multiplex assay to profile growth factors and cytokines in CSF of MS and ALS patients

Growth factors and cytokines play a critical role in the pathogenesis of multiple sclerosis (MS) and amyotrophic lateral sclerosis (ALS). The shift in the balance between pro-inflammatory and anti-inflammatory cytokines contributes toward autoimmunity. Epidermal growth factor (EGF) and fibroblast growth factor (FGF) are elevated in the cerebrospinal fluid (CSF) of MS and ALS patients. Identification of relevant biomarkers helps in the understanding of the disease pathogenesis. The goal is to establish a sandwich ELISA-based multiplex assay to assess growth factor and cytokine levels in CSF samples from MS and ALS patients. Capture antibodies against EGF, FGF, IFN-gamma, IL-6, IL-1beta and IL-4 imprinted in a multiplex array format into each well of a 96-well plate. Arrays subjected to multiplex sandwich ELISA of CSF samples. Test samples included CSF from Relapsing-Remitting MS (RRMS, N = 10), Secondary Progressive MS (SPMS, N = 10) and ALS patients [N=10]. Control samples included CSF from healthy subjects [N=10]. Colorimetric read-outs from multiplex ELISA are quantified using ImageJ analysis of standards and samples. Results suggest that multiplex array designed for ELISA is a unique, robust, and a cost-effective method for profiling growth factors and cytokines present in biological matrices.

[*In memoriam: abstract submitted as a tribute to honor <underline>Dr. Barbara Tomik</underline> for her valuable contributions towards the collection and preparation of patient samples].

Perceived stress level among patients with chronic illness during covid pandemia

Introduction

The emergence of SARS-CoV-2 has enormously impacted healthcare systems around the world. Both patients and health care professionals have been subjected to a novel stressor which affects their everyday life and functioning. This issue is especially important to patients suffering from chronic diseases which had already been exposed to a psychological strain related to their primary diagnosis. As chronically ill patients are depending on the availability of a specific treatment i.e. in need of specific healthcare facilities and have more reasons to worry about their future and hence be more prone to suffer adverse psychological consequences than the general population.

Objectives

In this study we aimed to examine whether the psychological results of the pandemic affect chronically ill and whether the specific illness and other demographic factors account for any changes in perceived stress levels.

Methods

An online questionnaire has been distributed to 4 groups (n=369): 92 psoriasis patients, 73 dialysis patients, 100 patients after kidney transplantation and 104 multiple sclerosis patients. The study was conducted during the pandemic in Poland (June-July 2020). Perceived stress levels were measured by the Perceived Stress Scale (PSS).

Results

The preliminary results suggest elevated perceived stress levels among the studied groups. As the data are currently under statistical evaluation specific statistical conclusions are to be expected in November 2020.

Conclusions

As the described study was conducted during the SARS-CoV-2 pandemic in Poland, it stands to reason that the epidemiological situation affected the levels of perceived stress among chronically ill patients.

Abstract PD8-03: Conversion rates from positive to negative axillary involvement in breast cancer patients presenting with biopsy-proven axillary metastases prior to primary systemic therapy (PST) – A transSENTINA subproject

Background:

Modern chemotherapy carries a high potential of converting patients with clinically suspicious axillary nodes (cN+) prior to PST to clinically (ycN0) or pathologically (ypN0) negative nodes after PST. Clinical and sonographical axillary assessment, however, may be inadequate and therefore pathological assessment of suspicious axillary nodes is recommended. We analyzed the association between clinical / pathological parameters and positive to negative conversion in patients with biopsy-proven axillary metastases in Arm C of the SENTINA trial (i.e. patients with “true conversion”).

Methods:

Arm C of the SENTINA trial included patients converting from cN+ to ycN0 through PST from a prospective study. We limited our analysis to patients who had biopsy-proven axillary involvement. Univariate regression analysis was carried out to assess the association between patients with vs. without axillary disease after PST in i) patients with biopsy-proven involvement and ii) patients without biopsy proof of metastases.

Results:

Among 596 patients in arm C of the SENTINA trial with clinically and or sonographically suspicious ipsilateral axillary nodes, 439 (73,7%) 157 (26,3%) patients had a biopsy. In 152 patients (96,8%), lymph node metastases were confirmed and in 5 patients (3,2%), no malignant cells were identified. In both groups, we found a significant association (p<0,05) between increased rate of axillary conversion and small tumor diameter after PST, absence of multifocality, absence of lymphovascular invasion (LVI), ER and/or PR negativity, HER2 negativity, triple negative disease, and complete pathological response (pCR). No multiple testing corrections were performed due to an exploratory setting. However, only among patients with biopsy-proven involvement prior to PST, we found grade-3-tumors to be significantly associated with reduced probability of residual axillary involvement (76.1 vs. 33.8%, compared to G1 and G2, p=0.0323).

Conclusion:

Our analysis demonstrates that in patients with biopsy-proven axillary involvement before NST, parameters associated with axillary conversion are similar to those among patients classified as having nodal disease based on clinical and or sonographical assessment (cN+). Our analyses demonstrate that in biopsy-proven axillary metastases before NST, modern chemotherapy regimens result in significant rates of axillary conversion. This underscores the need to deescalate axillary staging / treatment with the goal to further avoid unnecessary axillary surgery.

Citation Format: Liedtke C, Kolberg H-C, Krajewska M, Bauerfeind I, Fehm T, Fleige B, Helms G, Lebeau A, Staebler A, Loibl S, Untch M, Kühn T. Conversion rates from positive to negative axillary involvement in breast cancer patients presenting with biopsy-proven axillary metastases prior to primary systemic therapy (PST) – A transSENTINA subproject [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD8-03.

Beliefs about back pain and pain management behaviours, and their associations in the general population: A systematic review

Previous mass media campaigns have aimed to influence how people manage back pain, with mixed success. Campaigns should target beliefs which are related to the behaviours they aim to change. This systematic review brings together research that has measured the prevalence of beliefs about back pain in the general population and factors associated with these beliefs, including future pain‐related outcomes. Five databases were searched up until April 2017. Quantitative studies which reported a measure of agreement with a belief about back pain, cross‐sectional associations, or associations between beliefs and future outcomes were eligible. Eligibility was assessed and data extracted independently by two authors. Results were tabulated and narratively synthesized. Nineteen studies from 10 countries were eligible (median study n [IQR] = 990.5 [524.75–2387.5]). Beliefs were measured using eight questionnaires and 57 stand‐alone items. Beliefs about back pain's negative consequences were common across countries and populations, whereas most samples did not hold fear‐avoidance beliefs. Beliefs about back pain's consequences were associated with pain and disability, but only one study investigated this specific relationship prospectively. No studies investigated whether beliefs are associated with future pain management behaviours. Agreement with certain beliefs (e.g. about negative consequences) was associated with sociodemographic characteristics (e.g. older age) and poorer self‐rated health. Interventions may benefit from targeting beliefs about the perceived negative consequences of back pain in these populations. However, future research should explore how beliefs prospectively influence the management of back pain.

Significance

This review brings together studies which have assessed the prevalence of beliefs about back pain, and factors associated with holding them. It highlights that whether or not these beliefs represent important determinants of how people manage pain remains unknown.

Histopathological Relevance of Angiotensin II Type 1 Receptor in Renal Transplant Biopsy

The occurrence of anti-angiotensin II type 1 receptor (AT1R) antibodies is thought to be a risk factor for transplant injury, but the relationship of AT1R to graft loss in renal transplantation has not been assessed. The aim of our study was to evaluate the expression of AT1R and its relationship with graft loss in patients who had a renal transplant biopsy for cause.

METHODS

AT1R immunoreactivity was analyzed in 170 renal transplant biopsies. Immunohistochemical evaluation of AT1R expression was performed on 4 μm-thick paraffin sections mounted on silanized slides. AT1R expression was analyzed in 5 compartments: 1. glomeruli, 2. renal blood vessels (small and intermediate arteries), 3. peritubular capillaries, 4. tubular epithelium, and 5. interstitium based on a 3-step scale.

RESULTS

Initially we checked 170 consecutive samples of biopsies for the immunoreactivity of the AT1R. The study finally included 118 renal transplant patients in 1-year observation after the biopsy. The renal allograft biopsy was performed between 6 days and 24 years after transplantation and the diagnosis was based on Banff criteria. We observed positive immunostaining of AT1R in tubular epithelium in 26.3% (42/118) of patients. A total of 7 patients had staining assessed as 2 and 35 as 1. One year post-biopsy graft loss in the AT1R (+) patients was 35.7 % (15/42) compared to 14.5% (11/76) in the AT1R (-) group (P = .008).

CONCLUSIONS

The expression of AT1R in tubular epithelium of the biopsy for cause was associated with significantly higher graft loss. The relevance of AT1R should be considered for better transplant immunological risk assessment.

Endothelin A Receptors Expressed in Renal Blood Vessels of Renal Transplant Patients Are Connected With Acute Tubular Necrosis or Antibody-Mediated Rejection

BACKGROUND

The role of non-HLA antibodies named antiendothelin A receptor antibodies is potentially significant but not established. The significance of the endothelin A receptor (ETAR) and its expression in renal biopsy has not been defined. We decided to evaluate the presence and relevance of ETARs in renal transplant biopsy for cause. The aim of our study was to evaluate the immunoreactivity of the ETAR and its significance in patients who had a renal transplant biopsy due to deterioration of transplant function (biopsy for cause) with detailed characterization of staining in small and intermediate arteries of renal transplant biopsies.

METHODS

Immunohistochemical expression of ETARs was analyzed in 162 renal transplant biopsies. Microscopic evaluation of ETAR expression (polyclonal antibody) was performed on paraffin sections. ETAR expression was analyzed in renal blood vessels (small and intermediate arteries) based on three-step scale.

RESULTS

We analyzed 154 patients who had renal allograft biopsy between 6 days and 24 years (median 597 days) after transplantation. Positive staining of ETAR in small and intermediate arteries was noticed in 9 patients. Among these patients, 4 had early biopsies (<3 months after transplantation), all developed acute tubular necrosis, and 1 developed additionally acute humoral rejection. Further, 4 patients had late biopsy (1-8 years after transplantation) and all developed characteristics of antibody mediated rejection. Lastly, 1 patient had no characteristic changes in the biopsy 4 months after transplantation. Graft loss 1 year after biopsy was higher in patients who were ETAR-positive but statistical significance was not achieved.

CONCLUSIONS

The expression of endothelin receptors in renal blood vessels (small and intermediate arteries) seems to be important in diagnosis of damage during acute tubular necrosis and antibody-mediated rejection.

B Cell Activating Factor (BAFF) in Long-term Kidney Transplant Recipients Is Not a Prognostic Marker for Allograft Dysfunction or Survival

OBJECTIVE

B cell activating factor (BAFF) has been shown to play a role in B cell survival, maturation, and activation, and has been linked with renal transplant outcome. BAFF signaling has been associated with plasmablast survival, anti-HLA immunization, and loss of graft function. We aimed to analyze the interplay between BAFF, memory B cells, and plasmablasts in relation to allograft function in long-term kidney transplant (KTx) recipients and their anti-HLA sensitization.

MATERIALS AND METHODS

This study included 70 long-term KTx recipients on standard immunosuppression 15 ± 6 years post transplantation (44 stable, 26 chronic allograft dysfunction, CAD) and 25 healthy volunteers. CD19+ B cells, memory B cells (CD19+CD27+), and plasmablasts (CD19+CD24-CD27++CD38++) were enumerated with flow cytometry. BAFF serum level and anti-HLA antibodies were assessed by Luminex bead arrays.

RESULTS

We found no difference in BAFF levels between KTx recipients and controls (median, interquartile range: 1.67, 1.40-1.97 vs 1.78, 1.63-1.93 ng/mL, P = .478) and no correlation between BAFF level and cell counts. Recipients presented lower plasmablast count than controls (22.5, 8-57 vs 79, 48-166 cells/mL, P < .001). There was a positive correlation between estimated glomerular filtration rate and plasmablasts (r_s = 0.30, P = .013) in recipients. Cell populations and BAFF were not related to the presence of anti-HLA antibodies. None of the parameters investigated was related to deterioration of allograft function during the 2-year follow-up.

CONCLUSION

BAFF serum level is not related to anti-HLA sensitization, circulating memory B cells, plasmablast count, or allograft function. Circulating plasmablasts are associated with current allograft function but are not prognostic for future course.

Pretransplant Immune Interplay Between Donor and Recipient Influences Posttransplant Kidney Allograft Function

BACKGROUND

Renal transplant candidates present immune dysregulation caused by chronic uremia, and deceased kidney donors present immune activation induced by brain death. Pretransplant donor and recipient immune-related gene expression were examined in the search for novel predictive biomarkers crosslinking recipient and donor pretransplant immune status with transplant outcome.

MATERIALS AND METHODS

This study included 33 low-risk consecutive renal transplant recipients and matched deceased donors. The expression of 29 genes linked to tissue injury, T-cell activation, cell migration, and apoptosis were assessed in postreperfusion kidney biopsies, as well as 14 genes in pretransplant peripheral blood of the kidney recipients. Gene expression was analyzed with real-time polymerase chain reaction on custom-designed low-density arrays.

RESULTS

Donor MMP9 expression was related to delayed graft function occurrence (P = .036) and short term kidney allograft function (14th day r_s = -0.44, P = .012; 1st month r_s = -0.46, P = .013). Donor TGFB1 expression was associated with short- and long-term graft function (14th day r_s = -0.47, P = .007; 3rd month r_s = -0.63, P = .001; 6th month r_s = -0.52, P = .010; 12th month r_s = -0.45, P = .028; 24th month r_s = -0.64, P = .003). Donor TGFB1 expression was not related to donor age (r_s = 0.32, P = .081), which was also an independent factor influencing the outcome. Recipient gene expression was not related to graft function but determined the acute rejection risk. Recipient IFNG and, to a lesser extent, IL18 expression were protective against acute rejection (area under the curve [AUC] 0.84, P < .001, and AUC 0.79, P < .001, respectively).

CONCLUSION

Kidney transplant outcome depends on the interplay between donor-related immune factors, which mostly affect allograft function and recipient immune milieu, influencing an alloreactive response.

The Impact of Functioning Arteriovenous Fistula on Blood Pressure Control and Renal Allograft Function

INTRODUCTION

The prevalence of hypertension in renal graft recipients is high. It was postulated that central arteriovenous anastomosis may significantly reduce blood pressure. This preliminary study evaluates the impact of functioning arteriovenous fistula (AVF) on blood pressure control and renal allograft function.

MATERIALS AND METHODS

One hundred sixty-two previously hemodialyzed kidney transplant recipients (108 males, 54 females, aged 52.7 ± 13.2 years, mean 6.9 ± 5.1 years after transplantation), who had scheduled visits in the first two weeks of March 2015, were included in the study. The recipients were divided into two groups depending on AVF function (65 AVF+ and 97 AVF-).

RESULTS

Functioning AVF was more prevalent in males than females (47.2 % vs 25.9 %, P = .009). Both groups presented similar allograft function despite the fact that interval from transplantation to examination day in the AVF+ group was significantly shorter than in the AVF- group (5.2 ± 5.3 vs 8.1± 4.5 years; P < .001). The mean systolic blood pressure (135.0 ± 17.0 vs 138.7 ± 14.1 mm Hg, P = .13) was similar in both study groups, but diastolic blood pressure in the AVF+ group was lower than in the AVF- group (80.0 ± 7.0 vs and 83.7 ± 9.2 mm Hg, P = .006). The proportion of patients with diastolic blood pressure >80 mm Hg was significantly higher in patients without functioning AVF (35 % in the AVF- group vs 20 % in the AVF+ group, P= .038). In multivariate analysis, AVF presence was the only factor significantly influencing a diastolic blood pressure with odds ratio 0.43 (95% CI 0.19-0.99, P = .048), which supports AVF as a potentially positive influence on blood pressure control.

CONCLUSIONS

The presence of AVF in renal transplant recipients was associated with a slight decrease in diastolic blood pressure without clear effect on renal function.

Expression of PBMC TLR4 in Renal Graft Recipients Who Experienced Delayed Graft Function Reflects Dynamic Balance Between Blood and Tissue Compartments and Helps Select a Problematic Patient

Both Toll-like receptor 4 (TLR4) and monocytes focus stimuli, causing them to contribute differently to chronic injury of a transplanted kidney.

AIM

The aim of our study was to determine if TLR4 monocyte is a diagnostic tool and possibly a target for therapeutic intervention.

MATERIALS

We studied 143 kidney transplant (KT) patients (88 male, 55 female; 50.3 ± 12.8 years); median was 10.4 post KT, follow-up was 11.4 months, and 46 patients had delayed graft function (DGF+) history. Control group (38 healthy volunteers) had monocyte mRNA-TLR4 expression (TLR4ex). DGF+ were divided by median of TLR4ex (-0.1034) into 2 groups: low-TLR4 expression (L-TLR4ex) and high-TLR4 expression (H-TLR4ex).

RESULTS

We showed that in comparison with DGF-, the DGF+ had much lower TLR4ex, and worse KT function both currently (TLR-day) (serum creatinine [sCr] P = .002; estimated glomerular filtration rate [eGFR] P = .001) and post follow-up (sCr P = .006; eGFR P = .005). The DGF+ with L/H-TLR4ex comparison showed no differences in TLR-day KT function but did show differences in post follow-up (sCr P = .01; eGFR P = .02; ΔeGFR% P = .001). Regression analysis showed an association between recipient age, tacrolimus concentration, and uremic milieu (ie, TLR-day sCr and GFR with TLR4ex). Reverse regression analysis indicated an association of TLR4ex (especially L/H-TLR4ex) with post follow-up parameters of KT function and numeric/qualitative measures of change.

CONCLUSION

DGF affects the fate of a graft. Within a several months after transplantation, TLR4ex of peripheral blood mononuclear cells declines in DGF patients. Low LR4ex in patients with DGF+ is associated with poor prognosis for the efficiency of the KT. In patients with DGF+, the proper selection of immunosuppression (tacrolimus dosing) is very important. Higher concentrations of tacrolimus may improve prognosis. The analysis of TLR4ex change may be a useful parameter for the real assessment of immunosuppression efficacy. It is important for transplanted organ function that peripheral blood mononuclear cells effectively leave circulation and remain in the graft.

Endoscopic Islet Autotransplantation Into Gastric Submucosa-1000-Day Follow-up of Patients

BACKGROUND

Total pancreatectomy and autologous transplantation of pancreatic islets is a treatment option for patients with severe pain due to chronic pancreatitis. In the standard procedure, pancreatic islets are isolated and subsequently administered into the portal vein. In the case of patients with a history of thrombosis or at risk of thrombosis, this route of administration is not viable. Animal studies conducted in our department led to the development of a technique of endoscopic islets transplantation into the gastric submucosa. In 2013 and 2014, the first human autologous transplant procedures were performed. The objective of this study was to present the results of a 3-year follow-up of these patients.

METHODS

Two pancreatectomies were performed in our department, the first in 2013 and another in 2014, along with subsequent autologous transplantation of pancreatic islets into the gastric submucosa.

RESULTS

Both patients had been diagnosed previously with diabetes, and both had endogenous islet activity detected. Peptide C concentration after pancreatectomy and before pancreatic cell transplantation was 0.1 ng/mL. After the transplantation, peptide C concentrations for the 2 patients were 0.8 and 0.5 ng/mL on day 7, 1.2 and 0.6 ng/mL on day 30, 1.3 and 0.8 ng/mL on day 180, 1.1 and 0.7 ng/mL on day 360, and 3.0 and 0.6 ng/mL at 3 years, respectively, after transplantation. The pain symptoms resolved in both cases.

CONCLUSION

Pancreatic islets may survive in the gastric wall. Endoscopic submucosal transplantation may present an alternative for the management of patients who cannot undergo a classic transplantation procedure.

Islets Allotransplantation Into Gastric Submucosa in a Patient with Portal Hypertension: 4-year Follow-up

BACKGROUND

Islets transplantation is an established treatment method for patients suffering from brittle diabetes with hypoglycemia unawareness. The standard implantation technique is through the portal vein into the liver. In case of liver diseases or portal hypertension, finding an extra-hepatic site is recommended. There have been attempts to perform islets transplantations into muscles and into the gastric submucosa.

OBJECTIVE

The aim of this study is to show a 4-year follow-up of allotransplantation into gastric submucosa in a case of portal hypertension observed during the procedure of islets infusion.

PATIENTS AND METHODS

A 36-year-old woman with complicated diabetes for over 30 years was selected to receive simultaneous islets and kidney transplantation. The patient underwent an unsuccessful simultaneous pancreas and kidney transplantation 2 years earlier in another transplantation center. The patient's daily insulin requirement was 60 IU, which corresponded to 1.15 IU/kg of body weight. The HbA1c level was 7.4%. C-peptide levels, both fasting and stimulated, were 0.01 ng/mL. On December 7, 2013, the patient received transplanted kidney and islets procured from the same donor. Only 124,000 islets equivalents (IEQ) were isolated (2400 IEQ/kg body weight). Islets were suspended in 300 mL of Ringer's solution along with albumin, antibiotics, and heparin. After infusing 100 mL of the islets suspension into the portal vein, pressure in portal vein increased from 5 mm Hg to 23 mm Hg. Despite stopping the infusion, pressure did not drop after 30 minutes. The decision was made to transplant the reminder of the islets (200 mL) into the gastric wall.

RESULTS

No complications were observed after the procedure. Serum creatinine level was 1.6 mg/dL on day 10 and 1.5 mg/dL 4 years after the transplantation. Fasting C-peptide levels were 1.7, 0.65, 0.55, 0.69, 0.68, and 0.2 ng/mL at 1, 3, 6, 12, 18, and 36 months after the transplantation, respectively. HbA1c levels were 5.2, 6.4, 4.7, 5.2, and 5.9% at 3, 6, 12, 18, and 36 months, respectively. The patient's insulin requirement dropped to 15 U/day immediately after transplantation and equaled 20 and 27 U/day at 18 and 48 months after the simultaneous islet and kidney transplantation, respectively.

CONCLUSION

Allotransplantation of islets into the gastric wall may be a safe alternative in cases of contraindications for transplantation into the portal vein.

A new technique for autogenous brachiobasilic upper arm transposition for vascular access for hemodialysis

Purpose

Conventional brachiobasilic fistula creation consists of the mobilization and preparation of the brachial part of the basilic vein along its whole length, the vein transposition on the anterior surface of the arm and anastomosis using the brachial artery. In case of late thrombosis, the reparation of such a fistula is almost impossible.

Methods

To avoid total vein clotting in the case of thrombosis we decided to prepare only a short part of the vein in our method and not to mobilize the other part of the vein. The brachiobasilic fistula with our modification was performed as a two-stage procedure in 18 patients (8 females and 10 males), aged from 37–78 yrs (60 ± 13.6 yrs).

Results

In two patients early thrombosis occurred. The reparation procedure was not performed in two patients (the first patient died due to pneumonia; the second patient did not give his permission for further intervention). In 16 patients brachiobasilic fistula creation was successful. Late thrombotic complications occurred in three patients (in the 3rd, 8th and 12th months). A new successful fistula, a few centimeters proximally to the original one, was performed in 2 patients 24hr and in 1 patient 48hr after fistula clotting. On the following day after the procedure the fistula was ready to be used. The primary, assisted primary and cumulative secondary patency rates after 12 months of follow-up were 74, 89 and 100%, respectively.

Conclusion

In comparison with standard brachiobasilic techniques our method offers the possibility of a reparation procedure in the case of late thrombosis, which could improve the long-term patency of brachiobasilic fistulas. However, a prospective controlled study is necessary to establish if this new technique is superior to the traditional surgical procedure.

Increased plasma matrix metalloproteinase-2 (MMP-2), tissue inhibitor of proteinase-1 (TIMP-1), TIMP-2, and urine MMP-2 concentrations correlate with proteinuria in renal transplant recipients

BACKGROUND

The most frequent cause of kidney allograft loss is chronic allograft injury, often with proteinuria as the clinical feature. Occurrence of proteinuria late after kidney transplantation is associated with worse graft function and patient survival.

AIM

The aim of the study was to assess plasma and urine matrix metalloproteinases (MMP-2 and MMP-9) and tissue inhibitors of metalloproteinases (TIMP-1 and TIMP-2) in proteinuric renal transplant recipients (RTRs). The factors were determined by enzyme-linked immunosorbent assay in 150 RTRs (51 women and 99 men), aged 49.2 ± 11.5 years, at mean 73.4 ± 41.2 months after kidney transplantation (range: 12 to 240 months).

RESULTS

Proteinuric RTRs compared with non-proteinuric RTRs had higher median plasma MMP-2 (P = .012), TIMP-1 (P = .0003), and TIMP-2 (P = .0021) concentrations, as well as higher urine MMP-2 (P < .0001) excretion. The presence of proteinuria had no impact on plasma MMP-9 and urine MMP-9, TIMP-1, and TIMP-2. Proteinuria and estimated daily proteinuria (uPr:uCr) correlated positively with plasma MMP-2 (rs = 0.226, P = .0054 and rs = 0.241, P = .003), TIMP-1 (rs = 0.305, P = .00015 and rs = 0.323, P = .000055), TIMP-2 (rs = 0.273, P = .0007 and rs = 0.269, P = .001) and urine MMP-2 (rs = 0.464, P < .0001 and rs = 0.487, P < .0001), respectively. Proteinuric RTRs had impaired graft function with higher median serum creatinine concentrations (1.91 [1.60-2.43] mg/dL versus 1.41 [1.20-1.65] mg/dL, P < .00001) and lower estimated glomerular filtration rate (36 [28-45] mL/min/1.73 m(2) versus 53 [43-61] mL/min/1.73 m(2), P < .00001) than RTRs without proteinuria.

CONCLUSIONS

Our research revealed that in RTRs, proteinuria was significantly associated with increased concentrations of enzymes involved in extracellular matrix (ECM) degradation: plasma MMP-2, TIMP-1, TIMP-2, and urine MMP-2. Findings strongly emphasize increased plasma TIMPs in proteinuric RTRs that inhibit degradation of ECM by MMPs and favor excessive deposition of ECM proteins.

Advanced age of renal transplant recipients correlates with increased plasma concentrations of interleukin-6, chemokine ligand 2 (CCL2), and matrix metalloproteinase 2, and urine concentrations of CCL2 and tissue inhibitor of metalloproteinase 1

BACKGROUND

Advanced age of renal transplant recipients (RTRs) has a negative impact on kidney allograft survival through impaired extracellular matrix degradation by the matrix metalloproteinases/tissue inhibitors of metalloproteinases (MMPs/TIMPs) system. Moreover, older RTRs are at risk of smoldering inflammation, known as inflammaging.

AIM

The aim of the study was to assess the impact of a RTR's age on plasma and urine concentrations of interleukin 6 (IL-6), chemokine ligand 2 (CCL2), and the MMPs/TIMPs system.

MATERIAL AND METHODS

One hundred fifty adult RTRs (8.7% ≥ 65 years) and 37 adult healthy volunteers (10.8% ≥ 65 years) were enrolled in the study. The studied factors (IL-6, CCL2, MMP-2, MMP-9, TIMP-1 and TIMP-2) were quantified in plasma and urine with enzyme-linked immunosorbent assay. The Mann-Whitney U test and Spearman's (rs) rank correlation were applied, and differences with a P < .05 were considered statistically significant.

RESULTS

There was a weak but significant positive correlation between increasing RTR's age and plasma IL-6 (rs = 0.18, P = .028), CCL2 (rs = 0.27, P = .001), and MMP-2 (rs = 0.20, P = .017), as well as urine CCL2 (rs = 0.16, P = 0.050) and TIMP-1 (rs = 0.20, P = .014) concentrations.

CONCLUSIONS

Advancing age of RTRs correlates with increasing plasma IL-6 and CCL2 concentrations, reflecting smoldering inflammation (known as inflammaging) and alterations in MMPs/TIMPs profiles, especially with increased plasma MMP-2 and urine TIMP-1 concentrations.

The NLR-related protein NWD1 is associated with prostate cancer and modulates androgen receptor signaling

Prostate cancer (PCa) is among the leading causes of cancer-related death in men. Androgen receptor (AR) signaling plays a seminal role in prostate development and homeostasis, and dysregulation of this pathway is intimately linked to prostate cancer pathogenesis and progression. Here, we identify the cytosolic NLR-related protein NWD1 as a novel modulator of AR signaling. We determined that expression of NWD1 becomes elevated during prostate cancer progression, based on analysis of primary tumor specimens. Experiments with cultured cells showed that NWD1 expression is up-regulated by the sex-determining region Y (SRY) family proteins. Gene silencing procedures, in conjunction with transcriptional profiling, showed that NWD1 is required for expression of PDEF (prostate-derived Ets factor), which is known to bind and co-regulate AR. Of note, NWD1 modulates AR protein levels. Depleting NWD1 in PCa cell lines reduces AR levels and suppresses activity of androgen-driven reporter genes. NWD1 knockdown potently suppressed growth of androgen-dependent LNCaP prostate cancer cells, thus showing its functional importance in an AR-dependent tumor cell model. Proteomic analysis suggested that NWD1 associates with various molecular chaperones commonly related to AR complexes. Altogether, these data suggest a role for tumor-associated over-expression of NWD1 in dysregulation of AR signaling in PCa.

Abstract LB-74: The NLR-related protein NWD1 is associated with prostate cancer and modulates androgen receptor signaling

Prostate cancer (PCa) is among the leading causes of cancer-related death in men. Androgen receptor (AR) signaling plays a seminal role in prostate development and homeostasis, and dysregulation of this pathway is intimately linked to prostate cancer pathogenesis and progression. Here, we identify the cytosolic NLR-related protein NWD1 as a novel modulator of AR signaling. We determined that expression of NWD1 becomes elevated during prostate cancer progression, based on analysis of primary tumor specimens. Experiments with cultured cells showed that NWD1 expression is up-regulated by the sex-determining region Y (SRY) proteins. Gene silencing by short hairpin RNA (shRNA), in conjunction with transcriptional profiling, showed that NWD1 is required for expression of PDEF (prostate-derived Ets factor), which is known to bind and co-regulate AR. Of note, NWD1 modulates AR protein levels. Silencing NWD1 in PCa cell lines reduces the levels of androgen-stimulated accumulation of nuclear AR and suppresses activity of androgen-driven reporter genes. NWD1 knockdown potently suppressed growth of androgen-dependent LNCaP prostate cancer cells, thus showing its functional importance in an AR-dependent tumor cell model. Proteomics analysis suggested that NWD1 associates with various molecular chaperones commonly related to AR complexes. Altogether, our data suggest a role for tumor-associated over-expression of NWD1 in the dysregulation of AR signaling in PCa.

Citation Format: Ricardo G. Correa, Maryla Krajewska, Carl F. Ware, Motti Gerlic, John C. Reed. The NLR-related protein NWD1 is associated with prostate cancer and modulates androgen receptor signaling. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-74. doi:10.1158/1538-7445.AM2014-LB-74

PCTAIRE1 phosphorylates p27 and regulates mitosis in cancer cells

PCTAIRE1 is distant relative of the cyclin-dependent kinase family that has been implicated in spermatogenesis and neuronal development, but it has not been studied in cancer. Here, we report that PCTAIRE1 is expressed in prostate, breast, and cervical cancer cells, where its RNAi-mediated silencing causes growth inhibition with aberrant mitosis due to defects in centrosome dynamics. PCTAIRE1 was not similarly involved in proliferation of nontransformed cells, including diploid human IMR-90 fibroblasts. Through yeast two-hybrid screening, we identified tumor suppressor p27 as a PCTAIRE1 interactor. In vitro kinase assays showed PCTAIRE1 phosphorylates p27 at Ser10. PCTAIRE1 silencing modulated Ser10 phosphorylation on p27 and led to its accumulation in cancer cells but not in nontransformed cells. In a mouse xenograft model of PPC1 prostate cancer, conditional silencing of PCTAIRE1 restored p27 protein expression and suppressed tumor growth. Mechanistic studies in HeLa cells showed that PCTAIRE1 phosphorylates p27 during the S and M phases of the cell cycle. Notably, p27 silencing was sufficient to rescue cells from mitotic arrest caused by PCTAIRE1 silencing. Clinically, PCTAIRE1 was highly expressed in primary breast and prostate tumors compared with adjacent normal epithelial tissues. Together our findings reveal an unexpected role for PCTAIRE1 in regulating p27 stability, mitosis, and tumor growth, suggesting PCTAIRE1 as a candidate cancer therapeutic target.

Skull deformations in craniosynostosis and endocrine disorders: morphological and tomographic analysis of the skull from the crypt of the Silesian Piasts in Brzeg (16th-17th century), Poland

RESULTS

of morphological and tomographic (CT) studies of the skull that was found in the crypt of the Silesian Piasts in the St. Jadwiga church in Brzeg (Silesia, Poland) are presented and discussed here. The established date of burial of probably a 20-30 years old male was 16th-17th century. The analyzed skull showed premature obliteration of the major skull sutures. It resulted in the braincase deformation, similar to the forms found in oxycephaly and microcephaly. Tomographic analysis revealed gross pathology. Signs of increased intracranial pressure, basilar invagination and hypoplasia of the occipital bone were observed. Those results suggested the occurrence of the very rare Arnold-Chiari syndrome. Lesions found in the sella turcica indicated the development of pituitary macroadenoma, which resulted in the occurrence of discreet features of acromegaly in the facial bones. The studied skull was characterized by a significantly smaller size of the neurocranium (horizontal circumference 471 mm, cranial capacity ∼ 1080 ml) and strongly expressed brachycephaly (cranial index=86.3), while its height remained within the range for non-deformed skulls. A narrow face, high eye-sockets and prognathism were also observed. Signs of alveolar process hypertrophy with rotation and displacement of the teeth were noted. The skull showed significant morphological differences compared to both normal and other pathological skulls such as those with pituitary gigantism, scaphocephaly and microcephaly.

Pathogenic role of antibodies against monomeric C-reactive protein in tubulointerstitial nephritis and uveitis syndrome

Antibodies against monomeric C-reactive protein, which is a target antigen expressed both in kidney tubules and uveal cells, have been recently detected in patients with active tubulointerstitial nephritis and uveitis syndrome. We report the case of an 65-year-old woman with acute renal failure caused by biopsy-proven tubulointerstitial nephritis and the onset of uveitis 21 months later. The expression of monomeric C-reactive protein in kidney oligobiopsy was confirmed by immunohistochemical staining using mouse monoclonal antibody against human monomeric C-reactive protein. The levels of antibodies against monomeric C-reactive protein were 117% of the reference during the flare and 22% during the remission of the disease. The difference in the levels of antibodies against monomeric C-reactive protein during flare and remission, and above all positive biopsy staining, supports their pathogenic role in this disease.

The impact of de novo donor-specific anti-human leukocyte antigen antibodies on 5-year renal transplant outcome

Numerous studies have shown that circulating donor-specific antibodies targeting human leukocyte antigen (HLA) are associated with accelerated renal transplant failure, but many patients with these antibodies have good graft function. The aim of our study was to investigate the long-term graft function and survival in patients with de novo post-transplant donor-specific anti-HLA antibodies (DSA). Our prospective study included 78 consecutive recipients with a negative crossmatch before transplantation. Recipient serum samples were assayed for DSA in week 2 and 1, 3, 6, 9, 12 months after transplantation using a complement-dependent lymphocytotoxic technique with donor lymphocytes. Additionally, patients with DSA and stable renal function in the first year were tested with a more sensitive flow-panel-reactive antibody. DSA were present in 34 (44%) of our patients during the first 12 months after transplantation. Biopsy-proved acute rejection occurred in 11 DSA-positive and 10 DSA-negative patients. Seven DSA-positive patients had antibody-mediated rejection and no DSA-negative ones developed humoral rejection. The serum creatinine level in DSA-positive patients was significantly higher (2.48 vs 1.43 mg/dL) in year 5. The 13 (38%) DSA-positive patients with good graft function in month 12 were stable during a 5-year follow-up: their serum creatinine was 1.46 ± 0.4 in year 1 and 1.56 ± 0.4 mg/dL in year 5 and nobody lost their allograft. One- and 5- year graft survivals were appropriately 85% and 59% in DSA-positive patients compared to 93% and 93% in DSA-negative patients. To sum up, post-transplant DSA had a significant influence on kidney function and graft survival but in 38% of patients the presence of DSA did not decrease a 5-year renal function. A good renal allograft function in the presence of DSA in the first year after transplantation and cessation of their production in the subsequent years may be a good prognostic marker for a long-term allograft function and survival.

Increased plasma tissue inhibitors of metalloproteinase concentrations as negative predictors associated with deterioration of kidney allograft function upon long-term observation

Chronic allograft injury (CAI) is the most frequent cause of progressive kidney allograft impairment and eventual loss, which is due to interstitial fibrosis and tubular atrophy (IF/TA). Mechanisms of CAI are not fully understood. Chemokines, cytokines, metalloproteinases (MMPs), and tissue inhibitors of metalloproteinases (TIMPs) play roles in fibrosis development. The aims of this study were to evaluate plasma and urine TIMPs (TIMP-1 and TIMP-2), MMPs (MMP-2 and MMP-9), proinflammatory interleukin-6 (IL-6), chemokine (C-C motif) ligand 2 (CCL2 chemokines previously known as monocyte chemoattractant protein-1 [MCP-1]) among 150 recipients beyond 1 year post-renal transplantations and to explore the usefulness of these potential biomarkers of ongoing allograft injury. Renal transplant recipients compared with healthy volunteers (control group) showed significantly increased plasma and urine IL-6, MMP-9, TIMP-1, and TIMP-2, as well as lower plasma MMP-2 and urine CCL2 concentrations. Compared with recipients showing good function those with impairments displayed higher plasma TIMP-1 (P < .001) and TIMP-2 (P = .003) concentrations. The recipient estimated glomerular filtration rate (eGFR) values negatively correlated with plasma TIMP-1 and TIMP-2 levels (r = -0.43; P < .0001 and rs = -0.42; P < .0001, respectively) and with urine IL-6 excretion (rs = -0.33; P < .0001). Multivariate and receiver operating characteristic (ROC) analyses showed TIMP-1 plasma level assessments to be useful estimates of allograft injury.

Circulating microRNAs (miR-423-5p, miR-208a and miR-1) in acute myocardial infarction and stable coronary heart disease

AIM

The microRNAs (miRs) are small non-coding RNAs which regulate expression of multiple genes involved in atherogenesis. MicroRNA are also present in circulation. The aims of this study were: 1) assessment of expression level of miR-1, miR-208a and miR-423-5p in plasma in patients with STEMI, stable CAD and healthy individuals; 2) evaluation of correlation between plasma miRs and left ventricle ejection fraction, end- systolic and end-diastolic diameters and troponin release in patients with STEMI.

METHODS

Study group consisted of 26 patients: 1) acute MI group (N.=17); 2) stable CAD group (N.=4); and 3) subjects with no history of CAD (control group, N.=5). Expression of miR-423-5p, miR-208 and miR-1 was measured in plasma before PCI, 6, 12 and 24 hours later. Expression level ofmiRs was measured using TaqMan® MicroRNA Assays. Expression was assessed by Pfaffl method, and miR-39 was used for normalization of the results.

RESULTS

In stable CAD in comparison to control group the expression level of miR-1, miR-208a and miR-423-5p did not show significant differences. Also there was no significant increase of number of miR copies at 6, 12 and 24 hours after PCI. There was a significantly higher number of miR-423-5p copies in patients with acute MI before the pPCI. After 6, 12 and 24 hours post-procedure the expression level was similar to the control group and significantly lower than the baseline level. Conversely, the expression level of miR-1 and miR-208a were not significantly different than in the control group. In patients with acute MI there were no significant correlations between the expression level of miRs and any of the echocardiographic parameters of LV as well as level of troponin I at any time-point of the follow-up.

CONCLUSION

Early in acute myocardial infarction the expression of miR-423-5p in plasma is significantly increased with subsequent normalization within 6 hours. Potentially it is an early marker of myocardial necrosis.

Tumour cell survival mechanisms in lethal metastatic prostate cancer differ between bone and soft tissue metastases

The complexity of survival mechanisms in cancer cells from patients remains poorly understood. To obtain a comprehensive picture of tumour cell survival in lethal prostate cancer metastases, we examined five survival proteins that operate within three survival pathways in a cohort of 185 lethal metastatic prostate metastases obtained from 44 patients. The expression levels of BCL-2, BCL-XL, MCL-1, cytoplasmic survivin, nuclear survivin, and stathmin were measured by immunohistochemistry in a tissue microarray. Simultaneous expression of three or more proteins occurred in 81% of lethal prostate cancer metastases and BCL-2, cytoplasmic survivin and MCL-1 were co-expressed in 71% of metastatic sites. An unsupervised cluster analysis separated bone and soft tissue metastases according to patterns of survival protein expression. BCL-2, cytoplasmic survivin and MCL-1 had significantly higher expression in bone metastases (p < 10(-5)), while nuclear survivin was significantly higher in soft tissue metastases (p = 3 × 10(-14)). BCL-XL overexpression in soft tissue metastases almost reached significance (p = 0.09), while stathmin expression did not (p = 0.28). In addition, the expression of MCL-1 was significantly higher in AR-positive tumours. Neuroendocrine differentiation was not associated with specific survival pathways. These studies show that bone and soft tissue metastases from the same patient differ significantly in expression of a panel of survival proteins and that with regard to survival protein expression, expression is associated with the metastatic site and not the patient. Altogether, this suggests that optimal therapeutic inhibition may require combinations of drugs that target both bone and soft tissue-specific survival pathways.

Vaccinia virus F1L protein promotes virulence by inhibiting inflammasome activation

Host innate immune responses to DNA viruses involve members of the nucleotide-binding domain, leucine-rich repeat and pyrin domain containing protein (NLRP) family, which form "inflammasomes" that activate caspase-1, resulting in proteolytic activation of cytokines interleukin (IL)-1β and IL-18. We hypothesized that DNA viruses would target inflammasomes to overcome host defense. A Vaccinia virus (VACV) B-cell CLL/lymphoma 2 (Bcl-2) homolog, F1L, was demonstrated to bind and inhibit the NLR family member NLRP1 in vitro. Moreover, infection of macrophages in culture with virus lacking F1L (ΔF1L) caused increased caspase-1 activation and IL-1β secretion compared with wild-type virus. Virulence of ΔF1L virus was attenuated in vivo, causing altered febrile responses, increased proteolytic processing of caspase-1, and more rapid inflammation in lungs of infected mice without affecting cell death or virus replication. Furthermore, we found that a hexapeptide from F1L is necessary and sufficient for inhibiting the NLRP1 inflammasome in vitro, thus identifying a peptidyl motif required for binding and inhibiting NLRP1. The functional importance of this NLRP1-binding motif was further confirmed by studies of recombinant ΔF1L viruses reconstituted either with the wild-type F1L or a F1L mutant that fails to bind NLRP1. Cellular infection with wild-type F1L reconstituted virus-suppressed IL-1β production, whereas mutant F1L did not. In contrast, both wild-type and mutant versions of F1L equally suppressed apoptosis. In vivo, the NLR nonbinding F1L mutant virus exhibited an attenuated phenotype similar to ΔF1L virus, thus confirming the importance of F1L interactions with NLRP1 for viral pathogenicity in mice. Altogether, these findings reveal a unique viral mechanism for evading host innate immune responses.

A Pan-BCL2 inhibitor renders bone-marrow-resident human leukemia stem cells sensitive to tyrosine kinase inhibition

Leukemia stem cells (LSCs) play a pivotal role in the resistance of chronic myeloid leukemia (CML) to tyrosine kinase inhibitors (TKIs) and its progression to blast crisis (BC), in part, through the alternative splicing of self-renewal and survival genes. To elucidate splice-isoform regulators of human BC LSC maintenance, we performed whole-transcriptome RNA sequencing, splice-isoform-specific quantitative RT-PCR (qRT-PCR), nanoproteomics, stromal coculture, and BC LSC xenotransplantation analyses. Cumulatively, these studies show that the alternative splicing of multiple prosurvival BCL2 family genes promotes malignant transformation of myeloid progenitors into BC LSCS that are quiescent in the marrow niche and that contribute to therapeutic resistance. Notably, sabutoclax, a pan-BCL2 inhibitor, renders marrow-niche-resident BC LSCs sensitive to TKIs at doses that spare normal progenitors. These findings underscore the importance of alternative BCL2 family splice-isoform expression in BC LSC maintenance and suggest that the combinatorial inhibition of prosurvival BCL2 family proteins and BCR-ABL may eliminate dormant LSCs and obviate resistance.

Endoplasmic reticulum protein BI-1 regulates Ca²⁺-mediated bioenergetics to promote autophagy

Autophagy is a lysosomal degradation pathway that converts macromolecules into substrates for energy production during nutrient-scarce conditions such as those encountered in tumor microenvironments. Constitutive mitochondrial uptake of endoplasmic reticulum (ER) Ca²⁺ mediated by inositol triphosphate receptors (IP₃Rs) maintains cellular bioenergetics, thus suppressing autophagy. We show that the ER membrane protein Bax inhibitor-1 (BI-1) promotes autophagy in an IP₃R-dependent manner. By reducing steady-state levels of ER Ca²⁺ via IP₃Rs, BI-1 influences mitochondrial bioenergetics, reducing oxygen consumption, impacting cellular ATP levels, and stimulating autophagy. Furthermore, BI-1-deficient mice show reduced basal autophagy, and experimentally reducing BI-1 expression impairs tumor xenograft growth in vivo. BI-1's ability to promote autophagy could be dissociated from its known function as a modulator of IRE1 signaling in the context of ER stress. The results reveal BI-1 as a novel autophagy regulator that bridges Ca²⁺ signaling between ER and mitochondria, reducing cellular oxygen consumption and contributing to cellular resilience in the face of metabolic stress.

Anti-apoptotic BFL-1 is the major effector in activation-induced human mast cell survival

Mast cells are best known for their role in allergic reactions, where aggregation of FcεRI leads to the release of mast cell mediators causing allergic symptoms. The activation also induces a survival program in the cells, i.e., activation-induced mast cell survival. The aim of the present study was to investigate how the activation-induced survival is mediated. Cord blood-derived mast cells and the mast cell line LAD-2 were activated through FcεRI crosslinking, with or without addition of chemicals that inhibit the activity or expression of selected Bcl-2 family members (ABT-737; roscovitine). Cell viability was assessed using staining and flow cytometry. The expression and function of Bcl-2 family members BFL-1 and MCL-1 were investigated using real-time quantitative PCR and siRNA treatment. The mast cell expression of Bfl-1 was investigated in skin biopsies. FcεRI crosslinking promotes activation-induced survival of human mast cells and this is associated with an upregulation of the anti-apoptotic Bcl-2 family member Bfl-1. ABT-737 alone or in combination with roscovitine decreases viability of human mast cells although activation-induced survival is sustained, indicating a minor role for Bcl-X(L), Bcl-2, Bcl-w and Mcl-1. Reducing BFL-1 but not MCL-1 levels by siRNA inhibited activation-induced mast cell survival. We also demonstrate that mast cell expression of Bfl-1 is elevated in birch-pollen-provocated skin and in lesions of atopic dermatitis and psoriasis patients. Taken together, our results highlight Bfl-1 as a major effector in activation-induced human mast cell survival.

Neuronal deletion of caspase 8 protects against brain injury in mouse models of controlled cortical impact and kainic acid-induced excitotoxicity

Background

Acute brain injury is an important health problem. Given the critical position of caspase 8 at the crossroads of cell death pathways, we generated a new viable mouse line (Ncasp8^−/−), in which the gene encoding caspase 8 was selectively deleted in neurons by cre-lox system.

Methodology/Principal Findings

Caspase 8 deletion reduced rates of neuronal cell death in primary neuronal cultures and in whole brain organotypic coronal slice cultures prepared from 4 and 8 month old mice and cultivated up to 14 days in vitro. Treatments of cultures with recombinant murine TNFα (100 ng/ml) or TRAIL (250 ng/mL) plus cyclohexamide significantly protected neurons against cell death induced by these apoptosis-inducing ligands. A protective role of caspase 8 deletion in vivo was also demonstrated using a controlled cortical impact (CCI) model of traumatic brain injury (TBI) and seizure-induced brain injury caused by kainic acid (KA). Morphometric analyses were performed using digital imaging in conjunction with image analysis algorithms. By employing virtual images of hundreds of brain sections, we were able to perform quantitative morphometry of histological and immunohistochemical staining data in an unbiased manner. In the TBI model, homozygous deletion of caspase 8 resulted in reduced lesion volumes, improved post-injury motor performance, superior learning and memory retention, decreased apoptosis, diminished proteolytic processing of caspases and caspase substrates, and less neuronal degeneration, compared to wild type, homozygous cre, and caspase 8-floxed control mice. In the KA model, Ncasp8^−/− mice demonstrated superior survival, reduced seizure severity, less apoptosis, and reduced caspase 3 processing. Uninjured aged knockout mice showed improved learning and memory, implicating a possible role for caspase 8 in cognitive decline with aging.

Conclusions

Neuron-specific deletion of caspase 8 reduces brain damage and improves post-traumatic functional outcomes, suggesting an important role for this caspase in pathophysiology of acute brain trauma.