Early Kidney Transplantation or Conversion to Peritoneal Dialysis after First-Time Arteriovenous Access Creation.

OBJECTIVES: After autogenous arteriovenous (AV) access creation for end-stage renal disease, a majority of patients will continue on hemodialysis (HD), a minority will receive definitive treatment with kidney transplantation, and a subset of patients will convert to peritoneal dialysis (PD). Our goal was to identify patient factors associated with early transition from HD to either kidney transplantation or PD. METHODS: This is a case-control study of all patients with first-time AV access creation in the Vascular Quality Initiative (2011-2022) who had long-term follow-up. Patients who remained on HD after AV access creation were the control group while patients who received early kidney transplant or who converted to PD were the two case groups. Relationship among demographics, comorbidities, neighborhood social disadvantage, and functional status as they relate to renal replacement therapy modality was assessed. RESULTS: There were 19,782 patients included; the average age was 62±15 years and 57% were male. During the follow-up period of a median 306 (71-403) days, 1.3% underwent a kidney transplantation and 2.3% underwent conversion to PD. On univariable analysis, rates of kidney transplantation or conversion to PD varied with race (P<.001), insurance status (P<.001), Area Deprivation Index (ADI) quintile (P<.001), and several medical comorbidities. On multivariable analysis, impaired ambulation, current smoking, Medicaid or Medicare insurance, Black race, heart failure, body mass index, and older age were associated with decreased transplantation rates. Conversion to PD was associated with ADI Q5, Q4, and Q3. Decreased conversion to PD was associated with impaired ambulation, Hispanic ethnicity, Black race, former smoking, medication-controlled diabetes, and older age. CONCLUSION: Decreased kidney transplantation was associated with Black race and non-commercial health insurance but not ADI quintile, suggesting disparities exist beyond community-level access to care. Early kidney transplantation conveyed a 3-year survival benefit compared to HD and PD, which had similar survival. Further work is required to increase access to kidney transplantation and PD.

Alleviating iatrogenic effects of paclitaxel via antiinflammatory treatment.

BACKGROUND: Paclitaxel (PTX) is touted as an essential medicine due to its extensive use as a chemotherapeutic agent for various cancers and an antiproliferative agent for endovascular applications. Emerging studies in cardio-oncology implicate various vascular complications of chemotherapeutic agents. METHODS: We evaluated the inflammatory response induced by the systemic administration of PTX. The investigation included RNAseq analysis of primary human endothelial cells (ECs) treated with PTX to identify transcriptional changes in pro-inflammatory mediators. Additionally, we used dexamethasone (DEX), a well-known antiinflammatory compound, to assess its effectiveness in counteracting these PTX-induced changes. Further, we studied the effects of PTX on monocyte chemoattractant protein-1 (MCP-1) levels in the media of ECs. The study also extended to in vivo analysis, where a group of mice was injected with PTX and subsequently harvested at different times to assess the immediate and delayed effects of PTX on inflammatory mediators in blood and aortic ECs. RESULTS: Our RNAseq analysis revealed that PTX treatment led to significant transcriptional perturbations in pro-inflammatory mediators such as MCP-1 and CD137 within primary human ECs. These changes were effectively abrogated when DEX was administered. In vitro experiments showed a marked increase in MCP-1 levels in EC media following PTX treatment, which returned to baseline upon treatment with DEX. In vivo, we observed a threefold increase in MCP-1 levels in blood and aortic ECs 12 h post-PTX administration. Similar trends were noted for CD137 and other downstream mediators like tissue factor, vascular cell adhesion molecule 1, and E-selectin in aortic ECs. CONCLUSION: Our findings illustrate that PTX exposure induces an upregulation of atherothrombotic mediators, which can be alleviated with concurrent administration of DEX. Considering these observations, further long-term investigations should focus on understanding the systemic implications associated with PTX-based therapies and explore the clinical relevance of DEX in mitigating such risks.

Characterization of long-term survival in Medicare patients undergoing arteriovenous hemodialysis access.

BACKGROUND: Patients undergoing arteriovenous (AV) access creation for hemodialysis often have significant comorbidities. Our goal was to quantify the long-term survival and associated risks factors for long-term mortality in these patients to aid in optimization of goals and expectations. METHODS: The Vascular Implant Surveillance and Interventional Outcomes Network Vascular Quality Initiative Medicare linked data was used to assess long-term survival in the HD registry. Demographics, comorbidities, and interventions were recorded. Because the majority of hemodialysis patients are provided Medicare, Medicare linkage was used to obtain survival data. Multivariable analysis was used to identify independent associations with mortality. RESULTS: There were 13,945 AV access patients analyzed including 10,872 (78%) AV fistulas and 3073 (22%) AV grafts. The median age was 67 years and 56% of patients were male. Approximately one-third had a prior AV access and 44.7% had prior tunneled dialysis catheters. Patients receiving an AV fistula, compared with AV grafts, were more often younger, male, White, obese, independently ambulatory, preoperatively living at home, and less often have a prior AV access and tunneled dialysis catheters (P < .05 for all). The 5-year mortality overall was 62.9% with 61.2% for AV fistulas and 68.8% for AV grafts (P < .001). On multivariable analysis for 5 year mortality, nonambulatory status (hazard ratio [HR], 1.67; 95% confidence interval [CI], 1.53-1.83; P < .001), lower extremity access (HR, 1.67; 95% CI, 1.35-2.05; P < .001), human immunodeficiency virus or acquired immunodeficiency syndrome (HR, 1.44; 95% CI, 1.13-1.82; P < .001), White race (HR, 1.43; 95% CI, 1.35-1.51; P < .001), congestive heart failure (HR, 1.33; 95% CI, 1.26-1.41; P < .001), chronic obstructive pulmonary disease (HR, 1.23; 95% CI, 1.15-1.31; P < .001), and AV graft placement (HR, 1.12; 95% CI, 1.02-1.23, P = .016) were most associated with poor survival. Factors associated with improved survival were never smoking (HR, .73; 95% CI, 0.67-0.79; P < .001), prior/quit smoking (HR, .78; 95% CI, 0.72-0.84; P < .001), preoperative home living (HR, .75; 95% CI, 0.68-0.83; P < .001), and hypertension (HR, .89; 95% CI, 0.8-0.99; P = .03). CONCLUSIONS: Long-term survival in Medicare patients undergoing AV access creation is poor with nearly two-thirds of patients having died at 5 years. There are many modifiable risk factors that may improve survival in these patients and give an opportunity for transplantation.

Venous Thrombosis Assay in a Mouse Model of Cancer.

This methodology paper highlights the surgical nuances of a rodent model of venous thrombosis, specifically in the context of cancer-associated thrombosis (CAT). Deep venous thrombosis is a common complication in cancer survivors and can be potentially fatal. The current murine venous thrombosis models typically involve a complete or partial mechanical occlusion of the inferior vena cava (IVC) using a suture. This procedure induces a total or partial stasis of blood and endothelial damage, triggering thrombogenesis. The current models have limitations such as higher variability in clot weights, significant mortality rate, and prolonged learning curve. This report introduces surgical refinements using vascular clips to address some of these limitations. Using a syngeneic colon cancer xenograft mouse model, we employed customized vascular clips to ligate the infrarenal vena cava. These clips allow residual lip space similar to a 5-0 polypropylene suture after IVC ligations. Mice with the suture method served as controls. The vascular clip method resulted in a consistent reproducible partial vascular occlusion and greater clot weights with less variability than the suture method. The larger clot weights, greater clot mass, and clot to the IVC luminal surface area were expected due to the higher pressure profile of the vascular clips compared to a 6-0 polypropylene suture. The approach was validated by gray scale ultrasonography, which revealed consistently greater clot mass in the infrarenal vena cava with vascular clips compared to the suture method. These observations were further substantiated with the immunofluorescence staining. This study offers an improved method to generate a venous thrombosis model in mice, which can be employed to deepen the mechanistic understanding of CAT and in translational research such as drug discovery.

Recent evaluation by nephrologists is associated with decreased incidence of tunneled dialysis catheter being used at the time of first arteriovenous access creation.

OBJECTIVE: Late primary care provider (PCP) or nephrologist evaluation of patients with progressive kidney disease may be associated with increased morbidity and mortality. Among patients undergoing initial arteriovenous (AV) access creation, we aimed to study the relationship of recent PCP and nephrologist evaluations with perioperative morbidity and mortality. METHODS: We performed a retrospective review of patients from 2014 to 2022 who underwent initial AV access creation at an urban, safety-net hospital. Univariable and multivariable analyses identified associations of PCP and nephrologist evaluations <1 year and <3 months before surgery, respectively, with hemodialysis initiation via tunneled dialysis catheters (TDCs), 90-day readmission, and 90-day mortality. RESULTS: Among 558 patients receiving initial AV access, mean age was 59.7 ± 14 years, 59% were female gender, and 60.6% were Black race. Recent PCP and nephrology evaluations occurred in 386 (69%) and 362 (65%) patients, respectively. On multivariable analysis, unemployed and uninsured statuses were associated with decreased likelihood of PCP evaluation (unemployment: odds ratio [OR], 0.51; 95% confidence interval [CI], 0.34-0.77; uninsured status: OR, 0.05; 95% CI, 0.01-0.45) and nephrologist evaluation (unemployment: OR, 0.63; 95% CI, 0.43-0.91; uninsured status: OR, 0.22; 95% CI, 0.06-0.83) (all P < .05). Social support was associated with increased likelihood of PCP evaluation (OR, 1.81; 95% CI, 1.07-3.08) (all P < .05). Hemodialysis was initiated with TDCs in 304 patients (55%). Older age (OR, 0.98; 95% CI, 0.96-0.99), obesity (OR, 0.38; 95% CI, 0.25-0.58), and nephrologist evaluation (OR, 0.12; 95% CI, 0.08-0.19) were independently associated with decreased hemodialysis initiation with TDCs in patients receiving an initial AV access (all P < .05). Ninety-day readmission occurred in 270 cases (48%). Cirrhosis (OR, 2.5; 95% CI, 1.03-6.03; P = .04), coronary artery disease (OR, 2.31; 95% CI, 1.5-3.57), prosthetic AV access (OR, 1.84; 95% CI, 1.04-3.26), and impaired ambulation (OR, 1.75; 95% CI, 1.15-2.66) were independently associated with increased readmission (all P < .05). Older age (OR, 0.98; 95% CI, 0.97-0.99), prior TDC (OR, 0.65; 95% CI, 0.45-0.94), and unemployment (OR, 0.58; 95% CI, 0.39-0.86) were associated with decreased readmission (all P < .05). Ninety-day mortality occurred in 1.6% of patients. Neither PCP nor nephrologist evaluation was associated with readmission or mortality. CONCLUSIONS: Recent nephrology evaluation was associated with reduced hemodialysis initiation with TDCs among patients undergoing initial AV access creation. Unemployed and uninsured statuses posed barriers to accessing nephrology care.

High Prevalence of Adverse Social Determinants of Health in Dialysis Access Creation Patients in a Safety-Net Setting.

BACKGROUND: Patients receiving dialysis access surgery are often exposed to adverse social determinants of health (SDH) that negatively impact their care. Our goal was to characterize these factors experienced by our arteriovenous dialysis access patients and identify differences in health outcomes based on their SDH. METHODS: We performed a retrospective cohort study of all patients who underwent dialysis access creation (2017-2021) and were screened for SDH at a clinical visit (using THRIVE survey) implemented at an urban, safety-net hospital institution within 1 year of access creation. Demographics, procedural details, early postoperative outcomes, survey responses, and referral to our hospital's preventive food pantry were recorded. Univariable analysis and multivariable analyses were performed to assess for associations with key health outcomes. RESULTS: There were 190 patients who responded to the survey within 1 year of their operation. At least 1 adverse SDH was identified in 42 (22%) patients. Normalized to number of respondents for each question, adverse SDH identified were difficulty obtaining transportation to medical appointments (18%), food insecurity (16%), difficulty affording utilities (13%), difficulty affording medication (12%), unemployed and seeking employment (9%), unstable housing (7%), difficulty caring for family/friends (6%), and desiring more education (5%). There were 71 (37%) patients who received food pantry referrals. Mean age was 60 years and 38% of patients were female and 64% were Black. More than half of patients (57%) had a tunneled dialysis catheter (TDC) at the time of access creation. Dialysis accesses created were brachiocephalic (39%), brachiobasilic (25%), radiocephalic fistulas (16%), and arteriovenous grafts (14%). Thirty-day emergency department (ED) visits, 30-day readmissions, and 90-day mortality occurred in 23%, 21%, and 2%, respectively. On univariable and multivariable analyses, any adverse SDH determined on survey and food pantry referral were not associated with preoperative dialysis through TDCs, receiving nonautogenous dialysis access, 30-day ED visits and readmissions, or 90-day mortality. CONCLUSION: Nearly a quarter of dialysis access surgery patients at a safety-net hospital experienced adverse SDH and more than one-third received a food pantry referral. Most common difficulties experienced include difficulty obtaining transportation to medical appointments, food insecurity, and difficulty paying for utilities and medication. Although there were no differences in postoperative outcomes, the high prevalence of these adverse SDH warrants prioritization of resources in this population to ensure healthy equity and further investigation into their effects on health outcomes.

Pharmacologic Manipulation of Late SV40 Factor Suppresses Wnt Signaling and Inhibits Growth of Allogeneic and Syngeneic Colon Cancer Xenografts.

Aberrant hyperactivation of Wnt signaling, driven by nuclear ß-catenin in the colonic epithelium, represents the seminal event in the initiation and progression of colorectal cancer (CRC). Despite its established role in CRC tumorigenesis, clinical translation of Wnt inhibitors remains unsuccessful. Late SV40 factor (LSF; encoded by TFCP2) is a transcription factor and a potent oncogene. The current study identified a chemotype, named factor quinolinone inhibitors (FQIs), that specifically inhibits LSF DNA-binding, partner protein-binding, and transactivation activities. The role of LSF and FQIs in CRC tumor growth was examined. Herein, the study showed that LSF and ß-catenin interacted in several CRC cell lines irrespective of their mutational profile, which was disrupted by FQI2-34. FQI2-34 suppressed Wnt activity in CRC cells in a dose-dependent manner. Leveraging both allogeneic and syngeneic xenograft models showed that FQI2-34 suppressed CRC tumor growth, significantly reduced nuclear ß-catenin, and down-regulated Wnt targets such as axis inhibition protein 2 (AXIN-2) and SRY-box transcription factor 9, in the xenograft cells. FQI2-34 suppressed the proliferation of xenograft cells. Adenocarcinomas from a series of stage IV CRC patients revealed a positive correlation between LSF expression and Wnt targets (AXIN-2 and SRY-box transcription factor 9) within the CRC cells. Collectively, this study uncovers the Wnt inhibitory and CRC growth-suppressive effects of these LSF inhibitors in CRC cells, revealing a novel target in CRC therapeutics.

Indoleamine 2,3-dioxygenase-1, a Novel Therapeutic Target for Post-Vascular Injury Thrombosis in CKD.

BACKGROUND: CKD, characterized by retained uremic solutes, is a strong and independent risk factor for thrombosis after vascular procedures . Urem ic solutes such as indoxyl sulfate (IS) and kynurenine (Kyn) mediate prothrombotic effect through tissue factor (TF). IS and Kyn biogenesis depends on multiple enzymes, with therapeutic implications unexplored. We examined the role of indoleamine 2,3-dioxygenase-1 (IDO-1), a rate-limiting enzyme of kynurenine biogenesis, in CKD-associated thrombosis after vascular injury. METHODS: IDO-1 expression in mice and human vessels was examined. IDO-1-/- mice, IDO-1 inhibitors, an adenine-induced CKD, and carotid artery injury models were used. RESULTS: Both global IDO-1-/- CKD mice and IDO-1 inhibitor in wild-type CKD mice showed reduced blood Kyn levels, TF expression in their arteries, and thrombogenicity compared with respective controls. Several advanced IDO-1 inhibitors downregulated TF expression in primary human aortic vascular smooth muscle cells specifically in response to uremic serum. Further mechanistic probing of arteries from an IS-specific mouse model, and CKD mice, showed upregulation of IDO-1 protein, which was due to inhibition of its polyubiquitination and degradation by IS in vascular smooth muscle cells. In two cohorts of patients with advanced CKD, blood IDO-1 activity was significantly higher in sera of study participants who subsequently developed thrombosis after endovascular interventions or vascular surgery. CONCLUSION: Leveraging genetic and pharmacologic manipulation in experimental models and data from human studies implicate IS as an inducer of IDO-1 and a perpetuator of the thrombotic milieu and supports IDO-1 as an antithrombotic target in CKD.

Deep-Learning-Driven Quantification of Interstitial Fibrosis in Digitized Kidney Biopsies.

Interstitial fibrosis and tubular atrophy (IFTA) on a renal biopsy are strong indicators of disease chronicity and prognosis. Techniques that are typically used for IFTA grading remain manual, leading to variability among pathologists. Accurate IFTA estimation using computational techniques can reduce this variability and provide quantitative assessment. Using trichrome-stained whole-slide images (WSIs) processed from human renal biopsies, we developed a deep-learning framework that captured finer pathologic structures at high resolution and overall context at the WSI level to predict IFTA grade. WSIs (n = 67) were obtained from The Ohio State University Wexner Medical Center. Five nephropathologists independently reviewed them and provided fibrosis scores that were converted to IFTA grades: ≤10% (none or minimal), 11% to 25% (mild), 26% to 50% (moderate), and >50% (severe). The model was developed by associating the WSIs with the IFTA grade determined by majority voting (reference estimate). Model performance was evaluated on WSIs (n = 28) obtained from the Kidney Precision Medicine Project. There was good agreement on the IFTA grading between the pathologists and the reference estimate (κ = 0.622 ± 0.071). The accuracy of the deep-learning model was 71.8% ± 5.3% on The Ohio State University Wexner Medical Center and 65.0% ± 4.2% on Kidney Precision Medicine Project data sets. Our approach to analyzing microscopic- and WSI-level changes in renal biopsies attempts to mimic the pathologist and provides a regional and contextual estimation of IFTA. Such methods can assist clinicopathologic diagnosis.

Transmembrane and Immunoglobulin Domain Containing 1, a Putative Tumor Suppressor, Induces G2/M Cell Cycle Checkpoint Arrest in Colon Cancer Cells.

Colorectal cancer (CRC) is a leading nonfamilial cause of cancer mortality among men and women. Although various genetic and epigenetic mechanisms have been identified, the full molecular mechanisms deriving CRC tumorigenesis are not fully understood. This study demonstrates that cell adhesion molecule transmembrane and immunoglobulin domain containing 1 (TMIGD1) are highly expressed in mouse and human normal intestinal epithelial cells. TMIGD1 knockout mice were developed, and the loss of TMIGD1 in mice was shown to result in the development of adenomas in small intestine and colon. In addition, the loss of TMIGD1 significantly impaired intestinal epithelium brush border membrane, junctional polarity, and maturation. Mechanistically, TMIGD1 inhibits tumor cell proliferation and cell migration, arrests cell cycle at the G2/M phase, and induces expression of p21CIP1 (cyclin-dependent kinase inhibitor 1), and p27KIP1 (cyclin-dependent kinase inhibitor 1B) expression, key cell cycle inhibitor proteins involved in the regulation of the cell cycle. Moreover, TMIGD1 is shown to be progressively down-regulated in sporadic human CRC, and its downregulation correlates with poor overall survival. The findings herein identify TMIGD1 as a novel tumor suppressor gene and provide new insights into the pathogenesis of colorectal cancer and a novel potential therapeutic target.

Advances in BK Virus Complications in Organ Transplantation and Beyond.

Reactivation of BK virus (BKV) remains a dreaded complication in immunosuppressed states. Conventionally, BKV is known as a cause for BKV-associated nephropathy and allograft dysfunction in kidney transplant recipients. However, emerging studies have shown its negative impact on native kidney function and patient survival in other transplants and its potential role in diseases such as cancer. Because BKV-associated nephropathy is driven by immunosuppression, reduction in the latter is a convenient standard of care. However, this strategy is risk prone due to the development of donor-specific antibodies affecting long-term allograft survival. Despite its pathogenic role, there is a distinct lack of effective anti-BKV therapeutics. This limitation combined with increased morbidity and health care cost of BKV-associated diseases add to the complexity of BKV management. While summarizing recent advances in the pathogenesis of BKV-associated nephropathy and its reactivation in other organ transplants, this review illustrates the limitations of current and emerging therapeutic options and provides a compelling argument for an effective targeted anti-BKV drug.

Platelet Dysfunction and Thrombosis in JAK2V617F-Mutated Primary Myelofibrotic Mice.

OBJECTIVE: The risk of thrombosis in myeloproliferative neoplasms, such as primary myelofibrosis varies depending on the type of key driving mutation (JAK2 [janus kinase 2], CALR [calreticulin], and MPL [myeloproliferative leukemia protein or thrombopoietin receptor]) and the accompanying mutations in other genes. In the current study, we sought to examine the propensity for thrombosis, as well as platelet activation properties in a mouse model of primary myelofibrosis induced by JAK2V617F (janus kinase 2 with valine to phenylalanine substitution on codon 617) mutation. Approach and Results: Vav1-hJAK2V617F transgenic mice show hallmarks of primary myelofibrosis, including significant megakaryocytosis and bone marrow fibrosis, with a moderate increase in red blood cells and platelet number. This mouse model was used to study responses to 2 models of vascular injury and to investigate platelet properties. Platelets derived from the mutated mice have reduced aggregation in response to collagen, reduced thrombus formation and thrombus size, as demonstrated using laser-induced or FeCl3-induced vascular injury models, and increased bleeding time. Strikingly, the mutated platelets had a significantly reduced number of dense granules, which could explain impaired ADP secretion upon platelet activation, and a diminished second wave of activation. CONCLUSIONS: Together, our study highlights for the first time the influence of a hyperactive JAK2 on platelet activation-induced ADP secretion and dense granule homeostasis, with consequent effects on platelet activation properties.

Haploinsufficiency of Casitas B-Lineage Lymphoma Augments the Progression of Colon Cancer in the Background of Adenomatous Polyposis Coli Inactivation.

Casitas B-lineage lymphoma (c-Cbl) is a recently identified ubiquitin ligase of nuclear ß-catenin and a suppressor of colorectal cancer (CRC) growth in cell culture and mouse tumor xenografts. We hypothesized that reduction in c-Cbl in colonic epithelium is likely to increase the levels of nuclear ß-catenin in the intestinal crypt, augmenting CRC tumorigenesis in an adenomatous polyposis coli (APCΔ14/+) mouse model. Haploinsufficient c-Cbl mice (APCΔ14/+ c-Cbl+/-) displayed a significant (threefold) increase in atypical hyperplasia and adenocarcinomas in the small and large intestines; however, no differences were noted in the adenoma frequency. In contrast to the APCΔ14/+ c-Cbl+/+ mice, APCΔ14/+ c-Cbl+/- crypts showed nuclear ß-catenin throughout the length of the crypts and up-regulation of Axin2, a canonical Wnt target gene, and SRY-box transcription factor 9, a marker of intestinal stem cells. In contrast, haploinsufficiency of c-Cbl+/- alone was insufficient to induce tumorigenesis regardless of an increase in the number of intestinal epithelial cells with nuclear ß-catenin and SRY-box transcription factor 9 in APC+/+ c-Cbl+/- mice. This study demonstrates that haploinsufficiency of c-Cbl results in Wnt hyperactivation in intestinal crypts and accelerates CRC progression to adenocarcinoma in the milieu of APCΔ14/+, a phenomenon not found with wild-type APC. While emphasizing the role of APC as a gatekeeper in CRC, this study also demonstrates that combined partial loss of c-Cbl and inactivation of APC significantly contribute to CRC tumorigenesis.

Black Patients Experience Highest Rates of Cancer-associated Venous Thromboembolism.

PURPOSE: Cancer patients are at a higher risk of venous thromboembolism (VTE) than the general population. In the general population, blacks are at a higher risk of VTE compared with whites. The influence of race on cancer-associated VTE remains unexplored. We examined whether black cancer patients are at a higher risk of VTE and whether these differences are present in specific cancer types. DESIGN: A retrospective study was performed in the largest safety net hospital of New England using a cohort of cancer patients characterized by a substantial number of nonwhites. RESULTS: We identified 16,498 subjects with solid organ and hematologic malignancies from 2004 to 2018. Among them, we found 186 unique incident VTE events, of which the majority of the events accrued within the first 2 years of cancer diagnosis. Overall, blacks showed a 3-fold higher incidence of VTE (1.8%) compared with whites (0.6%; P<0.001). This difference was observed in certain cancer types such as lung, gastric and colorectal. In lung cancer, the odds of developing VTE in blacks was 2.77-times greater than those in white patients (confidence interval, 1.33-5.91; P=0.007). Despite the greater incidence of cancer-associated VTE in blacks, their Khorana risk score of VTE was not higher. CONCLUSIONS: In a diverse cancer cohort, we observed a higher incidence of cancer-associated VTE in blacks compared with patients from other races. This study indicates the consideration of race in the risk assessment of cancer-associated VTE. It could also lead to future mechanistic studies aiming at identifying reasons for differential VTE risk depending on cancer type.

Metabolites in a mouse cancer model enhance venous thrombogenicity through the aryl hydrocarbon receptor-tissue factor axis.

Patients with malignancy are at 4- to 7-fold higher risk of venous thromboembolism (VTE), a potentially fatal, yet preventable complication. Although general mechanisms of thrombosis are enhanced in these patients, malignancy-specific triggers and their therapeutic implication remain poorly understood. Here we examined a colon cancer-specific VTE model and probed a set of metabolites with prothrombotic propensity in the inferior vena cava (IVC) ligation model. Athymic mice injected with human colon adenocarcinoma cells exhibited significantly higher IVC clot weights, a biological readout of venous thrombogenicity, compared with the control mice. Targeted metabolomics analysis of plasma of mice revealed an increase in the blood levels of kynurenine and indoxyl sulfate (tryptophan metabolites) in xenograft-bearing mice, which correlated positively with the increase in the IVC clot size. These metabolites are ligands of aryl hydrocarbon receptor (AHR) signaling. Accordingly, plasma from the xenograft-bearing mice activated the AHR pathway and augmented tissue factor (TF) and plasminogen activator inhibitor 1 (PAI-1) levels in venous endothelial cells in an AHR-dependent manner. Consistent with these findings, the endothelium from the IVC of xenograft-bearing animals revealed nuclear AHR and upregulated TF and PAI-1 expression, telltale signs of an activated AHR-TF/PAI-1 axis. Importantly, pharmacological inhibition of AHR activity suppressed TF and PAI-1 expression in endothelial cells of the IVC and reduced clot weights in both kynurenine-injected and xenograft-bearing mice. Together, these data show dysregulated tryptophan metabolites in a mouse cancer model, and they reveal a novel link between these metabolites and the control of the AHR-TF/PAI-1 axis and VTE in cancer.

c-Cbl targets PD-1 in immune cells for proteasomal degradation and modulates colorectal tumor growth.

Casitas B lymphoma (c-Cbl) is an E3 ubiquitin ligase and a negative regulator of colorectal cancer (CRC). Despite its high expression in immune cells, the effect of c-Cbl on the tumor microenvironment remains poorly understood. Here we demonstrate that c-Cbl alters the tumor microenvironment and suppresses Programmed cell death-1 (PD-1) protein, an immune checkpoint receptor. Using syngeneic CRC xenografts, we observed significantly higher growth of xenografts and infiltrating immune cells in c-Cbl+/- compared to c-Cbl+/+ mice. Tumor-associated CD8+ T-lymphocytes and macrophages of c-Cbl+/- mice showed 2-3-fold higher levels of PD-1. Functionally, macrophages from c-Cbl+/- mice showed a 4-5-fold reduction in tumor phagocytosis, which was restored with an anti-PD-1 neutralizing antibody suggesting regulation of PD-1 by c-Cbl. Further mechanistic probing revealed that C-terminus of c-Cbl interacted with the cytoplasmic tail of PD-1. c-Cbl destabilized PD-1 through ubiquitination- proteasomal degradation depending on c-Cbl's RING finger function. This data demonstrates c-Cbl as an E3 ligase of PD-1 and a regulator of tumor microenvironment, both of which were unrecognized components of its tumor suppressive activity. Advancing immune checkpoint and c-Cbl biology, our study prompts for probing of PD-1 regulation by c-Cbl in conditions driven by immune checkpoint abnormalities such as cancers and autoimmune diseases.

Segmentation of Glomeruli Within Trichrome Images Using Deep Learning.

INTRODUCTION: The number of glomeruli and glomerulosclerosis evaluated on kidney biopsy slides constitute standard components of a renal pathology report. Prevailing methods for glomerular assessment remain manual, labor intensive, and nonstandardized. We developed a deep learning framework to accurately identify and segment glomeruli from digitized images of human kidney biopsies. METHODS: Trichrome-stained images (n = 275) from renal biopsies of 171 patients with chronic kidney disease treated at the Boston Medical Center from 2009 to 2012 were analyzed. A sliding window operation was defined to crop each original image to smaller images. Each cropped image was then evaluated by at least 3 experts into 3 categories: (i) no glomerulus, (ii) normal or partially sclerosed (NPS) glomerulus, and (iii) globally sclerosed (GS) glomerulus. This led to identification of 751 unique images representing nonglomerular regions, 611 images with NPS glomeruli, and 134 images with GS glomeruli. A convolutional neural network (CNN) was trained with cropped images as inputs and corresponding labels as output. Using this model, an image processing routine was developed to scan the test images to segment the GS glomeruli. RESULTS: The CNN model was able to accurately discriminate nonglomerular images from NPS and GS images (performance on test data: Accuracy: 92.67% ± 2.02% and Kappa: 0.8681 ± 0.0392). The segmentation model that was based on the CNN multilabel classifier accurately marked the GS glomeruli on the test data (Matthews correlation coefficient = 0.628). CONCLUSION: This work demonstrates the power of deep learning for assessing complex histologic structures from digitized human kidney biopsies.

c-Cbl: An Important Regulator and a Target in Angiogenesis and Tumorigenesis.

Casitas B lineage lymphoma (c-Cbl) is a multifunctional protein with a ubiquitin E3 ligase activity capable of degrading diverse sets of proteins. Although previous work had focused mainly on c-Cbl mutations in humans with hematological malignancies, recent emerging evidence suggests a critical role of c-Cbl in angiogenesis and human solid organ tumors. The combination of its unique structure, modular function, and ability to channelize cues from a rich network of signaling cascades, empowers c-Cbl to assume a central role in these disease models. This review consolidates the structural and functional insights based on recent studies that highlight c-Cbl as a target with tantalizing therapeutic potential in various models of angiogenesis and tumorigenesis.

Unique aspects of peripheral artery disease in patients with chronic kidney disease.

Peripheral artery disease (PAD) represents a major health care burden. Despite the advent of screening and interventional procedures, the long-term clinical outcomes remain suboptimal, especially in patients with chronic kidney disease (CKD). While CKD and PAD share common predisposing factors, emerging studies indicate that their co-existence is not merely an association; instead, CKD represents a strong, independent risk factor for PAD. These findings implicate CKD-specific mediators of PAD that remain incompletely understood. Moreover, there is a need to understand the mechanisms underlying poor outcomes after interventions for PAD in CKD. This review discusses unique clinical aspects of PAD in patients with CKD, including high prevalence and worse outcomes after vascular interventions and the influence of renal allograft transplantation. In doing so, it also highlights underappreciated aspects of PAD in patients with CKD, such as disparities in revascularization and higher peri-procedural mortality. While previous reviews have discussed general mechanisms of PAD pathogenesis, focusing on PAD in CKD, this review underscores a need to probe for CKD-specific pathogenic pathways that may unravel novel biomarkers and therapeutic targets in PAD and ultimately improve the risk stratification and management of patients with CKD and PAD.

c-Cbl Expression Correlates with Human Colorectal Cancer Survival and Its Wnt/ß-Catenin Suppressor Function Is Regulated by Tyr371 Phosphorylation.

The proto-oncogene ß-catenin drives colorectal cancer (CRC) tumorigenesis. Casitas B-lineage lymphoma (c-Cbl) inhibits CRC tumor growth through targeting nuclear ß-catenin by a poorly understood mechanism. In addition, the role of c-Cbl in human CRC remains largely underexplored. Using a novel quantitative histopathologic technique, we demonstrate that patients with high c-Cbl-expressing tumors had significantly better median survival (3.7 years) compared with low c-Cbl-expressing tumors (1.8 years; P = 0.0026) and were more than twice as likely to be alive at 3 years compared with low c-Cbl tumors (P = 0.0171). Our data further demonstrate that c-Cbl regulation of nuclear ß-catenin requires phosphorylation of c-Cbl Tyr371 because its mutation compromises its ability to target ß-catenin. The tyrosine 371 (Y371H) mutant interacted with but failed to ubiquitinate nuclear ß-catenin. The nuclear localization of the c-Cbl-Y371H mutant contributed to its dominant negative effect on nuclear ß-catenin. The biological importance of c-Cbl-Y371H was demonstrated in various systems, including a transgenic Wnt-8 zebrafish model. c-Cbl-Y371H mutant showed augmented Wnt/ß-catenin signaling, increased Wnt target genes, angiogenesis, and CRC tumor growth. This study demonstrates a strong link between c-Cbl and overall survival of patients with CRC and provides new insights into a possible role of Tyr371 phosphorylation in Wnt/ß-catenin regulation, which has important implications in tumor growth and angiogenesis in CRC.