Caspases and calpain are independent mediators of cisplatin-induced endothelial cell necrosis

Thromboembolic events in patients who received adjuvant chemotherapy for gastric cancer: a single-center retrospective study

BACKGROUND

Thromboembolic events (TEEs) are significant adverse events that can cause serious morbidities and mortality in cancer patients receiving chemotherapy. Patients with gastric cancer (GC) treated with palliative chemotherapy have been reported to experience a TEE incidence of 5-27%. However, very few reports have addressed TEEs in adjuvant chemotherapy (AC) for GC.

METHODS

This study retrospectively analyzed 611 GC patients (stage II: 309, III: 302) who started AC with capecitabine/oxaliplatin (167 patients) or S-1 (444 patients) after undergoing curative resection between January 2013 and June 2020 at a single center. The incidence of TEEs during AC or within 1 year after AC completion was investigated, while analyzing the factors that influenced the TEEs' occurrence.

RESULTS

TEEs were confirmed in 20 patients (3.3%), and TEEs occurred in almost all patients in the S-1 group (19 patients). The most common TEE types were cerebral infarction and pulmonary thromboembolism (five patients each). Although old age (≥ 70 years, p < 0.0001), S-1 treatment (p = 0.021), and hypertension (p = 0.017) were identified as significant risk factors for TEEs in univariate analysis, only old age showed a statistically significant correlation with TEEs' occurrence in multivariate analysis (odds ratio: 3.07; 95% confidence interval 1.11-8.48; p = 0.031).

CONCLUSIONS

TEEs occurred in fewer patients with GC who had been treated with AC than patients who had received palliative chemotherapy in previous reports. However, elderly GC patients who are undergoing AC require more careful surveillance for possible TEEs, considering relatively higher incidence of them.

Independent role of caspases and Bik in augmenting influenza A virus replication in airway epithelial cells and mice

Caspases and poly (ADP-ribose) polymerase 1 (PARP1) have been shown to promote influenza A virus (IAV) replication. However, the relative importance and molecular mechanisms of specific caspases and their downstream substrate PARP1 in regulating viral replication in airway epithelial cells (AECs) remains incompletely elucidated. Here, we targeted caspase 2, 3, 6, and PARP1 using specific inhibitors to compare their role in promoting IAV replication. Inhibition of each of these proteins caused significant decline in viral titer, although PARP1 inhibitor led to the most robust reduction of viral replication. We previously showed that the pro-apoptotic protein Bcl-2 interacting killer (Bik) promotes IAV replication in the AECs by activating caspase 3. In this study, we found that as compared with AECs from wild-type mice, bik-deficiency alone resulted in ~ 3 logs reduction in virus titer in the absence of treatment with the pan-caspase inhibitor (Q-VD-Oph). Inhibiting overall caspase activity using Q-VD-Oph caused additional decline in viral titer by ~ 1 log in bik-/- AECs. Similarly, mice treated with Q-VD-Oph were protected from IAV-induced lung inflammation and lethality. Inhibiting caspase activity diminished nucleo-cytoplasmic transport of viral nucleoprotein (NP) and cleavage of viral hemagglutinin and NP in human AECs. These findings suggest that caspases and PARP1 play major roles to independently promote IAV replication and that additional mechanism(s) independent of caspases and PARP1 may be involved in Bik-mediated IAV replication. Further, peptides or inhibitors that target and block multiple caspases or PARP1 may be effective treatment targets for influenza infection.

A review: Systematic research approach on toxicity model of liver and kidney in laboratory animals

Therapeutic experiments are commonly performed on laboratory animals to investigate the possible mechanism(s) of action of toxic agents as well as drugs or substances under consideration. The use of toxins in laboratory animal models, including rats, is intended to cause toxicity. This study aimed to investigate different models of hepatotoxicity and nephrotoxicity in laboratory animals to help researchers advance their research goals. The current narrative review used databases such as Medline, Web of Science, Scopus, and Embase and appropriate keywords until June 2021. Nephrotoxicity and hepatotoxicity models derived from some toxic agents such as cisplatin, acetaminophen, doxorubicin, some anticancer drugs, and other materials through various signaling pathways are investigated. To understand the models of renal or hepatotoxicity in laboratory animals, we have provided a list of toxic agents and their toxicity procedures in this review.

Venous thromboembolism risk in patients receiving neoadjuvant chemotherapy for bladder cancer

INTRODUCTION

There is limited evidence to inform thromboprophylaxis use for patients receiving neoadjuvant chemotherapy prior to surgery in bladder cancer. We sought to determine the incidence of venous thromboembolism (VTE) in patients receiving neoadjuvant chemotherapy and cystectomy. We also assessed if the Khorana score was associated with VTE risk.

METHODS

A retrospective cohort study was performed on consecutive patients who received a radical cystectomy for bladder cancer at The Ottawa Hospital between January 2016 and August 2020. Demographic information, chemotherapy data, operative characteristics, VTE and bleeding outcomes were collected from the start of treatment to 90 days postoperative. A Khorana score was calculated for each patient who received neoadjuvant chemotherapy. The primary outcome for this study was the incidence of VTE from the time the patient started treatment with neoadjuvant chemotherapy until 90 days post-cystectomy. Secondary outcomes included risk factors for VTE during neoadjuvant chemotherapy.

RESULTS

Among 181 radical cystectomy cases during the study period, 123 had muscle-invasive disease and 72 (39.8%) received neoadjuvant chemotherapy. Eighteen (25.0%) patients who received neoadjuvant chemotherapy and radical cystectomy developed a VTE from the start of chemotherapy to 90 days postoperative. Thirteen of the 18 VTEs (72%) occurred while the patient was receiving chemotherapy. In multivariable analysis, the only factor associated with a significantly increased risk of VTE was treatment with neoadjuvant chemotherapy (Relative risk (RR) 3.05, 95% confidence interval [CI] 1.16-8.02; P = 0.02). A higher Khorana score was not associated with an increased risk of VTE in patients who received neoadjuvant chemotherapy (RR = 0.33, 95% CI 0.08-1.28, P = 0.11). One (1.4%) patient had a major bleeding event during neoadjuvant chemotherapy.

CONCLUSIONS

Patients receiving neoadjuvant chemotherapy and radical cystectomy are at very high-risk of VTE. Prospective studies that assess the benefits and harms of pharmacologic thromboprophylaxis in this population are needed.

Analysis of thromboembolic events in patients with non-small cell lung cancer who received adjuvant chemotherapy: single-center real-world data

Thromboembolic events (TEEs) are common in cancer patients, with increased risk of TEE by chemotherapy in patients with lung cancer. However, TEEs in patients with non-small cell lung cancer (NSCLC) who received adjuvant chemotherapy have rarely been reported. This study retrospectively analyzed real-world data of 275 patients with NSCLC treated with adjuvant chemotherapy after surgery from October, 2005 to June, 2020, in a single institution. The incidence of TEEs during or within one year of completion of adjuvant chemotherapy was investigated, and factors related to TEEs were analyzed. TEEs were confirmed in nine patients (3.3%), without fatal event related to TEEs. None of the factors, including Khorana score, was significantly associated with the occurrence of TEEs. All patients with TEEs had pathologic stage IIB or higher and a history of smoking, except for one patient. In conclusion, TEEs occurred in a smaller proportion of patients with NSCLC treated with adjuvant chemotherapy in the real world compared with those treated with palliative chemotherapy in previous reports. Furthermore, prophylactic anticoagulation in patients with NSCLC receiving adjuvant chemotherapy may not be needed except for high-risk patients, although those patients should be informed about the possible risk of TEEs.

Protective Effect of Mannitol on Cisplatin-Induced Nephrotoxicity: A Systematic Review and Meta-Analysis

INTRODUCTION

Cisplatin, a chemotherapeutic drug, is widely used for the treatment of various malignant tumors with good effects. However, cisplatin-induced nephrotoxicity is a major dose-limiting factor and a significant adverse event. Mannitol is used to reduce cisplatin-induced nephrotoxicity, which is controversial. This study aimed to evaluate the efficacy and safety of a hydration regimen containing mannitol against cisplatin-induced nephrotoxicity through a meta-analysis.

METHODS

Potential records from PubMed, EMBASE, Cochrane Library, and ClinicalTrials that met the inclusion criteria were included from inception to May 2021. Cochrane Collaboration tools were used to assess the risk of bias in the included studies. Jadad's and NOS scores were applied to assess the quality of randomized controlled trials (RCTs) and case-control studies. A random-effects model or fixed-effects model was used depending on the heterogeneity. Subgroup analyses were performed to evaluate the potential study characteristics. The pooled odds ratios (ORs) and 95% confidence intervals (CIs) were evaluated.

RESULTS

Four RCTs and seven case-control studies involving 4168 patients were included. Pooled results showed that mannitol use could reduce the incidence of cisplatin-induced nephrotoxicity (OR = 0.66, 95% CI [0.45-0.97], p = 0.03), especially reducing grade 3 nephrotoxicity events according to CTCAE 4.0 (OR = 0.37,95% CI [0.16-0.84]). Moreover, mannitol use was not significantly associated with creatinine clearance, serum creatine, and electrolyte disturbance (p > 0.05). Gastrointestinal cancer (OR = 0.36, 95% CI [0.15-0.83], p = 0.02) and urinary tract cancer (OR = 0.32,95% CI [0.14-0.73], p = 0.007) may be more sensitive to mannitol, although the test for overall effect was significantly different (OR = 0.66, 95% CI [0.49-0.89], p = 0.007). For patients with diabetes and hypertension, mannitol may worsen renal function (OR = 1.80, 95% CI [1.18-2.72], p = 0.006; OR = 2.19, 95% CI [1.50, 3.19], p < 0.0001, respectively). Mannitol may have a better protective effect when doses of mannitol were ≥ 25 g (OR = 0.58, 95% CI [0.39-0.88], p = 0.01) and doses of cisplatin < 75 mg/m² (OR = 0.59, 95% CI [0.36-0.94], p = 0.03). It revealed that mannitol use was likely to cause nausea or vomiting (OR = 1.86, 95% CI [1.20-2.89], p = 0.006).

CONCLUSION

Current evidence revealed that mannitol was an effective and safe drug to reduce cisplatin-induced nephrotoxicity events, especially Grade 3 events. However, it may cause more nausea/vomiting events and deteriorate renal function in patients with diabetes or hypertension. We also found that mannitol had the best effect when mannitol was ≥ 25 g in total or cisplatin was < 75 mg/m². Meanwhile, mannitol may have a better effect on gastrointestinal and urinary tract cancers.

SYSTEMATIC REVIEW REGISTRATION

crd. york. ac. uk/PROSPERO, CRD 42021253990.

Prophylaxis Against Thromboembolic Events During Chemotherapy for Germ Cell Cancer

INTRODUCTION

Patients with advanced germ cell tumors (GCT) receiving cisplatin-based chemotherapy have high rates of thromboembolic events (TEE) which can negatively affect their overall survival. While primary TEE prophylaxis during chemotherapy may prevent these events, it is unclear which patients will benefit in this setting.

MATERIALS AND METHODS

A review of PubMed/Medline was conducted in December 2020 and all pertinent articles were evaluated for relevancy and quality of data for inclusion in the review.

RESULTS

Studies on patients receiving initial cisplatin-based chemotherapy for advanced GCT have reported up to a 19% rate of TEE. This high rate may be associated with multiple factors including retroperitoneal lymphadenopathy, advanced clinical stage, high risk Khorana scores and presence of a central line. Large phase III clinical trials have demonstrated the benefit of low-molecular-weight-heparin and direct oral anticoagulants for primary prophylaxis and against recurrent TEE. However, primary prophylaxis is currently underutilized with GCT patients starting chemotherapy.

CONCLUSION

Precise models to predict TEE risk and consideration of anticoagulation are difficult to develop owing to the relatively uncommon nature of GCT and lack of representation in primary TEE prophylaxis clinical trials. Despite these limitations, we believe that the benefits of prophylactic anticoagulation outweigh the risk of major bleeding in select GCT patients with higher risk of TEE. We have developed a simple algorithm to help guide TEE prophylaxis selection based on patient factors and route of chemotherapy administration. Given the high rate of TEE in GCT patients, we believe better utilization of primary prophylaxis in patient starting cisplatin-based chemotherapy will have clinical benefit.

Life after Cell Death-Survival and Survivorship Following Chemotherapy

Simple Summary

Treatment of aggressive cancers often relies on chemotherapy. This treatment has improved survival rates, but while effective at killing cancer cells, inevitably it also kills or alters the function of others. While many of the known effects are transient and resolve after treatment, as survival rates increase, so does our understanding of the long-term health costs that accompany cancer survivors. Here we provide an overview of common long-term morbidities known to be caused by conventional chemotherapy, including the risk of relapse, but more importantly, the cost of quality of life experienced, especially by those who have cancer in early life. We aim to highlight the importance of the development of targeted therapies to replace the use of conventional chemotherapy, but also that of treating the patients along with the disease to enable not only longer but also healthier life after cancer.

Abstract

To prevent cancer cells replacing and outnumbering their functional somatic counterparts, the most effective solution is their removal. Classical treatments rely on surgical excision, chemical or physical damage to the cancer cells by conventional interventions such as chemo- and radiotherapy, to eliminate or reduce tumour burden. Cancer treatment has in the last two decades seen the advent of increasingly sophisticated therapeutic regimens aimed at selectively targeting cancer cells whilst sparing the remaining cells from severe loss of viability or function. These include small molecule inhibitors, monoclonal antibodies and a myriad of compounds that affect metabolism, angiogenesis or immunotherapy. Our increased knowledge of specific cancer types, stratified diagnoses, genetic and molecular profiling, and more refined treatment practices have improved overall survival in a significant number of patients. Increased survival, however, has also increased the incidence of associated challenges of chemotherapy-induced morbidity, with some pathologies developing several years after termination of treatment. Long-term care of cancer survivors must therefore become a focus in itself, such that along with prolonging life expectancy, treatments allow for improved quality of life.

Thromboembolism in Muscle-Invasive Bladder Cancer. A Population-based Nationwide Study

BACKGROUND: Routine VTE prophylaxis within 30 days of radical cystectomy (RC) for urinary bladder cancer (UBC) is used to protect from venous thromboembolism (VTE). However, randomized studies and nationwide population-based studies are lacking. OBJECTIVE: To study VTE and risk factors for VTE in muscle-invasive UBC in a nationwide population-based series, with a focus on the association with RC with and without chemotherapy. MATERIALS AND METHODS: We studied all patients with clinical stage T2-T4 UBC diagnosed 1997 to 2014 in the Bladder Cancer Data Base Sweden (BladderBaSe). Previous VTE events and risk factors for VTE were registered from 1987. Cox regression analyses and Kaplan-Meier curves were performed to study risk factors for VTE and cumulative incidence of VTE. RESULTS: In 9720 patients (71%males) with a median age of 74 years 546 (5.6%) had VTE after diagnosis. In Cox analyses controlling for patient’s and tumour characteristics, and risk factors for VTE, VTE after diagnosis and first treatment date were associated with chemotherapy with or without RC. Cumulative incidence of VTE increased during 24 months after diagnosis and first treatment date. VTE were less common in patients with previous cardiovascular disease. CONCLUSIONS: VTE was commonly observed after 30 days from diagnosis and from first treatment date in patients with T2-T4 UBC, particularly after chemotherapy. The findings suggest that long-term intervention studies of benefit and possible harms of VTE prophylaxis after UBC should be undertaken.

Chemotherapy-induced acute vascular injury involves intracellular generation of ROS via activation of the acid sphingomyelinase pathway

Several categories of chemotherapy confer substantial risk for late-term vascular morbidity and mortality. In the present study, we aimed to investigate the mechanism of acute chemotherapy-induced vascular injury in normal tissues. Specifically, we looked at activation of the acid sphingomyelinase (ASMase)/ceramide pathway, which leads to generation of reactive oxygen species (ROS) and induction of oxidative stress that may result in vascular injury. In particular, we focused on two distinct drugs, doxorubicin (DOX) and cisplatin (CIS) and their effects on normal endothelial cells. In vitro, DOX resulted in increased ASMase activity, intra-cellular ROS production and induction of apoptosis. CIS treatment generated significantly reduced effects in endothelial cells. In-vivo, murine femoral arterial blood flow was measured in real-time, during and after DOX or CIS administration, using fluorescence optical imaging system. While DOX caused constriction of small vessels and disintegration of large vessels' wall, CIS induced minor vascular changes in arterial blood flow, correlating with the in vitro findings. These results demonstrate that DOX induces acute vascular injury by increased ROS production, via activation of ASMase/ceramide pathway, while CIS increases ROS production and its immediate extracellular translocation, without causing detectable acute vascular injury. Our findings may potentially lead to the development of new strategies to prevent long-term cardiovascular morbidity in cancer survivors.

Patterns of blood pressure changes in patients with head and neck cancer receiving radiotherapy or chemo-radiotherapy at a tertiary cancer centre

BACKGROUND

To evaluate patterns of blood pressure (BP) changes in patients with head and neck cancer (HNC) receiving radiation (RT)/chemo-radiation (CRT) METHODS: This study included data collection, compilation, and analysis of 451 consecutive HNC patients who underwent RT/CRT.

RESULTS

Out of 451 patients, 376 (82%) were male and 75 (18%) were female with a median age of 52 years. Patients receiving 3DCRT experienced greater fall in BP, including for SBP and MAP, compared to those receiving IMRT-IGRT. Female patients experienced greater fall in diastolic BP as compared to male patients (p: 0.03). At the end of treatment, we observed a significant association between a fall in systolic BP (decrease by 10% of baseline) and weight loss of more than 10% of baseline weight (p: 0.03).

CONCLUSION

Fall in BP during RT/CRT is significantly affected by treatment technique and sex and is strongly associated with significant weight loss.

Cisplatin induced neurotoxicity is mediated by Sarm1 and calpain activation

Cisplatin is a commonly used chemotherapy agent with significant dose-limiting neurotoxicity resulting in peripheral neuropathy. Although it is postulated that formation of DNA-platinum adducts is responsible for both its cytotoxicity in cancer cells and side effects in neurons, downstream mechanisms that lead to distal axonal degeneration are unknown. Here we show that activation of calpains is required for both neurotoxicity and formation of DNA-platinum adduct formation in neurons but not in cancer cells. Furthermore, we show that neurotoxicity of cisplatin requires activation of Sarm1, a key regulator of Wallerian degeneration, as mice lacking the Sarm1 gene do not develop peripheral neuropathy as evaluated by both behavioral or pathological measures. These findings indicate that Sarm1 and/or specific calpain inhibitors could be developed to prevent cisplatin induced peripheral neuropathy.

Identification of a Noncanonical Necrotic Cell Death Triggered via Enhanced Proteolysis by a Novel Sapogenol Derivative

Small molecules which activate distinct cell death pathways have promising high potential for anticancer drug research. Especially, regulated necrosis draws attention as an alternative cell death mechanism to overcome the drug resistance. Here, we report that a new semisynthetic saponin analogue (AG-08) triggers necrotic cell death with unprecedented pathways. AG-08-mediated necrosis depends on enhanced global proteolysis involving calpains, cathepsins, and caspases. Moreover, AG-08 generates several alterations in lysosomal function and physiology including membrane permeabilization, redistribution toward the perinuclear area, and lastly excessive tubulation. As a consequence of lysosomal impairment, the autophagic process was abolished via AG-08 treatment. Collectively, in addition to its ability to induce necrotic cell death, which makes AG-08 a promising candidate to cope with drug resistance, its unique activity mechanisms including autophagy/lysosome impairment and enhancement of proteolysis leading a strong death capacity emphasizes its potential for anticancer drug research.

Renal Tubular Cells from Hibernating Squirrels are Protected against Cisplatin Induced Apoptosis

Hibernating 13-lined ground squirrels are characterized by tolerance of severe hypothermia and hypoperfusion during torpor, followed by periodic warm reperfusion during IBA, conditions which are lethal to nonhibernating mammals. The aim of the present study was to determine whether protection from apoptosis was specific to torpor arousal cycles during hibernation or will also apply to cisplatin treatment on squirrel renal tubular cells (RTECs) that were procured during hibernation. Squirrel and mouse RTECs were treated with cisplatin, a potent inducer of RTEC apoptosis. Squirrel RTECs subjected to cisplatin had significantly less apoptosis, no cleaved caspase-3, and increased XIAP, pAkt, and pBAD versus mouse RTECs. To determine whether XIAP and Akt1 are necessary for RTEC protection against cisplatin induced apoptotic cell death, gene expression of Akt1 or XIAP was silenced in squirrel RTECs. Squirrel RTECs deficient in Akt1 and XIAP had increased apoptosis and cleaved caspase-3 when treated with cisplatin. Our results thus demonstrates that 13-lined ground squirrel RTECs possess intrinsic intracellular mechanisms by which they protect themselves from apoptotic cell death. Cisplatin induced acute kidney injury (AKI) may be avoided in cancer patients by employing mechanisms used by squirrel RTECs to protect against cisplatin induced tubular cell apoptosis.

The effect of MEK1/2 inhibitors on cisplatin-induced acute kidney injury (AKI) and cancer growth in mice

In a clinically-relevant model of 4 week, low-dose cisplatin-induced AKI, mice were injected subcutaneously with non small cell lung cancer (NSCLC) cells that harbor an activating Kirsten rat sarcoma viral oncogene homolog (KRAS)^G12V mutation. Phospho extracellular signal-regulated kinase1/2 (pERK1/2) expression in kidney and tumors was decreased by the MEK1/2 inhibitors, U0126 and trametinib, that potently inhibit pERK1/2. U0126 resulted in a significant improvement in kidney function, acute tubular necrosis (ATN) and tubular cell apoptosis in mice with AKI. Genes that were significantly decreased by U0126 were heat shock protein 1, cyclin-dependent kinase 4 (CDK4) and stratifin (14-3-3σ). U0126 resulted in a significant decrease in tumor weight and volume and significantly increased the chemotherapeutic effect of cisplatin. Trametinib, a MEK1/2 inhibitor that is FDA-approved for the treatment of cancer, did not result in functional protection against AKI or worse AKI, but dramatically decreased tumor growth more than cisplatin. Smaller tumors in cisplatin or MEK1/2 inhibitor-treated mice were not related to changes in microtubule-associated proteins 1A/1B light chain 3B (LC3-II), p62, cleaved caspase-3, granzyme B, or programmed death-ligand 1 (PD-L1). In summary, despite ERK inhibition by both U0126 and trametinib, only U0126 protected against AKI suggesting that the protection against AKI by U0126 was due to an off-target effect independent of ERK inhibition. The effect of U0126 to decrease AKI may be mediated by inhibition of heat shock protein 1, CDK4 or stratifin (14-3-3σ). Trametinib was more effective than cisplatin in decreasing tumor growth, but unlike cisplatin, trametinib did not cause AKI.

Inhibition of CXCL1-CXCR2 axis ameliorates cisplatin-induced acute kidney injury by mediating inflammatory response

One of the limiting side effects of cisplatin use in cancer chemotherapy is nephrotoxicity. Inflammation is now believed to play a major role in the pathogenesis of cisplatin-induced acute kidney injury (AKI), and the mediators of inflammation contribute to it. CXCL1 was recently reported to be involved in renal physiology and pathology in ischemia mouse model; however, its roles and mechanisms in cisplatin-induced AKI are completely unknown. We observed that CXCL1 and CXCR2 expression in the kidney was markedly increased on day 7 after cisplatin treatment. Subsequently, we demonstrate that inhibition of CXCL1-CXCR2 signaling axis, using genetic and pharmacological approaches, reduces renal damage following cisplatin treatment as compared with control mice. Specifically, deficiency of CXCL1 or CXCR2 extensively preserved the renal histology and maintained the kidney functions after cisplatin treatment, which was associated with reduced expression of the pro-inflammatory cytokines and infiltration of neutrophils in the kidneys as compared. Furthermore, inhibition of CXCR2 by intragastric administration of repertaxin in mice with AKI reduces kidney injury associated with a reduction of inflammatory cytokines and neutrophils infiltration. Finally, we found that CXCL1/CXCR2 regulated cisplatin-induced inflammatory responses via the P38 and NF-κB signaling pathways in vitro and in vivo. In conclusion, our results indicate that CXCL1-CXCR2 signaling axis plays a crucial role in the pathogenesis of cisplatin-induced AKI through regulation of inflammatory response and maybe a novel therapeutic target for cisplatin-induced AKI.

Hypertension in Cancer Patients and Survivors: Epidemiology, Diagnosis, and Management

Cancer patients and survivors of cancer have a greater burden of cardiovascular disease compared to the general population. Much of the elevated cardiovascular risk in these individuals is likely attributable to hypertension, as individuals with cancer have a particularly high incidence of hypertension following cancer diagnosis. Treatment with chemotherapy is an independent risk factor for hypertension due to direct effects of many agents on endothelial function, sympathetic activity, and renin-angiotensin system activity as well as nephrotoxicity. Diagnosis and management of hypertension in cancer patients requires accurate blood pressure measurement and consideration of potential confounding factors, such as adjuvant treatments and acute pain, that can temporarily elevate blood pressure readings. Home blood pressure monitoring can be a useful tool to facilitate longitudinal blood pressure monitoring for titration of antihypertensive medications. Selection of antihypertensive agents in cancer patients should account for treatment-specific morbidities and target organ injury.

Common Vascular Toxicities of Cancer Therapies

The introduction of targeted agents into modern cancer therapy pursued the goal of molecularly more specific, and thereby more effective and safer, therapies. Paradoxically, however, several toxicities were brought to greater attention, among these not only cardiac but also vascular toxicities. The latter reach far beyond venous thromboembolism and include a broad spectrum of presentations based on the vascular territories and pathomechanisms involved, including abnormal vascular reactivity, acute thrombosis, or accelerated atherosclerosis. This article provides an overview of the most common presentations and their management strategies.

Recent Advances in Models, Mechanisms, Biomarkers, and Interventions in Cisplatin-Induced Acute Kidney Injury

Cisplatin is a widely used chemotherapeutic agent used to treat solid tumours, such as ovarian, head and neck, and testicular germ cell. A known complication of cisplatin administration is acute kidney injury (AKI). The development of effective tumour interventions with reduced nephrotoxicity relies heavily on understanding the molecular pathophysiology of cisplatin-induced AKI. Rodent models have provided mechanistic insight into the pathophysiology of cisplatin-induced AKI. In the subsequent review, we provide a detailed discussion of recent advances in the cisplatin-induced AKI phenotype, principal mechanistic findings of injury and therapy, and pre-clinical use of AKI rodent models. Cisplatin-induced AKI murine models faithfully develop gross manifestations of clinical AKI such as decreased kidney function, increased expression of tubular injury biomarkers, and tubular injury evident by histology. Pathways involved in AKI include apoptosis, necrosis, inflammation, and increased oxidative stress, ultimately providing a translational platform for testing the therapeutic efficacy of potential interventions. This review provides a discussion of the foundation laid by cisplatin-induced AKI rodent models for our current understanding of AKI molecular pathophysiology.

Renal tubular injury exacerbated by vasohibin-1 deficiency in a murine cisplatin-induced acute kidney injury model

Acute kidney injury (AKI) is frequently encountered in clinical practice, particularly secondarily to cardiovascular surgery and administration of nephrotoxic agents, and is increasingly recognized for initiating a transition to chronic kidney disease. Clarifying the pathogenesis of AKI could facilitate the development of novel preventive strategies, because the occurrence of hospital-acquired AKI is often anticipated. Vasohibin-1 (VASH1) was initially identified as an antiangiogenic factor derived from endothelial cells. VASH1 expression in endothelial cells has subsequently been reported to enhance cellular stress tolerance. Considering the importance of maintaining peritubular capillaries in preventing the progression of AKI, the present study aimed to examine whether VASH1 deletion is involved in the pathogenesis of cisplatin-induced AKI. For this, we injected male C57BL/6J wild-type (WT) and VASH1 heterozygous knockout (VASH1^+/-) mice intraperitoneally with either 20 mg/kg cisplatin or vehicle solution. Seventy-two hours after cisplatin injection, increased serum creatinine concentrations and renal tubular injury accompanied by apoptosis and oxidative stress were more prominent in VASH1^+/- mice than in WT mice. Cisplatin-induced peritubular capillary loss was also accelerated by VASH1 deficiency. Moreover, the increased expression of ICAM-1 in the peritubular capillaries of cisplatin-treated VASH1^+/- mice was associated with a more marked infiltration of macrophages into the kidney. Taken together, VASH1 expression could have protective effects on cisplatin-induced AKI probably by maintaining the number and function of peritubular capillaries.

Comprehensive review on how platinum- and taxane-based chemotherapy of ovarian cancer affects biology of normal cells

One of the most neglected aspects of chemotherapy are changes, and possible consequences of these changes, that occur in normal somatic cells. In this review, we summarize effects of selected drugs used to treat ovarian cancer (platin derivatives-cisplatin and carboplatin; and taxanes-paclitaxel and docetaxel) on cellular metabolism, acquisition of reactive stroma features, cellular senescence, inflammatory reactions, apoptosis, autophagy, mitophagy, oxidative stress, DNA damage, and angiogenesis in various types of normal cells, including fibroblasts, epithelial cells, endothelial cells, and neurons. The activity of these drugs against the normal cells is presented from a broader perspective of their desirable anti-tumoral effects.

Thromboembolism in Patients with Bladder Cancer: Incidence, Risk Factors and Prevention

Patients with bladder cancer are at high risk of developing both venous and arterial thromboembolic events. Factors that contribute to this phenomenon include the hypercoagulable state induced by the malignancy itself, medical comorbidities that are common in this predominantly elderly patient population as well as treatments such as prolonged pelvic surgery and cisplatin-based chemotherapy. While formal guidelines address prevention of venous thromboembolism in patients undergoing radical cystectomy, consensus regarding the role of pharmacologic prophylaxis in patients with bladder cancer being treated with chemotherapy, either with neoadjuvant or adjuvant intent in conjunction with radical cystectomy, as part of bladder preservation protocols or for metastatic disease, has proved elusive. The present narrative review was undertaken to define the incidence of and identify risk factors for thromboembolism among patients with bladder cancer, as well as to assess the efficacy of pharmacologic prophylaxis in reducing the risk of thromboembolism in this patient population.

IL-33 deficiency slows cancer growth but does not protect against cisplatin-induced AKI in mice with cancer

The effect of IL-33 deficiency on acute kidney injury (AKI) and cancer growth in a 4-wk model of cisplatin-induced AKI in mice with cancer was determined. Mice were injected subcutaneously with murine lung cancer cells. Ten days later, cisplatin (10 mg·kg-¹·wk-¹) was administered weekly for 4 wk. The increase in kidney IL-33 preceded the AKI and tubular injury, suggesting that IL-33 may play a causative role. However, the increase in serum creatinine, blood urea nitrogen, serum neutrophil gelatinase-associated lipoprotein, acute tubular necrosis, and apoptosis scores in the kidney in cisplatin-induced AKI was the same in wild-type and IL-33-deficient mice. There was an increase in kidney expression of pro-inflammatory cytokines CXCL1 and TNF-α, known mediators of cisplatin-induced AKI, in IL-33-deficient mice. Surprisingly, tumor weight, tumor volume, and tumor growth were significantly decreased in IL-33-deficient mice, and the effect of cisplatin on tumors was enhanced in IL-33-deficient mice. As serum IL-33 was increased in cisplatin-induced AKI in mice, it was determined whether serum IL-33 is an early biomarker of AKI in patients undergoing cardiac surgery. Immediate postoperative serum IL-33 concentrations were higher in matched AKI cases compared with non-AKI controls. In conclusion, even though the cancer grows slower in IL-33-deficient mice, the data that IL-33 deficiency does not protect against AKI in a clinically relevant model suggest that IL-33 inhibition may not be useful to attenuate AKI in patients with cancer. However, serum IL-33 may serve as a biomarker of AKI.

Induction of hypoxia and necrosis in multicellular tumor spheroids is associated with resistance to chemotherapy treatment

Culture of cancerous cells in standard monolayer conditions poorly mirrors growth in three-dimensional architectures typically observed in a wide majority of cancers of different histological origin. Multicellular tumor spheroid (MCTS) culture models were developed to mimic these features. However, in vivo tumor growth is also characterized by the presence of ischemic and necrotic areas generated by oxygenation gradients and differential access to nutrients. Hypoxia and necrosis play key roles in tumor progression and resistance to treatment. To provide in vitro models recapitulating these events in highly controlled and standardized conditions, we have generated colorectal cancer (CRC) cell spheroids of different sizes and analyzed their gene expression profiles and sensitivity to treatment with 5FU, currently used in therapeutic protocols. Here we identify three MCTS stages, corresponding to defined spheroid sizes, characterized by normoxia, hypoxia, and hypoxia plus necrosis, respectively. Importantly, we show that MCTS including both hypoxic and necrotic areas most closely mimic gene expression profiles of in vivo-developing tumors and display the highest resistance to 5FU. Taken together, our data indicate that MCTS may mimic in vitro generation of ischemic and necrotic areas in highly standardized and controlled conditions, thereby qualifying as relevant models for drug screening purposes.

Incidence of Venous Thromboembolism in cancer patients treated with Cisplatin based chemotherapy - a cohort study

Background

Cancer related thrombosis not only increases morbidity and mortality but also poses a significant financial burden on health care system. Risk of venous thromboembolism (VTE) in these patients substantially increases with the addition of chemotherapy. Lately, cisplatin has been implicated as an independent factor. There is little data estimating the risk of venous thromboembolism in patients receiving cisplatin based chemotherapy when compared to other chemotherapeutic agents.

Methods

Patients who had received chemotherapy between November 2010 and October 2012 were retrospectively identified from a single institute cancer registry. 200 patients who had received cisplatin based chemotherapy were identified as the exposed group while 200 patients who had received non-Cisplatin based regimens were identified as the non-exposed group. Patients were followed for development of VTE throughout the entire duration of therapy and one month thereafter. Cox proportional hazard model was used to compute relative risks with 95% confidence intervals.

Results

The baseline characteristics were similar in the two groups. Mean age for the entire cohort was 55.4 ± 10.7 years and male to female ratio was almost 1:1. On univariate analysis, cisplatin based chemotherapy, presence of central venous catheter, female gender, poor performance status, high risk stratification according to the Khorana model and use of granulocyte colony stimulating factor were all significantly associated with the development of VTE. The crude relative risk for the incidence of VTE in cisplatin group was 2.8 (95% CI, 1.4 – 4.2) times compared to the non-Cisplatin group. When the relative risk was adjusted for the above variables in multivariable analysis, it increased to 3.3 (95% CI, 1.6 – 6.8) compared to the control group.

Conclusion

A high incidence of VTE in patients receiving cisplatin based chemotherapy was demonstrated in this study. Prospective studies are warranted to establish this observation with certainty and to explore the possible use of thromboprophylaxis in patients receiving cisplatin based chemotherapeutic regimens.

Chemokines, cytokines and exosomes help tumors to shape inflammatory microenvironment

Relationship between inflammation and cancer is now well-established and represents a paradigm that our immune response does not necessarily serves solely to protect us from infections and cancer. Many specific mechanisms that link chronic inflammation to cancer promotion and metastasis have been uncovered in the recent years. Here we are focusing on the effects that tumors may exert on inflammatory cascades, tuning the immune system ability to cause tumor promotion or regression. In particular, we discuss the contributions of chemokines, cytokines and exosomes to the processes such as induction of inflammation and tumorigenesis. Overall, tumor-elicited inflammation is a key driver of tumor progression and an essential component of tumor microenvironment.

CD4 T cell knockout does not protect against kidney injury and worsens cancer

Most previous studies of cisplatin-induced acute kidney injury (AKI) have been in models of acute, high-dose cisplatin administration that leads to mortality in non-tumor-bearing mice. The aim of the study was to determine whether CD4 T cell knockout protects against AKI and cancer in a clinically relevant model of low-dose cisplatin-induced AKI in mice with cancer. Kidney function, serum neutrophil gelatinase-associated lipocalin (NGAL), acute tubular necrosis (ATN), and tubular apoptosis score were the same in wild-type and CD4 -/- mice with AKI. The lack of protection against AKI in CD4 -/- mice was associated with an increase in extracellular signal-regulated kinase (ERK), p38, CXCL1, and TNF-α, mediators of AKI and fibrosis, in both cisplatin-treated CD4 -/- mice and wild-type mice. The lack of protection was independent of the presence of cancer or not. Tumor size was double, and cisplatin had an impaired therapeutic effect on the tumors in CD4 -/- vs. wild-type mice. Mice depleted of CD4 T cells using the GK1.5 antibody were not protected against AKI and had larger tumors and lesser response to cisplatin. In summary, in a clinically relevant model of cisplatin-induced AKI in mice with cancer, (1) CD4 -/- mice were not protected against AKI; (2) ERK, p38, CXCL1, and TNF-α, known mediators of AKI, and interstitial fibrosis were increased in CD4 -/- kidneys; and (3) CD4 -/- mice had faster tumor growth and an impaired therapeutic effect of cisplatin on the tumors. The data warns against the use of CD4 T cell inhibition to attenuate cisplatin-induced AKI in patients with cancer.

KEY MESSAGE

A clinically relevant low-dose cisplatin model of AKI in mice with cancer was used. CD4 -/- mice were not functionally or histologically protected against AKI. CD4 -/- mice had faster tumor growth. CD4 -/- mice had an impaired therapeutic effect of cisplatin on the tumors. Mice depleted of CD4 T cells were not protected against AKI and had larger tumors.

[Mechanism of Platinum Derivatives Induced Kidney Injury]

Platinum derivatives are the most widely used chemotherapeutic agents to treat solid tumors including ovarian, head and neck, and testicular germ cell tumors, lung cancer, and colorectal cancer. Two major problems exist, however, in the clinic use of platinum derivatives. One is the development of tumor resistance to the drug during therapy, leading to treatment failure. The other is the drug's toxicity such as the cisplatin's nephrotoxicity, which limits the dose that can be administered. This paper describes the mechanism of platinum derivatives induced kidney injury.

The caspase 3 sensor Phiphilux G2D2 is activated non-specifically in S1 renal proximal tubules

Tubular cell apoptosis is a major phenotype of cell death in various forms of acute kidney injury. Quantifying apoptosis in fixed tissues is problematic because apoptosis evolves over time and dead cells are rapidly cleared by the phagocytic system. Phiphilux is a fluorescent probe that is activated specifically by caspase 3 and does not inhibit the subsequent activity of this effector caspase. It has been used successfully to quantify apoptosis in cell culture. Here we examined the feasibility of using Phiphilux to measure renal tubular apoptosis progression over time in live animals using intravital 2-photon microscopy. Our results show that Phiphilux can detect apoptosis in S2 tubules but is activated non-specifically in S1 tubules.

An Early and Robust Activation of Caspases Heads Cells for a Regulated Form of Necrotic-like Cell Death

Apoptosis is triggered by the activation of caspases and characterized by chromatin condensation and nuclear fragmentation (type II nuclear morphology). Necrosis is depicted by a gain in cell volume (oncosis), swelling of organelles, plasma membrane leakage, and subsequent loss of intracellular contents. Although considered as different cell death entities, there is an overlap between apoptosis and necrosis. In this sense, mounting evidence suggests that both processes can be morphological expressions of a common biochemical network known as "apoptosis-necrosis continuum." To gain insight into the events driving the apoptosis-necrosis continuum, apoptotically proficient cells were screened facing several apoptotic inducers for the absence of type II apoptotic nuclear morphologies. Chelerythrine was selected for further studies based on its cytotoxicity and the lack of apoptotic nuclear alterations. Chelerythrine triggered an early plasma membrane leakage without condensed chromatin aggregates. Ultrastructural analysis revealed that chelerythrine-mediated cytotoxicity was compatible with a necrotic-like type of cell death. Biochemically, chelerythrine induced the activation of caspases. Moreover, the inhibition of caspases prevented chelerythrine-triggered necrotic-like cell death. Compared with staurosporine, chelerythrine induced stronger caspase activation detectable at earlier times. After using a battery of chemicals, we found that high concentrations of thiolic antioxidants fully prevented chelerythrine-driven caspase activation and necrotic-like cell death. Lower amounts of thiolic antioxidants partially prevented chelerythrine-mediated cytotoxicity and allowed cells to display type II apoptotic nuclear morphology correlating with a delay in caspase-3 activation. Altogether, these data support that an early and pronounced activation of caspases can drive cells to undergo a form of necrotic-like regulated cell death.

An mTOR kinase inhibitor slows disease progression in a rat model of polycystic kidney disease

BACKGROUND

The mTOR pathway, which consists of mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2), is activated in polycystic kidney disease (PKD) kidneys. Sirolimus and everolimus indirectly bind and inhibit mTORC1. A novel group of drugs, the mTOR kinase inhibitors, directly bind to mTOR kinase, thus inhibiting both mTORC1 and 2. The aim of the study was to determine the therapeutic effect of an mTOR kinase inhibitor, PP242, in the Han:SPRD rat (Cy/+) model of PKD.

METHODS

Male rats were treated with PP242 5 mg/kg/day IP or vehicle for 5 weeks.

RESULTS

PP242 significantly reduced the kidney enlargement, the cyst density and the blood urea nitrogen in Cy/+ rats. On immunoblot of kidneys, PP242 resulted in a decrease in pS6, a marker of mTORC1 signaling and pAkt(Ser473), a marker of mTORC2 signaling. mTORC plays an important role in regulating cytokine production. There was an increase in IL-1, IL-6, CXCL1 and TNF-α in Cy/+ rat kidneys that was unaffected by PP242. Apoptosis or proliferation is known to play a causal role in cyst growth. PP242 had no effect on caspase-3 activity, TUNEL positive or active caspase-3-positive tubular cells in Cy/+ kidneys. PP242 reduced the number of proliferating cells per cyst and per non-cystic tubule in Cy/+ rats.

CONCLUSIONS

In a rat model of autosomal dominant polycystic kidney disease, PP242 treatment (i) decreases proliferation in cystic and non-cystic tubules; (ii) inhibits renal enlargement and cystogenesis and (iii) significantly reduces the loss of kidney function.

Pathophysiology of cisplatin-induced acute kidney injury

Cisplatin and other platinum derivatives are the most widely used chemotherapeutic agents to treat solid tumors including ovarian, head and neck, and testicular germ cell tumors. A known complication of cisplatin administration is acute kidney injury (AKI). The nephrotoxic effect of cisplatin is cumulative and dose-dependent and often necessitates dose reduction or withdrawal. Recurrent episodes of AKI may result in chronic kidney disease. The pathophysiology of cisplatin-induced AKI involves proximal tubular injury, oxidative stress, inflammation, and vascular injury in the kidney. There is predominantly acute tubular necrosis and also apoptosis in the proximal tubules. There is activation of multiple proinflammatory cytokines and infiltration of inflammatory cells in the kidney. Inhibition of the proinflammatory cytokines TNF-α or IL-33 or depletion of CD4+ T cells or mast cells protects against cisplatin-induced AKI. Cisplatin also causes endothelial cell injury. An understanding of the pathogenesis of cisplatin-induced AKI is important for the development of adjunctive therapies to prevent AKI, to lessen the need for dose decrease or drug withdrawal, and to lessen patient morbidity and mortality.

An mTOR anti-sense oligonucleotide decreases polycystic kidney disease in mice with a targeted mutation in Pkd2

Autosomal dominant polycystic kidney disease (ADPKD) is the most common life-threatening hereditary disease in the USA. In human ADPKD studies, sirolimus, a mammalian target of rapamycin complex 1 (mTORC1) inhibitor, had little therapeutic effect. While sirolimus robustly inhibits mTORC1, it has a minimal effect on mTOR complex 2 (mTORC2). Polycystic kidneys of Pkd2WS25/- mice, an orthologous model of human ADPKD caused by a mutation in the Pkd2 gene, had an early increase in pS6 (marker of mTORC1) and pAktSer(473) (marker of mTORC2). To investigate the effect of combined mTORC1 and 2 inhibition, Pkd2WS25/- mice were treated with an mTOR anti-sense oligonucleotide (ASO) that blocks mTOR expression thus inhibiting both mTORC1 and 2. The mTOR ASO resulted in a significant decrease in mTOR protein, pS6 and pAktSer(473). Pkd2WS25/- mice treated with the ASO had a normalization of kidney weights and kidney function and a marked decrease in cyst volume. The mTOR ASO resulted in a significant decrease in proliferation and apoptosis of tubular epithelial cells. To demonstrate the role of mTORC2 on cyst growth, Rictor, the functional component of mTORC2, was silenced in Madin-Darby canine kidney cell cysts grown in 3D cultures. Silencing Rictor significantly decreased cyst volume and expression of pAktSer(473). The decreased cyst size in the Rictor silenced cells was reversed by introduction of a constitutively active Akt1. In vitro, combined mTORC1 and 2 inhibition reduced cyst growth more than inhibition of mTORC1 or 2 alone. In conclusion, combined mTORC1 and 2 inhibition has therapeutic potential in ADPKD.

The water-soluble triptolide derivative PG490-88 protects against cisplatin-induced acute kidney injury

Triptolide, a traditional Chinese medicine, has anti-inflammatory, antiproliferative, and proapoptotic properties. As interstitial inflammation and tubular apoptosis are features of cisplatin-induced acute kidney injury (AKI), we determined the effect of the water-soluble triptolide derivative 14-succinyl triptolide sodium salt (PG490-88) in a mouse model of cisplatin-induced AKI. PG490-88 resulted in a significant decrease in blood urea nitrogen (BUN), serum creatinine, and acute tubular necrosis (ATN) score, and a nonsignificant increase in tubular apoptosis score in AKI. The mitogen-activated protein kinase (MAPK) pathway is activated in AKI. On immunoblot analysis, phosphoextracellular signal-regulated kinase (p-ERK) was increased 3.6-fold in AKI and 2.0-fold inhibited by PG490-88. Phospho-c-Jun N-terminal kinase (p-JNK) was increased in AKI. PG490-88 resulted in a nonsignificant decrease in p-JNK. Phospho-p38 was not affected by cisplatin or PG490-88. MAPK phosphatase-1 (MKP-1) that negatively regulates MAPK signaling has not previously been studied in AKI. MKP-1 activity was not affected by cisplatin or PG490-88. Changes in p-ERK, p-JNK, and MKP-1 were confirmed on reverse protein phase analysis. The ERK inhibitor U0126 resulted in lower BUN and serum creatinine, suggesting a mechanistic role of ERK in AKI. The increase in interleukin-1α (IL-1α), IL-1β, IL-6, CXCL1, and IL-33 in the kidney in AKI was unaffected by PG490-88. In summary, PG490-88 protects against AKI and ATN despite no decrease in tubular apoptosis. The protection of PG490-88 against AKI was associated with a decrease in p-ERK and was independent of MKP-1 and proinflammatory cytokines. In conclusion, PG490-88 protects against cisplatin-induced AKI possibly by decreasing p-ERK.

Induction of cell death by graphene in Arabidopsis thaliana (Columbia ecotype) T87 cell suspensions

The toxicity of graphene on suspensions of Arabidopsis thaliana (Columbia ecotype) T87 cells was investigated by examining the morphology, mitochondrial dysfunction, reactive oxygen species generation (ROS), and translocation of graphene as the toxicological endpoints. The cells were grown in Jouanneau and Péaud-Lenoel (JPL) media and exposed to graphene at concentrations 0-80 mg/L. Morphological changes were observed by scanning electron microscope and the adverse effects such as fragmented nuclei, membrane damage, mitochondrial dysfunction was observed with fluorescence microscopy by staining with Hoechst 33342/propidium iodide and succinate dehydrogenase (mitochondrial bioenergetic enzyme). Analysis of intracellular ROS by 2',7'-dichlorofluorescein diacetate demonstrated that graphene induced a 3.3-fold increase in ROS, suggesting that ROS are key mediators in the cell death signaling pathway. Transmission electron microscopy verified the translocation of graphene into cells and an endocytosis-like structure was observed which suggested graphene entering into the cells by endocytosis. In conclusion, our results show that graphene induced cell death in T87 cells through mitochondrial damage mediated by ROS.

NLRP3 inflammasome knockout mice are protected against ischemic but not cisplatin-induced acute kidney injury

We have demonstrated that caspase-1 is a mediator of both cisplatin-induced acute kidney injury (AKI) and ischemic AKI. As caspase-1 is activated in the inflammasome, we investigated the inflammasome in cisplatin-induced and ischemic AKI. Mice were injected with cisplatin or subjected to bilateral renal pedicle clamping. Immunoblot analysis of whole kidney after cisplatin-induced AKI revealed: 1) an increase in apoptosis-associated Speck-like protein containing a caspase recruitment domain (ASC), the major protein that complexes with nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain containing proteins (NLRP) 1 or 3 to form the inflammasome; 2) an increase in caspase-1 activity, caspase-5, and NLRP1, components of the NLRP1 inflammasome; and 3) a trend toward increased NLRP3. To determine whether the NLRP3 inflammasome plays an injurious role in cisplatin-induced AKI, we studied NLRP knockout (NLRP3(-/-)) mice. In cisplatin-induced AKI, the blood urea nitrogen, serum creatinine, acute tubular necrosis score, and tubular apoptosis score were not significantly decreased in NALP3(-/-) mice compared with wild-type mice. We have previously demonstrated the injurious role of caspase-1 in ischemic AKI. NLRP3, but not ASC or NLRP1, is increased in ischemic AKI. NLRP3(-/-) mice with ischemic AKI had significantly lower blood urea nitrogen, serum creatinine, and acute tubular necrosis and apoptosis scores than the wild-type controls. The difference in protection against cisplatin-induced AKI compared with ischemic AKI in NLRP3(-/-) mice was not explained by the differences in proinflammatory cytokines interleukin (IL)-1β, IL-6, chemokine (C-X-C motif) ligand 1, or tumor necrosis factor α. NLRP3 inflammasome is a mediator of ischemic AKI but not cisplatin-induced AKI, and further investigation of the NLRP1 inflammasome in cisplatin-induced AKI should prove interesting.

Vegfa protects the glomerular microvasculature in diabetes

Vascular endothelial growth factor A (VEGFA) expression is increased in glomeruli in the context of diabetes. Here, we tested the hypothesis that this upregulation of VEGFA protects the glomerular microvasculature in diabetes and that therefore inhibition of VEGFA will accelerate nephropathy. To determine the role of glomerular Vegfa in the development and progression of diabetic nephropathy, we used an inducible Cre-loxP gene-targeting system that enabled genetic deletion of Vegfa selectively from glomerular podocytes of wild-type or diabetic mice. Type 1 diabetes was induced in mice using streptozotocin (STZ). We then assessed the extent of glomerular dysfunction by measuring proteinuria, glomerular pathology, and glomerular cell apoptosis. Vegfa expression increased in podocytes in the STZ model of diabetes. After 7 weeks of diabetes, diabetic mice lacking Vegfa in podocytes exhibited significantly greater proteinuria with profound glomerular scarring and increased apoptosis compared with control mice with diabetes or Vegfa deletion without diabetes. Reduced local production of glomerular Vegfa in a mouse model of type 1 diabetes promotes endothelial injury accelerating the progression of glomerular injury. These results suggest that upregulation of VEGFA in diabetic kidneys protects the microvasculature from injury and that reduction of VEGFA in diabetes may be harmful.

zVAD-fmk prevents cisplatin-induced cleavage of autophagy proteins but impairs autophagic flux and worsens renal function

Cisplatin injury to renal tubular epithelial cells (RTEC) is accompanied by autophagy and caspase activation. However, autophagy gradually decreases during the course of cisplatin injury. The role of autophagy and the mechanism of its decrease during cisplatin injury are not well understood. This study demonstrated that autophagy proteins beclin-1, Atg5, and Atg12 were cleaved and degraded during the course of cisplatin injury in RTEC and the kidney. zVAD-fmk, a widely used pancaspase inhibitor, blocked cleavage of autophagy proteins suggesting that zVAD-fmk would promote the autophagy pathway. Unexpectedly, zVAD-fmk blocked clearance of the autophagosomal cargo, indicating lysosomal dysfunction. zVAD-fmk markedly inhibited cisplatin-induced lysosomal cathepsin B and calpain activities and therefore impaired autophagic flux. In a mouse model of cisplatin nephrotoxicity, zVAD-fmk impaired autophagic flux by blocking autophagosomal clearance as revealed by accumulation of key autophagic substrates p62 and LC3-II. Furthermore, zVAD-fmk worsened cisplatin-induced renal dysfunction. Chloroquine, a lysomotropic agent that is known to impair autophagic flux, also exacerbated cisplatin-induced decline in renal function. These findings demonstrate that impaired autophagic flux induced by zVAD-fmk or a lysomotropic agent worsened renal function in cisplatin acute kidney injury (AKI) and support a protective role of autophagy in AKI. These studies also highlight that the widely used antiapoptotic agent zVAD-fmk may be contraindicated as a therapeutic agent for preserving renal function in AKI.

β-Caryophyllene ameliorates cisplatin-induced nephrotoxicity in a cannabinoid 2 receptor-dependent manner

(E)-β-caryophyllene (BCP) is a natural sesquiterpene found in many essential oils of spice (best known for contributing to the spiciness of black pepper) and food plants with recognized anti-inflammatory properties. Recently it was shown that BCP is a natural agonist of endogenous cannabinoid 2 (CB(2)) receptors, which are expressed in immune cells and mediate anti-inflammatory effects. In this study we aimed to test the effects of BCP in a clinically relevant murine model of nephropathy (induced by the widely used antineoplastic drug cisplatin) in which the tubular injury is largely dependent on inflammation and oxidative/nitrative stress. β-caryophyllene dose-dependently ameliorated cisplatin-induced kidney dysfunction, morphological damage, and renal inflammatory response (chemokines MCP-1 and MIP-2, cytokines TNF-α and IL-1β, adhesion molecule ICAM-1, and neutrophil and macrophage infiltration). It also markedly mitigated oxidative/nitrative stress (NOX-2 and NOX-4 expression, 4-HNE and 3-NT content) and cell death. The protective effects of BCP against biochemical and histological markers of nephropathy were absent in CB(2) knockout mice. Thus, BCP may be an excellent therapeutic agent to prevent cisplatin-induced nephrotoxicity through a CB(2) receptor-dependent pathway. Given the excellent safety profile of BCP in humans it has tremendous therapeutic potential in a multitude of diseases associated with inflammation and oxidative stress.

Evaluation of urine biomarkers of kidney injury in polycystic kidney disease

Progressive disruption of renal tubular integrity in the setting of increased cellular proliferation and apoptosis is a feature of ADPKD. Here we evaluated the effect of these processes on the expression of NGAL and IL-18, markers of tubular injury, in rodent models and in the cyst fluid and urine of patients with ADPKD. Two mouse models where Pkd2 was inactivated which resulted in early or adult onset cysts, were used to evaluate NGAL levels. Further, the Han:SPRD rat model of polycystic disease was used to study IL-18 levels. In four annual serial urine samples from 107 patients with ADPKD in the Consortium for Radiologic Imaging for the Study of Polycystic Kidney Disease (CRISP) study, NGAL and IL-18 excretion rates were determined in conjunction with measures of total kidney volume and estimated GFR (eGFR) by the MDRD equation. Kidneys from affected mice and rats showed prominent expression of NGAL and IL-18/IL-18R, respectively, in epithelial cells lining kidney cysts. In human ADPKD cyst fluid, both NGAL and IL-18 were elevated. In CRISP patients, the mean percentage increase in total kidney volume was 5.4 /year and the mean decline in eGFR 2.4 mL/min/year. The trend of increased mean urine NGAL and IL-18 over three years was statistically significant; however, there was no association of tertiles of IL-18 or quartiles of NGAL and the change in total kidney volume or eGFR over this period. Thus, urinary NGAL and IL-18 excretion are mildly and stably elevated in ADPKD, but do not correlate with changes in total kidney volume or kidney function. This may be due, in part, to the lack of communication between individual cysts and the urinary collecting system in this disorder.

Tumor promotion via injury- and death-induced inflammation

Inhibition of programmed cell death is considered to be a major aspect of tumorigenesis. Indeed, several key oncogenic transcription factors, such as NF-κB and STAT3, exert their tumor-promoting activity at least in part through upregulation of survival genes. However, many cancers develop in response to chronic tissue injury, in which the resulting cell death increases the tumorigenic potential of the neighboring cells. In this review, we discuss a resolution to this paradox based on cell death-mediated induction of tumor promoting inflammatory cytokines, which enhance cell survival and trigger compensatory proliferation in response to tissue injury.

IL-33 exacerbates acute kidney injury

Inflammation contributes to the pathogenesis of acute kidney injury (AKI). IL-33 is a proinflammatory cytokine, but its role in AKI is unknown. Here we observed increased protein expression of full-length IL-33 in the kidney following induction of AKI with cisplatin. To determine whether IL-33 promotes injury, we administered soluble ST2 (sST2), a fusion protein that neutralizes IL-33 activity by acting as a decoy receptor. Compared with cisplatin-induced AKI in untreated mice, mice treated with sST2 had fewer CD4 T cells infiltrate the kidney, lower serum creatinine, and reduced acute tubular necrosis (ATN) and apoptosis. In contrast, administration of recombinant IL-33 (rIL-33) exacerbated cisplatin-induced AKI, measured by an increase in CD4 T cell infiltration, serum creatinine, ATN, and apoptosis; this did not occur in CD4-deficient mice, suggesting that CD4 T cells mediate the injurious effect of IL-33. Wildtype mice that received cisplatin and rIL-33 also had higher levels of the proinflammatory chemokine CXCL1, which CD T cells produce, in the kidney compared with CD4-deficient mice. Mice deficient in the CXCL1 receptor also had lower serum creatinine, ATN, and apoptosis than wildtype mice following cisplatin-induced AKI. Taken together, IL-33 promotes AKI through CD4 T cell-mediated production of CXCL1. These data suggest that inhibiting IL-33 or CXCL1 may have therapeutic potential in AKI.