The induction strategies administered in the treatment of multiple myeloma exhibit a deleterious effect on the endothelium

Endothelial injury and dysfunction with emerging immunotherapies in multiple myeloma, the impact of COVID-19, and endothelial protection with a focus on the evolving role of defibrotide

Patients with multiple myeloma (MM) were among the groups impacted more severely by the COVID-19 pandemic, with higher rates of severe disease and COVID-19-related mortality. MM and COVID-19, plus post-acute sequelae of SARS-CoV-2 infection, are associated with endothelial dysfunction and injury, with overlapping inflammatory pathways and coagulopathies. Existing treatment options for MM, notably high-dose therapy with autologous stem cell transplantation and novel chimeric antigen receptor (CAR) T-cell therapies and bispecific T-cell engaging antibodies, are also associated with endothelial cell injury and mechanism-related toxicities. These pathologies include cytokine release syndrome (CRS) and neurotoxicity that may be exacerbated by underlying endotheliopathies. In the context of these overlapping risks, prophylaxis and treatment approaches mitigating the inflammatory and pro-coagulant effects of endothelial injury are important considerations for patient management, including cytokine receptor antagonists, thromboprophylaxis with low-molecular-weight heparin and direct oral anticoagulants, and direct endothelial protection with defibrotide in the appropriate clinical settings.

The proteasome inhibitor carfilzomib exerts anti-inflammatory and antithrombotic effects on the endothelium

BACKGROUND

Carfilzomib (CFZ) is a second-generation proteasome inhibitor used to treat multiple myeloma. Potent inhibition of the proteasome results in chronic proteotoxic endoplasmic reticulum (ER) stress, leading to apoptosis. While CFZ has improved survival rates in multiple myeloma, it is associated with an increased risk of cardiovascular adverse effects. While this has been putatively linked to cardiotoxicity, CFZ could potentially also exhibit adverse effects on the endothelium.

OBJECTIVES

To investigate the effects of CFZ on the endothelium.

METHODS

Human umbilical vein endothelial cells (HUVECs) were treated with CFZ, and expression of relevant markers of ER stress, inflammation, and thrombosis was measured and functionally assessed.

RESULTS

CFZ failed to induce ER stress in HUVECs but induced the expression of Kruppel-like factor 4, endothelial nitric oxide synthase, tissue plasminogen activator, and thrombomodulin and reduced tumor necrosis factor alpha (TNFα)-mediated intercellular adhesion molecule 1 and tissue factor expression, suggesting a potential protective effect on the endothelium. Consistent with these observations, CFZ reduced leukocyte adhesion under shear stress and reduced factor Xa generation and fibrin clot formation on the endothelium following TNFα treatment and inhibited von Willebrand factor (VWF) and angiopoietin-2 exocytosis from Weibel-Palade bodies. Subsequently, CFZ inhibited the formation of VWF-platelet strings, and moreover, media derived from myeloma cell lines induced VWF release, a process also inhibited by CFZ.

CONCLUSION

These data demonstrate that CFZ is unable to induce ER stress in confluent resting endothelial cells and can conversely attenuate the prothrombotic effects of TNFα on the endothelium. This study suggests that CFZ does not negatively alter HUVECs, and proteasome inhibition of the endothelium may offer a potential way to prevent thrombosis.

Endothelial activation and damage as a common pathological substrate in different pathologies and cell therapy complications

The endothelium is a biologically active interface with multiple functions, some of them common throughout the vascular tree, and others that depend on its anatomical location. Endothelial cells are continually exposed to cellular and humoral factors, and to all those elements (biological, chemical, or hemodynamic) that circulate in blood at a certain time. It can adapt to different stimuli but this capability may be lost if the stimuli are strong enough and/or persistent in time. If the endothelium loses its adaptability it may become dysfunctional, becoming a potential real danger to the host. Endothelial dysfunction is present in multiple clinical conditions, such as chronic kidney disease, obesity, major depression, pregnancy-related complications, septic syndromes, COVID-19, and thrombotic microangiopathies, among other pathologies, but also in association with cell therapies, such as hematopoietic stem cell transplantation and treatment with chimeric antigen receptor T cells. In these diverse conditions, evidence suggests that the presence and severity of endothelial dysfunction correlate with the severity of the associated disease. More importantly, endothelial dysfunction has a strong diagnostic and prognostic value for the development of critical complications that, although may differ according to the underlying disease, have a vascular background in common. Our multidisciplinary team of women has devoted many years to exploring the role of the endothelium in association with the mentioned diseases and conditions. Our research group has characterized some of the mechanisms and also proposed biomarkers of endothelial damage. A better knowledge would provide therapeutic strategies either to prevent or to treat endothelial dysfunction.

Characteristics of Engraftment Syndrome following Autologous Stem Cell Transplantation in Light Chain Amyloidosis with Renal Involvement

Engraftment syndrome (ES) is a clinical complication that occurs during the neutrophil recovery phase following hematopoietic stem cell transplantation. The clinical features of ES in light chain (AL) amyloidosis remains to be thoroughly investigated. This study was conducted to better understand the characteristics of ES following autologous stem cell transplantation (ASCT) in AL amyloidosis with renal involvement. We conducted this single-center retrospective study in 302 patients with AL amyloidosis who underwent ASCT between July 2010 and December 2021. Sixty-seven of the 302 patients (22.2%) developed ES, with a median time to the occurrence of ES after stem cell reinfusion of 11 days (range, 7 to 17 days). Among the outcome measures in this study, estimated glomerular filtration rate (eGFR) at baseline and C-reactive protein (CRP) level on the day of granulocyte engraftment were statistically different between the ES patients and non-ES patients. We observed no significant difference between the 2 groups in transplantation-related adverse events (grade ≥ 2), hematologic and organ responses, overall survival, and progression-free survival. Furthermore, CRP level at granulocyte engraftment (odds ratio [OR], 1.012; 95% confidence interval [CI], 1.004 to 1.020; P = .002) and the absence of induction chemotherapy before ASCT (OR, 1.977; 95% CI, 1.047 to 3.731; P = .036) were identified as risk factors for the development of ES, whereas a higher eGFR at baseline (OR, .981; 95% CI, .969 to .993; P = .002) was identified as a protective factor against ES. Our data show a 22.2% incidence of ES in AL amyloidosis patients with renal involvement after ASCT and identify associated risk and protective factors, which can improve the understanding of this clinical complication.

Mafosfamide, a cyclophosphamide analog, causes a proinflammatory response and increased permeability on endothelial cells in vitro

Post-transplantation cyclophosphamide (PTCy) has decreased GVHD incidence. Endothelial damage in allo-HCT is caused by multiple factors, including conditioning treatments and some immunosupressants, and underlies HCT-complications as GVHD. Nevertheless, the specific impact of PTCy on the endothelium remains unclear. We evaluated the effect of mafosfamide (MAF), an active Cy analog, on endothelial cells (ECs) vs. cyclosporine A (CSA), with known damaging endothelial effect. ECs were exposed to MAF and CSA to explore changes in endothelial damage markers: (i) surface VCAM-1, (ii) leukocyte adhesion on ECs, (iii) VE-cadherin expression, (iv) production of VWF, and (v) activation of intracellular signaling proteins (p38MAPK, Akt). Results obtained (expressed in folds vs. controls) indicate that both compounds increased VCAM-1 expression (3.1 ± 0.3 and 2.8 ± 0.6, respectively, p < 0.01), with higher leukocyte adhesion (5.5 ± 0.6, p < 0.05, and 2.8 ± 0.4, respectively). VE-cadherin decreased with MAF (0.8 ± 0.1, p < 0.01), whereas no effect was observed with CSA. Production of VWF augmented with CSA (1.4 ± 0.1, p < 0.01), but diminished with MAF (0.9 ± 0.1, p < 0.05). p38MAPK activation occurred with both compounds, being more intense and faster with CSA. Both drugs activated Akt, with superior MAF effect at longer exposure. Therefore, the cyclophosphamide analog MAF is not exempt from a proinflammatory effect on the endothelium, though without modifying the subendothelial characteristics.

Endothelial TFEB signaling-mediated autophagic disturbance initiates microglial activation and cognitive dysfunction

Cognitive impairment caused by systemic chemotherapy is a critical question that perplexes the effective implementation of clinical treatment, but related molecular events are poorly understood. Herein, we show that bortezomib exposure leads to microglia activation and cognitive impairment, this occurs along with decreased nuclear translocation of TFEB (transcription factor EB), which is linked to macroautophagy/autophagy disorder, STAT3 (signal transducer and activator of transcription 3) phosphorylation and IL23A (interleukin 23 subunit alpha) expression. Pharmacological enhancement of TFEB nuclear translocation by digoxin restores lysosomal function and reduces STAT3-dependent endothelial IL23A secretion. As a consequence, we found that brain endothelial-specific ablation of Il23a ameliorated both microglia activation and cognitive dysfunction. Thus, the endothelial TFEB-STAT3-IL23A axis in the brain represents a critical cellular event for initiating bortezomib-mediated aberrant microglial activation and synapse engulfment. Our results suggest the reversal of TFEB nuclear translocation may provide a novel therapeutic approach to prevent symptoms of cognitive dysfunction during clinical use of bortezomib.Abbreviations: AAV: adeno-associated virus; BBB: blood-brain barrier; BTZ: bortezomib; DG: digoxin; DGs: dentate gyrus; DLG4/PSD95: discs large MAGUK scaffold protein 4; HBMECs: human brain microvascular endothelial cells; HP: hippocampus; IL23A: interleukin 23 subunit alpha; MBVECs: mouse brain vascular endothelial cells; mPFC: medial prefrontal cortex; NORT: novel object recognition test; OLT: object location test; PLX5622: 6-fluoro-N-([5-fluoro-2-methoxypyridin-3-yl]methyl)-5-(5-methyl-1H-pyrrolo[2,3-b]pyridin-3- yl)methyl; PPP3/calcineurin: protein phosphatase 3; SBEs: STAT3 binding elements; shRNA: small hairpin RNA; SLC17A7/VGLUT1: solute carrier family 17 member 7; SLC32A1/VGAT: solute carrier family 32 member 1; STAT3: signal transducer and activator of transcription 3, TFEB: transcription factor EB; Ub: ubiquitin.

The role of VWF/FVIII in thrombosis and cancer progression in multiple myeloma and other hematological malignancies

Cancer associated thrombosis (CAT) is associated with significant morbidity and mortality, highlighting an unmet clinical need to improve understanding of the pathophysiology of CAT. Multiple myeloma (MM) is associated with one of the highest rates of thrombosis despite widespread use of thromboprophylactic agents. The pathophysiology of thrombosis in MM is multifactorial and patients with MM appear to display a hypercoagulable phenotype with potential contributory factors including raised von Willebrand factor (VWF) levels, activated protein C resistance, impaired fibrinolysis, and abnormal thrombin generation. In addition, the toxic effect of anti-myeloma therapies on the endothelium and contribution to thrombosis has been widely described. Elevated VWF/factor VIII (FVIII) plasma levels have been reported in heterogeneous cohorts of patients with MM and other hematological malignancies. In specific studies, high plasma VWF levels have been shown to associate with VTE risk and reduced overall survival. While the mechanisms underpinning this remain unclear, dysregulation of the VWF and A Disintegrin And Metalloprotease Thrombospondin type 1, motif 13 (ADAMTS-13) axis is evident in certain solid organ malignancies and correlates with advanced disease and thrombosis. Furthermore, thrombotic microangiopathic conditions arising from deficiencies in ADAMTS-13 and thus an accumulation of prothrombotic VWF multimers have been reported in patients with MM, particularly in association with specific myeloma therapies. This review will discuss current evidence on the pathophysiological mechanisms underpinning thrombosis in MM and in particular summarize the role of VWF/FVIII in hematological malignancies with a focus on thrombotic risk and emerging evidence for contribution to disease progression.

Circulating Soluble Urokinase-Type Plasminogen Activator Receptor Levels Reflect Renal Function in Newly Diagnosed Patients with Multiple Myeloma Treated with Bortezomib-Based Induction

(1) Background: Soluble urokinase-type plasminogen activator receptor (suPAR) has been implicated in the pathogenesis of kidney disease in different disease settings. The aim of this study was to investigate a possible link between suPAR circulating levels and renal impairment (RI) in newly diagnosed patients with symptomatic multiple myeloma (NDMM) before and after frontline therapy with bortezomib-based regimens. (2) Methods: We studied 47 NDMM patients (57% males, median age 69.5 years) before the administration of anti-myeloma treatment and at best response to bortezomib-based therapy. suPAR was measured in the serum of all patients and of 24 healthy matched controls, using an immuno-enzymatic assay (ViroGates, Denmark). (3) Results: suPAR levels were elevated in NDMM patients at diagnosis compared to healthy individuals (p < 0.001). suPAR levels strongly correlated with disease stage (p-ANOVA < 0.001). suPAR levels both at diagnosis and at best response negatively correlated with estimated glomerular filtration rate (eGFR) values (p < 0.001). Interestingly, no significance changes in suPAR levels were observed at best response compared to baseline values (p = 0.31) among 18 responding patients with baseline eGFR < 50 mL/min/1.73 m². (4) Conclusions: SuPAR levels reflect renal function in NDMM patients treated with bortezomib-based induction. Responders may have elevated circulating suPAR levels, possibly reflecting persistent kidney damage, despite their renal response.