Primaquine Diphosphate, a Known Antimalarial Drug, Blocks Vascular Leakage Acting Through Junction Stabilization

Abstract

Endothelial barrier integrity is important for vascular homeostasis, and hyperpermeability participates in the progression of many pathological states, such as diabetic retinopathy, ischemic stroke, chronic bowel disease, and inflammatory disease. Here, using drug repositioning, we discovered that primaquine diphosphate (PD), previously known as an antimalarial drug, was a potential blocker of vascular leakage. PD inhibited the linear pattern of vascular endothelial growth factors (VEGF)-induced disruption at the cell boundaries, blocked the formation of VEGF-induced actin stress fibers, and stabilized the cortactin actin rings in endothelial cells. PD significantly reduced leakage in the Miles assay and mouse model of streptozotocin (STZ)-induced diabetic retinopathy. Targeted prediction programs and deubiquitinating enzyme activity assays identified a potential mechanism of action for PD and demonstrated that this operates via ubiquitin specific protease 1 (USP1). USP1 inhibition demonstrated a conserved barrier function by inhibiting VEGF-induced leakage in endothelial permeability assays. Taken together, these findings suggest that PD could be used as a novel drug for vascular leakage by maintaining endothelial integrity.

Roles of ubiquitin-specific proteases in inflammatory diseases

“…Diabetic retinopathy (DR) is a common microvascular complication of diabetes, and endothelial barrier integrity is important for vascular steady ( 126 ). Several pharmacological inhibitors of USP1 have been identified as potential treatments for DR, such as Primaquine Diphosphate, as they can alleviate β-cell death or inhibit vascular endothelial growth factor (VEGF)-induced leakage, thus improving DR outcomes ( 109 , 127 , 128 ). In DR patients, USP14 can modulate inflammatory response through the TGF-β1 signal transduction, IκBα and NF-κB signaling pathway s in HG-treated Müller cells, as well as reactive oxygen species (ROS) ( 126 ).This modulation plays a role in mediating the progression of DR ( 126 ) ( Table 9 ).…”

Ubiquitin-Specific Proteases (USPs) and Metabolic Disorders

“…In contrast to USP48, there are reports that two USPs, namely USP1 and 14, are deteriorative in diabetic retinopathy. An anti-malarial drug, primaquine diphosphate (PD), interrupted vascular endothelial growth factor (VEGF)-induced conformational changes of actin fibers in vascular endothelial cells [ 160 ]. Consequently, PD blocked vascular leakage and attenuated the severity of diabetic retinopathy [ 160 ].…”

“…An anti-malarial drug, primaquine diphosphate (PD), interrupted vascular endothelial growth factor (VEGF)-induced conformational changes of actin fibers in vascular endothelial cells [ 160 ]. Consequently, PD blocked vascular leakage and attenuated the severity of diabetic retinopathy [ 160 ]. PD also blocked more than 50% of the DUB activity of USP1, but not USP2 [ 160 ].…”

“…Consequently, PD blocked vascular leakage and attenuated the severity of diabetic retinopathy [ 160 ]. PD also blocked more than 50% of the DUB activity of USP1, but not USP2 [ 160 ]. Moreover, the Usp1 shRNA conserved VEGF-induced permeabilization of vessels, implying that USP1 contributes to diabetic retinopathy.…”

Spotlights on ubiquitin-specific protease 12 (USP12) in diseases: from multifaceted roles to pathophysiological mechanisms

“…For example, the interaction between USP5 and oxysterol-binding protein-related protein 8 (ORP8) facilitated the accumulation of ORP8 via USP5-mediated deubiquitination, leading to aggravation of ER (endoplasmic reticulum) stress in CRC cells treated with brigatinib, which was an anaplastic lymphoma kinase (ALK) inhibitor and originally approved for ALK-positive NSCLC, thus promoting apoptotic cell death of CRC cells [ 137 ]. Moreover, primaquine diphosphate (PD), a known antimalarial drug, was found to be able to inhibit USP1/Uaf1, and then suppress VEGF and histamine-induced vascular permeability [ 138 ]. Therefore, it is possible that drugs applied to other diseases are also relevant to deubiquitinase, but further studies are needed to see if they can be effective to USP12 as well.…”