Efficacy and safety of crisaborole ointment, 2%, in participants aged ≥45 years with stasis dermatitis: Results from a fully decentralized, randomized, proof-of-concept phase 2a study.

BACKGROUND: Crisaborole ointment, 2%, is a nonsteroidal topical phosphodiesterase 4 inhibitor approved for the treatment of mild-to-moderate atopic dermatitis. OBJECTIVE: To evaluate the efficacy and safety of crisaborole in stasis dermatitis (SD). METHODS: In this randomized, double-blind, vehicle-controlled, decentralized phase 2a study (NCT04091087), 65 participants aged ≥45 years with SD without active ulceration received crisaborole or vehicle (1:1) twice-daily for 6 weeks. The primary end point was percentage change from baseline in total sign score at week 6 based on in-person assessment. RESULTS: Crisaborole-treated participants had significantly reduced total sign score from baseline versus vehicle based on in-person (nondermatologist) assessment (-32.4% vs -18.1%, P = .0299) and central reader (dermatologists) assessment of photographs (-52.5% vs -10.3%, P = .0004). Efficacy according to success and improvement per Investigator's Global Assessment score and lesional percentage body surface area reached statistical significance based on central reader but not in-person assessments. Skin and subcutaneous tissue disorders were common all-causality treatment-emergent adverse events with crisaborole. LIMITATIONS: Small sample size and short treatment duration were key limitations. In-person assessment was not conducted by dermatologists. CONCLUSION: Crisaborole improved signs and symptoms of SD and was well tolerated. Central reader assessment represents a promising approach for siteless clinical research.

Endothelial cells overexpressing CXCR1/2 are renoprotective in rats with acute kidney injury.

Inflammation that develops with the release of chemokines and cytokines during acute kidney injury (AKI) has been shown to participate in functional renal recovery. Although a major research focus has been on the role of macrophages, the family of C-X-C motif chemokines that promote neutrophil adherence and activation also increases with kidney ischemia-reperfusion (I/R) injury. This study tested the hypothesis that intravenous delivery of endothelial cells (ECs) that overexpress (C-X-C motif) chemokine receptors 1 and 2 (CXCR1 and CXCR2, respectively) improves outcomes in kidney I/R injury. Overexpression of CXCR1/2 enhanced homing of endothelial cells to I/R-injured kidneys and limited interstitial fibrosis, capillary rarefaction, and tissue injury biomarkers (serum creatinine concentration and urinary kidney injury molecule-1) following AKI and also reduced expression of P-selectin and the rodent (C-X-C motif) chemokine cytokine-induced neutrophil chemoattractant (CINC)-2ß as well as the number of myeloperoxidase-positive cells in the postischemic kidney. The serum chemokine/cytokine profile, including CINC-1, showed similar reductions. These findings were not observed in rats given endothelial cells transduced with an empty adenoviral vector (null-ECs) or a vehicle alone. These data indicate that extrarenal endothelial cells that overexpress CXCR1 and CXCR2, but not null-ECs or vehicle alone, reduce I/R kidney injury and preserve kidney function in a rat model of AKI.NEW & NOTEWORTHY Inflammation facilitates kidney ischemia-reperfusion (I/R) injury. Endothelial cells (ECs) that were modified to overexpress (C-X-C motif) chemokine receptor (CXCR)1/2 (CXCR1/2-ECs) were injected immediately following kidney I/R injury. The interaction of CXCR1/2-ECs, but not ECs transduced with an empty adenoviral vector, with injured kidney tissue preserved kidney function and reduced production of inflammatory markers, capillary rarefaction, and interstitial fibrosis. The study highlights a functional role for the C-X-C chemokine pathway in kidney damage following I/R injury.

Matrix metalloproteinase-9 regulates afferent arteriolar remodeling and function in hypertension-induced kidney disease.

This study tested if matrix metalloproteinase (MMP)-9 promoted microvascular pathology that initiates hypertensive (HT) kidney disease in salt-sensitive (SS) Dahl rats. SS rats lacking Mmp9 (Mmp9-/-) and littermate control SS rats were studied after one week on a normotensive 0.3% sodium chloride (Pre-HT SS and Pre-HT Mmp9-/-) or a hypertension-inducing diet containing 4.0% sodium chloride (HT SS and HT Mmp9-/-). Telemetry-monitored blood pressure of both the HT SS and HT Mmp9-/- rats increased and did not differ. Kidney microvessel transforming growth factor-beta 1 (Tgfb1) mRNA did not differ between Pre-HT SS and Pre-HT Mmp9-/- rats, but with hypertension and expression of Mmp9 and Tgfb1 increased in HT SS rats, along with phospho-Smad2 labeling of nuclei of vascular smooth muscle cells, and with peri-arteriolar fibronectin deposition. Loss of MMP-9 prevented hypertension-induced phenotypic transformation of microvascular smooth muscle cells and the expected increased microvascular expression of pro-inflammatory molecules. Loss of MMP-9 in vascular smooth muscle cells in vitro prevented cyclic strain-induced production of active TGF-ß1 and phospho-Smad2/3 stimulation. Afferent arteriolar autoregulation was impaired in HT SS rats but not in HT Mmp9-/- rats or the HT SS rats treated with doxycycline, an MMP inhibitor. HT SS but not HT Mmp9-/- rats showed decreased glomerular Wilms Tumor 1 protein-positive cells (a marker of podocytes) along with increased urinary podocin and nephrin mRNA excretion, all indicative of glomerular damage. Thus, our findings support an active role for MMP-9 in a hypertension-induced kidney microvascular remodeling process that promotes glomerular epithelial cell injury in SS rats.

The Plasmodium falciparum parasitophorous vacuole protein P113 interacts with the parasite protein export machinery and maintains normal vacuole architecture.

Infection with Plasmodium falciparum parasites results in approximately 627,000 deaths from malaria annually. Key to the parasite's success is their ability to invade and subsequently grow within human erythrocytes. Parasite proteins involved in parasite invasion and proliferation are therefore intrinsically of great interest, as targeting these proteins could provide novel means of therapeutic intervention. One such protein is P113 which has been reported to be both an invasion protein and an intracellular protein located within the parasitophorous vacuole (PV). The PV is delimited by a membrane (PVM) across which a plethora of parasite-specific proteins are exported via the Plasmodium Translocon of Exported proteins (PTEX) into the erythrocyte to enact various immune evasion functions. To better understand the role of P113 we isolated its binding partners from in vitro cultures of P. falciparum. We detected interactions with the protein export machinery (PTEX and exported protein-interacting complex) and a variety of proteins that either transit through the PV or reside on the parasite plasma membrane. Genetic knockdown or partial deletion of P113 did not significantly reduce parasite growth or protein export but did disrupt the morphology of the PVM, suggesting that P113 may play a role in maintaining normal PVM architecture.

Aristolochic acid-induced nephropathy is attenuated in mice lacking the neutral amino acid transporter B0AT1 (Slc6a19).

B0AT1 (Slc6a19) mediates absorption of neutral amino acids in the small intestine and in the kidneys, where it is primarily expressed in early proximal tubules (S1-S2). To determine the role of B0AT1 in nephropathy induced by aristolochic acid (AA), which targets the proximal tubule, littermate female B0AT1-deficient (Slc6a19-/-), heterozygous (Slc6a19+/-), and wild-type (WT) mice were administered AA (10 mg/kg ip) or vehicle every 3 days for 3 wk, and analyses were performed after the last injection or 3 wk later. Vehicle-treated mice lacking Slc6a19 showed normal body and kidney weight and plasma creatinine versus WT mice. The urinary glucose-to-creatinine ratio (UGCR) and urinary albumin-to-creatinine ratio (UACR) were two to four times higher in vehicle-treated Slc6a19-/- versus WT mice, associated with lesser expression of early proximal transporters Na+-glucose cotransporter 2 and megalin, respectively. AA caused tubular injury independently of B0AT1, including robust increases in cortical mRNA expression of p53, p21, and hepatitis A virus cellular receptor 1 (Havcr1), downregulation of related proximal tubule amino acid transporters B0AT2 (Slc6a15), B0AT3 (Slc6a18), and Slc7a9, and modest histological tubular damage and a rise in plasma creatinine. Absence of B0AT1, however, attenuated AA-induced cortical upregulation of mRNA markers of senescence (p16), inflammation [lipocalin 2 (Lcn2), C-C motif chemokine ligand 2 (Ccl2), and C-C motif chemokine receptor 2 (Ccr2)], and fibrosis [tissue inhibitor of metallopeptidase 1 (Timp1), transforming growth factor-ß1 (Tgfb1), and collagen type I-α1 (Col1a1)], associated with lesser fibrosis staining, lesser suppression of proximal tubular organic anion transporter 1, restoration of Na+-glucose cotransporter 2 expression, and prevention of the AA-induced fivefold increase in the urinary albumin-to-creatinine ratio observed in WT mice. The data suggest that proximal tubular B0AT1 is important for the physiology of renal glucose and albumin retention but potentially deleterious for the kidney response following AA-induced kidney injury.NEW & NOTEWORTHY Based on insights from studies manipulating glucose transport, the hypothesis has been proposed that inhibiting intestinal uptake or renal reabsorption of energy substrates has unique therapeutic potential to improve metabolic disease and kidney outcome in response to injury. The present study takes this idea to B0AT1, the major transporter for neutral amino acids in the intestine and kidney, and shows that its absence attenuates aristolochic acid-induced nephropathy.

Clinicopathologic predictors of renal outcomes in light chain cast nephropathy: a multicenter retrospective study.

Light chain cast nephropathy (LCCN) in multiple myeloma often leads to severe and poorly reversible acute kidney injury. Severe renal impairment influences the allocation of chemotherapy and its tolerability; it also affects patient survival. Whether renal biopsy findings add to the clinical assessment in predicting renal and patient outcomes in LCCN is uncertain. We retrospectively reviewed clinical presentation, chemotherapy regimens, hematologic response, and renal and patient outcomes in 178 patients with biopsy-proven LCCN from 10 centers in Europe and North America. A detailed pathology review, including assessment of the extent of cast formation, was performed to study correlations with initial presentation and outcomes. Patients presented with a mean estimated glomerular filtration rate (eGFR) of 13 ± 11 mL/min/1.73 m2, and 82% had stage 3 acute kidney injury. The mean number of casts was 3.2/mm2 in the cortex. Tubulointerstitial lesions were frequent: acute tubular injury (94%), tubulitis (82%), tubular rupture (62%), giant cell reaction (60%), and cortical and medullary inflammation (95% and 75%, respectively). Medullary inflammation, giant cell reaction, and the extent of cast formation correlated with eGFR value at LCCN diagnosis. During a median follow-up of 22 months, mean eGFR increased to 43 ± 30 mL/min/1.73 m2. Age, ß2-microglobulin, best hematologic response, number of cortical casts per square millimeter, and degree of interstitial fibrosis/tubular atrophy (IFTA) were independently associated with a higher eGFR during follow-up. This eGFR value correlated with overall survival, independently of the hematologic response. This study shows that extent of cast formation and IFTA in LCCN predicts the quality of renal response, which, in turn, is associated with overall survival.

TSH receptor specific monoclonal autoantibody K1-70TM targeting of the TSH receptor in subjects with Graves' disease and Graves' orbitopathy-Results from a phase I clinical trial.

OBJECTIVES: In Graves' disease (GD), autoantibodies to the thyroid stimulating hormone receptor (TSHR) cause hyperthyroidism. The condition is often associated with eye signs including proptosis, oedema, and diplopia (collectively termed Graves' orbitopathy [GO]). The safety profile of K1-70TM (a human monoclonal TSHR specific autoantibody, which blocks ligand binding and stimulation of the receptor) in patients with GD was evaluated in a phase I clinical trial. PATIENTS AND STUDY DESIGN: Eighteen GD patients stable on antithyroid drug medication received a single intramuscular (IM) or intravenous (IV) dose of K1-70TM during an open label phase I ascending dose, safety, tolerability, pharmacokinetic and pharmacodynamic (PD) study. Immunogenic effects of K1-70TM were also determined. RESULTS: K1-70TM was well-tolerated in all subjects at all doses and no significant immunogenic response was observed. There were no deaths or serious adverse events. Increased systemic exposure to K1-70TM was observed following a change to IV dosing, indicating this was the correct dosage route. Expected PD effects occurred after a single IM dose of 25 mg or single IV dose of 50 mg or 150 mg with fT3, fT4, and TSH levels progressing into hypothyroid ranges. There were also clinically significant improvements in symptoms of both GD (reduced tremor, improved sleep, improved mental focus, reduced toilet urgency) and GO (reduced exophthalmos measurements, reduced photosensitivity). CONCLUSIONS: K1-70TM was safe, well tolerated and produced the expected PD effects with no immunogenic responses. It shows considerable promise as a new drug to block the actions of thyroid stimulators on the TSHR.

Characterisation of complexes formed by parasite proteins exported into the host cell compartment of Plasmodium falciparum infected red blood cells.

During its intraerythrocytic life cycle, the human malaria parasite Plasmodium falciparum supplements its nutritional requirements by scavenging substrates from the plasma through the new permeability pathways (NPPs) installed in the red blood cell (RBC) membrane. Parasite proteins of the RhopH complex: CLAG3, RhopH2, RhopH3, have been implicated in NPP activity. Here, we studied 13 exported proteins previously hypothesised to interact with RhopH2, to study their potential contribution to the function of NPPs. NPP activity assays revealed that the 13 proteins do not appear to be individually important for NPP function, as conditional knockdown of these proteins had no effect on sorbitol uptake. Intriguingly, reciprocal immunoprecipitation assays showed that five of the 13 proteins interact with all members of the RhopH complex, with PF3D7_1401200 showing the strongest association. Mass spectrometry-based proteomics further identified new protein complexes; a cytoskeletal complex and a Maurer's clefts/J-dot complex, which overall helps clarify protein-protein interactions within the infected RBC (iRBC) and is suggestive of the potential trafficking route of the RhopH complex itself to the RBC membrane.

Renoprotective effect of Stat1 deletion in murine aristolochic acid nephropathy.

Injured tubule epithelium stimulates a profibrotic milieu that accelerates loss of function in chronic kidney disease (CKD). This study tested the role of signal transducer and activator of transcription 1 (STAT1) in the progressive loss of kidney function in aristolochic acid (AA) nephropathy, a model of CKD. Mean serum creatinine concentration increased in wild-type (WT) littermates treated with AA, whereas Stat1-/- mice were protected. Focal increases in the apical expression of kidney injury molecule (KIM)-1 were observed in the proximal tubules of WT mice with AA treatment but were absent in Stat1-/- mice in the treatment group as well as in both control groups. A composite injury score, an indicator of proximal tubule injury, was reduced in Stat1-/- mice treated with AA. Increased expression of integrin-ß6 and phosphorylated Smad2/3 in proximal tubules as well as interstitial collagen and fibronectin were observed in WT mice following AA treatment but were all decreased in AA-treated Stat1-/- mice. The data indicated that STAT1 activation facilitated the development of progressive kidney injury and interstitial fibrosis in AA nephropathy.

Restoration of afferent arteriolar autoregulatory behavior in ischemia-reperfusion injury in rat kidneys.

Renal autoregulation is critical in maintaining stable renal blood flow (RBF) and glomerular filtration rate (GFR). Renal ischemia-reperfusion (IR)-induced kidney injury is characterized by reduced RBF and GFR. The mechanisms contributing to renal microvascular dysfunction in IR have not been fully determined. We hypothesized that increased reactive oxygen species (ROS) contributed to impaired renal autoregulatory capability in IR rats. Afferent arteriolar autoregulatory behavior was assessed using the blood-perfused juxtamedullary nephron preparation. IR was induced by 60 min of bilateral renal artery occlusion followed by 24 h of reperfusion. Afferent arterioles from sham rats exhibited normal autoregulatory behavior. Stepwise increases in perfusion pressure caused pressure-dependent vasoconstriction to 65 ± 3% of baseline diameter (13.2 ± 0.4 µm) at 170 mmHg. In contrast, pressure-mediated vasoconstriction was markedly attenuated in IR rats. Baseline diameter averaged 11.7 ± 0.5 µm and remained between 90% and 101% of baseline over 65-170 mmHg, indicating impaired autoregulatory function. Acute antioxidant administration (tempol or apocynin) to IR kidneys for 20 min increased baseline diameter and improved autoregulatory capability, such that the pressure-diameter profiles were indistinguishable from those of sham kidneys. Furthermore, the addition of polyethylene glycol superoxide dismutase or polyethylene glycol-catalase to the perfusate blood also restored afferent arteriolar autoregulatory responsiveness in IR rats, indicating the involvement of superoxide and/or hydrogen peroxide. IR elevated mRNA expression of NADPH oxidase subunits and monocyte chemoattractant protein-1 in renal tissue homogenates, and this was prevented by tempol pretreatment. These results suggest that ROS accumulation, likely involving superoxide and/or hydrogen peroxide, impairs renal autoregulation in IR rats in a reversible fashion.NEW & NOTEWORTHY Renal ischemia-reperfusion (IR) leads to renal microvascular dysfunction manifested by impaired afferent arteriolar autoregulatory efficiency. Acute administration of scavengers of reactive oxygen species, polyethylene glycol-superoxide dismutase, or polyethylene glycol-catalase following renal IR restored afferent arteriolar autoregulatory capability in IR rats, indicating that renal IR led to reversible impairment of afferent arteriolar autoregulatory capability. Intervention with antioxidant treatment following IR may improve outcomes in patients by preserving renovascular autoregulatory function and potentially preventing the progression to chronic kidney disease after acute kidney injury.

UAB-UCSD O'Brien Center for Acute Kidney Injury Research.

Acute kidney injury (AKI) remains a significant clinical problem through its diverse etiologies, the challenges of robust measurements of injury and recovery, and its progression to chronic kidney disease (CKD). Bridging the gap in our knowledge of this disorder requires bringing together not only the technical resources for research but also the investigators currently endeavoring to expand our knowledge and those who might bring novel ideas and expertise to this important challenge. The University of Alabama at Birmingham-University of California-San Diego O'Brien Center for Acute Kidney Injury Research brings together technical expertise and programmatic and educational efforts to advance our knowledge in these diverse issues and the required infrastructure to develop areas of novel exploration. Since its inception in 2008, this O'Brien Center has grown its impact by providing state-of-the-art resources in clinical and preclinical modeling of AKI, a bioanalytical core that facilitates measurement of critical biomarkers, including serum creatinine via LC-MS/MS among others, and a biostatistical resource that assists from design to analysis. Through these core resources and with additional educational efforts, our center has grown its investigator base to include >200 members from 51 institutions. Importantly, this center has translated its pilot and catalyst funding program with a $37 return per dollar invested. Over 500 publications have resulted from the support provided with a relative citation ratio of 2.18 ± 0.12 (iCite). Through its efforts, this disease-centric O'Brien Center is providing the infrastructure and focus to help the development of the next generation of researchers in the basic and clinical science of AKI. This center creates the promise of the application at the bedside of the advances in AKI made by current and future investigators.

Spatial organization of protein export in malaria parasite blood stages.

Plasmodium falciparum, which causes malaria, extensively remodels its human host cells, particularly erythrocytes. Remodelling is essential for parasite survival by helping to avoid host immunity and assisting in the uptake of plasma nutrients to fuel rapid growth. Host cell renovation is carried out by hundreds of parasite effector proteins that are exported into the erythrocyte across an enveloping parasitophorous vacuole membrane (PVM). The Plasmodium translocon for exported (PTEX) proteins is thought to span the PVM and provide a channel that unfolds and extrudes proteins across the PVM into the erythrocyte. We show that exported reporter proteins containing mouse dihydrofolate reductase domains that inducibly resist unfolding become trapped at the parasite surface partly colocalizing with PTEX. When cargo is trapped, loop-like extensions appear at the PVM containing both trapped cargo and PTEX protein EXP2, but not additional components HSP101 and PTEX150. Following removal of the block-inducing compound, export of reporter proteins only partly recovers possibly because much of the trapped cargo is spatially segregated in the loop regions away from PTEX. This suggests that parasites have the means to isolate unfoldable cargo proteins from PTEX-containing export zones to avert disruption of protein export that would reduce parasite growth.

Gene knockout of the Na+-glucose cotransporter SGLT2 in a murine model of acute kidney injury induced by ischemia-reperfusion.

In the early proximal tubule, Na+-glucose cotransporter 2 (SGLT2) mediates the bulk of renal glucose reabsorption. Gene deletion in mice (Sglt2-/-) was used to determine the role of SGLT2 in acute kidney injury induced by bilateral ischemia-reperfusion (IR). In Sglt2-/- and littermate wild-type mice, plasma creatinine increased similarly on day 1 after IR. This was associated with an equal increase in both genotypes in the urinary kidney injury molecule-1-to-creatinine ratio, a tubular injury marker, and similarly reduced urine osmolality and increased plasma osmolality, indicating impaired urine concentration. In both IR groups, FITC-sinistrin glomerular filtration rate was equally reduced on day 14, and plasma creatinine was similarly and incompletely restored on day 23. In Sglt2-/- mice subjected to IR, fractional urinary glucose excretion was increased on day 1 but reduced and associated with normal renal Na+-glucose cotransporter 1 (Sglt1) mRNA expression on day 23, suggesting temporary SGLT1 suppression. In wild-type mice subjected to IR, renal Sglt1 mRNA was likewise normal on day 23, whereas Sglt2 mRNA was reduced by 57%. In both genotypes, IR equally reduced urine osmolality and renal mRNA expression of the Na+-K+-2Cl- cotransporter and renin on day 23, suggesting thick ascending limb dysfunction, and similarly increased renal mRNA expression of markers of injury, inflammation, oxidative stress, and fibrosis (kidney injury molecule-1, neutrophil gelatinase-associated lipocalin, monocyte chemoattractant protein-1, transforming growth factor-ß1, NADPH oxidase-2, and collagen type 1). This was associated with equal increases in kidney histological damage scores and similar degree of capillary loss in both genotypes. The data indicate that genetic deletion of SGLT2 did not protect the kidneys in the initial injury phase or the subsequent recovery phase in a mouse model of IR-induced acute kidney injury.

Avian erythroblastosis virus E26 oncogene homolog-1 (ETS-1) plays a role in renal microvascular pathophysiology in the Dahl salt-sensitive rat.

Prior studies reported that haploinsufficiency of the transcription factor ETS-1 is renoprotective in Dahl salt-sensitive rats, but the mechanism is unclear. Here, we tested whether ETS-1 is involved in hypertension-induced renal microvascular pathology and autoregulatory impairment. Hypertension was induced in salt-sensitive rats and salt-sensitive rats that are heterozygous with 1 wild-type or reference allele of Ets1 (SSEts1+/-) by feeding a diet containing 4% sodium chloride for 1 week. Increases in blood pressure did not differ. However, phosphorylated ETS-1 increased in afferent arterioles of hypertensive salt-sensitive rats, but not in hypertensive SSEts1+/- rats. Afferent arterioles of hypertensive salt-sensitive rats showed increased monocyte chemotactic protein-1 expression and infiltration of CD68 positive monocytes/macrophages. Isolated kidney microvessels showed increased mRNA expression of vascular cell adhesion molecule, intercellular adhesion molecule, P-selectin, fibronectin, transforming growth factor-ß, and collagen I in hypertensive salt-sensitive rats compared with hypertensive SSEts1+/- rats. Using the in vitro blood-perfused juxtamedullary nephron preparation, pressure-mediated afferent arteriolar responses were significantly blunted in hypertensive salt-sensitive rats compared to hypertensive SSEts1+/- rats. Over a 65-170 mm Hg pressure range tested baseline arteriolar diameters averaged 15.1 µm and remained between 107% and 89% of baseline diameter in hypertensive salt-sensitive rats vs. 114% and 73% in hypertensive SSEts1+/- rats (significantly different). Thus, ETS-1 participates in renal arteriolar pathology and autoregulation and thereby is involved in hypertension-mediated kidney injury in salt-sensitive rats.

PTEX is an essential nexus for protein export in malaria parasites.

During the blood stages of malaria, several hundred parasite-encoded proteins are exported beyond the double-membrane barrier that separates the parasite from the host cell cytosol. These proteins have a variety of roles that are essential to virulence or parasite growth. There is keen interest in understanding how proteins are exported and whether common machineries are involved in trafficking the different classes of exported proteins. One potential trafficking machine is a protein complex known as the Plasmodium translocon of exported proteins (PTEX). Although PTEX has been linked to the export of one class of exported proteins, there has been no direct evidence for its role and scope in protein translocation. Here we show, through the generation of two parasite lines defective for essential PTEX components (HSP101 or PTEX150), and analysis of a line lacking the non-essential component TRX2 (ref. 12), greatly reduced trafficking of all classes of exported proteins beyond the double membrane barrier enveloping the parasite. This includes proteins containing the PEXEL motif (RxLxE/Q/D) and PEXEL-negative exported proteins (PNEPs). Moreover, the export of proteins destined for expression on the infected erythrocyte surface, including the major virulence factor PfEMP1 in Plasmodium falciparum, was significantly reduced in PTEX knockdown parasites. PTEX function was also essential for blood-stage growth, because even a modest knockdown of PTEX components had a strong effect on the parasite's capacity to complete the erythrocytic cycle both in vitro and in vivo. Hence, as the only known nexus for protein export in Plasmodium parasites, and an essential enzymic machine, PTEX is a prime drug target.

Demographics and Baseline Disease Characteristics of Early Responders to Crisaborole for Atopic Dermatitis.

INTRODUCTION: Crisaborole ointment, 2%, is a nonsteroidal phosphodiesterase 4 inhibitor for the treatment of mild-to-moderate atopic dermatitis (AD). This post hoc, pooled analysis identified demographic characteristics associated with early response to crisaborole. METHODS: Early response was defined as day 8 Investigator’s Static Global Assessment (ISGA) success (clear [0] or almost clear [1] with ≥2-grade improvement), ISGA clear/almost clear, or Severity of Pruritus Scale (SPS) response (≥1-point improvement). Correlations between early response and day-29 response were calculated. RESULTS: Patients were more likely to be early ISGA success responders if they were aged <12 years (P=0.0023), were white (P=0.0316), had moderate baseline disease by ISGA (P=0.0003), had not received prior AD treatment (P=0.0213), had disease duration shorter than or equal to the median (≤6.45 years; P=0.0349), or did not concurrently use antihistamines (P=0.0148). Similar early response results were observed for patients achieving ISGA clear or almost clear; however, they were more likely to have mild baseline disease by ISGA (P<0.0001) or mild percentage of treatable body surface area involvement (5 to <16; P<0.0001). Patients aged <12 years (P=0.0001) or with moderate baseline disease (P=0.0475) were more likely to be early responders based on SPS criteria. By all 3 definitions, patients who achieved early response at day 8 were more likely to be responders at day 29 (P<0.0001). CONCLUSION: Based on this analysis, patients aged <12 years were more likely to be early responders to crisaborole per all 3 definitions. Early response to crisaborole was a predictor of response at day 29. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT02118766 and NCT02118792 J Drugs Dermatol. 2020;19(6): doi:10.36849/JDD.2020.5095THIS ARTICLE HAD BEEN MADE AVAILABLE FREE OF CHARGE. PLEASE SCROLL DOWN TO ACCESS THE FULL TEXT OF THIS ARTICLE WITHOUT LOGGING IN. NO PURCHASE NECESSARY. PLEASE CONTACT THE PUBLISHER WITH ANY QUESTIONS.

Improvement in disease severity and pruritus outcomes with crisaborole ointment, 2%, by baseline atopic dermatitis severity in children and adolescents with mild-to-moderate atopic dermatitis.

BACKGROUND/OBJECTIVES: Crisaborole ointment, 2%, is a nonsteroidal phosphodiesterase 4 inhibitor for the treatment of mild-to-moderate atopic dermatitis (AD). This pooled post hoc analysis of two phase 3 trials (NCT02118766, NCT02118792) assessed improvement and time to improvement in Investigator's Static Global Assessment (ISGA) and Severity of Pruritus Scale (SPS) outcomes in pediatric patients with mild-to-moderate AD. METHODS: Patients aged ≥2 years were randomly assigned 2:1 to receive twice-daily crisaborole or vehicle for 28 days. Patients aged 2-17 years were pooled for this analysis. Proportions of patients and time to achieving ISGA success (clear [0] or almost clear [1] with ≥2-grade improvement from baseline), ISGA clear/almost clear, ≥1-grade improvement in ISGA, SPS success (SPS score ≤1 with ≥1-grade improvement), or ≥1-grade improvement in SPS score were analyzed and stratified by baseline ISGA. RESULTS: At first postbaseline assessment (day 8), significantly higher proportions of crisaborole- than vehicle-treated patients achieved ISGA success, ISGA clear/almost clear, ≥1-grade ISGA improvement, SPS success, or ≥1-grade improvement in SPS regardless of baseline ISGA. Differences were significantly greater over time for all outcomes for patients with moderate baseline ISGA and numerically greater for those with mild baseline ISGA. Median times to ISGA and SPS outcomes were shorter for crisaborole versus vehicle. CONCLUSION: Improvement in ISGA and SPS outcomes were observed with crisaborole in pediatric patients with mild-to-moderate baseline AD.

Functional Conservation of the AMA1 Host-Cell Invasion Ligand Between P. falciparum and P. vivax: A Novel Platform to Accelerate Vaccine and Drug Development.

Plasmodium vivax and P. falciparum malaria species have diverged significantly in receptor-ligand interactions and host-cell invasion. One protein common to both is the merozoite invasion ligand AMA1. While the general structure of AMA1 is similar between species, their sequences are divergent. Surprisingly, it was possible to genetically replace PfAMA1 with PvAMA1 in P. falciparum parasites. PvAMA1 complemented PfAMA1 function and supported invasion of erythrocytes by P. falciparum. Genetically modified P. falciparum expressing PvAMA1 evaded the invasion inhibitory effects of antibodies to PfAMA1, demonstrating species specificity of functional antibodies. We generated antibodies to recombinant PvAMA1 that effectively inhibited invasion, confirming the function of PvAMA1 in genetically modified parasites. Results indicate significant molecular flexibility in AMA1 enabling conserved function despite substantial sequence divergence across species. This provides powerful new tools to quantify the inhibitory activities of antibodies or drugs targeting PvAMA1, opening new opportunities for vaccine and therapeutic development against P. vivax.

The Plasmodium rhoptry associated protein complex is important for parasitophorous vacuole membrane structure and intraerythrocytic parasite growth.

Plasmodium parasites must invade erythrocytes in order to cause the disease malaria. The invasion process involves the coordinated secretion of parasite proteins from apical organelles that include the rhoptries. The rhoptry is comprised of two compartments: the neck and the bulb. Rhoptry neck proteins are involved in host cell adhesion and formation of the tight junction that forms between the invading parasite and erythrocyte, whereas the role of rhoptry bulb proteins remains ill-defined due to the lack of functional studies. In this study, we show that the rhoptry-associated protein (RAP) complex is not required for rhoptry morphology or erythrocyte invasion. Instead, post-invasion when the parasite is bounded by a parasitophorous vacuolar membrane (PVM), the RAP complex facilitates the survival of the parasite in its new intracellular environment. Consequently, conditional knockdown of members of the RAP complex leads to altered PVM structure, delayed intra-erythrocytic growth, and reduced parasitaemias in infected mice. This study provides evidence that rhoptry bulb proteins localising to the parasite-host cell interface are not simply by-products of the invasion process but contribute to the growth of Plasmodium in vivo.

Novel Paradigms of Salt and Hypertension.

Salt resistance/sensitivity refers specifically to the effect of dietary sodium chloride (salt) intake on BP. Increased dietary salt intake promotes an early and uniform expansion of extracellular fluid volume and increased cardiac output. To compensate for these hemodynamic changes and maintain constant BP in salt resistance, renal and peripheral vascular resistance falls and is associated with an increase in production of nitric oxide. In contrast, the decline in peripheral vascular resistance and the increase in nitric oxide are impaired or absent in salt sensitivity, promoting an increase in BP in these individuals. Endothelial dysfunction may pose a particularly significant risk factor in the development of salt sensitivity and subsequent hypertension. Vulnerable salt-sensitive populations may have in common underlying endothelial dysfunction due to genetic or environmental influences. These individuals may be very sensitive to the hemodynamic stress of increased effective blood volume, setting in motion untoward molecular and biochemical events that lead to overproduction of TGF-ß, oxidative stress, and limited bioavailable nitric oxide. Finally, chronic high-salt ingestion produces endothelial dysfunction, even in salt-resistant subjects. Thus, the complex syndrome of salt sensitivity may be a function of the endothelium, which is integrally involved in the vascular responses to high salt intake.