Patients and mice with deficiency in the SNARE protein SYNTAXIN-11 have a secondary B cell defect

SYNTAXIN-11 (STX11) is a SNARE protein that mediates the fusion of cytotoxic granules with the plasma membrane at the immunological synapses of CD8 T or NK cells. Autosomal recessive inheritance of deleterious STX11 variants impairs cytotoxic granule exocytosis, causing familial hemophagocytic lymphohistiocytosis type 4 (FHL-4). In several FHL-4 patients, we also observed hypogammaglobulinemia, elevated frequencies of naive B cells, and increased double-negative DN2:DN1 B cell ratios, indicating a hitherto unrecognized role of STX11 in humoral immunity. Detailed analysis of Stx11-deficient mice revealed impaired CD4 T cell help for B cells, associated with disrupted germinal center formation, reduced isotype class switching, and low antibody avidity. Mechanistically, Stx11-/- CD4 T cells exhibit impaired membrane fusion leading to reduced CD107a and CD40L surface mobilization and diminished IL-2 and IL-10 secretion. Our findings highlight a critical role of STX11 in SNARE-mediated membrane trafficking and vesicle exocytosis in CD4 T cells, important for successful CD4 T cell-B cell interactions. Deficiency in STX11 impairs CD4 T cell-dependent B cell differentiation and humoral responses.

Antibody-dye Conjugates Targeting EGFR and HER2 for the Photoimmunotherapy of Bladder Cancer

BACKGROUND/AIM

Although there are curative treatment options for non-muscle-invasive bladder cancer, the recurrence of this tumor is high. Therefore, novel targeted therapies are needed for the complete removal of bladder cancer cells in stages of localized disease, in order to avoid local recurrence, to spare bladder cancer patients from stressful and expensive treatment procedures and to increase their quality of life and life expectancy. This study tested a new approach for the photoimmunotherapy (PIT) of bladder cancer.

MATERIALS AND METHODS

We generated a cysteine modified recombinant version of the antibody cetuximab targeting the epidermal growth factor receptor (EGFR) on the surface of bladder cancer cells. Then, we coupled the novel photoactivatable phthalocyanine dye WB692-CB1 via a maleimide linker to the free cysteines of the antibody. PIT was performed by incubating bladder cancer cells with the antibody dye conjugate followed by irradiation with visible red light.

RESULTS

The conjugate was able to induce specific cytotoxicity in EGFR-positive bladder cancer cells in a light dose-dependent manner. Enhanced cytotoxicity in RT112 bladder cancer cells was evoked by addition of a second antibody dye conjugate targeting HER2 or by repeated cycles of PIT.

CONCLUSION

Our new antibody dye conjugate targeting EGFR-expressing bladder cancer cells is a promising candidate for the future PIT of bladder cancer patients.

Prevalence of Chlamydia trachomatis, Neisseria gonorrhoeae and Mycoplasma genitalium at pharyngeal and anorectal sites in patients presenting to an STI outpatient ward

BACKGROUND

The incidence of sexually transmitted infections (STIs) is unbridled and on the rise. Extragenital STIs (anal and pharyngeal infections) are commonly asymptomatic, resulting in delayed diagnosis and treatment and consequently higher chances of onward transmission.

OBJECTIVE

The aim of this observational single-centre study was to determine the prevalence of STIs at extragenital sites in symptomatic and asymptomatic patients presenting at an STI outpatient clinic.

METHODS

We conducted a retrospective analysis of patients who presented between October 2019 and February 2021 at the STI outpatient clinic of a tertiary centre in Central Europe. Patients were included in the study if they received at least one pharyngeal and/or anorectal swab in addition to a genital swab for multiplex-PCR STI diagnostics. Demographic data, symptoms and serological results were collected and analysed.

RESULTS

Data collected from 440 patients were analysed (mean age: 33.9 years, male: n = 345, 78.4%, female: n = 95, 21.6%). Ninety-seven males reported having sex with men (MSM); 174 patients identified as heterosexual (132 males, 42 females), and 10 females as bisexual. The sexual orientation was not reported in 159 cases. An STI was confirmed in 195 patients (44.3%) and, among those, 109 patients (55.9%) tested positive for an STI at extragenital sites. Seventy-one patients had a pharyngeal STI whereas 61 were infected in the anorectal region. Of those suffering from an extragenital STI, 64.2% (70 out of 109) tested negative for relevant pathogens at genital sites. The most frequently detected extragenital pathogen was Neisseria gonorrhoeae (71.8% of all pharyngeal STIs [51 out of 71], 55.7% of anorectal STIs [34 out of 61]), followed by Chlamydia trachomatis (41.0% of all anal infections [25 out of 61], 5.6% of pharyngeal infections [4 out of 71]). Pharyngeal and anorectal infections were asymptomatic in 88.7% [63 out of 71] and 65.6% [40 out of 61] of the cases, respectively.

CONCLUSION

These results underline the need to perform multisite testing, regardless of the presence of symptoms.

Consensus statement on the diagnosis and treatment of sclerosing diseases of the skin, Part 1: Localized scleroderma, systemic sclerosis and overlap syndromes

The term 'sclerosing diseases of the skin' comprises specific dermatological entities, which have fibrotic changes of the skin in common. These diseases mostly manifest in different clinical subtypes according to cutaneous and extracutaneous involvement and can sometimes be difficult to distinguish from each other. The present consensus provides an update to the 2017 European Dermatology Forum Guidelines, focusing on characteristic clinical and histopathological features, diagnostic scores and the serum autoantibodies most useful for differential diagnosis. In addition, updated strategies for the first- and advanced-line therapy of sclerosing skin diseases are addressed in detail. Part 1 of this consensus provides clinicians with an overview of the diagnosis and treatment of localized scleroderma (morphea), and systemic sclerosis including overlap syndromes.

Health-related quality of life in patients with generalized pustular psoriasis: A systematic literature review

Generalized pustular psoriasis (GPP) is a rare, chronic, neutrophilic inflammatory skin disease characterized by episodes of widespread eruption of sterile, macroscopic pustules that can be accompanied by systemic inflammation and symptoms. A systematic literature review and narrative synthesis were conducted to determine the impact of GPP on patients' health-related quality of life (HRQoL) and patient-reported severity of symptoms and to compare its impact to patients with plaque psoriasis (plaque PsO). Searches were undertaken in Embase, MEDLINE and the Cochrane Library from 1 January 2002 to 15 September 2022. Screening was carried out by two reviewers independently. Outcome measures included generic (e.g. EQ-5D, SF-36) and dermatology-specific (e.g. DLQI) clinical outcome assessments, and other relevant patient-reported outcome measures (PROMs) (e.g. severity of pain measured by a numerical rating scale). Overall, 20 studies were found to be eligible for inclusion, of which seven also had data for plaque PsO. The DLQI was the most frequently reported outcome measure (16 out of 20 studies). When reported, mean DLQI (SD) scores varied from 5.7 (1.2) to 15.8 (9.6) across the studies, indicating a moderate to very large effect on HRQoL; the wide range of scores and large SDs were explained by the small population sizes (n ≤ 12 for all studies except two). Similar ranges and large SDs were also observed for other measures within individual studies. However, in general, people with GPP reported a greater impact of their skin condition on HRQoL, when compared to people with plaque PsO (i.e. higher DLQI scores) and higher severity for itch, pain and fatigue. This systematic review highlighted the need for studies with a larger population size, a better understanding of the impact of cutaneous and extracutaneous symptoms and comorbidities on HRQoL during and between GPP flares, and outcome measures specifically tailored to the unique symptoms and the natural course/history of GPP.

Characteristics and management of generalized pustular psoriasis (GPP): Experience from the Central and Eastern Europe (CEE) GPP Expert Network

BACKGROUND

Generalized pustular psoriasis (GPP) is a rare, inflammatory skin disease characterized by widespread eruption of sterile pustules with or without systemic symptoms.

OBJECTIVES

This study aimed to describe the demographics of patients with GPP in Central and Eastern Europe (CEE), present the clinical characteristics of individual GPP flares and explore the current treatment landscape.

METHODS

Patient demographics were collected at the times of last observation and previous treatment. Characteristics of a patient's last (most recent) and most severe (from all documented episodes) flare were provided at clinician's discretion.

RESULTS

Fifty-eight patients were recruited from 12 centres in nine CEE countries; median (range) age was 61 (16-92) years and 60.3% (35 out of 58) were female. The most common comorbidities were hypertension (43.1% [25 out of 58]) and hyperlipidaemia (32.8% [19 out of 58]). Thirty-four patients (58.6%) presented with concomitant plaque psoriasis before or during the course of GPP. Data from two separate flares were recorded in 26 individuals; in 32 patients, the most recent flare was reported as the most severe. Over 90% of patients with a flare episode classified as most severe by clinicians were hospitalized, with >75% of these individuals having a Generalized Pustular Psoriasis Physician Global Assessment (GPPGA) total score of 3 or 4. Systemic symptoms were more common in patients with a GPPGA score of 3 or 4 but were also manifest in individuals with a GPPGA score ≤2. A significant correlation was observed between a combined systemic disease score of clinical and laboratory features and both GPPGA total score (r = 0.385, p < 0.001) and GPPGA pustulation subscore (r = 0.305, p < 0.05).

CONCLUSIONS

Considerable heterogeneity in the presentation of GPP flares was observed, both between patients and within-patient. All GPP flares were associated with a significant clinical burden, highlighting the unmet need for accurate and early diagnosis.

Formation of dsRNA by-products during in vitro transcription can be reduced by using low steady-state levels of UTP

Introduction: Exogeneous messenger ribonucleic acid (mRNA) can be used as therapeutic and preventive medication. However, during the enzymatic production process, commonly called in vitro transcription, by-products occur which can reduce the therapeutic efficacy of mRNA. One such by-product is double-stranded RNA (dsRNA). We therefore sought to limit the generation of dsRNA by-products during in vitro transcription. Materials and methods: In vitro transcription was performed with a DNA template including a poly(A)-tail-encoding region, dinucleotide or trinucleotide cap analogs for cotranscriptional capping, and relevant nucleoside triphosphates. Concentrations of UTP or modified UTP (m1ΨTP) and GTP were reduced and fed over the course of the reaction. mRNA was analyzed for dsRNA contamination, yield of the reaction, RNA integrity, and capping efficiency before translational activity was assessed. Results: Limiting the steady-state level of UTP or m1ΨTP during the enzymatic reaction reduced dsRNA formation, while not affecting mRNA yield or RNA integrity. Capping efficiency was optimized with the use of a combined GTP and UTP or m1ΨTP feed, while still reducing dsRNA formation. Lower dsRNA levels led to higher protein expression from the corresponding mRNAs. Discussion: Low steady-state concentrations of UTP and GTP, fed in combination over the course of the in vitro transcription reaction, produce mRNA with high capping and low levels of dsRNA formation, resulting in high levels of protein expression. This novel approach may render laborious purification steps to remove dsRNA unnecessary.

VEPdgets: Towards Richer Interaction Elements Based on Visually Evoked Potentials

For brain-computer interfaces, a variety of technologies and applications already exist. However, current approaches use visual evoked potentials (VEP) only as action triggers or in combination with other input technologies. This paper shows that the losing visually evoked potentials after looking away from a stimulus is a reliable temporal parameter. The associated latency can be used to control time-varying variables using the VEP. In this context, we introduced VEP interaction elements (VEP widgets) for a value input of numbers, which can be applied in various ways and is purely based on VEP technology. We carried out a user study in a desktop as well as in a virtual reality setting. The results for both settings showed that the temporal control approach using latency correction could be applied to the input of values using the proposed VEP widgets. Even though value input is not very accurate under untrained conditions, users could input numerical values. Our concept of applying latency correction to VEP widgets is not limited to the input of numbers.

Synergistic Cytotoxicity of a Toxin Targeting the Epidermal Growth Factor Receptor and the Glycosylated Triterpenoid SO1861 in Prostate Cancer

Treatment of advanced prostate cancer lacks specificity and curative intent. Therefore, the need for new targeted therapeutic approaches is high. In the present study, we generated the new targeted toxin EGF-PE24mutΔREDLK binding to the epidermal growth factor receptor (EGFR) on the surface of prostate cancer cells. It consists of the human epidermal growth factor (EGF) as binding domain and a de-immunized variant of Pseudomonas Exotoxin A (PE), called PE24mutΔREDLK, as toxin domain. The toxin domain contains a deletion of the C-terminal KDEL-like motif REDLK to prevent its transport from sorting endosomes via the KDEL receptor mediated pathway into the cytosol, where it can inhibit cellular protein biosynthesis and induce apoptosis. Indeed, REDLK deletion resulted in a strong decrease in cytotoxicity of the targeted toxin in prostate cancer cells compared to the parental targeted toxin EGF-PE24mut. However, addition of the plant glycosylated triterpenoid SO1861, which is known to mediate the release of biomolecules from endolysosomal compartments into the cytosol, resulted in an up to almost 7,000-fold enhanced synergistic cytotoxicity. Moreover, combination of PE24mutΔREDLK with SO1861 led to a cytotoxicity that was even 16- to 300-fold enhanced compared to that of EGF-PE24mut. Endolysosomal entrapment of the non-toxic targeted toxin EGF-PE24mutΔREDLK followed by activation through enhanced endosomal escape therefore represents a new promising approach for the future treatment of advanced prostate cancer with high efficacy and diminished side effects.

Enhanced cytotoxicity of a Pseudomonas Exotoxin A based immunotoxin against prostate cancer by addition of the endosomal escape enhancer SO1861

Immunotoxins consist of an antibody or antibody fragment that binds to a specific cell surface structure and a cytotoxic domain that kills the cell after cytosolic uptake. Pseudomonas Exotoxin A (PE) based immunotoxins directed against a variety of tumor entities have successfully entered the clinic. PE possesses a KDEL-like motif (REDLK) that enables the toxin to travel from sorting endosomes via the KDEL-receptor pathway to the endoplasmic reticulum (ER), from where it is transported into the cytosol. There, it ADP-ribosylates the eukaryotic elongation factor 2, resulting in ribosome inhibition and finally apoptosis. One major problem of immunotoxins is their lysosomal degradation causing the need for much more immunotoxin molecules than finally required for induction of cell death. The resulting dose limitations and substantially increased side effects require new strategies to achieve improved cytosolic uptake. Here we generated an immunotoxin consisting of a humanized single chain variable fragment (scFv) targeting the prostate specific membrane antigen (PSMA) and the de-immunized PE variant PE24mut. This immunotoxin, hD7-1(VL-VH)-PE24mut, showed high and specific cytotoxicity in PSMA-expressing prostate cancer cells. We deleted the REDLK sequence to prevent transport to the ER and achieve endosomal entrapment. The cytotoxicity of this immunotoxin, hD7-1(VL-VH)-PE24mutΔREDLK, was greatly reduced. To restore activity, we added the endosomal escape enhancer SO1861 and observed an up to 190,000-fold enhanced cytotoxicity corresponding to a 57-fold enhancement compared to the initial immunotoxin with the REDLK sequence. A biodistribution study with different routes of administration clearly showed that the subcutaneous injection of hD7-1(VL-VH)-PE24mutΔREDLK in mice resulted in the highest tumor uptake. Treatment of mice bearing prostate tumors with a combination of hD7-1(VL-VH)-PE24mutΔREDLK plus SO1861 resulted in inhibition of tumor growth and enhanced overall survival compared to the monotherapies. The endosomal entrapment of non-toxic anti-PSMA immunotoxins followed by enhanced endosomal escape by SO1861 provides new therapeutic options in the future management of prostate cancer.

Inhibitor of apoptosis proteins as therapeutic targets in bladder cancer

Evasion from apoptosis is a hallmark of cancer. Inhibitor of apoptosis proteins (IAPs) contribute to this hallmark by suppressing the induction of cell death. IAPs were found to be overexpressed in cancerous tissues and to contribute to therapeutic resistance. The present review focuses on the IAP members cIAP1, cIAP2, XIAP, Survivin and Livin and their importance as potential therapeutic targets in bladder cancer.

S2k guideline for diving accidents

For the purposes of this guideline, a diving accident is defined as an event that is either potentially life-threatening or hazardous to health as a result of a reduction in ambient pressure while diving or in other hyperbaric atmospheres with and without diving equipment. This national consensus-based guideline (development grade S2k) presents the current state of knowledge and recommendations on the diagnosis and treatment of diving accident victims. The treatment of a breath-hold diver as well as children and adolescents does not differ in principle. In this regard only unusual tiredness and itching without visible skin changes are mild symptoms. The key action statements: on-site 100% oxygen first aid treatment, immobilization/no unnecessary movement, fluid administration and telephone consultation with a diving medicine specialist are recommended. Hyperbaric oxygen therapy (HBOT) remains unchanged as the established treatment in severe cases, as there are no therapeutic alternatives. The basic treatment scheme recommended for diving accidents is hyperbaric oxygenation at 280 kPa.

Pro-apoptotic complexes of BAX and BAK on the outer mitochondrial membrane

In multicellular organisms the regulated cell death apoptosis is critically important for both ontogeny and homeostasis. Mitochondria are indispensable for stress-induced apoptosis. The BCL-2 protein family controls mitochondrial apoptosis and initiates cell death through the pro-apoptotic activities of BAX and BAK at the outer mitochondrial membrane (OMM). Cellular survival is ensured by the retrotranslocation of mitochondrial BAX and BAK into the cytosol by anti-apoptotic BCL-2 proteins. BAX/BAK-dependent OMM permeabilization releases the mitochondrial cytochrome c (cyt c), which initiates activation of caspase-9. The caspase cascade leads to cell shrinkage, plasma membrane blebbing, chromatin condensation, and apoptotic body formation. Although it is clear that ultimately complexes of active BAX and BAK commit the cell to apoptosis, the nature of these complexes is still enigmatic. Excessive research has described a range of complexes, varying from a few molecules to several 10,000, in different systems. BAX/BAK complexes potentially form ring-like structures that could expose the inner mitochondrial membrane. It has been suggested that these pores allow the efflux of small proteins and even mitochondrial DNA. Here we summarize the current state of knowledge for mitochondrial BAX/BAK complexes and the interactions between these proteins and the membrane.

PDGFRβ promotes oncogenic progression via STAT3/STAT5 hyperactivation in anaplastic large cell lymphoma

BACKGROUND

Anaplastic large cell lymphoma (ALCL) is an aggressive non-Hodgkin T cell lymphoma commonly driven by NPM-ALK. AP-1 transcription factors, cJUN and JUNb, act as downstream effectors of NPM-ALK and transcriptionally regulate PDGFRβ. Blocking PDGFRβ kinase activity with imatinib effectively reduces tumor burden and prolongs survival, although the downstream molecular mechanisms remain elusive.

METHODS AND RESULTS

In a transgenic mouse model that mimics PDGFRβ-driven human ALCL in vivo, we identify PDGFRβ as a driver of aggressive tumor growth. Mechanistically, PDGFRβ induces the pro-survival factor Bcl-xL and the growth-enhancing cytokine IL-10 via STAT5 activation. CRISPR/Cas9 deletion of both STAT5 gene products, STAT5A and STAT5B, results in the significant impairment of cell viability compared to deletion of STAT5A, STAT5B or STAT3 alone. Moreover, combined blockade of STAT3/5 activity with a selective SH2 domain inhibitor, AC-4-130, effectively obstructs tumor development in vivo.

CONCLUSIONS

We therefore propose PDGFRβ as a novel biomarker and introduce PDGFRβ-STAT3/5 signaling as an important axis in aggressive ALCL. Furthermore, we suggest that inhibition of PDGFRβ or STAT3/5 improve existing therapies for both previously untreated and relapsed/refractory ALK+ ALCL patients.

Prostate Cancer Stem Cells: Clinical Aspects and Targeted Therapies

Despite decades of research and successful improvements in diagnosis and therapy, prostate cancer (PC) remains a major challenge. In recent years, it has become clear that PC stem cells (PCSCs) are the driving force in tumorigenesis, relapse, metastasis, and therapeutic resistance of PC. In this minireview, we discuss the impact of PCSCs in the clinical practice. Moreover, new therapeutic approaches to combat PCSCs are presented with the aim to achieve an improved outcome for patients with PC.

The effects of stature, age, gender, and posture preferences on preferred joint angles after real driving

Few studies have investigated preferred driving posture involving real-world driving. For this purpose, seven preferred joint angles of 127 participants were recorded three times from sagittal plane photographs after a short, standardized drive on public roads. Participants' individual driving posture preferences were determined using a word-based questionnaire. The inter- and intraindividual joint angle differences were calculated and some significant effects of stature, age, and gender on these joint angle differences were found. Additionally, significant correlations were found between posture preferences and joint angles, except for the lower extremities. The results show that the factors stature, age, gender, and posture preferences have influence on the preferred joint angles. However, other human-, vehicle-, and context-related factors also seem relevant and should be considered in future studies. The results provide important field-based knowledge for an application-oriented understanding of driving posture and for the human-centered design process of future vehicle interior research and development.

Orthogonal Peptide-Templated Labeling Elucidates Lateral ETA R/ETB R Proximity and Reveals Altered Downstream Signaling

Fine‐tuning of G protein‐coupled receptor (GPCR) signaling is important to maintain cellular homeostasis. Recent studies demonstrated that lateral GPCR interactions in the cell membrane can impact signaling profiles. Here, we report on a one‐step labeling method of multiple membrane‐embedded GPCRs. Based on short peptide tags, complementary probes transfer the cargo (e. g. a fluorescent dye) by an acyl transfer reaction with high spatial and temporal resolution within 5 min. We applied this approach to four receptors of the cardiovascular system: the endothelin receptor A and B (ET_AR and ET_BR), angiotensin II receptor type 1, and apelin. Wild type‐like G protein activation after N‐terminal modification was demonstrated for all receptor species. Using FRET‐competent dyes, a constitutive proximity between hetero‐receptors was limited to ET_AR/ET_BR. Further, we demonstrate, that ET_AR expression regulates the signaling of co‐expressed ET_BR. Our orthogonal peptide‐templated labeling of different GPCRs provides novel insight into the regulation of GPCR signaling.

Systemic antipsoriatic treatment: do women respond better than men and if so, why?

Linked Article: Maul et al. Br J Dermatol 2021; 185:1160–1168.

Targeted Toxins for the Treatment of Prostate Cancer

Prostate cancer is the second most common cancer and the fifth leading cause of cancer deaths worldwide. Despite improvements in diagnosis and treatment, new treatment options are urgently needed for advanced stages of the disease. Targeted toxins are chemical conjugates or fully recombinant proteins consisting of a binding domain directed against a target antigen on the surface of cancer cells and a toxin domain, which is transported into the cell for the induction of apoptosis. In the last decades, targeted toxins against prostate cancer have been developed. Several challenges, however, became apparent that prevented their direct clinical use. They comprise immunogenicity, low target antigen binding, endosomal entrapment, and lysosomal/proteasomal degradation of the targeted toxins. Moreover, their efficacy is impaired by prostate tumors, which are marked by a dense microenvironment, low target antigen expression, and apoptosis resistance. In this review, current findings in the development of targeted toxins against prostate cancer in view of effective targeting, reduction of immunogenicity, improvement of intracellular trafficking, and overcoming apoptosis resistance are discussed. There are promising approaches that should lead to the clinical use of targeted toxins as therapeutic alternatives for advanced prostate cancer in the future.

Epidermal Growth Factor Based Targeted Toxin for the Treatment of Bladder Cancer

BACKGROUND/AIM

Reports on over-expression of the epidermal growth factor receptor (EGFR) in bladder cancer and its function in tumorigenesis have suggested to target this antigen.

MATERIALS AND METHODS

We generated the targeted toxin EGF-PE40 consisting of the human epidermal growth factor (EGF) as the binding domain and PE40, a truncated version of Pseudomonas Exotoxin A, as the toxin domain. EGF-PE40 was tested on EGFR-expressing bladder cancer cells in view of binding via flow cytometry, and cytotoxicity via WST viability assay. Induction of apoptosis was examined by western blot.

RESULTS

The targeted toxin specifically triggered cytotoxicity in the bladder cancer cells with 50% inhibitory concentration (IC50) values in the low nanomolar or picomolar range, and was about 1,250- to 1,500-fold more cytotoxic than the EGFR inhibitor erlotinib. Cytotoxicity of EGF-PE40 was based on the induction of apoptosis.

CONCLUSION

EGF-PE40 represents a promising candidate for the future treatment of bladder cancer.

Ligand-binding and -scavenging of the chemerin receptor GPR1

Tight regulation of cytokines is essential for the initiation and resolution of inflammation. Chemerin, a mediator of innate immunity, mainly acts on chemokine-like receptor 1 (CMKLR1) to induce the migration of macrophages and dendritic cells. The role of the second chemerin receptor, G protein-coupled receptor 1 (GPR1), is still unclear. Here we demonstrate that GPR1 shows ligand-induced arrestin3 recruitment and internalization. The chemerin C-terminus triggers this activation by folding into a loop structure, binding to aromatic residues in the extracellular loops of GPR1. While this overall binding mode is shared between GPR1 and CMKLR1, differences in their respective extracellular loop 2 allowed for the design of the first GPR1-selective peptide. However, our results suggest that ligand-induced arrestin recruitment is not the only mode of action of GPR1. This receptor also displays constitutive internalization, which allows GPR1 to internalize inactive peptides efficiently by an activation-independent pathway. Our results demonstrate that GPR1 takes a dual role in regulating chemerin activity: as a signaling receptor for arrestin-based signaling on one hand, and as a scavenging receptor with broader ligand specificity on the other.

Strategies for Site-Specific Labeling of Receptor Proteins on the Surfaces of Living Cells by Using Genetically Encoded Peptide Tags

Fluorescence microscopy imaging enables receptor proteins to be investigated within their biological context. A key challenge is to site-specifically incorporate reporter moieties into proteins without interfering with biological functions or cellular networks. Small peptide tags offer the opportunity to combine inducible labeling with small tag sizes that avoid receptor perturbation. Herein, we review the current state of live-cell labeling of peptide-tagged cell-surface proteins. Considering their importance as targets in medicinal chemistry, we focus on membrane receptors such as G protein-coupled receptors (GPCRs) and receptor tyrosine kinases (RTKs). We discuss peptide tags that i) are subject to enzyme-mediated modification reactions, ii) guide the complementation of reporter proteins, iii) form coiled-coil complexes, and iv) interact with metal complexes. Given our own contributions in the field, we place emphasis on peptide-templated labeling chemistry.

The ring size of monocyclic ET-1 controls selectivity and signaling efficiency at both endothelin receptor subtypes

Cardiovascular diseases (CVDs) like hypertension are a major cause for death worldwide. In the cardiovascular tissue, the endothelin system-consisting of the receptor subtypes A (ET_A R) and B (ET_B R) and the mixed agonist endothelin 1 (ET-1)-is a major key player in the regulation of vascular tone and blood pressure. Tight control of this system is required to maintain homeostasis; otherwise, the endothelin system can cause severe CVDs like pulmonary artery hypertension. The high sequence homology between both receptor subtypes limits the development of novel and selective ligands. Identification of small differences in receptor-ligand interactions and determination of selectivity constraints are crucial to fine-tune ligand properties and subsequent signaling events. Here, we report on novel ET-1 analogs and their detailed pharmacological characterization. We generated simplified ET-1-derived monocyclic peptides to provide an accessible synthesis route. By detailed in vitro characterization, we demonstrated that both G protein signaling and the subsequent arrestin recruitment of activated ET_B R remain intact, whereas activation of the ET_A R depends on the intramolecular ring size. Increasing of the intramolecular ring structure reduces activity at the ET_A R and shifts the peptide toward ET_B R selectivity. All ET-1 analogs displayed efficient ET_B R-mediated signaling by G protein activation and arrestin 3 recruitment. Our study provides in-depth characterization of the ET-1/ET_A R and ET-1/ET_B R interactions, which has the potential for future development of endothelin-based drugs for CVD treatment. By identification of Lys⁹ for selective labeling, novel analogs for peptide-mediated shuttling by ET-1 are proposed.

[Management of COVID-19 mass casualty incidents in nursing and retirement homes]

BACKGROUND

During the coronavirus disease 2019 (COVID-19) pandemic, outbreaks in inpatient care facilities, which grow into a large-scale emergency scenario, are frequently observed. A standardized procedure analogous to algorithms for mass casualty incidents (MCI) is lacking.

METHODS

Based on a case report and the literature, the authors present a management strategy for infectious MCI during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic and distinguish it from traumatic MCI deployment tactics.

RESULTS

This management strategy can be divided into three phases, beginning with the acute emergency response including triage, stabilization of critical patients, and transport of patients requiring hospitalization. Phase 2 involves securing the facility's operational readiness, or housing residents elsewhere in case staff are infected or quarantined to a relevant degree. Phase 3 marks the return to regular operations.

DISCUSSION

Phase 1 is based on usual MCI principles, phase 2 on hospital crisis management. Avoiding evacuation of residents to relieve hospitals is an important operational objective. The lack of mission and training experience with such situations, the limited applicability of established triage algorithms, and the need to coordinate a large number of participants pose challenges.

CONCLUSION

This strategic model offers a practical, holistic approach to the management of infectious mass casualty scenarios in nursing facilities.

Identification of a novel leptin receptor (LEPR) variant and proof of functional relevance directing treatment decisions in patients with morbid obesity

BACKGROUND

Deficiency in the leptin-leptin receptor (LEPR) axis leads to severe, and potentially treatable, obesity in humans. To guide clinical decision-making, the functional relevance of variants in the LEPR gene needs to be carefully investigated.

CASES AND METHODS

We characterized the functional impact of LEPR variants identified in two patients with severe early-onset obesity (1: compound heterozygous for the novel variant p.Tyr411del and p.Trp664Arg; 2: heterozygous for p.Arg612His) by investigating leptin-mediated signaling, leptin binding, receptor expression on cell surfaces, and receptor dimerization and activation for either wild-type and/or mutant LEPR.

RESULTS

Leptin-induced STAT3-phosphorylation was blunted the novel p.Tyr411del or the p.Trp664Arg variant and mildly reduced with the p.Arg612His variant. Computational structure prediction suggested impaired leptin binding for all three LEPR variants. Experimentally, reduced leptin binding of all mutant proteins was due to diminished LEPR expression on the cell surface, with the p.Trp664Arg mutations being the most affected. Considering the heterozygosity in our patients, we assessed the heterodimerization capacity with the wild-type LEPR, which was retained for the p.Tyr411del and p.Arg612His variants. Finally, mimicking (compound) heterozygosity, we confirmed abolished STAT3-phosphorylation for the variant combination [p.Tyr411del + p.Trp664Arg] as found in patient 1, whereas it was retained for [p.Arg612His + wilde type] as found in patient 2.

CONCLUSIONS

The novel p.Tyr411del mutation causes complete loss of function alone (and combined with p.Trp664Arg) and is likely the cause for the early onset obesity, qualifying the patient for pharmacologic treatment. Heterozygosity for the p.Arg612His variant, however, appears unlikely to be solely responsible for the phenotype.

Micro- and macrovascular function in patients suffering from primary adrenal insufficiency: a cross-sectional case-control study

BACKGROUND

Despite adequate glucocorticoid (GC) and mineralocorticoid (MC) replacement therapy, patients suffering from primary adrenal insufficiency (AI) have an increased mortality, mainly due to cardiovascular diseases. Only little knowledge exists on the contribution of MC substitution to the cardiovascular risk. Therefore, this study investigates the impact of plasma renin concentration on parameters of micro- and macrovascular function.

METHODS

26 patients with primary AI [female = 18, age: 51 (28; 78) years; BMI: 24 (18; 40) kg/m²; disease duration: 18 (5; 36) years] were included in this cross-sectional analysis. Intima media thickness (IMT) and pulse wave velocity (PWV) were investigated to assess macrovascular remodeling and arterial stiffness. Microvascular function was estimated by post-occlusive reactive hyperemia using laser Doppler fluxmetry. Baseline perfusion, biological zero, peak perfusion, time to peak and recovery time were recorded. Patients were grouped according to their median plasma renin concentration of previous visits (Renin_high vs Renin_low) and were compared to a group of healthy women [age: 44 (43; 46) years; BMI: 24.2 (21.8; 27.5)].

RESULTS

PWV was significantly higher in AI patients compared to controls [9.9 (5; 18.5) vs 7.3 (6.8; 7.7) m/s; p < .01], whereas no differences in microvascular function could be found. In Renin_low time to peak perfusion was significantly longer [6.0 (3; 15) vs 3.5 (1.5; 11) s; p < .05], whereas no differences in IMT and PWV were observed between Renin_high and Renin_low. No impact of GC dose was observed.

CONCLUSIONS

Microvascular function is not impaired in patients with primary AI under adequate replacement therapy, although higher renin concentrations are associated with subclinical improvements. No relation between RAAS activity and macrovascular function is observed, while arterial stiffness might be increased in primary AI.

Biologic drug survival rates in the era of anti-interleukin-17 antibodies: a time-period-adjusted registry analysis

Background

Drug survival rates reflect efficacy and safety and may be influenced by the availability of alternative treatment options. Little is known about time‐dependent drug survival in psoriasis and the effect of increasing numbers of biologic treatment options.

Objectives

To determine whether drug survival is influenced by the availability of treatment options and by factors such as gender, psoriatic arthritis or previous biologic treatment.

Methods

This observational, retrospective, multicentre cohort study analysed data from patients registered in the Austrian Psoriasis Registry (PsoRA) who were treated with biologics between 1 January 2015 and 30 November 2019.

Results

A total of 1572 patients who received 1848 treatment cycles were included in this analysis. The highest long‐term Psoriasis Area and Severity Index improvement was observed after treatment with ixekizumab, followed by ustekinumab and secukinumab, adalimumab and etanercept. Overall, ustekinumab surpassed all other biologics in drug survival up to 48 months. However, when adjusted for biologic naïvety, its superiority vanished and drug survival rates were similar for ixekizumab (91·6%), secukinumab (90·2%) and ustekinumab (92·8%), all of them superior to adalimumab (76·5%) and etanercept (71·9%) at 12 months and beyond. Besides biologic non‐naïvety (2·10, P < 0·001), the introduction of a new drug such as secukinumab or ixekizumab (relative hazard ratio 1·6, P = 0·001) and female gender (1·50, P = 0·019) increased the risk of treatment discontinuation overall, whereas psoriatic arthritis did not (1·12, P = 0·21).

Conclusions

The time‐dependent availability of drugs should be considered when analysing and comparing drug survival. Previous biologic exposure significantly influences drug survival. Women are more likely to stop treatment.

What is already known about this topic?

Female gender and previous biologic exposure have been discussed as predictors for decreased drug survival in patients with psoriasis, but it remains unknown whether a time‐dependent increased availability of treatment options alters biologic drug survival.

What does this study add?

The increased availability of alternative biologic treatments over time leads to an elevated risk for treatment discontinuation overall; therefore, drug survival analysis has to be time adjusted.

Moreover, the study reveals that the impact of previous biologic treatment on drug survival is tremendous and confirms worse drug survival in female patients.

Linked Comment: Gniadecki. Br J Dermatol 2021; 184:996–997.

Pseudomonas Exotoxin A Based Toxins Targeting Epidermal Growth Factor Receptor for the Treatment of Prostate Cancer

The epidermal growth factor receptor (EGFR) was found to be a valuable target on prostate cancer (PCa) cells. However, EGFR inhibitors mostly failed in clinical studies with patients suffering from PCa. We therefore tested the targeted toxins EGF-PE40 and EGF-PE24mut consisting of the natural ligand EGF as binding domain and PE40, the natural toxin domain of Pseudomonas Exotoxin A, or PE24mut, the de-immunized variant thereof, as toxin domains. Both targeted toxins were expressed in the periplasm of E.coli and evoked an inhibition of protein biosynthesis in EGFR-expressing PCa cells. Concentration- and time-dependent killing of PCa cells was found with IC50 values after 48 and 72 h in the low nanomolar or picomolar range based on the induction of apoptosis. EGF-PE24mut was found to be about 11- to 120-fold less toxic than EGF-PE40. Both targeted toxins were more than 600 to 140,000-fold more cytotoxic than the EGFR inhibitor erlotinib. Due to their high and specific cytotoxicity, the EGF-based targeted toxins EGF-PE40 and EGF-PE24mut represent promising candidates for the future treatment of PCa.

European dermatology forum - updated guidelines on the use of extracorporeal photopheresis 2020 - part 1

Background

Following the first investigational study on the use of extracorporeal photopheresis for the treatment of cutaneous T‐cell lymphoma published in 1983, this technology has received continued use and further recognition for additional earlier as well as refractory forms. After the publication of the first guidelines for this technology in the JEADV in 2014, this technology has maintained additional promise in the treatment of other severe and refractory conditions in a multi‐disciplinary setting. It has confirmed recognition in well‐known documented conditions such as graft‐versus‐host disease after allogeneic bone marrow transplantation, systemic sclerosis, solid organ transplant rejection including lung, heart and liver and to a lesser extent inflammatory bowel disease.

Materials and methods

In order to further provide recognized expert practical guidelines for the use of this technology for all indications, the European Dermatology Forum (EDF) again proceeded to address these questions in the hands of the recognized experts within and outside the field of dermatology. This was done using the recognized and approved guidelines of EDF for this task. All authors had the opportunity to review each contribution as it was added.

Results and conclusion

These updated 2020 guidelines provide at present the most comprehensive available expert recommendations for the use of extracorporeal photopheresis based on the available published literature and expert consensus opinion. The guidelines are divided in two parts: PART I covers cutaneous T‐cell lymphoma, chronic graft‐versus‐host disease and acute graft‐versus‐host disease while PART II will cover scleroderma, solid organ transplantation, Crohn's disease, use of ECP in paediatrics practice, atopic dermatitis, type 1 diabetes, pemphigus, epidermolysis bullosa acquisita and erosive oral lichen planus.

Health assessment of harbour porpoises (PHOCOENA PHOCOENA) from Baltic area of Denmark, Germany, Poland and Latvia

Harbour porpoise (Phocoena phocoena), the only resident cetacean species of the Baltic Sea is formed of two subpopulations populations, occurring in the western Baltic, Belt Seas and Kattegat and the Baltic Proper, respectively. Harbour porpoises throughout these areas are exposed to a large number of human activities causing direct and indirect effects on individuals, that might also harm this species on a population level. From Latvia, Poland, Germany and Denmark 385 out of 1769 collected dead harbour porpoises were suitable for extensive necropsy. The animals were collected between 1990 and 2015 and were either by-caught or found dead on the coastline. Following necropsies, histopathological, microbiological, virological and parasitological investigations were conducted. Females and males were equally distributed among the 385 animals. Most animals from the different countries were juveniles between 3 months and 3 years old (varying between 46.5 and 100% of 385 animals per country). The respiratory tract had the highest number of morphological lesions, including lungworms in 25 to 58% and pneumonia in 21 to 58% of the investigated animals. Of those with pneumonia 8 to 33% were moderate or severe. The alimentary, hearing, and haematopoietic systems had inflammatory lesions and parasitic infections with limited health impact. 45.5 to 100% of the animals from the different countries were known by-caught individuals, of which 20 to 100% varying between countries had netmarks. Inflammatory lesions, especially in the respiratory tract were found in higher numbers when compared to control populations in areas with less human activities such as arctic waters. The high number of morphological changes in the respiratory tract and of bycatches especially among immature animals before reaching sexual maturity is of serious concern, as well as the low number of adult animals among the material. Data on health status and the causes of death are valuable for management. A next step in this regard will combine data from health and genetic investigations in order to detect differences between the two populations of the Baltic.

European dermatology forum: Updated guidelines on the use of extracorporeal photopheresis 2020 - Part 2

Background

Following the first investigational study on the use of extracorporeal photopheresis for the treatment of cutaneous T‐cell lymphoma published in 1983, this technology has received continued use and further recognition for additional earlier as well as refractory forms. After the publication of the first guidelines for this technology in the JEADV in 2014, this technology has maintained additional promise in the treatment of other severe and refractory conditions in a multidisciplinary setting. It has confirmed recognition in well‐known documented conditions such as graft‐vs.‐host disease after allogeneic bone marrow transplantation, systemic sclerosis, solid organ transplant rejection including lung, heart and liver and to a lesser extent inflammatory bowel disease.

Materials and methods

In order to further provide recognized expert practical guidelines for the use of this technology for all indications, the European Dermatology Forum (EDF) again proceeded to address these questions in the hands of the recognized experts within and outside the field of dermatology. This was done using the recognized and approved guidelines of EDF for this task. All authors had the opportunity to review each contribution as it was added.

Results and conclusion

These updated 2020 guidelines provide at present the most comprehensive available expert recommendations for the use of extracorporeal photopheresis based on the available published literature and expert consensus opinion. The guidelines were divided into two parts: PART I covers Cutaneous T‐cell lymphoma, chronic graft‐vs.‐host disease and acute graft‐vs.‐host disease, while PART II will cover scleroderma, solid organ transplantation, Crohn’s disease, use of ECP in paediatric patients, atopic dermatitis, type 1 diabetes, pemphigus, epidermolysis bullosa acquisita and erosive oral lichen planus.

Ulcus vulvae acutum Lipschütz: a systematic literature review and a diagnostic and therapeutic algorithm

The case report literature on ulcus vulvae acutum Lipschütz (UVAL) is scant, and specific guidelines on its diagnosis and treatment are lacking. Our study's aim was to perform a systematic literature review of UVAL in order to formulate a diagnostic and therapeutic algorithm. Using the PRISMA criteria, we searched PubMed and MEDLINE for the terms 'ulcus vulvae acutum', 'Lipschütz ulcer' and 'acute genital ulcer AND vulva'. We extracted relevant data on 'type of article', 'patients' age', 'amount and localization of ulcers', 'presence of flu-like symptoms', 'prior sexual contacts', 'diagnostic workup' (including histology, blood count and serology such as Epstein-Barr virus testing) and 'treatment/outcome'. Data were meta-analysed and comparative analyses were discussed in order to create a diagnostic algorithm and recommendations for management. Twenty-one publications reporting a total of 60 cases of UVAL were included for analysis. On this basis, we formulated a diagnostic and therapeutic algorithm defined by two major and four minor criteria. The major criteria were (i) acute onset of one or more painful ulcerous lesions in the vulvar region and (ii) exclusion of infectious and non-infectious causes for the ulcer. The minor criteria were (i) localization of ulcer at vestibule or labia minora, (ii) no sexual intercourse ever (i.e. patient was a virgin) or within the last 3 months, (iii) flu-like symptoms and/or (iv) systemic infection within 2-4 weeks prior to onset of vulvar ulcer. Use of a symptom-based treatment algorithm based on our proposed major and minor criteria will improve the diagnosis and management of UVAL.

An Anti-PSMA Immunotoxin Reduces Mcl-1 and Bcl2A1 and Specifically Induces in Combination with the BAD-Like BH3 Mimetic ABT-737 Apoptosis in Prostate Cancer Cells

Background: Upregulation of anti-apoptotic Bcl-2 proteins in advanced prostate cancer leads to therapeutic resistance by prevention of cell death. New therapeutic approaches aim to target the Bcl-2 proteins for the restoration of apoptosis. Methods: The immunotoxin hD7-1(VL-VH)-PE40 specifically binds to the prostate specific membrane antigen (PSMA) on prostate cancer cells and inhibits protein biosynthesis. It was tested with respect to its effects on the expression of anti-apoptotic Bcl-2 proteins. Combination with the BAD-like mimetic ABT-737 was examined on prostate cancer cells and 3D spheroids and in view of tumor growth and survival in the prostate cancer SCID mouse xenograft model. Results: The immunotoxin led to a specific inhibition of Mcl-1 and Bcl2A1 expression in PSMA expressing target cells. Its combination with ABT-737, which inhibits Bcl-2, Bcl-xl, and Bcl-w, led to an induction of the intrinsic apoptotic pathway and to a synergistic cytotoxicity in prostate cancer cells and 3D spheroids. Furthermore, combination therapy led to a significantly prolonged survival of mice bearing prostate cancer xenografts based on an inhibition of tumor growth. Conclusion: The combination therapy of anti-PSMA immunotoxin plus ABT-737 represents the first tumor-specific therapeutic approach on the level of Bcl-2 proteins for the induction of apoptosis in prostate cancer.

Supersolid Properties of a Bose-Einstein Condensate in a Ring Resonator

We investigate the dynamics of a Bose-Einstein condensate interacting with two noninterfering and counterpropagating modes of a ring resonator. Superfluid, supersolid, and dynamic phases are identified experimentally and theoretically. The supersolid phase is obtained for sufficiently equal pump strengths for the two modes. In this regime we observe the emergence of a steady state with crystalline order, which spontaneously breaks the continuous translational symmetry of the system. The supersolidity of this state is demonstrated by the conservation of global phase coherence at the superfluid to supersolid phase transition. Above a critical pump asymmetry the system evolves into a dynamic runaway instability commonly known as collective atomic recoil lasing. We present a phase diagram and characterize the individual phases by comparing theoretical predictions with experimental observations.

Biofabrication of SDF-1 Functionalized 3D-Printed Cell-Free Scaffolds for Bone Tissue Regeneration

Large segmental bone defects occurring after trauma, bone tumors, infections or revision surgeries are a challenge for surgeons. The aim of our study was to develop a new biomaterial utilizing simple and cheap 3D-printing techniques. A porous polylactide (PLA) cylinder was printed and functionalized with stromal-derived factor 1 (SDF-1) or bone morphogenetic protein 7 (BMP-7) immobilized in collagen type I. Biomechanical testing proved biomechanical stability and the scaffolds were implanted into a 6 mm critical size defect in rat femur. Bone growth was observed via x-ray and after 8 weeks, bone regeneration was analyzed with µCT and histological staining methods. Development of non-unions was detected in the control group with no implant. Implantation of PLA cylinder alone resulted in a slight but not significant osteoconductive effect, which was more pronounced in the group where the PLA cylinder was loaded with collagen type I. Addition of SDF-1 resulted in an osteoinductive effect, with stronger new bone formation. BMP-7 treatment showed the most distinct effect on bone regeneration. However, histological analyses revealed that newly formed bone in the BMP-7 group displayed a holey structure. Our results confirm the osteoinductive character of this 3D-biofabricated cell-free new biomaterial and raise new options for its application in bone tissue regeneration.

Pathogenic Bi-allelic Mutations in NDUFAF8 Cause Leigh Syndrome with an Isolated Complex I Deficiency

Leigh syndrome is one of the most common neurological phenotypes observed in pediatric mitochondrial disease presentations. It is characterized by symmetrical lesions found on neuroimaging in the basal ganglia, thalamus, and brainstem and by a loss of motor skills and delayed developmental milestones. Genetic diagnosis of Leigh syndrome is complicated on account of the vast genetic heterogeneity with >75 candidate disease-associated genes having been reported to date. Candidate genes are still emerging, being identified when “omics” tools (genomics, proteomics, and transcriptomics) are applied to manipulated cell lines and cohorts of clinically characterized individuals who lack a genetic diagnosis. NDUFAF8 is one such protein; it has been found to interact with the well-characterized complex I (CI) assembly factor NDUFAF5 in a large-scale protein-protein interaction screen. Diagnostic next-generation sequencing has identified three unrelated pediatric subjects, each with a clinical diagnosis of Leigh syndrome, who harbor bi-allelic pathogenic variants in NDUFAF8. These variants include a recurrent splicing variant that was initially overlooked due to its deep-intronic location. Subject fibroblasts were found to express a complex I deficiency, and lentiviral transduction with wild-type NDUFAF8-cDNA ameliorated both the assembly defect and the biochemical deficiency. Complexome profiling of subject fibroblasts demonstrated a complex I assembly defect, and the stalled assembly intermediates corroborate the role of NDUFAF8 in early complex I assembly. This report serves to expand the genetic heterogeneity associated with Leigh syndrome and to validate the clinical utility of orphan protein characterization. We also highlight the importance of evaluating intronic sequence when a single, definitively pathogenic variant is identified during diagnostic testing.

Influence of different types of bedding material on the prevalence of pododermatitis in rabbits

Pododermatitis is a disorder with a complex etiology, because potentially determined by various factors such as posture, nutrition and genetics. In the case of presence of pododermal lesions, it is often noticed that rabbits go to eat at the bowl less frequently, but an evident weight loss is not always perceptible. In fact, similarly to poultry, overweight animals seem to be prone to the onset of pododermatitis. An experiment was carried out to test the effect of different types of bedding material (straw vs. wood shavings vs. coarse bark mulch vs. cotton) on the prevalence of pododermatitis in 30 fattening Separator rabbits. Once a week, the four experimental runs were assessed for contamination (macroscopic contamination by faeces/urine/litter) as well as for lesion scoring of the footpad. In addition, the water and ammonia binding behaviour of bedding was tested. The most favourable values as to dry matter, NH₃ (p < .05) and also scoring of the litter were generally observed when cotton was used as bedding material. This is probably due to the high water binding capacity, the faster water release and the structural effects of the material itself (softness). By contrast, the structure of the coarse bark mulch was not suitable for binding liquids (especially urine) and led to increased contamination of the barrels. These results suggest that rabbits with an increased tendency to sore soles should be kept on bedding materials with desirable physical properties (e.g. cotton litter).