Efficacy and safety of visepegenatide, a long-acting weekly GLP-1 receptor agonist as monotherapy in type 2 diabetes mellitus: a randomised, double-blind, parallel, placebo-controlled phase 3 trial.

Background: Type 2 diabetes (T2DM) remains a challenge to treat despite the expansion of various therapeutic classes. Visepegenatide (PB-119) is a once a week, subcutaneous, glucagon-like peptide-1 receptor agonist (GLP-1 RA) injection without the requirement of dose titration that has shown glycaemic control and safety profile in two phase 2 studies conducted in China and the United States, respectively. The aim of this study was to evaluate the efficacy and safety of visepegenatide as a monotherapy in treatment-naïve patients with T2DM. Methods: This was a multicentre, double-blind, parallel, placebo-controlled, phase 3 trial conducted in 30 centres in China. Adult participants (aged 18-75 years) with T2DM, glycated haemoglobin (HbA1c) of 7.5%-11.0% [58.47-96.73 mmol/mol], body mass index (BMI) of 18-40 kg/m2, and who had been treated with diet and exercise alone for at least 8 weeks before the screening visit were eligible for enrolment. After a 4-week placebo injection run-in period, participants with HbA1c of 7.0%-10.5% [53.0-91.3 mmol/mol] and fasting plasma glucose (FPG) < 15 mmol/L were randomised in a ratio of 1:1 to receive visepegenatide (150 µg) or placebo subcutaneous injections once a week for 24 weeks. The treatment was extended to another 28 weeks during which all participants received visepegenatide. The primary outcome was a change in HbA1c from baseline to week 24. This study was registered with ClinicalTrials.gov, as NCT04504370. Findings: Between November 2, 2020, and November 2, 2022, we randomly assigned 273 adult participants to the visepegenatide (n = 137) and placebo (n = 136) groups. In total, 257 (94.12%) participants, 131 (95.6%) on visepegenatide, and 126 (92.6%) on placebo, completed the double-blinded treatment period. At baseline, the mean (SD) HbA1c was 8.47% (0.81) [69.07 [8.81] mmol/mol], which rapidly decreased to 7.63% (0.80) [59.94 [8.70] mmol/mol] with visepegenatide by week 4 of treatment, and the change from baseline was significantly greater than that in the placebo group (-0.82% [-0.90 to -0.74]; [-8.99 [-9.89 to -8.10] mmol/mol] vs -0.30% [-0.41 to -0.19]; [-3.30 [-4.50 to -2.09] mmol/mol]). At week 24, when evaluating the effects of treatment with treatment policy estimand, the least square mean (LSM change in HbA1c from baseline was -1.36 (95% confidence interval [CI] -1.52 to -1.20) [-14.84 [-16.60 to -13.08] mmol/mol] in the visepegenatide group vs -0.63 (-0.79 to -0.46) [-6.84 [-8.61 to -5.07] mmol/mol] in the placebo group. The reduction in HbA1c was significantly greater with visepegenatide than placebo (LSM difference -0.73, 95% CI -0.96 to -0.50; p < 0.001). When evaluating the treatment estimand with hypothetic policy, the LSM change in HbA1c from baseline in the visepegenatide group (-1.37 [-1.53 to -1.20]) [-14.95 [-16.76 to -13.14] mmol/mol] was significantly greater than the placebo group (-0.63 [-0.81 to -0.45]) [6.90 (-8.89 to -4.90) mmol/mol]. The LSM difference was (-0.74, 95% CI -0.98 to -0.49; [-8.00 [-10.50 to -5.50] mmol/mol]; p < 0.001]. A significantly greater proportion of the visepegenatide group achieved a target HbA1c level of <7% (<53 mmol/mol) than the placebo (50.4% vs 14.2%; p < 0.05) and stringent HbA1c level of ≤6.5% (≤48 mmol/mol) (26.7% vs 7.9%), respectively. There was also a significantly greater improvement in FPG, 2-h postprandial glucose, homeostasis model assessment (HOMA) of beta cell function, post-prandial insulin, fasting, and post-prandial C-peptide level (p < 0.05) with visepegenatide treatment. The number (3 [2.2%]) of participants who received rescue therapy in the visepegenatide group was remarkably lower compared with those (17 [12.5%]) in the placebo group (p < 0.05). During the extended treatment period, visepegenatide consistently maintained the efficacy till week 52 confirmed by all the above endpoints. The reduction in HbA1c at week 52 was -1.39% (-1.58 to -1.19) [-15.14 [-17.28 to -13.01] mmol/mol], which was even greater than that at week 24. There was also a significant improvement in HOMA-insulin resistance (p = 0.004) at week 52 compared with the baseline value. For the placebo→visepegenatide group, which received visepegenatide in the extended treatment period, a notable decrease in HbA1c at week 52 compared to baseline was observed. The change from baseline in HbA1c was -1.49% (-1.68 to -1.30) [-16.27 [-18.37 to -14.16] mmol/mol]. The outcome was in the same direction as the visepegenatide group from the double-blind treatment period. Comprehensive benefits of visepegenatide including weight loss, improvement in lipid profile, and reduction in blood pressure have been demonstrated in this study. Visepegenatide reduced the body weight in a BMI-dependent manner that was prominent in BMI ˃32 kg/m2 with a mean (SD) reduction of -4.77 (13.94) kg at week 52 (p < 0.05). Incidences of gastrointestinal adverse events were less common than other weekly GLP-1 RA in the market, and most of the adverse events were mild and moderate in nature, occurring in the first weeks of the treatment, and were transient. No serious hypoglycaemia or grade 2 hypoglycaemia (blood glucose: ≤3 mmol/L) was reported during the study. Interpretation: As a monotherapy, visepegenatide provided rapid without the risk of hypoglycaemia, significant, and sustainable glycaemic control by improving islet ß-cell function and insulin resistance. Treatment with visepegenatide induced early treatment response in reducing HbA1c and maintaining glycaemic control for 52 weeks. Meanwhile, visepegenatide provided a comprehensive benefit in body weight loss, lipids, and blood pressure reduction. Visepegenatide had a better safety profile than other weekly GLP-1 RA in participants with T2DM even without the requirement of dose titration. Visepegenatide would provide an optimal treatment approach with its high benefit and low-risk balance. Funding: PegBio Co., Ltd.

Long-term imaging of three-dimensional hyphal development using the ePetri dish.

Imaging three-dimensional microbial development and behavior over extended periods is crucial for advancing microbiological studies. Here, we introduce an upgraded ePetri dish system specifically designed for extended microbial culturing and 3D imaging, addressing the limitations of existing methods. Our approach includes a sealed growth chamber to enable long-term culturing, and a multi-step reconstruction algorithm that integrates 3D deconvolution, image filtering, ridge, and skeleton detection for detailed visualization of the hyphal network. The system effectively monitored the development of Aspergillus brasiliensis hyphae over a seven-day period, demonstrating the growth medium's stability within the chamber. The system's 3D imaging capability was validated in a volume of 5.5 mm × 4 mm × 0.5 mm, revealing a radial growth pattern of fungal hyphae. Additionally, we show that the system can identify potential filter failures that are undetectable with 2D imaging. With these capabilities, the upgraded ePetri dish represents a significant advancement in long-term 3D microbial imaging, promising new insights into microbial development and behavior across various microbiological research areas.

Clamping enables enhanced electromechanical responses in antiferroelectric thin films.

Thin-film materials with large electromechanical responses are fundamental enablers of next-generation micro-/nano-electromechanical applications. Conventional electromechanical materials (for example, ferroelectrics and relaxors), however, exhibit severely degraded responses when scaled down to submicrometre-thick films due to substrate constraints (clamping). This limitation is overcome, and substantial electromechanical responses in antiferroelectric thin films are achieved through an unconventional coupling of the field-induced antiferroelectric-to-ferroelectric phase transition and the substrate constraints. A detilting of the oxygen octahedra and lattice-volume expansion in all dimensions are observed commensurate with the phase transition using operando electron microscopy, such that the in-plane clamping further enhances the out-of-plane expansion, as rationalized using first-principles calculations. In turn, a non-traditional thickness scaling is realized wherein an electromechanical strain (1.7%) is produced from a model antiferroelectric PbZrO3 film that is just 100 nm thick. The high performance and understanding of the mechanism provide a promising pathway to develop high-performance micro-/nano-electromechanical systems.

Bioengineering of vascularized porcine flaps using perfusion-recellularization.

Large volume soft tissue defects greatly impact patient quality of life and function while suitable repair options remain a challenge in reconstructive surgery. Engineered flaps could represent a clinically translatable option that may circumvent issues related to donor site morbidity and tissue availability. Herein, we describe the regeneration of vascularized porcine flaps, specifically of the omentum and tensor fascia lata (TFL) flaps, using a tissue engineering perfusion-decellularization and recellularization approach. Flaps were decellularized using a low concentration sodium dodecyl sulfate (SDS) detergent perfusion to generate an acellular scaffold with retained extracellular matrix (ECM) components while removing underlying cellular and nuclear contents. A perfusion-recellularization strategy allowed for seeding of acellular flaps with a co-culture of human umbilical vein endothelial cell (HUVEC) and mesenchymal stromal cells (MSC) onto the decellularized omentum and TFL flaps. Our recellularization technique demonstrated evidence of intravascular cell attachment, as well as markers of endothelial and mesenchymal phenotype. Altogether, our findings support the potential of using bioengineered porcine flaps as a novel, clinically-translatable strategy for future application in reconstructive surgery.

Modeling Temperature-Dependent Electron Thermal Diffuse Scattering via Machine-Learned Interatomic Potentials and Path-Integral Molecular Dynamics.

Electron thermal diffuse scattering is shown to be sensitive to subtle changes in atomic vibrations and shows promise in assessing lattice dynamics at nanometer resolution. Here, we demonstrate that machine-learned interatomic potentials (MLIPs) and path-integral molecular dynamics can accurately capture the potential energy landscape and lattice dynamics needed to describe electron thermal diffuse scattering. Using SrTiO_{3} as a test bed at cryogenic and room temperatures, we compare electron thermal diffuse scattering simulations using different approximations to incorporate thermal motion. Only when the simulations are based on quantum mechanically accurate MLIPs in combination with path-integral molecular dynamics that include nuclear quantum effects is there excellent agreement with experiments.

Impact of electronic AKI alert/care bundle on AKI inpatient outcomes: a retrospective single-center cohort study.

BACKGROUND: Outcomes among acute kidney injury (AKI) patients are poor in United Kingdom (UK) hospitals, and electronic alerts and care bundles may improve them. We implemented such a system at West Suffolk Hospital (WSH) called the 'AKI order set'. We aimed to assess its impact on all-cause mortality, length of stay (LOS) and renal function among AKI patients, and its utilization. METHODS: Retrospective, single-center cohort study of patients ≥ 18 years old with AKI at WSH, a 430-bed general hospital serving a rural UK population of approximately 280,000. 7243 unique AKI events representing 5728 patients with full data were identified automatically from our electronic health record (EHR) between 02 September 2018 and 1 July 2021 (median age 78 years, 51% male). All-cause mortality, LOS and improvement in AKI stage, demographic and comorbidity data, medications and AKI order set use were automatically collected from the EHR. RESULTS: The AKI order set was used in 9.8% of AKI events and was associated with 28% lower odds of all-cause mortality (multivariable odds ratio [OR] 0.72, 95% confidence interval [CI] 0.57-0.91). Median LOS was longer when the AKI order set was utilized than when not (11.8 versus 8.8 days, p < .001), but was independently associated with improvement in the AKI stage (28.9% versus 8.7%, p < .001; univariable OR 4.25, 95% CI 3.53-5.10, multivariable OR 4.27, 95% CI 3.54-5.14). CONCLUSIONS: AKI order set use led to improvements in all-cause mortality and renal function, but longer LOS, among AKI patients at WSH.

Population Pharmacokinetic/Pharmacodynamic Analysis of the Glucokinase Activator PB201 in Healthy Volunteers and Patients with Type 2 Diabetes Mellitus: Facilitating the Clinical Development of PB201 in China.

PB201 is an orally active, partial glucokinase activator targeting both pancreatic and hepatic glucokinase. As the second glucokinase activator studied beyond phase I, PB201 has demonstrated promising glycemic effects as well as favorable pharmacokinetic (PK) and safety profiles in patients with type 2 diabetes mellitus (T2DM). This study aims to develop a population PK/pharmacodynamic (PD) model for PB201 using the pooled data from nine phase I/II clinical trials conducted in non-Chinese healthy volunteers and a T2DM population and to predict the PK/PD profile of PB201 in a Chinese T2DM population. We developed the PK/PD model using the non-linear mixed-effects modeling approach. All runs were performed using the first-order conditional estimation method with interaction. The pharmacokinetics of PB201 were well fitted by a one-compartment model with saturable absorption and linear elimination. The PD effects of PB201 on reducing the fasting plasma glucose and glycosylated hemoglobin levels in the T2DM population were described by indirect response models as stimulating the elimination of fasting plasma glucose, where the production of glycosylated hemoglobin was assumed to be stimulated by fasting plasma glucose. Covariate analyses revealed enhanced absorption of PB201 by food and decreased systemic clearance with ketoconazole co-administration, while no significant covariate was identified for the pharmacodynamics. The population PK model established for non-Chinese populations was shown to be applicable to the Chinese T2DM population as verified by the PK data from the Chinese phase I study. The final population PK/PD model predicted persistent and dose-dependent reductions in fasting plasma glucose and glycosylated hemoglobin levels in the Chinese T2DM population receiving 50/50 mg, 100/50 mg, and 100/100 mg PB201 twice daily for 24 weeks independent of co-administration of metformin. Overall, the proposed population PK/PD model quantitatively characterized the PK/PD properties of PB201 and the impact of covariates on its target populations, which allows the leveraging of extensive data in non-Chinese populations with the limited data in the Chinese T2DM population to successfully supported the waiver of the clinical phase II trial and facilitate the optimal dose regimen design of a pivotal phase III study of PB201 in China.

Does prehabilitation before esophagectomy improve postoperative outcomes? A systematic review and meta-analysis.

Esophagectomy for esophageal cancer is associated with high morbidity. It remains unclear whether prehabilitation, a strategy aimed at optimizing patients' physical and mental functioning prior to surgery, improves postoperative outcomes. A systematic review and meta-analysis was conducted to evaluate the effect of prehabilitation on post-operative outcomes after esophagectomy. Data sources included Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, CINAHL, and PEDro, with information from 1 January 2000 to 5 August 2023. The analysis included randomized controlled trials and observational studies that compared prehabilitation interventions to standard care prior to esophagectomy. A random effects model was used to generate a pooled estimate for pairwise meta-analysis, meta-analysis of proportions, and meta-analysis of means. A total of 1803 patients were included with 584 in randomized controlled trials (RCTs) and 1219 in observational studies. In the randomized evidence, there were no significant differences between prehabilitation and control in the odds of postoperative pneumonia (15.0 vs. 18.9%, odds ratio (OR) 1.06 [95% confidence interval (CI): 0.66;1.72]) or pulmonary complications (14 vs. 25.6%, OR 0.68 [95% CI: 0.32;1.45]). In the observational data, there was a reduction in both postoperative pneumonia (22.5 vs. 32.9%, OR 0.48 [95% CI: 0.28;0.83]) and pulmonary complications (26.1 vs. 52.3%, OR 0.35 [95% CI: 0.17;0.75]) with prehabilitation. Hospital and intensive care unit length of stay (days), operative mortality, and severe complications (Clavien-Dindo ≥ 3) did not differ between groups in both the randomized data and observational data. Prehabilitation demonstrated reductions in postoperative pneumonia and pulmonary complications in observational studies, but not RCTs. The overall certainty of these findings is limited by the low quality of the available evidence.

The plethora of immunomodulatory drugs: opportunities for immune-mediated kidney diseases.

In recent decades, insights into the molecular pathways involved in disease have revolutionized the treatment of autoimmune diseases. A plethora of targeted therapies have been identified and are at varying stages of clinical development in renal autoimmunity. Some of these agents, such as rituximab or avacopan, have been approved for the treatment of immune-mediated kidney disease, but kidney disease lags behind more common autoimmune disorders in new drug development. Evidence is accumulating as to the importance of adaptive immunity, including abnormalities in T-cell activation and signaling, and aberrant B-cell function. Furthermore, innate immunity, particularly the complement and myeloid systems, as well as pathologic responses in tissue repair and fibrosis, play a key role in disease. Collectively, these mechanistic studies in innate and adaptive immunity have provided new insights into mechanisms of glomerular injury in immune-mediated kidney diseases. In addition, inflammatory pathways common to several autoimmune conditions exist, suggesting that the repurposing of some existing drugs for the treatment of immune-mediated kidney diseases is a logical strategy. This new understanding challenges the clinical investigator to translate new knowledge into novel therapies leading to better disease outcomes. This review highlights promising immunomodulatory therapies tested for immune-mediated kidney diseases as a primary indication, details current clinical trials and discusses pathways that could be targeted in the future.

Tunable Artificial Relaxor Behavior in [BaTiO_{3}]_{m}/[BaZrO_{3}]_{n} Superlattices.

[BaTiO_{3}]_{m}/[BaZrO_{3}]_{n} (m, n=4-12) superlattices are used to demonstrate the fabrication and deterministic control of an artificial relaxor. X-ray diffraction and atomic-resolution imaging studies confirm the production of high-quality heterostructures. With decreasing BaTiO_{3} layer thickness, dielectric measurements reveal systematically lower dielectric-maximum temperatures, while hysteresis loops and third-harmonic nonlinearity studies suggest a transition from ferroelectriclike to relaxorlike behavior driven by tuning the random-field strength. This system provides a novel platform for studying the size effect and interaction length scale of the nanoscale-polar structures in relaxors.

PROphylaxis for paTiEnts at risk of COVID-19 infecTion (PROTECT-V).

BACKGROUND: Despite the introduction of vaccination, there remains a need for pre-exposure prophylactic agents against SARS-CoV-2. Several patient groups are more vulnerable to SARS-CoV-2 infection by virtue of underlying health conditions, treatments received or suboptimal responses to vaccination. METHODS: PROTECT-V is a platform trial testing pre-exposure prophylactic interventions against SARS-CoV-2 infection in vulnerable patient populations (organ transplant recipients; individuals with oncological/haematological diagnoses, immune deficiency or autoimmune diseases requiring immunosuppression or on dialysis). Multiple agents can be evaluated across multiple vulnerable populations sharing placebo groups, with the option of adding additional treatments at later time points as these become available. The primary endpoint is symptomatic SARS-CoV-2 infection, and each agent will be independently evaluated in real time when the required number of events occurs. Presently, three agents are approved in the platform: intranasal niclosamide, nasal and inhaled ciclesonide and intravenous sotrovimab. DISCUSSION: Despite the introduction of vaccination, there remains a need for pre-exposure prophylactic agents against SARS-CoV-2. Several patient groups are more vulnerable to COVID-19 disease by virtue of underlying health conditions, treatments received or suboptimal responses to vaccination. TRIAL REGISTRATION: ClinicalTrials.gov NCT04870333. EudraCT 2020-004144-28.

Harnessing transcriptionally driven chromosomal instability adaptation to target therapy-refractory lethal prostate cancer.

Metastatic prostate cancer (PCa) inevitably acquires resistance to standard therapy preceding lethality. Here, we unveil a chromosomal instability (CIN) tolerance mechanism as a therapeutic vulnerability of therapy-refractory lethal PCa. Through genomic and transcriptomic analysis of patient datasets, we find that castration and chemotherapy-resistant tumors display the highest CIN and mitotic kinase levels. Functional genomics screening coupled with quantitative phosphoproteomics identify MASTL kinase as a survival vulnerability specific of chemotherapy-resistant PCa cells. Mechanistically, MASTL upregulation is driven by transcriptional rewiring mechanisms involving the non-canonical transcription factors androgen receptor splice variant 7 and E2F7 in a circuitry that restrains deleterious CIN and prevents cell death selectively in metastatic therapy-resistant PCa cells. Notably, MASTL pharmacological inhibition re-sensitizes tumors to standard therapy and improves survival of pre-clinical models. These results uncover a targetable mechanism promoting high CIN adaptation and survival of lethal PCa.

Correlating local chemical and structural order using Geographic Information Systems-based spatial statistics.

Analysis of nanoscale short-range chemical and/or structural order via (scanning) transmission electron microscopy (S/TEM) imaging is fundamentally limited by projection of the three dimensional sample, which averages informational along the beam direction. Extracting statistically significant spatial correlations between the structure and chemistry determined from these two-dimensional datasets thus remains challenging. Here, we apply methods commonly used in Geographic Information Systems (GIS) to determine the spatial correlation between measures of local chemistry and structure from atomic-resolution STEM imaging of a compositionally complex relaxor, Pb(Mg1/3Nb2/3)O3 (PMN). The approach is used to determine the type of ordering present and to quantify the spatial variation of chemical order, oxygen octahedral distortions, and oxygen octahedral tilts. The extent of autocorrelation and inter-feature correlation among these short-range ordered regions are then evaluated through a spatial covariance analysis, showing correlation as a function of distance. The results demonstrate that integrating GIS tools for analyzing microscopy datasets can serve to unravel subtle relationships among chemical and structural features in complex materials that can be hidden when ignoring their spatial distributions.

Microfluidic antibody profiling after repeated SARS-CoV-2 vaccination links antibody affinity and concentration to impaired immunity and variant escape in patients on anti-CD20 therapy.

Background: Patients with autoimmune/inflammatory conditions on anti-CD20 therapies, such as rituximab, have suboptimal humoral responses to vaccination and are vulnerable to poorer clinical outcomes following SARS-CoV-2 infection. We aimed to examine how the fundamental parameters of antibody responses, namely, affinity and concentration, shape the quality of humoral immunity after vaccination in these patients. Methods: We performed in-depth antibody characterisation in sera collected 4 to 6 weeks after each of three vaccine doses to wild-type (WT) SARS-CoV-2 in rituximab-treated primary vasculitis patients (n = 14) using Luminex and pseudovirus neutralisation assays, whereas we used a novel microfluidic-based immunoassay to quantify polyclonal antibody affinity and concentration against both WT and Omicron (B.1.1.529) variants. We performed comparative antibody profiling at equivalent timepoints in healthy individuals after three antigenic exposures to WT SARS-CoV-2 (one infection and two vaccinations; n = 15) and in convalescent patients after WT SARS-CoV-2 infection (n = 30). Results: Rituximab-treated patients had lower antibody levels and neutralisation titres against both WT and Omicron SARS-CoV-2 variants compared to healthy individuals. Neutralisation capacity was weaker against Omicron versus WT both in rituximab-treated patients and in healthy individuals. In the rituximab cohort, this was driven by lower antibody affinity against Omicron versus WT [median (range) KD: 21.6 (9.7-38.8) nM vs. 4.6 (2.3-44.8) nM, p = 0.0004]. By contrast, healthy individuals with hybrid immunity produced a broader antibody response, a subset of which recognised Omicron with higher affinity than antibodies in rituximab-treated patients [median (range) KD: 1.05 (0.45-1.84) nM vs. 20.25 (13.2-38.8) nM, p = 0.0002], underpinning the stronger serum neutralisation capacity against Omicron in the former group. Rituximab-treated patients had similar anti-WT antibody levels and neutralisation titres to unvaccinated convalescent individuals, despite two more exposures to SARS-CoV-2 antigen. Temporal profiling of the antibody response showed evidence of affinity maturation in healthy convalescent patients after a single SARS-CoV-2 infection, which was not observed in rituximab-treated patients, despite repeated vaccination. Discussion: Our results enrich previous observations of impaired humoral immune responses to SARS-CoV-2 in rituximab-treated patients and highlight the significance of quantitative assessment of serum antibody affinity and concentration in monitoring anti-viral immunity, viral escape, and the evolution of the humoral response.

Towards Augmented Microscopy with Reinforcement Learning-Enhanced Workflows.

Here, we report a case study implementation of reinforcement learning (RL) to automate operations in the scanning transmission electron microscopy workflow. To do so, we design a virtual, prototypical RL environment to test and develop a network to autonomously align the electron beam position without prior knowledge. Using this simulator, we evaluate the impact of environment design and algorithm hyperparameters on alignment accuracy and learning convergence, showing robust convergence across a wide hyperparameter space. Additionally, we deploy a successful model on the microscope to validate the approach and demonstrate the value of designing appropriate virtual environments. Consistent with simulated results, the on-microscope RL model achieves convergence to the goal alignment after minimal training. Overall, the results highlight that by taking advantage of RL, microscope operations can be automated without the need for extensive algorithm design, taking another step toward augmenting electron microscopy with machine learning methods.

STEAP1-4 (Six-Transmembrane Epithelial Antigen of the Prostate 1-4) and Their Clinical Implications for Prostate Cancer.

Six-Transmembrane Epithelial Antigen of the Prostate 1-4 (STEAP1-4) compose a family of metalloproteinases involved in iron and copper homeostasis and other cellular processes. Thus far, five homologs are known: STEAP1, STEAP1B, STEAP2, STEAP3, and STEAP4. In prostate cancer, STEAP1, STEAP2, and STEAP4 are overexpressed, while STEAP3 expression is downregulated. Although the metalloreductase activities of STEAP1-4 are well documented, their other biological functions are not. Furthermore, the properties and expression levels of STEAP heterotrimers, homotrimers, heterodimers, and homodimers are not well understood. Nevertheless, studies over the last few decades have provided sufficient impetus to investigate STEAP1-4 as potential biomarkers and therapeutic targets for prostate cancer. In particular, STEAP1 is the target of many emerging immunotherapies. Herein, we give an overview of the structure, physiology, and pathophysiology of STEAP1-4 to provide context for past and current efforts to translate STEAP1-4 into the clinic.

Procurement and Perfusion-Decellularization of Porcine Vascularized Flaps in a Customized Perfusion Bioreactor.

Large volume soft tissue defects lead to functional deficits and can greatly impact the patient's quality of life. Although surgical reconstruction can be performed using autologous free flap transfer or vascularized composite allotransplantation (VCA), such methods also have disadvantages. Issues such as donor site morbidity and tissue availability limit autologous free flap transfer, while immunosuppression is a significant limitation of VCA. Engineered tissues in reconstructive surgery using decellularization/recellularization methods represent a possible solution. Decellularized tissues are generated using methods that remove native cellular material while preserving the underlying extracellular matrix (ECM) microarchitecture. These acellular scaffolds can then be subsequently recellularized with recipient-specific cells. This protocol details the procurement and decellularization methods used to achieve acellular scaffolds in a pig model. In addition, it also provides a description of the perfusion bioreactor design and setup. The flaps include the porcine omentum, tensor fascia lata, and the radial forearm. Decellularization is performed via ex vivo perfusion of low concentration sodium dodecyl sulfate (SDS) detergent followed by DNase enzyme treatment and peracetic acid sterilization in a customized perfusion bioreactor. Successful tissue decellularization is characterized by a white-opaque appearance of flaps macroscopically. Acellular flaps show the absence of nuclei on histological staining and a significant reduction in DNA content. This protocol can be used efficiently to generate decellularized soft tissue scaffolds with preserved ECM and vascular microarchitecture. Such scaffolds can be used in subsequent recellularization studies and have the potential for clinical translation in reconstructive surgery.