Phase Response Research Articles

Liver matrin-3 protects mice against hepatic steatosis and stress response via constitutive androstane receptor

ObjectiveThe prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) continues to rise with the increasing obesity epidemic. Rezdiffra as an activator of a thyroid hormone receptor-beta is the only Food and Drug Administration approved therapy. As such, there is a critical need to improve our understanding of gene expression regulation and signaling transduction in MASLD to develop new therapies. Matrin-3 is a DNA- and RNA-binding protein involved in the pathogenesis of human diseases. Here we examined its previously uncharacterized role in limiting hepatic steatosis and stress response via the constitutive androstane receptor (CAR). MethodsMatrin-3 floxed and liver-specific knockout mice were fed either a chow diet or 60 kcal% high-fat diet (HFD) for up to 16 weeks. The mice were euthanized for different analysis including liver histology, lipid levels, and gene expression. Bulk RNA-seq, bulk ATAC-seq, and single-nucleus Multiome were used to examine changes of transcriptome and chromatin accessibility in the liver. Integrative bioinformatics analysis of our data and publicly available datasets and different biochemical assays were performed to identify underlying the molecular mechanisms mediating matrin-3's effects. Liver-tropic adeno-associated virus was used to restore the expression of CAR for lipid, acute phase genes, and histological analysis. ResultsMatrin-3 expression is induced in the steatotic livers of mice. Liver-specific matrin-3 deletion exacerbated HFD-induced steatosis, acute phase response, and inflammation in the liver of female mice. The transcriptome and chromatin accessibility were re-programmed in the liver of these mice with signatures indicating that CAR signaling is dysregulated. Mechanistically, matrin-3 interacts with CAR mRNA, and matrin-3 deficiency promotes CAR mRNA degradation. Consequently, matrin-3 deletion impaired CAR signaling by reducing CAR expression. Matrin-3 levels positively correlate with CAR expression in human livers. Ces2a and Il1r1 were identified as new target genes of CAR. Interestingly, we found that CAR discords with the expression of its target genes including Cyp2b10 and Ces2a in response to HFD, indicating CAR signaling is dysregulated by HFD despite increased CAR expression. Dysregulated CAR signaling upon matrin-3 deficiency reduced Ces2a and de-repressed Il1r1 expression. CAR restoration partially abrogated the dysregulated gene expression, exacerbated hepatic steatosis, acute phase response, and inflammation in liver-specific matrin-3 knockout mice fed a HFD. ConclusionsOur findings demonstrate that matrin-3 is a key upstream regulator maintaining CAR signaling upon metabolic stress, and the matrin-3-CAR axis limits hepatic steatosis and stress response signaling that may give insights for therapeutic intervention.

Programmable metasurfaces with high angular stability for arbitrarily-polarized obliquely-incident waves

Programmable metasurfaces show enormous potential in real-time electromagnetic (EM) manipulation and their stable responses to variable EM waves including incident angle and polarization changes are crucial for related applications. However, the demonstrated programmable metasurfaces are commonly considered in normal-incident waves with fixed polarization; how to achieve stable performance in more realistic scenarios of wide-angle and full-polarized wave incidences is still a challenge. Here, we propose and realize a wide-angle and full-polarization programmable metasurface, which can generate stabilized amplitude and phase responses at both transverse electric (TE) and transverse magnetic (TM) oblique incidences. These are achieved by introducing metallic walls around the metasurface element to reduce element coupling, which greatly improves the angular stability of its reflection responses. The mechanisms of angular insensitivity are analyzed comprehensively, and as a proof of concept, obliquely-incident beam steering, large-angle beam scanning and oblique vortex beam emitting are demonstrated on this programmable metasurface. Both the simulation and experimental results demonstrate that the programmable metasurface can operate well at both TE and TM wide-angle oblique incidences in the upper half space. Our work offers an actual route for improving the angular stability and polarization insensitivity of metasurfaces, which could push them one step closer towards more complicated applications.

4-bit millimeter-wave Janus metasurface enabled polarization-spatial multiplexing holography.

Metasurface holography has become a surging and revolutionized field due to its flexible manipulation of amplitude and/or phase, which enhances the quality and capacity of holographic images. However, the current meta-holograms primarily focus on half-space manipulation, posing a challenge in developing simplified meta-hologram structures for spatial multiplexing. To address this situation, what we believe to be a novel 4-bit "Janus" metasurface combined with the weighted Gerchberg-Saxton (WGS) algorithm is proposed to record and reconstruct two distinct images in millimeter wave band. By meticulously designing the single-layer units, the 4-bit Janus metasurface achieves independent amplitude and phase responses in two orthogonal information channels. Moreover, the imaging ability of the proposed metasurface is investigated under different amplitude and phase dispersion. Comparative analysis also highlights several notable advantages of our work, including a low-profile design, polarization-frequency multiplexing, and enhanced imaging efficiency. The proposed method is verified through theoretical calculations, simulations, and experiments, and promises a versatile platform for applications in data storage, encryption, and auxiliary sensing.

Simultaneous Circular Dichroism and Wavefront Manipulation with Generalized Pancharatnam-Berry Phase Metasurfaces.

Simultaneous circular dichroism and wavefront manipulation have gained considerable attention in various applications, such as chiroptical spectroscopy, chiral imaging, sorting and detection of enantiomers, and quantum optics, which can improve the miniaturization and integration of the optical system. Typically, structures with n-fold rotational symmetry (n ≥ 3) are used to improve circular dichroism, as they induce stronger interactions between the electric and magnetic fields. However, manipulating the wavefront with these structures remains challenging because they are commonly considered isotropic and lack a geometric phase response in linear optics. Here, we propose and experimentally demonstrate an approach to achieve simultaneous circular dichroism (with a maximum value of ∼0.62) and wavefront manipulation using a plasmonic metasurface made up of C3 Archimedes spiral nanostructures. The circular dichroism arises from the magnetic dipole-dipole resonance and strong interactions between adjacent meta-atoms. As a proof of concept, two metadevices are fabricated and characterized in the near-infrared regime. This configuration possesses the potential for future applications in photodetection, chiroptical spectroscopy, and the customization of linear and nonlinear optical responses.

Acoustic ejection mass spectrometry empowers ultra-fast protein biomarker quantification

The global scientific response to COVID 19 highlighted the urgent need for increased throughput and capacity in bioanalytical laboratories, especially for the precise quantification of proteins that pertain to health and disease. Acoustic ejection mass spectrometry (AEMS) represents a much-needed paradigm shift for ultra-fast biomarker screening. Here, a quantitative AEMS assays is presented, employing peptide immunocapture to enrich (i) 10 acute phase response (APR) protein markers from plasma, and (ii) SARS-CoV-2 NCAP peptides from nasopharyngeal swabs. The APR proteins were quantified in 267 plasma samples, in triplicate in 4.8 h, with %CV from 4.2% to 10.5%. SARS-CoV-2 peptides were quantified in triplicate from 145 viral swabs in 10 min. This assay represents a 15-fold speed improvement over LC-MS, with instrument stability demonstrated across 10,000 peptide measurements. The combination of speed from AEMS and selectivity from peptide immunocapture enables ultra-high throughput, reproducible quantitative biomarker screening in very large cohorts.

Interactions of Serum Amyloid A Proteins with the Blood-Brain Barrier: Implications for Central Nervous System Disease.

Serum amyloid A (SAA) proteins are highly conserved lipoproteins that are notoriously involved in the acute phase response and systemic amyloidosis, but their biological functions are incompletely understood. Recent work has shown that SAA proteins can enter the brain by crossing the intact blood-brain barrier (BBB), and that they can impair BBB functions. Once in the central nervous system (CNS), SAA proteins can have both protective and harmful effects, which have important implications for CNS disease. In this review of the thematic series on SAA, we discuss the existing literature that relates SAA to neuroinflammation and CNS disease, and the possible roles of the BBB in these relations.

Profiling the neuroimmune cascade in 3xTg-AD mice exposed to successive mild traumatic brain injuries

Repetitive mild traumatic brain injuries (rmTBI) sustained within a window of vulnerability can result in long term cognitive deficits, depression, and eventual neurodegeneration associated with tau pathology, amyloid beta (Aβ) plaques, gliosis, and neuronal and functional loss. However, a comprehensive study relating acute changes in immune signaling and glial reactivity to neuronal changes and pathological markers after single and repetitive mTBIs is currently lacking. In the current study, we addressed the question of how repeated injuries affect the brain neuroimmune response in the acute phase of injury (< 24 h) by exposing the 3xTg-AD mouse model of tau and Aβ pathology to successive (1x-5x) once-daily weight drop closed-head injuries and quantifying immune markers, pathological markers, and transcriptional profiles at 30 min, 4 h, and 24 h after each injury. We used young adult 2–4 month old 3xTg-AD mice to model the effects of rmTBI in the absence of significant tau and Aβ pathology. We identified pronounced sexual dimorphism in this model, with females eliciting more diverse changes after injury compared to males. Specifically, females showed: (1) a single injury caused a decrease in neuron-enriched genes inversely correlated with inflammatory protein expression and an increase in AD-related genes within 24 h, (2) each injury significantly increased a group of cortical cytokines (IL-1α, IL-1β, IL-2, IL-9, IL-13, IL-17, KC) and MAPK phospho-proteins (phospho-Atf2, phospho-Mek1), several of which co-labeled with neurons and correlated with phospho-tau, and (3) repetitive injury caused increased expression of genes associated with astrocyte reactivity and macrophage-associated immune function. Collectively our data suggest that neurons respond to a single injury within 24 h, while other cell types, including astrocytes, transition to inflammatory phenotypes within days of repetitive injury.

A Bayesian adaptive phase III design for multi-arm trials with time-to-event endpoint for nonproportional hazards utilizing the generalized gamma distribution

In case of trials with time-to-event endpoints, sample size calculations are well-studied under the assumption of proportional hazards or when the endpoint of interest follows an exponential distribution. When prior evidence suggests otherwise, using traditional approaches may lead to inefficiently designed and underpowered studies. In such situations, a recently introduced frequentist approach proposes a sample size calculation for a fixed two-arm trial based on the accelerated failure time model thereby allowing nonproportional hazards and can be utilized for any distribution from the generalized gamma family. Advances in the field of clinical trials research have focused on the need for adaptive phase III designs with complex features, however, existing methods in literature have ignored the nonproportional hazards scenario. In this article, we propose a Bayesian adaptive design for a multi-arm phase III trial with nonproportional hazards allowing many complex features such as incorporation of prior knowledge of early phase studies, arms dropping, and response adaptive randomization. We extend the frequentist approach utilizing a generalized gamma distribution to a Bayesian setting while simultaneously addressing one of the key limitations of the frequentist approach. Extensive simulations are performed to study the operation characteristics of the proposed design using two examples representing real-life applications.

Aging is associated with an insufficient early inflammatory response of lung endothelial cells in SARS-CoV-2 infection.

Advanced age is associated with an increased susceptibility to Coronavirus Disease (COVID)-19 and more severe outcomes, although the underlying mechanisms are understudied. The lung endothelium is located next to infected epithelial cells and bystander inflammation may contribute to thromboinflammation and COVID-19-associated coagulopathy. Here, we investigated age-associated SARS-CoV-2 pathogenesis and endothelial inflammatory responses using humanized K18-hACE2 mice. Survival was reduced to 20% in aged mice (85-112 weeks) versus 50% in young mice (12-15 weeks) at 10 days post infection (dpi). Bulk RNA-sequencing of endothelial cells from mock and infected mice at 2dpi of both age groups (aged: 72-85 weeks; young: 15 weeks) showed substantially lower significant differentially regulated genes in infected aged mice than in young mice (712 versus 2294 genes). Viral recognition and anti-viral pathways such as RIG-I-like receptor signaling, NOD-like receptor signaling and interferon signaling were regulated in response to SARS-CoV-2. Young mice showed several fold higher interferon responses (Ifitm3, Ifit1, Isg15, Stat1) and interferon-induced chemokines (Cxcl10 and Cxcl11) than aged mice. Endothelial cells from infected young mice displayed elevated expression of chemokines (Cxcl9, Ccl2) and leukocyte adhesion markers (Icam1) underscoring that inflammation of lung endothelium during infection could facilitate leukocyte adhesion and thromboinflammation. TREM1 and acute phase response signaling were particularly prominent in endothelial cells from infected young mice. Immunohistochemistry was unable to detect viral protein in pulmonary endothelium. In conclusion, our data demonstrate that the early host response of the endothelium to SARS-CoV-2 infection declines with aging, which could be a potential contributor to disease severity.

Safety, tolerability and efficacy of 212Pb-DOTAMTATE as a targeted alpha therapy for subjects with unresectable or metastatic somatostatin receptor-expressing gastroenteropancreatic neuroendocrine tumors (SSTR+ GEP-NETs): A phase 2 study.

4020 Background: 212Pb-DOTAMTATE is a Targeted Alpha Therapy (TAT) in clinical development for subjects with SSTR+ neuroendocrine tumors. A phase I dose-escalation study has already been completed (Delpassand et al. J Nucl Med 2022). TAT holds the promise to improve outcomes versus Peptide Receptor Radionuclide Therapy (PRRT) with beta-emitters like 177Lu-DOTATATE, currently considered the standard of care for subjects with GEP-NETs. Methods: ALPHAMEDIX 02 is a Phase II, open-label, multicenter study evaluating the safety, tolerability and efficacy of 212Pb-DOTAMTATE in PRRT-naïve (Cohort 1, N = 36) and PRRT-refractory (Cohort 2, Target N = 30) subjects with histologically confirmed unresectable or metastatic GEP-NETs, positive somatostatin analogue imaging and at least 1 site of measurable disease per RECIST 1.1. 212Pb-DOTAMTATE was administered at 67.6 μCi/kg per cycle, with a maximum activity administered per cycle of 5.5 mCi every 8 weeks, for up to 4 cycles. Primary endpoints include overall response rate (ORR) per RECIST1.1, and incidence and severity of adverse events (AEs). Secondary endpoints include progression free survival, overall survival , and health-related quality of life. Initial results of the already completed cohort 1 are presented. Results: In cohort 1, 17 out of 36 subjects with metastatic SSTR+ GEP-NETs achieved a confirmed response (ORR 47.2% (32.0-63.0%)). In the Phase I trial, five out of eight PRRT- naïve subjects with SSTR+ GEP-NETs treated with the same regimen of 212Pb-DOTAMTATE achieved a response (ORR 62.5% (30.6-86.3%)): the combined ORR from both studies is 50% (22 out of 44, 95%-CI:36% - 64%). Median Duration of Response (DOR) has not been reached in both studies. Four out of five subjects (80%) with confirmed response in Phase I had a DOR of ≥ 12 months. In the ongoing Phase II study the response follow-up for 10 subjects with confirmed response is currently shorter than 6 months: so far 7 out of 17 subjects (41%) with confirmed response had a DOR of ≥ 6 months, and one of these subjects had a DOR of ≥ 12 months. Lymphocytopenia is a lead cause of the 59% grade 3 and 4 AEs reported in subjects in cohort 1. Overall, 4 fatal AEs were reported: death / progressive disease (N = 2), carcinoid syndrome (N = 1) and sepsis (N = 1). Conclusions: In PRRT-naïve subjects with SSTR+ unresectable or metastatic GEP-NETs treatment with up to 4 cycles of ²¹²Pb-DOTAMTATE (67.6 μCi/kg/cycle) was well-tolerated, with a safety profile consistent with the underlying disease and expected toxicities of radioligand therapy, similar to 177Lu-DOTATATE. The ORR of 47.2% in cohort 1 (50% in the pooled dataset) appears to be substantially higher than the ORR previously reported for 177Lu-DOTATATE in the pivotal NETTER-1 study (ORR 18% (10–25%)). Clinical trial information: NCT05153772 .

Double reading performance and the impact of adjudication on progression-free survival estimations: Findings from a lung clinical trial.

e23010 Background: The FDA recommends Blinded Independent Central Review (BICR) with double read for clinical trials with imaging. However, inter-reader variability is a concern in these trials. While studies have investigated the variability of RECIST, the primary response criteria, little attention has been given to the optimal association of readers. The evaluation of therapeutic response in phase III trials relies on the Date of first Progressive Disease (DoPD), with the Discrepancy Rate (DR) as the preferred index for measuring inter-reader variability in DoPD evaluation. Another important index measures readers' bias, assessing their tendency to over or under-estimate diagnoses. In cases of discrepancies, a third reader is brought in for adjudication. However, the impact of adjudication on trials' Progression-Free Survival (PFS) is not well-documented. Our study examines the variability in a lung clinical trial using RECIST, analyzing double reading performance, reader association prediction, and the impact of adjudication on PFS estimations. Methods: We retrospectively analyzed five phase III lung clinical trials using the RECIST 1.1 criteria in BICR with double reads. The trials involved 7 readers organized into 11 teams, each reader having participated in multiple trials and performed over 50 reads, resulting in 1017 patients' reviews. Our analysis included: Calculation of DR and bias for each team, and testing the correlation between DR and bias. Computation of the signed bias for each individual reader. Evaluation of a probabilistic model to predict the DR for each team and the bias for each reader. Comparison of PFS between single and double reads after adjudication and endorsement of one of the readings. Results: A multiple comparisons test did not reveal any difference between teams’ DR (Marascuilo test; q &gt; 0.05). The average DR across all teams was 39.9% [95%CI; 37.8; 41.9]. However, we did find significant differences in bias when comparing 9/55 pairs of teams (Marascuilo test; q &lt; 0.05). The range of absolute bias values was 20% to 100%. We did not find a correlation between bias and DR (p = 0.64). Additionally, when comparing the average bias value per reader, no differences were observed (Marascuilo test; q &lt; 0.05). We failed to predict teams DR and readers' bias. The endorsement rate of readers ranged [18%; 82%]. After adjudication, we found that 27% of the PFS were lower than the minimum value obtained from the single readers, in one case 20.6% shorter. Conclusions: Significant readers' bias has a notable impact on double readings, independent of the DR values. The performance of one reader cannot be generalized based on others. Additionally, adjudication significantly affects the PFS of clinical trials. These findings emphasize the importance of considering readers' bias and the potential consequences of adjudication in clinical trial assessments.

Identification of novel biomarkers of acute phase response in chickens challenged with Escherichia coli lipopolysaccharide endotoxin

BackgroundThe chicken’s inflammatory response is an essential part of the bird’s response to infection. A single dose of Escherichia coli (E. coli) lipopolysaccharide (LPS) endotoxin can activate the acute phase response (APR) and lead to the production of acute phase proteins (APPs). In this study, the responses of established chicken APPs, Serum amyloid A (SAA) and Alpha-1-acid-glycoprotein (AGP), were compared to two novel APPs, Hemopexin (Hpx) and Extracellular fatty acid binding protein (Ex-FABP), in 15-day old broilers over a time course of 48 h post E.coli LPS challenge. We aimed to investigate and validate their role as biomarkers of an APR. Novel plant extracts, Citrus (CTS) and cucumber (CMB), were used as dietary supplements to investigate their ability to reduce the inflammatory response initiated by the endotoxin.ResultsA significant increase of established (SAA, AGP) and novel (Ex-FABP, Hpx) APPs was detected post E.coli LPS challenge. Extracellular fatty acid binding protein (Ex-FABP) showed a similar early response to SAA post LPS challenge by increasing ~ 20-fold at 12 h post challenge (P < 0.001). Hemopexin (Hpx) showed a later response by increasing ∼5-fold at 24 h post challenge (P < 0.001) with a similar trend to AGP. No differences in APP responses were identified between diets (CTS and CMB) using any of the established or novel biomarkers.ConclusionsHpx and Ex-FABP were confirmed as potential biomarkers of APR in broilers when using an E. coli LPS model along with SAA and AGP. However, no clear advantage for using either of dietary supplements to modulate the APR was identified at the dosage used.

Investigation of virginiamycin to improve health of growing and finishing steers: I. Effects on ruminal acidosis and liver health*

ObjectiveOur objective was to observe the effects of the interrelationship among virginiamycin (VM) inclusion (240 mg/d), ruminal pH dynamics, and hepatic plasma metabolites on rumen and animal health during a 150-d feeding trial. Materials and MethodsSteers (304 ± 27 kg; n = 120) were assigned randomly to 1 of 6 dietary treatments: no VM (T000); VM for the last 50 d (T001); VM for the last 100 d (T011); VM for the first 50 d (T100); VM for the first 100 d (T110); and VM for 150 d (T111). All animals were orally administered 2 indwelling rumen pH and temperature recording boli on d 0 and 84. Blood samples were collected via jugular venipuncture on d −7, 28, 56, 84, 112, and 140, and plasma was analyzed for concentrations of albumin, alkaline phosphatase, direct bilirubin, total bilirubin, gamma-glutamyl transferase, and total protein using an automated blood analyzer. Concurrently, haptoglobin (HPT) was measured following a colorimetric method based on peroxidase activity. A random coefficients model with pen and animals within treatment as a random effect was used. Results and DiscussionAnimals that received VM for the first 100 d (T110 and T111) had greater mean ruminal pH during d 50 to 100 when compared with animals that did not receive VM (T000 and T001; 6.12 vs. 6.00, respectively). Moreover, T111 tended to have less time under pH 5.8 (3.01 h/d) when compared with T100 and T001 (5.83 and 6.45 h/d, respectively). At slaughter, overall, 3.36% of cattle in the study were identified with liver abscesses (A and A−), and 24.3% had lung lesions. Plasma metabolite concentrations before slaughter did not predict the presence of liver abscesses (P ≥ 0.182). Based on acute phase responses, HPT was notably lower on d 84 after diet transition in VM-treated animals (46.1 vs. 68.9 mg/L). Additionally, VM inclusion boosted indicators of overall health with greater alkaline phosphatase levels and albumin-toglobulin ratios. Implications and ApplicationsVirginiamycin has practical implications for rumen health and overall cattle health, where supplementation during the whole growing to finishing phases was more effective in capturing its full potential.

High-accuracy optical vector network analyzer for optical notch and bandpass responses

A high-accuracy optical vector network analyzer (OVNA) based on optical carrier-suppressed double sideband (CS-DSB) modulation is proposed and experimentally demonstrated. The ±1st-order sideband signals are generated by CS-DSB modulation and then pass through the symmetric optical device under test (DUT). The band-stop or band-pass responses can be realized by detecting and processing the double frequency of the driven RF signal. Compared with the conventional symmetrical DSB-based OVNA, the measurement accuracy is improved by eliminating the errors caused by the even-order sidebands, and the complexity is reduced as the proposed method with only one step measurement can avoid the complex postprocessing. In addition, the optical carrier is aligned to the center frequency of the DUT by employing the Pound–Drever–Hall (PDH) technique, which provides stable measurement. At the same time, the limitation that the band-pass responses cannot be measured by the traditional single-sideband (SSB)-based OVNA is overcome. Additionally, accurate magnitude and phase responses of the DUT near the optical carrier can be also achieved since the proposed OVNA is optical filter-immune. The proposed method is theoretically analyzed and verified by experiment. A Fabry–Perot (FP) interferometer serves as the symmetric DUT; the band-stop responses in a frequency range of 6 GHz are obtained with a resolution of 1.2 MHz; and the band-pass responses with the range from 0 to 13 GHz offsetting the optical carrier are also obtained. The measurement time can reach up to 30 min with high stability. The proposed OVNA offers enhanced accuracy and a stable approach for applications in photonic systems and other innovations.

Full-space energy-controlled multi-wavefront generators enabled by hybrid graphene-VO2 terahertz metasurfaces

In terahertz communication, multi-wavefront reconfigurable metasurfaces allowing for energy control are highly desirable for multiple channels and high capacity. However, existing metasurfaces can only produce limited wavefronts in either transmission or reflection space, severely hindering their practical application ranges. Herein, a dual-controlled reconfigurable metasurface integrated with graphene and VO2 is demonstrated for an energy-controlled multi-wavefront generator in full-space. By altering the geometry sizes and rotation angles of the meta-atoms as well as external excitations, the polarization independent phase responses are achieved to actively generate energy-controlled multiple wavefronts in full-space. As a proof-of-concept demonstration, three types of full-space metasurfaces are constructed to respectively realize various meta-deflectors, metalens/meta-deflector/orbital angular momentum (OAM) generator, and multimode OAM generator in full-space by utilizing the spin-decoupling method. Moreover, the intensities of these wavefronts can be actively modulated by adjusting the Fermi energy of graphene. Therefore, such diversified metasurface will possess a promising application prospect in terahertz multifunctional devices, and communication and imaging systems.

Combined effects of ambient temperature and food availability on induced innate immune response of a fruit-eating bat (Carollia perspicillata).

Resilience of mammals to anthropogenic climate and land-use changes is associated with the maintenance of adequate responses of several fitness-related traits such as those related to immune functions. Isolated and combined effects of decreased food availability and increased ambient temperature can lead to immunosuppression and greater susceptibility to disease. Our study tested the general hypothesis that decreased food availability, increased ambient temperature and the combined effect of both factors would affect selected physiological and behavioral components associated with the innate immune system of fruit-eating bats (Carollia perspicillata). Physiological (fever, leukocytosis and neutrophil/lymphocyte ratio) and behavioral (food intake) components of the acute phase response, as well as bacterial killing ability of the plasma were assessed after immune challenge with lipopolysaccharide (LPS: 10 mg/kg) in experimental groups kept at different short-term conditions of food availability (ad libitum diet or 50% food-deprived) and ambient temperature (27 and 33°C). Our results indicate that magnitude of increase in body temperature was not affected by food availability, ambient temperature or the interaction of both factors, but the time to reach the highest increase took longer in LPS-injected bats that were kept under food restriction. The magnitude of increased neutrophil/lymphocyte ratio was affected by the interaction between food availability and ambient temperature, but food intake, total white blood cell count and bacterial killing ability were not affected by any factor or interaction. Overall, our results suggest that bacterial killing ability and most components of acute phase response examined are not affected by short-term changes in food availability and ambient temperature within the range evaluated in this study, and that the increase of the neutrophil/lymphocyte ratio when bats are exposed to low food availability and high ambient temperature might represent an enhancement of cellular response to deal with infection.

#1138 Urine proteomic characterisation of DahlS rat model shows robust translatability of molecular profile with human hypertensive kidney damage

Abstract Background and Aims The role of hypertension in CKD is complex. Hypertensive nephropathy or arterionephrosclerosis is caused by prolonged periods of poorly controlled high blood pressure and is characterized by gradual loss of kidney function with various grades of proteinuria over a period of many years. This complexity requires novel analysis strategies for a successful understanding of pathomechanisms, drug target and biomarker identification including well characterized translatable models where the DalhS rats could be relevant. Method We analysed the urinary proteome of hypertensive Dahl S rats at baseline and 2, 4, and 7-weeks of high salt diet (4%, n = 5 in each cohort). A TMT MS/LC method was performed to obtain proteomics profile of the urine, to then filter, normalize and apply a differential analysis based on linear models and empirical Bayes statistics (limma) in R language. Additionally, we did a pathway enrichment analysis using IPA. Finally, to assess the translatability of the findings, we compared the rat urinary proteome data with publicly available urinary proteome from patients with CKD. Results The DalhS rats developed hypertension, proteinuria, and glomerulosclerosis. In the urine, we identified a total of 36 differentially expressed proteins comparing 4 weeks of high salt diet (HSD) versus the baseline, and 85 differentially expressed proteins at 7 weeks of HSD. Pathway analysis of the differentially abundant urinary proteome showed robust enrichment of pathways related to hypertensive kidney damage including ‘acute phase response signaling’, a pathway that activates rapidly in inflammatory settings and can sustain chronically, and liver / retinoid-x-receptor (LXR/RXR) activation​, which was also activated. Additionally, the coagulation system and complement cascade also showed positive z-scores in high-salt-exposed rats (after 7 weeks). Moreover, we observed an inactivation of several immune related pathways such as IL-12 signaling and STAT3 pathways. Finally, analysis of publicly available data of the urinary proteome of CKD patients (PMID 34963468, N = 40) exhibited enrichment of more than 20 pathways in common with the DalhS cohort, suggesting a high translatability between the urinary proteome of the animal model and patients. Specifically, we observe activation of acute phase response signalling, LXR/RXR activation, and complement cascade in DalhS and human datasets, as well as inhibition of IL-12 and STAT3 signaling pathways. Conclusion Molecules targeting the complement pathway are under intensive development. Prior development of LXR agonists have been limited by Ph1 findings. The findings with acute-phase response, IL-12 and STAT3 pathways suggests the importance of immune-driven damage mechanisms in hypertensive CKD. Identified proteins and enriched pathways in this work provide a rich resource for future investigation. In conclusion, the Dahl S rat model urinary proteome captures multiple underlying mechanisms of the human hypertensive CKD phenotype.

Microwave fractional Hilbert transformer implemented in a dispersion-tailored few-mode fiber

We experimentally demonstrate, for the first time to our knowledge, a microwave fractional Hilbert transformer in a few-mode fiber using a transversal filtering approach. The filter taps are provided by a tunable true-time delay line that is realized by exploiting the spatial dimension of a dispersion-engineered double-clad step-index few-mode fiber. Both the fractional order and operational bandwidth of the fractional Hilbert transformer can be continuously tuned by adjusting the tap coefficients and varying the operational optical wavelength, respectively. The magnitude and phase response for different fractional orders, ranging from 0.17 to 1.00 that correspond to phase shifts of 15° to 90°, are measured. Operational bandwidths of 7.4 to 10.6 GHz are demonstrated for a classical Hilbert transformer. Real-time temporal fractional Hilbert transform of a Gaussian-like pulse is also performed. Our results are in good agreement with theory, validating the viability of our approach for implementation of microwave fractional Hilbert transformers.

Optogenetic Interrogation of Electrophysiological Dendritic Properties and Their Effect on Pacemaking Neurons from Acute Rodent Brain Slices.

Understanding dendritic excitability is essential for a complete and precise characterization of neurons' input-output relationships. Theoretical and experimental work demonstrates that the electrotonic and nonlinear properties of dendrites can alter the amplitude (e.g., through amplification) and latency of synaptic inputs as viewed in the axosomatic region where spike timing is determined. The gold-standard technique to study dendritic excitability is using dual-patch recordings with a high-resistance electrode used to patch a piece of distal dendrite in addition to a somatic patch electrode. However, this approach is often impractical when distal dendrites are too fine to patch. Therefore, we developed a technique that utilizes the expression of Channelrhodopsin-2 (ChR2) to study dendritic excitability in acute brain slices through the combination of a somatic patch electrode and optogenetic activation. The protocol describes how to prepare acute slices from mice that express ChR2 in specific cell types, and how to use two modes of light stimulation: proximal (which activates the soma and proximal dendrites in a ~100 µm diameter surrounding the soma) with the use of a high-magnification objective and full-field stimulation through a low-magnification objective (which activates the entire somato-dendritic field of the neuron). We use this technique in conjunction with various stimulation protocols to estimate model-based spectral components of dendritic filtering and the impact of dendrites on phase response curves, peri-stimulus time histograms, and entrainment of pacemaking neurons. This technique provides a novel use of optogenetics to study intrinsic dendritic excitability through the use of standard patch-clamp slice physiology. Key features • A method for studying the effects of electrotonic and nonlinear dendritic properties on the sub- and suprathreshold responses of pacemaking neurons. • Combines somatic patch clamp or perforated patch recordings with optogenetic activation in acute brain slices to investigate dendritic linear transformation without patching the dendrite. • Oscillatory illumination at various frequencies estimates spectral properties of the dendrite using subthreshold voltage-clamp recordings and studies entrainment of pacemakers in current clamp recordings. • This protocol uses Poisson white noise illumination to estimate dendritic phase response curves and peri-stimulus time histograms.

Analysis of Acute Phase Response Using Acute Phase Proteins Following Simultaneous Vaccination of Lumpy Skin Disease and Foot-and-Mouth Disease.

Since 2011, South Korea has implemented biannual vaccinations against foot-and-mouth disease (FMD) and recently, lumpy skin disease (LSD), to mitigate the spread of transboundary animal diseases. However, due to past adverse reactions, potentially linked to acute phase responses from FMD vaccinations, there is hesitancy among Korean livestock farmers regarding new strategies for simultaneous vaccinations against both FMD and LSD. This study was conducted to assess possible adverse reactions to the LSD vaccination by analyzing acute phase proteins (APPs) in three groups: cows vaccinated against FMD (G1-FMDV), LSD (G2-LSDV), and both (G3-FMDV/LSDV). In G1-FMDV, APP levels peaked on day 3 post-vaccination (p < 0.001) and returned to baseline. In G2-LSDV, APP levels increased gradually, peaking on day 10 post-vaccination. In G3-FMDV/LSDV, APP levels peaked on day 3 post-vaccination and remained high until day 10 (p < 0.001). These results indicate that LSD vaccines trigger a later immune response compared to FMD vaccines, possibly due to different adjuvants. Therefore, a longer follow-up period for monitoring adverse reactions to LSD vaccinations may be required to understand and mitigate potential risks.