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Coordinated use of three homocysteine methyltransferases supports l-methionine biosynthesis and environmental adaptation among plant-associated bacteria.

Plant pathogens colonize multiple plant-associated habitats throughout their life cycle, encountering distinct nutrient conditions and microbial communities. l-methionine is required for bacterial growth and environmental adaptation. However, how plant pathogens coordinate l-methionine biosynthetic pathways to adapt to different plant-associated environments remains poorly understood. Here, using the plant pathogen Xanthomonas campestris pv. campestris strain XC1 as a model, we show that three homocysteine methyltransferase pathways allow XC1 to catalyze the final step of l-methionine biosynthesis using different methyl donors and cofactors under different environmental conditions. Bioinformatic and transcriptional analyses identified three homocysteine methyltransferase-associated operons in XC1, mesMXD, mmuPM, and metHRHaHb, corresponding to the MesD-, MmuM-, and MetHaHb-dependent pathways, respectively. MesD uses an endogenously synthesized methyl donor and functions as the dominant homocysteine methyltransferase under l-methionine-limiting conditions, supporting bacterial growth, intracellular l-methionine accumulation, and full virulence. Furthermore, MmuM enables XC1 to use plant-derived S-methylmethionine for l-methionine biosynthesis, whereas MetHaHb enables XC1 to use vitamin B12 supplied by a neighboring bacterium for l-methionine biosynthesis in co-culture. Expression analyses showed that mesMXD was the only homocysteine methyltransferase-associated operon that responded to l-methionine availability, and its expression also decreased when S-methylmethionine- or vitamin B12-dependent pathways supported l-methionine biosynthesis. Comparative genomic analysis further showed that the three-homocysteine methyltransferase configuration is conserved in Xanthomonas and is also present in other plant-associated bacteria. Together, these findings show that a plant pathogen can coordinate endogenous, plant-derived, and microbially supported homocysteine methyltransferase pathways to maintain l-methionine biosynthesis, providing a metabolic strategy for adaptation to plant-associated environments.

Methionine

Three-dimensional porous nano-hydroxyapatite@gelatin composite as efficient adsorbent for uranyl ion removal from low-level radioactive wastewater.

The contamination of water resources by uranyl (UO22+) ions poses significant environmental and health risks, requiring the development of efficient and sustainable remediation strategies. Adsorption-based techniques have emerged as promising approaches in the field of UO22+ removal, but the design of cost-effective, high-capacity, and environmentally friendly adsorbents remains challenging. In this study, a three-dimensional porous nano-hydroxyapatite@gelatin (nHAP@Ge) composite was synthesized through glutaraldehyde cross-linking, combining the structural stability of Ge with the high uranium affinity of nHAP. The optimized nHAP@Ge, with a nHAP:Ge mass ratio of 1:0.5, exhibited exceptional UO22+ removal efficiency (97 %), along with high adsorption capacity (364.03 mg/g). Systematic characterizations using scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR) spectroscopy, and X-ray photoelectron spectroscopy (XPS) methods revealed that the porous structure and surface functional groups (-OH, Ca2+, and PO43-) of the material synergistically contributed to binding UO22+ species. Furthermore, the incorporation of nHAP into the Ge framework resulted in enhanced thermal stability while significantly improving the UO22+ adsorption performance. This work presents a scalable, eco-friendly, and recyclable strategy for the effective treatment of uranium-contaminated water, with potential applications in nuclear wastewater treatment and environmental remediation.

Adsorption

Cryo-EM structure of TGFBIp fibrils driven by a corneal dystrophy-linked mutation enables design of peptide inhibitors of aggregation.

Corneal dystrophy is a heterogeneous group of diseases which manifests clinically by progressive corneal opacity and diminishing visual acuity. A group of corneal dystrophies are linked to autosomal dominant mutations in transforming growth factor β-induced protein (TGFBIp) and characterized by extracellular amyloid-positive deposits of unknown molecular structure. Here, we determined the cryogenic-electron microscopy (cryo-EM) structure of amyloid fibrils formed by the TGFBIp FAS1-4 domain with corneal dystrophy-linked mutation V624M. The L569 to N609 fibril core, which includes the Y571-R588 segment enriched in patient corneal deposits, forms symmetrical protofilaments with internal solvent channels. Leveraging this structure, we designed peptide inhibitors intended to bind onto fibril ends to block elongation, targeting the unequal growth of symmetrical protofilaments. Our G1 and H4 inhibitors exhibit concentration-dependent reduction of TGFBIp FAS1-4 aggregation as assessed by Thioflavin T, solubility fractionation, and electron microscopy. Our work illustrates how fibril structures can guide rational inhibitor design and suggests the targeting of protein aggregates as a therapeutic approach for corneal and ocular diseases.

betaIG-H3 Protein

The cold case of state transition 7 (stt7) mutants of Chlamydomonas reinhardtii, solved by whole-genome sequencing.

The process of State Transitions (ST) corresponds to an STT7 kinase-driven redistribution of the transmembrane LHCII antenna proteins between Photosystem II (PSII) and Photosystem I (PSI), which results from changes in their phosphorylation state. For the past two decades, two LHCII-kinase mutants, stt7-1 and stt7-9, have been instrumental in the study of STs in Chlamydomonas reinhardtii, the former being a null mutant for the kinase but quasi-sterile in crosses, while the latter, although fertile, has a leaky phenotype. Using long-read sequencing, this study further characterized the genetic lesions of the stt7 mutant strains through whole-genome reconstruction and de novo chromosome assembly. In addition, two new stt7 null mutants were generated, one derived by crosses from the original stt7-1 and one obtained by Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-associated protein 9 (Cas9) technology. This work provides a comprehensive genomic characterization of the original stt7-1 null mutant, revealing extensive chromosomal rearrangements and high levels of aneuploidy, associated with increased cell size and meiotic dysfunction. Reassessment of their physiology and genetic backgrounds highlights the need for caution in interpreting genetic information. We thus produced more reliable null mutants for the LHCII-kinase, amenable to genetic crosses for the study of STs in a variety of genetic backgrounds.

Chlamydomonas reinhardtii

Transcription regulation of cell fate plasticity - from embryonic development to tissue regeneration.

Cell fate plasticity refers to the capacity of cells sharing the same genome to alter, reverse, or reconfigure their identity under physiological, pathological, or experimental conditions. This property underlies embryonic development, cellular reprogramming, and tissue regeneration, but becomes progressively restricted as lineage identity is stabilized. Embryonic development represents an intrinsic process of fate transitions, whereas reprogramming and regeneration reveal how differentiated cells can dedifferentiate or transdifferentiate under specific conditions. Across these contexts, plasticity is governed by multilayered regulatory networks involving transcription factors, epigenetic regulators, cofactors, and the core transcription machinery. Robust regulatory programs stabilize cell identity, whereas stochastic fluctuations in gene expression and chromatin state can prime cells for fate transitions, adding a tunable dimension to plasticity control. In this review, we synthesize recent advances in the regulation of cell fate plasticity across development, reprogramming, and regeneration, highlighting how transcription factors, epigenetic modifications, transcriptional cofactors, and core transcription machinery cooperate to control cell fate decisions and plasticity.

Animals

Development and validation of a novel LC-MS/MS method for simultaneous quantification of fidaxomicin and metabolite (OP-1118) from feces for gut pharmacobiome studies.

Fidaxomicin is a first-line antibiotic for treating Clostridioides difficile infection. While it has low systemic absorption and reaches high colonic concentrations, it is hydrolyzed to a less active metabolite, OP-1118. Few studies have completely described critical experimental details of liquid chromatography-tandem mass spectrometry (LC-MS/MS) for quantifying fecal fidaxomicin and OP-1118. This study developed and validated a simple, fast, and sensitive LC-MS/MS method to quantify fidaxomicin and OP-1118 in human and mouse feces. This method simplified fecal sample preparation without the use of solid phase extraction and optimized LC-MS/MS parameters. A broad working range (0.3-1000 ng/ml) in both diluted human and murine fecal matrices was achieved with good intra- and inter-day accuracy (93-107%), precision (1-7%), and recovery (70-105%) as well as little IS-normalized matrix effects. This method was utilized to quantify fidaxomicin and OP-1118 in human and murine fecal samples. This novel method was simple, fast, sensitive, and accurate in analyzing fecal fidaxomicin and OP-1118 and could be deployed to facilitate gut pharmacobiome research.

Feces

Clinical Performance in Critical Care Simulation under Sleep Deprivation: Effects of Power Napping in the Recovery Napping Protocol for Anesthesiologist Performance (R-NAP) Randomized Controlled Trial.

BACKGROUND: Sleep deprivation is common among anesthesia residents and impairs both technical and nontechnical skills such as leadership. Napping is recommended in fatigue management across healthcare and other safety-sensitive sectors, yet its effectiveness for healthcare providers remains underexplored. This study evaluated whether a 30-min nap opportunity improved simulated crisis performance after a 24-h shift. METHODS: Residents were tested twice: once rested and once using a 24-h shift to induce partial sleep deprivation. Between sessions, they were trained in fatigue management. In the sleep-deprived condition, they were randomized to a nap opportunity or a control condition. Actigraphy objectively assessed sleep and nap duration. The primary endpoint was overall simulated clinical performance (0 to 200; combined technical and nontechnical scores). Secondary endpoints were technical and nontechnical subscales. Group effects were primarily tested using intention-to-treat regression models adjusted for rested performance, previous sleep, and critical care experience. RESULTS: Thirty-five residents were enrolled (nap opportunity, n = 19; control, n = 16). In the primary analysis sample (n = 27), clinical performance was 14.8 points higher after the nap opportunity compared with controls (95% CI, 2.8 to 26.9; P = 0.018), corresponding to a 7.4% improvement. Technical skills did not differ significantly between groups, although more sleep was associated with better technical performance. Nontechnical skills were higher in the nap opportunity condition (+11.0 points; 95% CI, 2.2 to 19.8; P = 0.016), including significant effects of leadership and resource utilization. Exploratory analyses suggested associations between longer nap duration and multiple performance domains, strongest for technical skills ( P = 0.010). CONCLUSIONS: Napping appears to enhance clinical performance, while the nap opportunity, nap duration, and previous sleep deprivation each influenced technical and nontechnical performance in distinct ways. These findings support integrating napping and recovery into medical education and scheduling.

Adult

Identification of the BrSK gene family in flowering Chinese cabbage and functional characterization of BrSK2 subfamily involvement in heat stress.

Glycogen synthase kinase 3 (GSK3) kinases are evolutionarily conserved regulators of plant development and stress signaling, yet their contributions to thermotolerance in cool-adapted Brassica crops remain poorly understood. Here, we identified 16 BrSK genes in the Caixin (Brassica rapa ssp. chinensis var. parachinensis) genome, all harboring intact catalytic motifs indicative of functional kinase activity. Spatiotemporal expression profiling revealed preferential accumulation of BrSK transcripts in stem apices and floral organs during reproductive transition, while promoter analysis identified abundant heat- and abiotic stress-responsive cis-elements. Under heat stress, BrSK21, BrSK22, and BrSK23 displayed striking genotype-specific expression dynamics. BrSK21/22/23 transcripts were stably suppressed in the heat-tolerant cultivar '49-19' but transiently declined before rapidly rebounding in the heat-sensitive 'Liuye 50', mirroring RNA-seq profiles. Protein-protein interaction assays (Y2H, BiFC, and LCI) demonstrated specific associations between BrSK kinases and BrHSFA1. Functional validation via VIGS revealed that silencing of BrSK21 significantly enhanced thermotolerance, with triple silencing of BrSK21/22/23 conferring additive protection, indicating functional redundancy within the BrSK2 subfamily. Collectively, these findings establish the BrSK2 subfamily as negative regulators of heat tolerance in Caixin, likely via modulation of BrHSFA1 expression. This work identifies high-priority targets for molecular breeding of climate-resilient Brassica vegetables.

Plant Proteins

A risk-need-responsivity (RNR)-informed systematic review of needs during the pretrial period.

OBJECTIVE: Pretrial risk assessments are becoming increasingly popular in the United States. Despite the importance of assessing and intervening around "needs" in the risk-need-responsivity model, few pretrial risk assessments include comprehensive assessment of needs. We aim to provide a systematic review of the prevalence of and predictive utility of needs within the pretrial population. HYPOTHESES: There were no hypotheses given the nature of the study. METHOD: We conducted searches for articles in the EBSCO, ProQuest, and Google Scholar databases using key words related to 11 needs domains: antisocial personality, procriminal attitudes, procriminal associates, substance use, family/marital relationships, school/work, prosocial recreational activities, self-esteem, housing, mental health, and physical health. We identified 215 articles that reported on the prevalence of needs or explored their predictive associations with pretrial misconduct outcomes in adult populations. RESULTS: Overall, we find few comprehensive investigations of needs in the pretrial domain, apart from substance use. Variation in methodology and operationalization contributes to wide variability in prevalence estimates. We found only 15 articles that examined predictive associations between pretrial needs and outcomes, which were limited to investigations of behavioral health, employment, and housing needs. Substance use and housing needs emerged as the only consistent predictors of pretrial misconduct. CONCLUSIONS: Researchers should more directly assess the prevalence and predictive utility of needs within the pretrial period to bolster the evidence base for including these factors in pretrial risk assessments. (PsycInfo Database Record (c) 2026 APA, all rights reserved).

Humans

Morphological changes and transcriptomic insights into skeletal development of embryos and larvae of the sea urchin Strongylocentrotus intermedius.

To explore morphological features and molecular dynamics underlying skeletogenesis in the sea urchin Strongylocentrotus intermedius, we conducted combined morphological observation and comparative transcriptome analyses across representative embryonic and larval developmental stages. Morphological results showed that triradiate spicules first emerged at the gastrula stage. The 8-arm pluteus stage was identified as a key phase for skeletal remodeling, during which new three-radiate crystals transformed into complex stereoscopic ossicles including tube feet, spines and test plates. Transcriptomic data indicated that most differentially expressed genes (DEGs) were downregulated from the blastula to gastrula. The altered expression of basal metabolic genes and extracellular matrix genes including Colp2α and calm may be correlated with the linear mineralization of early spicules, which potentially reflects an energy adjustment pattern in developing larvae. During the transition from 6-arm to 8-arm pluteus, expression changes of calmodulin-like, Colp2α and SISin18G001660 suggest potential associations with regional calcium deposition and modifications of skeletal matrix properties. This work systematically characterizes morphological traits and transcriptional dynamics of skeletogenesis in S. intermedius. Its early spiculogenesis follows the conserved developmental pattern of echinoderms, while massive formation of stereoscopic ossicles occurs at the 8-arm pluteus stage. Stage-specific transcriptional changes across key larval skeletogenic stages are uncovered, offering transcriptomic resources for functional verification of skeletal regulatory genes.

Animals

Systematic identification pepper CaE2F transcription factor reveals the role of CaDPb in drought stress response.

The EARLY 2 FACTOR (E2F) transcription factor (TF) family plays a pivotal role in regulating plant development and adaptations to environmental stresses. However, the physiological function of E2Fs in pepper (Capsicum annuum L.) are not well elucidated. In this work, we conduct a comprehensive genome-wide annotation of the E2F family within the Zunla-1 pepper genome and further explore the biological roles of CaDPb in response to drought stress. Through systematic bioinformatics analysis, we identify a total of nine CaE2F genes within the Zunla-1 genome, categorizing them into three distinct subgroups. Additionally, we discover multiple cis-regulatory elements in the CaE2F promoter regions associated with responses to plant hormones and drought stress. Public RNA-seq datasets reveal distinct expression profiles of CaE2F genes across various pepper tissues and their responses to environmental stimuli and plant hormones. Subsequently, the CaDPb gene is further functionally verified in drought response. Our findings indicate that TRV2:CaDPb silenced pepper plants are more sensitivity to drought. Furthermore, we show that CaDPb participates in the regulation of reactive oxygen species (ROS) production, the expression of drought-responsive genes, and the modulation of stomatal aperture. Taken together, our findings provide a comprehensive characterization of E2F genes in pepper and offer insights into the biological function of CaDPb in pepper drought stress response.

Capsicum

Synchronicity of parent-child sleep and potential mechanisms: A systematic review and meta-analysis.

Existing evidence indicates that parent and child circadian rhythms are associated, but studies have mainly examined factors affecting child sleep health. This systematic review addressed two questions: a) is there a synchronous relationship between parent and offspring sleep? and b) what are the potential mechanisms? PubMed, Embase, PsychINFO, and Scopus were searched from inception to April 2025. Forty-six studies comprising over 100000 parent-child dyads across 16 countries were included. Results showed small-to-moderate parent-child synchronicity in sleep duration (r = 0.18, 95% CI [0.14, 0.23]), sleep efficiency (r = 0.30, 95% CI [0.19, 0.41]), bedtime (r = 0.34, 95% CI [0.20, 0.46]), and wake up time (r = 0.48, 95% CI [0.24, 0.66]), with stronger effects observed in mother-child dyads. Synchronicity in sleep continuity was moderate, whereas associations in sleep satisfaction were small and non-significant. Mechanisms included genetic and hormonal factors, bedtime routines, shared environments, and attachment. These findings are consistent with family systems theory's premise that sleep is a relational phenomenon. Observed synchronicity in sleep timing may partly reflect shared external constraints like work and school schedules. Most studies were cross-sectional, limiting causal or directional conclusions. Future research should adopt standardized methodologies and longitudinal designs to clarify mechanistic pathways.

Humans

Effects of carbohydrate mouth rinse on psychophysiological responses, kinematic variables and technical actions during small-sided soccer games.

BACKGROUND: This study investigated the effects of carbohydrate mouth rinsing (CHOMR) on various psychophysiological, kinematic, and technical actions during 4-a-side small-sided soccer games (SSGs). METHODS: In a randomized, crossover, double-blind design, 16 young male soccer players (age: 15&#x2009;&#xb1;&#x2009;1 years; height: 172.6&#x2009;&#xb1;&#x2009;7.0&#x2009;cm; body mass: 57.8&#x2009;&#xb1;&#x2009;7.9 kg) participated in two 4-a-side SSGs separated by one week following either CHOMR or placebo (PLA). During each SSGs, heart rate (HRmean, %HR, and HRmax), rating of perceived exertion (RPE), enjoyment, visual analogue scale (VAS) to perceived mental fatigue, mood states, total distance (TD), high-speed running distance (HSRD), average metabolic power (AMP), high metabolic load distance (HMLD), sprint distance (SD), acceleration (ACC), deceleration (DEC), and technical actions (e.g. passing, tackling, shooting, and interceptions) were assessed. RESULTS: Compared with PLA, CHOMR resulted in significantly higher RPE (p&#x2009;=&#x2009;0.025, g&#x2009;=&#x2009;0.86) and significantly lower VAS scores (p&#x2009;=&#x2009;0.010, g&#x2009;=&#x2009;-0.71). In addition, the CHOMR condition showed significantly higher values for interceptions, successful tackles, unsuccessful tackles, unsuccessful shots, and goals (p&#x2009;<&#x2009;0.05, g&#x2009;=&#x2009;0.96-2.02), whereas block values were significantly higher in the PLA condition. There were no statistically significant differences in HRmean, %HR, HRmax, enjoyment, TD, HSRD, AMP, HMLD, SD, ACC, DEC, successful passes, unsuccessful passes, successful shots, or mood states between the conditions (p&#x2009;>&#x2009;0.05). CONCLUSION: The current study findings suggest that CHOMR may enhance selected technical actions and lower VAS scores during 4-a-side SSGs, although it was also associated with higher RPE and did not alter the kinematic responses. In conclusion, CHOMR was associated with higher RPE, lower mental fatigue, and selective improvements in technical actions, with no significant effects on kinematic variables or HR.

Humans

Triacylglycerol metabolism is a novel target to combat West Nile virus infection.

West Nile virus (WNV) is a zoonotic Orthoflavivirus transmitted by mosquitoes that is responsible for outbreaks of meningitis and encephalitis worldwide. Driven by climate change, WNV has expanded as a global public health concern, particularly in temperate regions. However, there are still no specific approved therapies, reinforcing the need for antiviral development. Previous works have documented that WNV multiplication strictly depends on certain cellular lipids. To identify novel lipid-related therapeutic targets, we analyzed the infection driven alterations in the CNS lipidome, the primary tissue supporting WNV replication. Our results indicated that the major alterations in the brain lipid content of WNV-infected mice corresponded to triacylglycerols (TAGs). Moreover, transcriptomic analysis showed that infected brains underwent changes in the expression of TAG metabolism. Supplementation with exogenous fatty acids increased lipid droplets (LD) content and promoted viral replication in cell culture models. On the contrary, pharmacological intervention in TAG metabolism using diacylglycerol acyltransferase inhibitors (DGATi) suppressed WNV multiplication in cell culture models. As a proof-of-concept of the therapeutic potential of DGATi, treatment of mice with A922500 reduced viral burden in the brain and proinflammatory cytokine production. Overall, our results unveil the importance of LDs and glycerolipid metabolism for WNV and highlight the potential of therapeutic interventions targeting this pathway to control viral replication and neuroinflammation.

West Nile virus; lipid

Identification of molecular subtypes in clear cell renal cell carcinoma based on chromatin regulators and tumor immune microenvironment profiling.

In the histological classification of renal cell carcinoma, clear cell renal cell carcinoma (ccRCC) accounts for the highest proportion and is the most common subtype. Despite advances in management, it continues to be associated with considerable incidence and mortality. Although surgery and systemic therapies are available, their efficacy is constrained by pronounced intratumoral heterogeneity and treatment resistance. Identifying robust biomarkers and clarifying the underlying biological mechanisms are therefore essential to improving diagnosis, risk stratification and therapeutic decision-making. In this work, we identified two ccRCC molecular subtypes displaying divergent chromatin regulator (CR) profiles and different clinical prognoses. Using the genes differentially expressed between these subgroups, we constructed a CR-related score (CRS) that effectively stratified patients according to survival. More analysis concluded that the low expression of CR was more linked with the immune-activated tumors, which encompassed the immune pathway enrichment, as well as the elevation of numerous immune cell subtypes. Moreover, elevated CRS was associated with improved immunotherapy responsiveness. Drug-sensitivity analyses nominated several candidate agents, and SMARCD3 knockdown in 786-O cells inhibited proliferation and migration and reduced sensitivity to masitinib. Collectively, these findings support the prognostic and therapeutic relevance of CR-related states in ccRCC and provide a framework for future experimental validation of chromatin-regulated tumor-immune interactions.

Humans

Comparative analysis of DDR-related genes and microRNA expression during rice germination: Implications for salinity susceptibility screening.

Soil salinity poses a significant threat to the agri-food sector and particularly to rice cultivation. High salinity during germination induces overproduction of reactive oxygen species (ROS) that cause lesions in the DNA resulting in reduced vigor. MicroRNAs (miRNAs) are known to modulate stress response in plants, however, studies focusing on its relation with the expression of the DNA damage response (DDR)-related genes are not thoroughly explored. In this regard, the aim of this work was to investigate the link between the expression of miRNAs and putative targeted DDR-related genes in response to salinity stress during germination. Eight varieties representative of indica and japonica rice subspecies were categorized into clusters through a principal component analysis (PCA) based on their germination performance and stress tolerance index under varying concentrations of NaCl. Subsequently, the expression patterns of six miRNAs and their putative targeted DDR genes were measured in two contrastive cultivars through quantitative real-time PCR (qRT-PCR) while correlations were examined through Pearson's analysis. Results showed distinct expression profiles between halotolerant and sensitive cultivars. Two miRNAs were further investigated in mature dry seeds of all the cultivars to verify their earliest, seed-specific discriminative potential. The distinct miR414 expression pattern may represent a potential biomarker for identifying salinity-susceptible cultivars during early-stage breeding screening.

Oryza

Inducible flocculation in Komagataella phaffii enables enhanced biomass separation for biopharmaceutical production.

Biomass separation represents a critical bottleneck in Komagataella phaffii-based biopharmaceutical processes, as typically high cell densities of 40 - 50&#x202f;% create significant operational, technical and economic challenges for harvest operations. Yeast cell aggregation (flocculation) provides a solution to accelerate cell sedimentation by increasing particle size, thus allowing to improve biomass-supernatant separation efficiency during both natural gravity settling and (continuous) centrifugation operations. This study demonstrates successful engineering of K. phaffii strains with an inducible flocculation phenotype using CRISPR/Cas9-based genome editing to integrate the Saccharomyces cerevisiae FLO1 (ScFLO1) gene under control of various regulatory elements, including methanol-inducible and derepressible promoters. Flocculation strength could be enhanced by implementing transcriptional positive feedback circuits based on the methanol-inducible AOX1 promoter. To address methanol-free production requirements, we developed alternative systems to retrofit PAOX1-based ScFLO1 expression and exploited the derepressible PDF promoter, offering broader compatibility with biopharmaceutical manufacturing facilities. Flocculating cells cultivated in a bioreactor demonstrated significantly improved sedimentation behavior, with considerably lower supernatant turbidity after short low-speed centrifugation or gravity sedimentation compared to non-flocculating controls. Crucially, cell flocculation had no negative impact on product amount and quality when expressing a multivalent NANOBODY&#xae; VHH molecule with pharmaceutical relevance. Thus, this work establishes the first genetically engineered flocculation system in K. phaffii compatible with recombinant protein production, providing the basis for an innovative approach to streamline harvest operations in biopharmaceutical processes.

Flocculation

The impact of acute sleep fragmentation on muscle blood flow responses to handgrip exercise.

Sleep fragmentation is reported to impair resting vascular function. The aim of this study was to test the hypothesis that acute sleep fragmentation would impair muscle blood flow during exercise. Twenty adults (10 females and 10 males) participated in a randomized crossover study that included one night of habitual sleep and one night of fragmented sleep. Sleep was assessed at home using wrist actigraphy. Arousals from sleep were increased by an audio alarm sounding every 30 min. The morning following each sleep condition, participants performed single handgrip contractions and rhythmic handgrip exercise at 15%, 30%, and 45% MVC. Forearm blood flow (FBF) was measured using Doppler ultrasound. Nightly awakenings and wake after sleep onset significantly increased by 18% and 43%, respectively, after fragmented sleep, leading to lower sleep duration (P < 0.001). Peak FBF and total hyperemic responses following single contractions were similar between sleep conditions (all P > 0.05). During rhythmic handgrip exercise, brachial artery dilation was reduced after fragmented sleep (main effect: 5.5 &#xb1; 4.8 vs. 3.3 &#xb1; 3.7%; P = 0.01), leading to a lower FBF response to rhythmic exercise (main effect: 122 &#xb1; 58 vs. 110 &#xb1; 56 mL/min; P = 0.04). Endothelial sensitivity to shear rate was similar between sleep conditions (habitual vs. fragmented: 0.039 &#xb1; 0.024 vs. 0.042 &#xb1; 0.031%/s-1; P = 0.77). In summary, acute sleep fragmentation decreases skeletal muscle blood flow during exercise. This finding suggests that blunted oxygen delivery may be a contributing factor for exercise performance deficits after disturbed sleep.NEW & NOTEWORTHY We demonstrate that one night of fragmented sleep decreases steady-state blood flow and vascular conductance during low- to moderate-intensity handgrip exercise. This impairment was not due to an impaired rapid vasodilation to single contractions nor altered endothelial sensitivity to shear rate as these variables were unchanged after acute sleep fragmentation. These results reveal a negative impact of disrupted sleep on the steady-state muscle vasodilatory response to rhythmic contractions.

Humans