Biology subjects

Yu, S.

Publications and source records attributed to Yu, S..

At least 91 records · Page 5Linked to original sources

bioRxiv2024

PlateletBase: A Comprehensive Knowledgebase for Platelet Research and Disease Insights

Platelets are vital in many pathophysiological processes, yet there is a lack of a comprehensive resource dedicated specifically to platelet research. To fill this gap, we have developed PlateletBase, a knowledge base aimed at enhancing the understanding and study of platelets and related diseases. Our team retrieved information from various public databases, specifically extracting and analyzing RNA-seq data from 3,711 samples across 41 different conditions available on NCBI. PlateletBase offers six analytical and visualization tools, enabling users to perform gene similarity analysis, pair correlation, multi-correlation, expression ranking, clinical information association, and gene annotation for platelets. The current version of PlateletBase includes 10,278 genomic entries, 31,758 transcriptomic entries, 4,869 proteomic entries, 2,614 omics knowledge entries, 1,833 drugs, 97 platelet resources, 438 diseases/traits, and six analysis modules. Each entry has been carefully curated and supported by experimental evidence. Additionally, PlateletBase features a user-friendly interface designed for efficient querying, manipulation, browsing, visualization, and analysis of detailed platelet protein and gene information. Case study results, such as those from gray platelet syndrome and angina pectoris, demonstrate that this tool can aid in identifying diagnostic biomarkers and exploring disease mechanisms, significantly advancing research in platelet functionality and its applications. PlateletBase is accessible at http://plateletbase.clinlabomics.org.cn/.

bioinformatics↗

bioRxiv2024

ANKRD5: a key component of the axoneme required for spermmotility and male fertility

Sperm motility is essential for male fertility and depends on the structural integrity of the sperm axoneme, which features a canonical "9+2" microtubule arrangement. This structure comprises nine outer doublet microtubules (DMTs) that are associated with various macromolecular complexes. Among them, the nexin-dynein regulatory complex (N-DRC) forms crossbridges between adjacent DMTs, contributing to their stabilization and enabling flagellar bending. In this study, we investigated Ankyrin repeat domain 5 (ANKRD5, also known as ANK5 or ANKEF1), a protein highly expressed in the sperm axoneme. We found that ANKRD5 interacts with DRC5/TCTE1 and DRC4/GAS8, two key components of the N-DRC, and these interactions occur independently of calcium regulation. Male Ankrd5-/- mice exhibited impaired sperm motility and infertility. Cryo-electron tomography revealed a typical "9+2" axoneme structure with intact DMTs in Ankrd5 null sperm; however, the DMTs showed pronounced morphological variability and increased structural heterogeneity. Notably, ANKRD5 deficiency did not alter ATP levels, reactive oxygen species (ROS) levels, or mitochondrial membrane potential. These findings suggest that ANKRD5 may attenuate the N-DRCs mechanical buffering-akin to a "car bumper"-between adjacent DMTs, thereby compromising axonemal stability under high mechanical stress during vigorous flagellar beating. Graphic Abstract O_FIG O_LINKSMALLFIG WIDTH=184 HEIGHT=200 SRC="FIGDIR/small/626701v3_ufig1.gif" ALT="Figure 1"> View larger version (39K): org.highwire.dtl.DTLVardef@1ca36eforg.highwire.dtl.DTLVardef@dcafe3org.highwire.dtl.DTLVardef@9f6086org.highwire.dtl.DTLVardef@17a0a0b_HPS_FORMAT_FIGEXP M_FIG C_FIG Significance StatementMale infertility affects approximately 8%-12% of men globally, with defects in sperm motility accounting for over 80% of these cases. The axoneme, which functions as the motor apparatus of the sperm, adopts a canonical "9+2" microtubule arrangement, where the nexin-dynein regulatory complex (N-DRC) plays a critical role in providing structural support between adjacent outer microtubule doublets. Elucidating the interplay between the structural organization and protein composition of the N-DRC is essential for advancing the understanding of male reproductive biology. In this study, we identify ANKRD5 as a new component of N-DRC that is essential for maintaining normal sperm motility. These findings contribute to the molecular understanding of sperm motility and highlight ANKRD5 as a potential target for the development of novel male contraceptives.

developmental biology↗

bioRxiv2024

Structural insights into cholesterol sensing by the LYCHOS-mTORC1 pathway

The mechanistic target of rapamycin complex 1 (mTORC1) pathway regulates cellular metabolism and growth by coordinating nutrient resources, including cholesterol, and its aberrant activation is linked to various age-related diseases. LYCHOS is a cholesterol sensor on the lysosome and bound to the GATOR1 complex, a GTPase-activating protein for the Rag GTPase, at high cholesterol concentrations, thereby activating the protein kinase mTORC1. However, how LYCHOS senses cholesterol and transduces signal to GATOR1 remain largely unknown. Here we report six cryo-electron microscopy structures of human LYCHOS, depicting five distinct states. These are categorized into a contracted state when complexed with a sufficient amount of the cholesterol analogue cholesteryl hemisuccinate (CHS), and an expanded state when CHS is deficient. The structure forms a homodimer, within each monomer the transmembrane region is divided into a permease-like domain (PLD) and a GPCR-like domain (GLD) with two clearly defined adjacent cholesterol binding sites between them. The PLD shares a conserved Na+/H+ antiporter (NhaA) fold, which much resembles plant auxin transporter PINs. Cholesterol locates between PLD and GLD and cholesterol binding induces a translation of GLD towards PLD and exposes the cytosolic extension of transmembrane 15, which mediates the interaction between LYCHOS and GATOR1. Strikingly, structure-guided mutations of Gly702 in GLD of LYCHOS increase its affinity for cholesterol, leading to sustained mTORC1 activation in cells. This indicates that LYCHOSs moderate affinity for cholesterol is crucial as a cholesterol sensor. Our results not only showed a solute carrier mechanistically coordinates a GPCR domain, elucidating the structural mechanism of cholesterol sensing by the mTORC1 pathway on the lysosome; but also provides a structural basis for developing inhibitors that selectively target to mTORC1 pathway to treat age-related diseases by blocking LYCHOS in its expanded state.

biochemistry↗

bioRxiv2024

CRAGE-RB-PI-seq enables transcriptional profiling of rhizobacteria during plant-root colonization

Plant roots release a wide array of metabolites into the rhizosphere, shaping microbial communities and their functions. While metagenomics has expanded our understanding of these communities, little is known about the physiology of their members in host environments. Transcriptome analysis via RNA sequencing is a common approach to learning more, but its use has been challenging because plant RNA masks bacterial transcripts. To overcome this, we developed randomly-barcoded promoter-library insertion sequencing (RB-PI-seq) and combined it with chassis-independent recombinase assisted genome engineering (CRAGE), using Pseudomonas simiae WCS417 as a model rhizobacterium. This method enables targeted amplification of barcoded transcripts, bypassing plant RNA interference and allowing measurement of thousands of promoter activities during root colonization. Our analysis revealed time-resolved dynamics of promoter activities, highlighting early transcriptional reprogramming as a key determinant of successful colonization. Additionally, we discovered that transcriptional activation of xanthine dehydrogenase and a lysozyme inhibitor are crucial for evading plant immune system defenses. This framework is scalable to other bacterial species and provides new opportunities for understanding rhizobacterial gene regulation in native environments.

microbiology↗

bioRxiv2024

A unified central thalamus mechanism underlying diverse recoveries in disorders of consciousness

Disorders of consciousness (DoC) encompass a range of states characterized by prolonged altered awareness due to heterogeneous brain damage and are associated with highly diverse prognoses. However, the neural mechanisms underlying such diverse recoveries in DoC remain unclear. To address this issue, we analysed neuronal spiking activities recorded from the central thalamus (CT), a key hub in arousal regulation, in a cohort of 23 DoC patients receiving deep brain stimulation treatment. Using machine learning techniques, we identified a core set of electrophysiological features of the CT, particularly the theta rhythm, that could account for individual recovery outcomes across highly varied etiologies (trauma, brainstem hemorrhage, and anoxia), clinical baselines and patient ages. These features also correctly identified one subgroup of patients who exhibited poor initial clinical manifestations but recovered unexpectedly. Simulating a conductance-based model further revealed the neurodynamics of the theta rhythm in the CT during different stages of consciousness recovery. Taken together, these findings uncover a previously unknown, unified CT mechanism that governs the recoveries in DoC.

neuroscience↗

bioRxiv2024

Aerobic carbon metabolism modulates nitrite ammonifiers for inhibiting nitrogen loss as revealed by microcosm experiment of agricultural upland soil

Denitrification and dissimilatory nitrate reduction to ammonium (DNRA), two divergent nitrogen metabolism pathways, share nitrite as a common intermediate during anaerobic reduction. However, these pathways influence the environment and soil nutrients differently. Unlike denitrification, which involves nitrogen loss through gaseous nitrogen emission and nitrate leaching, DNRA is beneficial for the conservation of nitrogen. Nevertheless, the key mechanism underlying the joint regulation of aerobic carbon metabolism to nitrite ammonifiers in soil is still unclear, although previous studies have reported factors such as carbon and oxygen can independently affect DNRA. Here, microcosm experiments with agricultural upland soil were conducted under different aeration conditions supplemented with labile carbon to analyze the process of anaerobic nitrogen metabolism. The results indicated that denitrification exclusively dominated nitrite reduction when the soil was directly placed in an anaerobic environment. Nonetheless, a significant increase in DNRA activity and the attenuation of denitrification were detected when the soil was incubated aerobically with the addition of glucose prior to anaerobic incubation. Specifically, up to 55.8% of nitrite reduction switched to nitrogen conservation mainly via DNRA under high-carbon conditions. Quantitative assays of the nrfA gene and metagenomic data revealed a significant increase in DNRA-related genes after aerobic carbon metabolism. Furthermore, nrfA gene sequence analysis revealed a significant shift in the composition of nitrite ammonifiers community. These results indicate that nitrate/nitrite metabolic flux in the soil could be regulated to enhance DNRA by stimulating facultative anaerobic nitrite ammonifiers such as Sedimentibacter under alternating aerobic and anaerobic environments with carbon metabolism. IMPORTANCEThis study revealed that aerobic conditions with a carbon supply strongly influence the community assembly of nitrite ammonifiers. Nitrite ammonifiers such as Sedimentibacter enriched under sufficient carbon and aeration conditions promoted the subsequent DNRA process under anaerobic conditions. Therefore, regulating the competition between DNRA and denitrification by altering functional microbiota would be a promising approach for improving the efficiency of fertilizer application and for reducing greenhouse gas emissions from denitrification. These findings are essential for understanding the biological mechanism of nitrogen cycling in dryland agricultural soil. Based on these findings, we may design a strategy to increase the abundance of nitrite ammonifiers in agricultural soil, which might promote DNRA metabolism to improve nitrogen retention. This strategy would ultimately enhance fertilizer use efficiency and mitigate the detrimental environmental effects of nitrogen fertilizer abuse.

microbiology↗

bioRxiv2024

5-methylcytosine and 5-hydroxymethylcytosine are synergistic biomarkers for early detection of colorectal cancer

Early cancer detection has the potential to significantly improve treatment outcomes and survival rates. This study investigates the roles of 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) as biomarkers for early-stage colorectal cancer (CRC) detection in cell-free DNA (cfDNA). Using whole genome sequencing, we analyzed cfDNA from 37 treatment-naive CRC patients and 32 healthy controls. Our findings indicate that combining measurements of 5mC and 5hmC significantly enhances diagnostic accuracy (AUC = 0.95) compared to traditional approaches that conflate these markers (modified C, AUC = 0.66). Notably, 71.7% of differentially methylated regions (DMRs) exhibiting an increase in 5hmC in stage I cfDNA also showed a corresponding decrease in 5mC in stage IV, suggesting that 5hmC can effectively track regions undergoing demethylation during tumor development. These results support the hypothesis that distinguishing between 5mC and 5hmC can improve the sensitivity of liquid biopsy tests for early cancer detection.

cancer biology↗

bioRxiv2024

Domain-specific Schema Reuse Supports Flexible Learning to Learn in Primate Brain

Prior knowledge accelerates subsequent learning of similarly structured problems - a phenomenon termed "learning to learn" - by forming and reusing generalizable neural representations, i.e., the schemas. However, the stability-plasticity dilemma, i.e., how to exploit stable schemas to facilitate learning while remaining flexible towards possible changes, is not well understood. We hypothesize that restricting schemas to specific functional, e.g., decision-making, subspace and making it orthogonal to other subspaces allows the brain to balance stability and plasticity. To test it, we trained three macaques on visuomotor mapping tasks and recorded neural activity in the dorsolateral premotor cortex. By delineating decision and stimulus subspaces, we identified a schema-like manifold within only the decision subspace. The reuse of decision schemas significantly facilitated subsequent learning. In addition, the decision subspace exhibited a trend to be orthogonal to the stimulus subspace, minimizing interference between these two domains. Our results revealed that restricting schemas to specific functional domains can preserve useful knowledge while maintaining orthogonality with other subspaces, allowing for flexible adaptation to new environments, thereby resolving the stability-plasticity dilemma. This finding provides new insights into the mechanisms underlying brains capability to learn both fast and flexibly, which can also inspire more efficient learning algorithms for artificial intelligence systems towards working in open, dynamic environments.

neuroscience↗

bioRxiv2024

Multi-modal profiling identifies CD4+CXCR5+PD-1- Tfh cells as prognostic and predictive biomarkers for response to R-CHOP therapy in human DLBCL

Despite the improvements in clinical outcomes for patients with Diffuse Large B-Cell Lymphoma (DLBCL), a significant proportion of those patients still face challenges with refractory/relapsed (R/R) disease after receiving first-line R-CHOP treatment. Characterizing the heterogeneity of the tumor microenvironment (TME) in diffuse large B cell lymphoma (DLBCL) is crucial for understanding relapsed/refractory disease. However, the complex and diverse nature of the TME has impeded progress. Here, using single-cell RNA sequencing(scRNA-seq), we explored the DLBCL landscape at single-cell resolution, profiling 77,344 cells from both primary and relapsed DLBCL patients. We further investigated the shared and distinct molecular and cellular features of tumor microenvironment in both primary and relapsed DLBCL tumors by integrating next-generation DNA sequencing data and multiple scRNA-seq datasets from total 72,351 cells. Our results demonstrated that there was a significant decrease of CD4+CXCR5+PD-1- Tfh cells, along with excessive activation of the TNF-NF{kappa}B signaling pathways in malignant B cells in R/R disease. Furthermore, by using multiplex IHC, we confirmed that CD4+CXCR5+PD-1- Tfh cells are prognostic and predictive biomarkers for response to R-CHOP treatment. As a proof of concept, we successfully generated mutilplexed images of CD4+CXCR5+PD-1- Tfh cells from a single DAPI staining in human DLBCL tissues through using generative artificial intelligence. Our study offers critical insights into the heterogeneity and molecular features of DLBCL, shedding light on the crucial role of CD4+CXCR5+PD-1- Tfh cells in the recurrent process. HighlightsO_LIShared and distinct molecular and cellular features of tumor microenvironment in both primary and relapsed DLBCL tumors; C_LIO_LIThe characteristic of relapsed DLBCL TME is a dysfunctional immune microenvironment with a significant decrease of CD4+CXCR5+PD-1- Tfh cells. C_LIO_LICD4+CXCR5+PD-1- Tfh cells are prognostic and predictive biomarkers for response to R-CHOP treatment C_LIO_LIDetermination of CD4+CXCR5+PD-1- Tfh cells in human DLBCL tissues through using generative artificial intelligence. C_LI

immunology↗

bioRxiv2024

Hand Position Fields of Neurons in the Premotor Cortex of Macaques during Natural Reaching

Planning and execution for goal-directed movements requires the integration of the current position of body or body parts with various kinematic parameters of the movement itself. In the hippocampus, the field-based representation of spatial information plays an essential role in this process during navigation. However, if a similar, field-based encoding framework is also utilized by the motor areas during hand reaching remains unclear. In this study, we investigated the hand position tuning in the dorsal premotor cortex (PMd) neurons (n = 601) when four monkeys performing a naturalistic reach-and-grasp task. We show that 132/601 (22%) of PMd neurons increased their firing rates when the monkeys hand occupied specific positions in the space, forming the "position fields" in their spatial firing maps that can be well described by 2D Gaussian functions/kernels. We further analyzed how the field-tuning of hand position is co-represented with other task-related parameters including the hand moving direction, speed, and reward location in the same population of PMd neurons, revealing a mixed-selective framework also similar to that discovered in the hippocampus. These position-tuned cells demonstrated high efficiency in encoding hand position, with ~10% of overall recorded neurons contributing >80% of accuracy in decoding instantaneous hand moving trajectories. These results suggest that a field-based encoding framework of position may be a common component to representing spatial information and integrating it with kinematic parameters for guiding goal-directed movements of the body or body parts.

neuroscience↗

bioRxiv2024

Longitudinal multi-omics reveals pathogenic TSC2 variants disrupt developmental trajectories of human cortical organoids derived from Tuberous Sclerosis Complex

Tuberous Sclerosis Complex (TSC), an autosomal dominant condition, is caused by heterozygous mutations in either the TSC1 or TSC2 genes, manifesting in systemic growth of benign tumors. In addition to brain lesions, neurologic sequelae represent the greatest morbidity in TSC patients. Investigations utilizing TSC1/2-knockout animal or human stem cell models suggest that TSC deficiency-causing hyper-activation of mTOR signaling might precipitate anomalous neurodevelopmental processes. However, how the pathogenic variants of TSC1/2 genes affect the longitudinal trajectory of human brain development remains largely unexplored. Here, we employed 3-dimensional cortical organoids derived from induced pluripotent stem cells (iPSCs) from TSC patients harboring TSC2 variants, alongside organoids from age- and sex-matched healthy individuals as controls. Through comprehensively longitudinal molecular and cellular analyses of TSC organoids, we found that TSC2 pathogenic variants dysregulate neurogenesis, synaptogenesis, and gliogenesis, particularly for reactive astrogliosis. The altered developmental trajectory of TSC organoids significantly resembles the molecular signatures of neuropsychiatric disorders, including autism spectrum disorders, epilepsy, and intellectual disability. Intriguingly, single cell transcriptomic analyses on TSC organoids revealed that TSC2 pathogenic variants disrupt the neuron/reactive astrocyte crosstalk within the NLGN-NRXN signaling network. Furthermore, cellular and electrophysiological assessments of TSC cortical organoids, along with proteomic analyses of synaptosomes, demonstrated that the TSC2 variants precipitate perturbations in synaptic transmission, neuronal network activity, mitochondrial translational integrity, and neurofilament formation. Notably, similar perturbations were observed in surgically resected cortical specimens from TSC patients. Collectively, our study illustrates that disease-associated TSC2 variants disrupt the neurodevelopmental trajectories through perturbations of gene regulatory networks during early cortical development, leading to mitochondrial dysfunction, aberrant neurofilament formation, impaired synaptic formation and neuronal network activity.

neuroscience↗

bioRxiv2024

An Atlas of Linkage Disequilibrium Across Species

Linkage disequilibrium (LD) is a key metric that characterizes populations in flux. To reach a genomic scale LD illustration, which has a substantial computational cost of[O] (nm2), we introduce a framework with two novel algorithms for LD estimation: X-LD, with a time complexity of[O] (n2m) suitable for small sample sizes (n < 104); X-LDR, a stochastic algorithm with a time complexity of[O] (nmB) for biobank-scale data (B iterations); n the sample size, and m the number of SNPs. These methods can refine the entire genome into high-resolution LD grids, such as more than 9 million grids for UK Biobank samples ([~]4.2 million SNPs). The efficient resolution for genome-wide LD leads to intriguing biological discoveries. I) High-resolution LD illustrations revealed how the pericentromeric regions and the HLA region lead to intense and extended LD patterns. II) Two universal LD patterns, identified as Norm I and Norm II patterns, provide insights on the evolutionary history of populations and can also highlight genomic regions of deviation, such as chromosomes 6 and 11 or ncRNA regions. III) The results of our innovative LD decay method aligned with the LD decay scores of 59.5 for Europeans, 60.2 for East Asians, and 33.2 for Africans; correspondingly, the length of the LD was approximately 2.85 Mb, 2.18 Mb, and 1.58 Mb for these three ethnicities. Rare or imputed variants universally increased LD. IV) An unprecedented LD atlas for 25 reference populations contoured interspecies diversity in terms of their Norm I and Norm II LD patterns, highlighting the impact of refined population structure, quality of reference genomes, and uncovered a profound status quo of these populations. The algorithms have been implemented in C++ and are freely available (https://github.com/gc5k/gear2).

genetics↗

bioRxiv2024

Global remodeling of ADP-ribosylation by PARP1 suppresses influenza A virus infection

ADP-ribosylation is a highly dynamic and fully reversible post-translational modification performed by poly(ADP-ribose) polymerases (PARPs) that modulates protein function, abundance, localization and turnover. Here we show that influenza A virus infection causes a rapid and dramatic upregulation of global ADP-ribosylation that inhibits viral replication. Mass spectrometry defined for the first time the global ADP-ribosylome during infection, creating an infection-specific profile with almost 4,300 modification sites on [~]1,080 host proteins, as well as over 100 modification sites on viral proteins. Our data indicate that the global increase likely reflects a change in the form of ADP-ribosylation rather than modification of new targets. Functional assays demonstrated that modification of the viral replication machinery antagonizes its activity and further revealed that the anti-viral activity of PARPs and ADP-ribosylation is counteracted by the influenza A virus protein NS1, assigning a new activity to the primary viral antagonist of innate immunity. We identified PARP1 as the enzyme producing the majority of poly(ADP-ribose) present during infection. Influenza A virus replicated faster in cells lacking PARP1, linking PARP1 and ADP-ribosylation to the anti-viral phenotype. Together, these data establish ADP-ribosylation as an anti-viral innate immune-like response to viral infection antagonized by a previously unknown activity of NS1.

microbiology↗

bioRxiv2024

Flexible and robust cell type annotation for highly multiplexed tissue images

Identifying cell types in highly multiplexed images is essential for understanding tissue spatial organization. Current cell type annotation methods often rely on extensive reference images and manual adjustments. In this work, we present a tool, Robust Image-Based Cell Annotator (RIBCA), that enables accurate, automated, unbiased, and fine-grained cell type annotation for images with a wide range of antibody panels, without requiring additional model training or human intervention. Our tool has successfully annotated over 3 million cells, revealing the spatial organization of various cell types across more than 40 different human tissues. It is open-source and features a modular design, allowing for easy extension to additional cell types.

bioinformatics↗

bioRxiv2024

Genetic code expansion reveals site-specific lactylation in living cells reshapes protein function

Still in its infancy, the functions of lactylation remain elusive. To address this, we established a comprehensive workflow for lactylation studies that integrates the discovery of lactylation sites with proteomics, the expression of site-specifically lactylated proteins in living cells via genetic code expansion (GCE), and the evaluation of the resulting biological consequences. Specifically, we developed a wet-and-dry-lab combined proteomics strategy, and identified highly conserved lactylation at ALDOA-K147. Driven by its potential biological significance, we site-specifically expressed this lactylated ALDOA in mammalian cells and interrogated the biological changes. We discovered that it not only inhibited enzyme activity but also elicited gain-of-function effects----it dramatically reshaped the functionality of ALDOA by improving stability, enhancing nuclear translocation and affecting gene expression. Further, we demonstrated broad applicability of this workflow to study distinct histone lactylation sites. Together, we anticipate its wide uses in elucidating causative links between site-specific lactylation and target-centric or cell-wide changes.

molecular biology↗

bioRxiv2024

A Nerve-Fibroblast Axis in Mammalian Lung Fibrosis

Fibrosis contributes to incurable pathologies in vital organs including the lung. Myofibroblasts are fibrogenic effector cells that accumulate via incompletely understood mechanisms. We discovered that 1-adrenoreceptor expressing myofibroblasts receive sympathetic nerve-derived noradrenergic inputs in fibrotic mouse and human lungs. We combined optical clearing, whole lung imaging, cell-specific gene deletion in sympathetic nerves and myofibroblasts, pharmacologic interventions, sympathetic nerve co-culture and precision-cut lung slices, with analysis of bronchoalveolar lavage fluid, lung tissues, single-cell RNA sequencing datasets, and isolated lung fibroblasts from patients with diverse forms of pulmonary fibrosis to characterize a fibrogenic unit comprised of aberrantly patterned sympathetic nerves and 1-adrenoreceptor subtype D expressing myofibroblasts. The discovery of this previously undefined nerve-fibroblast axis that is conserved across species demonstrates the pivotal contribution of nerves to tissue remodeling and heralds a novel paradigm in fibrosis research.

cell biology↗

bioRxiv2024

Identification of leptolin as a novel anti-obesity adipokine

Adipokines are key factors in regulating energy homeostasis. We identified a novel adipokine; we named it Leptolin. In humans, leptolin levels in white adipose tissue were positively corrected with exercise, and negatively associated with body mass index. Leptolin levels were positively correlated with lipolysis-promoting gene expression. Elevated leptolin in plasma of athletes, whereas lowered leptolin in plasma of obese individuals were observed. Leptolin gene-knockout mice exhibited increased adiposity and body weight, and decreased energy expenditure. Leptolin gene-overexpression mice showed obesity-resistant phenotypes. Treatment with leptolin promoted fat mobilization and energy expenditure, and reduced body weight, without affecting food-intake and motor activity. Together, leptolin, a novel adipokine with a capacity to improve metabolic status, may serve as a new therapeutic agent for obesity and metabolic disorders.

physiology↗

bioRxiv2024

3D printed microtissue cassettes enabling high throughput proton radiobiological assays

Uncertainties on proton relative biological effectiveness (RBE) across the spread out of Bragg peak (SOBP) (typically assumed to be 1.1) may lead to suboptimal treatment plan and unwarranted toxicity to organs-at-risk. Herein, we report a reliable analytical method to determine the proton RBE along the SOBP and distal fall-off region. The 3D microtissue cassette enables the high throughput assessment of biological assays including clonogenic assay and {gamma}-H2AX assay following a single proton irradiation. Clonogenic assay shows the RBE of 1.6 (10% cellular survival) which is consistent with the deter-mined RBE of 1.58 using the {gamma}-H2AX assay. Besides, we also show that the high spatial resolution of the cassette can distinguish the minute but significant foci changes (number, area) in response to small proton radiation dose fraction. The results validate the reliability of our setup in addressing critical proton radiobiological questions.

bioengineering↗