Rapid detection of inflammatory biomarkers from whole blood samples (such as fingertip blood) is crucial for early sepsis assessment and critical care intervention, yet great challenges remain. Here, we report an ultra-sensitive lateral flow immunoassay (LFIA) that employs SiO2 shell-protected magnetofluorescent probes, combined with click reaction for efficient antibody conjugation, enabling bedside, simultaneous detection of sepsis biomarkers interleukin-6 (IL-6) and procalcitonin (PCT). An ester-activated diyne linker enables universal functionalization of MagTQD@Si surface antibodies without the need for concurrent catalyst activation, while preserving high activity and stability of the nanoprobes. The MagTQD@Si probes enable rapid capture and ultrasensitive detection below the pg/mL level on LFIA, benefiting from magnetic enrichment and signal amplification provided by thousands of quantum dots. The SiO2 shell not only stabilizes luminescence in whole blood but also improves chromatographic flow, thereby enhancing detection accuracy. The established MagTQD@Si-LFIA achieved detection limits of 0.73 pg mL 1 for IL-6 and 2.32 pg mL 1 for PCT, and provided quantitative analysis over a 4-order-of-magnitude dynamic range. Validation with 66 clinical samples showed concordance with ELISA results, with assay time reduced to only 20 min. Collectively, this platform enables direct, simultaneous multi-marker detection and holds promise for low-cost, bedside sepsis monitoring.

The experiment aimed to investigate the molecular mechanisms of ochratoxin A (OTA)-induced liver injury in livestock and poultry through network toxicology and reverse network pharmacology, and to screen for natural Chinese medicine components with detoxification potential. Potential targets of OTA and liver injury were screened through databases, and the overlapping targets were used to construct a protein-protein interaction (PPI) network. Core targets were selected based on degree values, and the target genes were imported into the DAVID database for Gene Ontology (GO) functional and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Core targets were used to reversely predict potential detoxifying Chinese medicine components, and a 'Chinese medicine-ingredient-target' network was constructed to screen for core components. Molecular docking was performed to validate the binding affinity between core components and core targets. The results showed that a total of 83 potential targets of OTA-induced liver injury were identified, with core targets including epidermal growth factor receptor (EGFR), tumor necrosis factor (TNF), and matrix metalloproteinase-9 (MMP9). KEGG enrichment analysis focused on the phosphatidylinositol 3-kinase-protein kinase B (PI3K-Akt) signaling pathway and cancer-related pathways. Reverse screening identified six Chinese medicine herbs, including Salvia miltiorrhiza and Scutellaria baicalensis, as well as five core components, including quercetin and kaempferol. Molecular docking results demonstrated strong binding affinity between the core components and core targets. The study shows that OTA-induced liver injury involves multi-target and multi-pathway mechanisms. The screened natural Chinese medicine components, such as quercetin and kaempferol, may exert antioxidant, anti-inflammatory, and anti-apoptotic effects by acting on core targets including EGFR, TNF, and MMP9, and intervening in signaling pathways such as PI3K-Akt, thereby alleviating OTA-induced liver injury. These findings provide a reference for the prevention and control of OTA poisoning in livestock and poultry and the development of novel detoxifying agents.

Lateral flow immunochromatographic assays (LFIAs) with fluorescent labels have emerged as powerful analytical tools for point-of-care diagnostics, offering superior sensitivity over conventional colorimetric methods. However, quantitative analysis at low analyte concentrations remains challenging due to insufficient signal contrast and background interference. To address this challenge, this study developed a two-stage signal-enhancement method integrating the Gaussian mixture model (GMM) and adaptive rolling ball (ARB) technique, achieving the ultrasensitive detection and precise quantification of weak fluorescent signals. The method employed a "coarse classification-fine refinement" collaborative strategy and combined the Hill equation to establish quantitative relationships between signal intensity and target concentration. Validation using a quantum dot fluorescent labeling system demonstrated a detection sensitivity of 10-10 mol L-1, representing 1-2 orders of magnitude improvement over conventional methods. Under limited concentration conditions, the method achieved a signal-to-noise ratio of 27.3 ± 2.64 dB, contrast-to-noise ratio of 12.62 ± 2.87, peak-to-valley ratio of 151.65 ± 30.2, and background suppression rate of 73% ± 3.4%, which were significantly superior to those of control methods. In Escherichia coli detection, the detection limit improved from 103 to 102 CFU mL-1, with a Pearson correlation coefficient of 0.998 compared with the PCR gold standard. The method exhibited excellent performance in high-noise environments and multi-target detection (Staphylococcus aureus/Klebsiella pneumoniae), with R2 > 0.99, providing a practical solution for ultrasensitive point-of-care diagnostics and pathogen screening in resource-limited settings.

Objective To investigate the prevalence and influencing factors of cognitive impairment in patients with temporal lobe epilepsy (TLE). Methods Total 58 patients with TLE admitted to Shenzhen People's Hospital from May 2017 to January 2026 were enrolled. Montreal Cognitive Assessment (MoCA) was used to evaluate cognitive function. Univariate and multivariate Logistic regression analyses were performed to identify risk factors for comorbid cognitive impairment in TLE patients. Receiver operating characteristic (ROC) curves were plotted to evaluate predictive efficacy of these factors for cognitive impairment. Results A total of 58 patients were divided into a cognitive impairment group (MoCA score<26, n=42) and a normal cognitive function group (MoCA score≥26, n=16). Logistic regression analysis showed that education level of junior high school or below (OR=4.788, 95%CI: 1.298-17.664; P=0.019) and the use of≥2 kinds of antiepileptic seizure medicine (ASM; OR=5.421, 95%CI: 1.032-28.482, P=0.046) were risk factors for cognitive impairment in patients with TLE. ROC curve showed that area under the curve (AUC) for education level of junior high school or below, the use of≥2 kinds of ASM, and their combination in predicting cognitive impairment were 0.701 (95%CI: 0.547-0.855, P=0.019), 0.676 (95%CI: 0.530-0.821, P=0.040) and 0.774 (95%CI: 0.639-0.908, P=0.001), respectively. The corresponding sensitivities were 71.40%, 47.60% and 83.30%, and the specificities were 68.70%, 87.50% and 62.50%, respectively. The predictive performance of the combined indicator was superior only to that of using≥2 kinds of ASM (Z=2.426, P=0.015). Conclusions Patients with TLE have a high risk of comorbid cognitive impairment, which is influenced by factors such as education and the kinds of ASM.

Accurate bedside diagnosis of sepsis is essential for timely treatment and reducing mortality, yet technical limitations persist. Here, we present a multiplex-compatible lateral flow immunoassay (LFIA) that integrates a universal click-chemistry conjugation strategy with highly dispersible, film-like magnetic fluorescent probes (GFDQD@Si) to enable precise diagnosis through concurrent monitoring of pathogens and protein biomarkers. GFDQD@Si combines a two-dimensional high-area reactive interface; a magnetic interlayer for target enrichment and signal amplification; a multilayer of quantum dots for fluorescence enhancement; and an outer silica shell that suppresses background fluorescence and confers superior flowability. This architecture overcomes the size disparity between bacteria and proteins, enabling efficient cocapture of multiple proteins/bacteria and achieving faster, more sensitive detection on an LFIA platform. The platform quantitatively detects two key sepsis biomarkers─procalcitonin (PCT) and interleukin-6 (IL6)─as well as the pathogen Pseudomonas aeruginosa, with limits of detection of 4.44 pg mL-1 for PCT, 0.94 pg mL-1 for IL6, and 7 CFU mL-1 for bacteria. Validation in 75 clinical whole-blood samples demonstrated high sensitivity, ease of operation, and robustness, underscoring its potential for real-time bedside sepsis diagnosis. By simultaneously providing dual readouts of host-response biomarkers and pathogen detection, the GFDQD@Si-LFIA platform is expected to accelerate and improve clinical decision-making for sepsis.

The outbreak of chikungunya virus (CHIKV) infections has again highlighted the urgent need to develop rapid, accurate, and cost-effective point-of-care diagnostic technologies. Here, we report a field-deployable method that integrates an ultrasensitive fluorescent lateral flow immunoassay (FLFIA) with an artificial intelligence (AI)driven quantitative algorithm, enabling one-step, ultrasensitive detection and precise quantification of CHIKV within 15 min. The platform uses high-performance sheet-like multilayer fluorescent probe with a protective SiO2 shell (GO@TQD@Si) nanoprobes, characterized by: (i) a large reaction interface and high fluorescent loading; (ii) a silica shell that provides enhanced stability and chromatographic mobility; and (iii) covalent modification that yields high immunorecognition efficiency-thereby ensuring strongly sensitive fluorescent signal output and high accuracy for the LFIA. Concurrently, we developed an AI-based quantitative model for precise viral concentration measurement that directly extracts signal features from photos taken by a portable reader, enabling true on-site real-time diagnosis. The proposed AI-assisted GO@TQD@Si-FLFIA system achieves a detection limit for CHIKV as low as 2.06 pg & sdot;mL-1 and demonstrated 94.24% diagnostic sensitivity and 96.10% specificity in testing 293 clinical samples, showing great potential for epidemic field control.

Simultaneous detection of chemical and biological contaminants in complex samples remains a major analytical challenge. Here, we present a dual-mode lateral flow assay (LFA) based on magnetic-SiO2-fluorescent probes (Fe@Si@QDs) possessing dual "enrichment-signal amplification" functions. The platform integrates both sandwich and competitive formats, enabling ultrasensitive and quantitative detection of a representative antibiotic (gentamicin) and pathogen (Escherichia coli O157) on a single test strip. The Fe@Si@QDs probe incorporates a SiO2 interlayer between the 180 nm Fe3O4 core and outer quantum dots (QDs), effectively suppressing fluorescence inner-filter effects from the magnetic core while enhancing probe dispersibility and chromatographic mobility. Antibody-functionalized Fe@Si@QDs facilitate efficient cocapture of both microorganisms and antibiotics, enabling precise quantitative detection through fluorescence signal enhancement on the microbial test line and attenuation on the small-molecule test line. The developed LFA method achieved detection limits of 36 cfu/mL for E. coli O157 (E. coli O157) and 2.05 pg/mL for gentamicin (GEN), offering at least a 500-fold sensitivity improvement over conventional colorimetric-LFA methods. Validation with real environmental and food samples demonstrated excellent reliability and stability, underscoring the platform's broad applicability for on-site, household, and laboratory use.

Healthcare-associated infection (HAI) pathogens cause severe nosocomial outbreaks, jeopardizing patient safety and straining healthcare systems. Conventional loop-mediated isothermal amplification-lateral flow immunoassay (LAMP-ICA) allows rapid pathogen detection but is constrained by low sensitivity, a high false-positive rate, and an extended detection time. To address these limitations, we present a dual-mode (colorimetric/fluorescent) microfluidic biosensing platform based on silicon-gold/quantum dot core-shell nanoprobes (Si@Au/DQD NPs). The platform incorporates two key innovations: (1) The colorimetric/fluorescent dual-signal Si@Au/DQD nanoprobe enhances detection reliability and sensitivity through dual-signal complementary verification and multilayered QD design, halving the LAMP amplification time compared to traditional colloidal gold systems, and (2) a modular microfluidic chip integrates LAMP amplification and ICA detection within a closed system, effectively preventing leakage and contamination of amplification products. Performance evaluation showed that the fluorescence detection limit of this system for Staphylococcus aureus (S. aureus), Legionella pneumophila (L. pneumophila), and Klebsiella pneumoniae (K. pneumoniae) reaches 82-140 CFU/mL, with the entire process completed within 30 min. In addition, the detection of 25 clinical environmental samples verifies the practicality of the designed integrated detection platform. With high sensitivity, strong specificity, and dual-mode capability for qualitative colorimetric screening and quantitative fluorescence analysis, this technology offers an efficient solution for point-of-care testing (POCT) of HAI pathogens, particularly in resource-limited settings and in on-site emergency diagnostics.

Adipose-resident T cells play a crucial role in the development of obesity-induced insulin resistance. However, the specific mechanisms, particularly those involving non-immune cytokines, remain unclear. Here, we report significantly elevated levels of sclerostin domain-containing protein 1 (SOSTDC1) in individuals with type 2 diabetes (T2D), showing positive correlations with fasting glucose and HbA1c. T cell-specific Sostdc1-deficient mice exhibit resistance to age-induced adipose lipid accumulation and glucose dysregulation at 12 months and protect against obesity-induced insulin resistance without affecting proinflammatory macrophage infiltration or adipose inflammation. Mechanistically, SOSTDC1 disrupts the lipid balance in adipocytes by promoting lipogenesis and inhibiting lipolysis through the LRP5/6-β-catenin pathway. Furthermore, T cell receptor (TCR) signaling significantly amplifies SOSTDC1 secretion in CD4+ T cells. In summary, our study uncovers an additional mechanism by which T cells contribute to obesity and insulin resistance, suggesting that inhibiting SOSTDC1 could be a promising immunotherapeutic strategy for metabolic disorders.

Interleukin-27 (IL-27), an Interleukin-12 (IL-12) family heterodimeric cytokine, plays a central yet complex role in immunoregulation within the intestinal mucosa, where its context-dependent actions can promote both protective and pathogenic outcomes. Although its cellular sources, receptor structure (IL-27Rα/gp130 complex), and involvement in regulating key immune cells (e.g., T-cell subsets, macrophages, neutrophils) and epithelial functions are established, the precise mechanisms underlying its paradoxical effects-balancing homeostasis with inflammation-remain incompletely resolved. This review synthesizes current understanding of IL-27 biology to clarify its multifaceted role. Crucial insights into these dual functions have emerged from preclinical models, including murine colitis (e.g., DSS-, TNBS-induced), enteric infection (e.g., Toxoplasma gondii, Citrobacter rodentium), and colorectal cancer models. These studies demonstrate that IL-27 critically orchestrates gut immunity, maintaining homeostasis through antimicrobial defense and barrier enhancement while suppressing immunopathology. Conversely, its dysregulation drives chronic inflammation and carcinogenesis. Clinically, IL-27 expression correlates with disease activity in inflammatory bowel disease (IBD), colorectal cancer (CRC), and infections, highlighting its biomarker potential. Consequently, targeting the IL-27 pathway presents promising therapeutic avenues: augmenting signaling may mitigate IBD hyperinflammation, while inhibition could bolster antitumor immunity or resolve infection-driven pathology. Future research must prioritize defining context-specific IL-27 functions, optimizing delivery strategies, and integrating IL-27 targeting with existing biologics to translate its immunomodulatory potential into novel therapies for intestinal diseases.

Diabetic foot ulcer (DFU), a serious complication of diabetes, is a life-threatening disease that often leads to lower limb amputation and a shortened lifespan. Interleukin-27 (IL-27) is a member of the IL-12 family and has the potential to exert dual effects on the immune response. The role of IL-27 in diabetic skin wound healing is unknown. The aim of this study was to investigate whether there is abnormal expression of IL-27 in diabetic skin and whether supplementation with IL-27 can promote diabetic wound healing by modulating macrophage polarization. We established a streptozotocin (STZ)-induced diabetic mouse model and constructed diabetic wounds. We assessed protein expression by western blotting (WB) and immunohistochemical (IHC) staining. We also performed hematoxylin-eosin (H&E) staining and Masson's trichrome staining. In the presence of lipopolysaccharide (LPS) and high glucose (HG), we treated the mononuclear macrophage line RAW264.7 and bone marrow-derived macrophages (BMDMs) with IL-27. To assess macrophage polarization, we examined the expression of inducible nitric oxide synthase (iNOS), IL-1β and arginase-1 (Arg-1). To understand the underlying mechanisms, we used macrophage IL-27ra knockout mice to knockout macrophage IL-27 receptors. Our in vivo experiments revealed that the expression of IL-27 in the skin of diabetic mice was significantly decreased and that supplementation with IL-27 promoted diabetic wound healing. In vitro, compared with the LPS group, supplementation with IL-27 alleviated the suppression of multiple cellular functions, such as iNOS and IL-1β expression, cell migration, and phagocytosis, in macrophages after HG exposure. Mechanistically, we found that IL-27 expression was decreased and that the activation of signal transducer and activator of transcription 3 (STAT3) by phosphorylation was inhibited in diabetic skin, leading to an inability of wound macrophages to polarize to an M1 phenotype effectively, which in turn blocked M1-to-M2 polarization of wound macrophages and ultimately delayed wound healing. The present study revealed that supplementation with IL-27 promoted M1-to-M2 polarization of wound macrophages and diabetic wound healing through the IL-27-IL-27Rα-p-STAT3 axis. These findings suggest that IL-27 may be a potential therapeutic target for DFU.

Fluorescence lateral flow assays (FLFA) based on quantum dot probes have attracted significant attention in recent years due to their high sensitivity and quantitative detection capabilities. FLFA requires the use of a straightforward fluorescence reader for quantitative detection. Most fluorescence readers employ narrowband filters for auxiliary imaging, which facilitates the acquisition of high-contrast signals. However, during trace detection, the weak signal from FLFA can be easily lost due to optical flux loss associated with narrowband filters, thereby indirectly diminishing detection sensitivity. To address this issue, we developed a fluorescence signal reader that employs CMOS imaging without optical filters and proposed a highly sensitive signal detection algorithm based on continuous wavelet transform (CWT) to identify weak fluorescence signals with low contrast. Experimental results demonstrate that the method achieves a fluorescence detection sensitivity for quantum dots of 10-10 mol/L, with a relative standard deviation (RSD) of < 1.45%. The designed filter-free detection system and CWT analysis algorithm were applied to various FLFA systems (including the sandwich method and the competition method), with the correlation coefficient (R2) between all detection results and sample concentration exceeding 0.997. The findings of this study offer a highly sensitive signal detection method for the precise quantification of FLFA.

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a globally prevalent disorder linked to metabolic syndrome, currently lacking approved therapies, and existing treatments offer only limited benefits. Complement factor D (CFD), a rate-limiting serine protease in the alternative complement pathway, has been suggested to be associated with metabolic diseases in previous studies. Its inhibitor, danicopan, is primarily used for paroxysmal nocturnal hemoglobinuria (PNH), but its role in metabolic liver diseases remains underexplored. Here, we assessed the role of CFD in MAFLD and danicopan therapy using HFD mice, patient sera, and hepatocytes via CRISPR knockout and pharmacological interventions. Key findings demonstrated significant upregulation of CFD in MAFLD mice livers and patient sera. Genetic CFD ablation attenuated hepatocyte lipid deposition. Danicopan reduced intracellular triglycerides/cholesterol, improved glucose tolerance, lowered ALT, and alleviated hepatic steatosis in obese mice without weight change. Mechanistically, danicopan suppressed NF-κB signaling, inhibiting lipid-related genes (CD36/FASN/ FATP2) and inflammatory mediators (MMP12/IL-6/TNF-α). These results establish CFD as a novel MAFLD mediator, validating FDA-approved danicopan's therapeutic efficacy and translational potential. This work provides critical evidence for targeting the CFD pathway in MAFLD management.

Liver diseases, ranging from chronic liver disease (CLD) to acute liver injury (ALI), pose significant global health challenges. Metabolic dysfunction and inflammatory disorders are key to the progression of both CLD and ALI, suggesting that dual-targeting of metabolism and immune response may lead to better clinical performance for patients with liver disease. Interleukin-27 (IL-27) is a classic cytokine known for its immune-modulating role, with many ongoing clinical trials in the context of anti-tumoral therapy and inflammatory bowel disease. Our previous studies have revealed an unexpected role of IL-27 in promoting adipocyte thermogenesis and ameliorating role in systemic metabolism. This review outlines the involvement of the IL-27/IL-27R signaling pathway in hepatic metabolism and immunity, highlighting its potential as a therapeutic target for both CLD and ALI. Meanwhile, when serum IL-27 displays a disease-specific change in dynamic liver diseases, a summary and elaboration on its diagnostic potential are also carried out.

Detecting respiratory bacteria and viruses quickly and accurately under field conditions still faces huge challenges. Here, we developed a rambutan-like magnetic nanozyme (Fe-DAu@Ir-WGA) by coating Fe3O4 particles with multiple layers of 5 nm Au@Ir nanoparticles (NPs) to provide magnetic enrichment capability and numerous three-dimensional catalytic sites while applying wheat germ agglutinin (WGA) on the outer layer as a broad-spectrum recognition molecule for glycoproteins from respiratory microorganisms. The Fe-DAu@Ir-WGA probe exhibits highly efficient universal enrichment capability for bacteria and viruses (capture efficiency >90%), while effectively eliminating various matrix interferences in complex samples, thereby improving the sensitivity, reliability, and universality of the current nanozyme lateral flow immunoassay (LFA). The developed Fe-DAu@Ir-WGA-LFA can simultaneously detect respiratory bacteria (Streptococcus pneumoniae and Legionella pneumophila) and respiratory virus (SARS-CoV-2) within 38 min, achieving limits of detection of 4 cells/mL for bacteria and 1.8 pg/mL for virus. This represents at least a 555-fold increase in sensitivity compared to traditional AuNP-based LFA and approximately a 116-fold increase compared to an enzyme-linked immunosorbent assay. The practicality of the proposed assay was validated by testing various complex real-world samples and 32 clinical respiratory samples, showcasing its significant potential for broad-spectrum detection of pathogens in clinical and field settings.

Recipients’ age has emerged as a key factor that impacts on acute renal allograft rejection and graft survival. Age-related functional and structural changes in the immune system have been observed, yet the precise influence of aged immunity on kidney transplant remains unclear. In an initial retrospective analysis of clinical data gathered from two major centers in China and Germany, we found a correlation between aging and mitigated rejection outcomes in kidney recipients. To study the mechanism, we performed kidney transplantation on mice and observed attenuated allograft rejection in senescent recipients. Single-cell transcriptome analysis of allograft kidneys indicated a protective role of p21high macrophages in aged mice. Supernatant collected from p21high macrophage primary culture inhibited the cytotoxic function and proliferation of CD8+ T cells. Zfp36 is highly expressed in senescent p21high macrophages. To determine its role in renal allograft rejection, we studied mice with Zfp36 conditionally deleted in macrophages (Zfp36-cKO). These mice developed exacerbated allograft rejection with enhanced IL-27 production and CD8+ T cell hyperactivation. Inhibition of IL-27 with neutralizing antibody or deletion of IL-27 receptor on CD8+ T cells reversed acute renal allograft rejection in Zfp36-cKO mice. Moreover, in vitro silencing Zfp36 with siRNA led to impaired degradation of IL-27 p28 mRNA and a subsequent increase of IL-27 in p21high macrophages. In conclusion, senescent macrophages protect renal allograft rejection by suppressing CD8+ T cells via a Zfp36/IL-27-dependent mechanism. These findings may provide innovative therapeutic strategies for addressing kidney allograft rejection.

Neonicotinoid insecticides (NEOs) find widespread application globally as a safeguard for agricultural production. While these pollutants exhibit toxicity towards non-target organisms and pose potential risks to human health, there is a noticeable dearth of studies documenting the adverse effects of neonicotinoid insecticides (NEOs) specifically in humans. In this study, the concentrations of six NEOs and their five metabolites were measured in the blood samples collected from the normal (n = 130) and obesity (n = 130) cohorts in South China. An evaluation was undertaken to examine the associations between the levels of target analytes and either fasting blood glucose (FBG) or the condition of being overweight. Results showed that the NEOs and their metabolites were frequently detected (63–100

IL-17+ γδ T cells (γδ T17) are kick-starters of inflammation due to their strict immunosurveillance of xenobiotics or cellular damages and rapid response to pro-inflammatory stimulators. IL-27 is a well-recognized pleiotropic immune regulator with potent inhibitory effects on type 17 immune responses. However, its actions on γδ T17 mediated inflammation and the underlying mechanisms are less well understood. Here we find that IL-27 inhibits the production of IL-17 from γδ T cells. Mechanistically, IL-27 promotes lipolysis while inhibits lipogenesis, thus reduces the accumulation of lipids and subsequent membrane phospholipids, which leads to mitochondrial deactivation and ensuing reduction of IL-17. More importantly, Il27ra deficient γδ T cells are more pathogenic in an imiquimod-induced murine psoriasis model, while intracutaneous injection of rmIL-27 ameliorates psoriatic inflammation. In summary, this work uncovered the metabolic basis for the immune regulatory activity of IL-27 in restraining γδ T17 mediated inflammation, which provides novel insights into IL-27/IL-27Ra signaling, γδ T17 biology and the pathogenesis of psoriasis.

Thermogenic brown adipose tissue (BAT) has a positive impact on whole-body metabolism. However, in vivo mapping of BAT activity typically relies on techniques involving ionizing radiation, such as [ 18 F]fluorodeoxyglucose ([ 18 F]FDG) positron emission tomography (PET) and computed tomography (CT). Here we report a noninvasive metabolic magnetic resonance imaging (MRI) approach based on creatine chemical exchange saturation transfer (Cr-CEST) contrast to assess in vivo BAT activity in rodents and humans. In male rats, a single dose of the β 3 -adrenoceptor agonist (CL 316,243) or norepinephrine, as well as cold exposure, triggered a robust elevation of the Cr-CEST MRI signal, which was consistent with the [ 18 F]FDG PET and CT data and 1 H nuclear magnetic resonance measurements of creatine concentration in BAT. We further show that Cr-CEST MRI detects cold-stimulated BAT activation in humans (both males and females) using a 3T clinical scanner, with data-matching results from [ 18 F]FDG PET and CT measurements. This study establishes Cr-CEST MRI as a promising noninvasive and radiation-free approach for in vivo mapping of BAT activity.