Ionic Liquid Gating Induces Anomalous Permeation through Membrane Channel Proteins.

Membrane channel proteins (MCPs) play key roles in matter transport through cell membranes and act as major targets for vaccines and drugs. For emerging ionic liquid (IL) drugs, a rational understanding of how ILs affect the structure and transport function of MCP is crucial to their design. In this work, GPU-accelerated microsecond-long molecular dynamics simulations were employed to investigate the modulating mechanism of ILs on MCP. Interestingly, ILs prefer to insert into the lipid bilayer and channel of aquaporin-2 (AQP2) but adsorb on the entrance of voltage-gated sodium channels (Nav). Molecular trajectory and free energy analysis reflect that ILs have a minimal impact on the structure of MCPs but significantly influence MCP functions. It demonstrates that ILs can decrease the overall energy barrier for water through AQP2 by 1.88 kcal/mol, whereas that for Na+ through Nav is increased by 1.70 kcal/mol. Consequently, the permeation rates of water and Na+ can be enhanced and reduced by at least 1 order of magnitude, respectively. Furthermore, an abnormal IL gating mechanism was proposed by combining the hydrophobic nature of MCP and confined water/ion coordination effects. More importantly, we performed experiments to confirm the influence of ILs on AQP2 in human cells and found that treatment with ILs significantly accelerated the changes in cell volume in response to altered external osmotic pressure. Overall, these quantitative results will not only deepen the understanding of IL-cell interactions but may also shed light on the rational design of drugs and disease diagnosis.

Aspartate ß-Hydroxylase Is Upregulated in Head and Neck Squamous Cell Carcinoma and Regulates Invasiveness in Cancer Cell Models.

Aspartate ß-hydroxylase (ASPH) is a protein associated with malignancy in a wide range of tumors. We hypothesize that inhibition of ASPH activity could have anti-tumor properties in patients with head and neck cancer. In this study, we screened tumor tissues of 155 head and neck squamous cell carcinoma (HNSCC) patients for the expression of ASPH using immunohistochemistry. We used an ASPH inhibitor, MO-I-1151, known to inhibit the catalytic activity of ASPH in the endoplasmic reticulum, to show its inhibitory effect on the migration of SCC35 head and neck cancer cells in cell monolayers and in matrix-embedded spheroid co-cultures with primary cancer-associated fibroblast (CAF) CAF 61137 of head and neck origin. We also studied a combined effect of MO-I-1151 and HfFucCS, an inhibitor of invasion-blocking heparan 6-O-endosulfatase activity. We found ASPH was upregulated in HNSCC tumors compared to the adjacent normal tissues. ASPH was uniformly high in expression, irrespective of tumor stage. High expression of ASPH in tumors led us to consider it as a therapeutic target in cell line models. ASPH inhibitor MO-I-1151 had significant effects on reducing migration and invasion of head and neck cancer cells, both in monolayers and matrix-embedded spheroids. The combination of the two enzyme inhibitors showed an additive effect on restricting invasion in the HNSCC cell monolayers and in the CAF-containing co-culture spheroids. We identify ASPH as an abundant protein in HNSCC tumors. Targeting ASPH with inhibitor MO-I-1151 effectively reduces CAF-mediated cellular invasion in cancer cell models. We propose that the additive effect of MO-I-1151 with HfFucCS, an inhibitor of heparan 6-O-endosulfatases, on HNSCC cells could improve interventions and needs to be further explored.

Preparation of Rehmanniae Radix Praeparata polysaccharide iron(III) complex and evaluation of its biological activity.

This study extracted and purified a polysaccharide from Rehmanniae radix praeparata (RGP) with an average molecular weight. The structural characteristics of RGP and its iron(III) complex, RGP-Fe(III), were examined for their antioxidant properties and potential in treating iron deficiency anemia (IDA). Analysis revealed that RGP comprised Man, Rha, Gal, and Xyl, with a sugar residue skeleton featuring 1→3; 1→2, 3; and 1→2, 3, 4 linkages, among others. RGP-Fe(III) had a molecular weight of 4.39×104 Da. Notably, RGP-Fe(III) exhibited superior antioxidant activity compared to RGP alone. In IDA rat models, treatment with RGP-Fe(III) led to increased weight gain, restoration of key blood parameters including hemoglobin, red blood cells, and mean hemoglobin content, elevated serum iron levels, and decreased total iron-binding capacity. Histological examination revealed no observable toxic effects of RGP-Fe(III) on the liver and spleen. These findings suggest the potential of RGP-Fe(III) as a therapeutic agent for managing IDA and highlight its promising antioxidant properties.

Tracking the effects of PLGA-based nanoparticles on protein expression in living cells through quantitative proteomics.

Mass spectrometry (MS)-based proteomics can identify and quantify the differential abundance of expressed proteins in parallel, and bottom-up proteomic approaches are even approaching comprehensive coverage of the complex eukaryotic proteome. Protein-nanoparticle (NP) interactions have been extensively studied owing to their importance in biological applications and nanotoxicology. However, the proteome-level effects of NPs on cells have received little attention, although changes in protein abundance can reflect the direct effects of nanocarriers on protein expression. Herein, we investigated the effect of PLGA-based NPs on protein expression in HepG2 cells using a label-free quantitative proteomics approach with data independent acquisition (DIA). The percentage of two-fold change in the protein expression of cells treated with PLGA-based NPs was less than 10.15% during a 6 hour observation period. Among the changed proteins, we found that dynamic proteins involved in cell division, localization, and transport are more likely to be more susceptible to PLGA-based NPs.

Overexpression of a Fragaria vesca NAM, ATAF, and CUC (NAC) Transcription Factor Gene (FvNAC29) Increases Salt and Cold Tolerance in Arabidopsis thaliana.

The NAC (NAM, ATAF1/2, CUC2) family of transcription factors (TFs) is a vital transcription factor family of plants. It controls multiple parts of plant development, tissue formation, and abiotic stress response. We cloned the FvNAC29 gene from Fragaria vesca (a diploid strawberry) for this research. There is a conserved NAM structural domain in the FvNAC29 protein. The highest homology between FvNAC29 and PaNAC1 was found by phylogenetic tree analysis. Subcellular localization revealed that FvNAC29 is localized onto the nucleus. Compared to other tissues, the expression level of FvNAC29 was higher in young leaves and roots. In addition, Arabidopsis plants overexpressing FvNAC29 had higher cold and high-salinity tolerance than the wild type (WT) and unloaded line with empty vector (UL). The proline and chlorophyll contents of transgenic Arabidopsis plants, along with the activities of the antioxidant enzymes like catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) under 200 mM NaCl treatment or -8 °C treatment, were higher than those activities of the control. Meanwhile, malondialdehyde (MDA) and the reactive oxygen species (ROS) content were higher in the WT and UL lines. FvNAC29 improves transgenic plant resistance to cold and salt stress by regulating the expression levels of AtRD29a, AtCCA1, AtP5CS1, and AtSnRK2.4. It also improves the potential to tolerate cold stress by positively regulating the expression levels of AtCBF1, AtCBF4, AtCOR15a, and AtCOR47. These findings suggest that FvNAC29 may be related to the processes and the molecular mechanisms of F. vesca response to high-salinity stress and LT stress, providing a comprehensive understanding of the NAC TFs.

Identification of Bromophenols' glucuronidation and its induction on UDP- glucuronosyltransferases isoforms.

Bromophenols (BPs) are prominent environmental pollutants extensively utilized in aquaculture, pharmaceuticals, and chemical manufacturing. This study aims to identify UDP- glucuronosyltransferases (UGTs) isoforms involved in the metabolic elimination of BPs. Mono-glucuronides of BPs were detected in human liver microsomes (HLMs) incubated with the co-factor uridine-diphosphate glucuronic acid (UDPGA). The glucuronidation metabolism reactions catalyzed by HLMs followed Michaelis-Menten or substrate inhibition kinetics. Recombinant enzymes and inhibition experiments with chemical reagents were employed to phenotype the principal UGT isoforms participating in BP glucuronidation. UGT1A6 emerged as the major enzyme in the glucuronidation of 4-Bromophenol (4-BP), while UGT1A1, UGT1A6, and UGT1A8 were identified as the most essential isoforms for metabolizing 2,4-dibromophenol (2,4-DBP). UGT1A1, UGT1A8, and UGT2B4 were deemed the most critical isoforms in the catalysis of 2,4,6-tribromophenol (2,4,6-TBP) glucuronidation. Species differences were investigated using the liver microsomes of pig (PLM), rat (RLM), monkey (MyLM), and dog (DLM). Additionally, 2,4,6-TBP effects on the expression of UGT1A1 and UGT2B7 in HepG2 cells were evaluated. The results demonstrated potential induction of UGT1A1 and UGT2B7 upon exposure to 2,4,6-TBP at a concentration of 50 µM. Collectively, these findings contribute to elucidating the metabolic elimination and toxicity of BPs.

Proteomic analysis reveals that the co-ordination of cytosolic and mitochondrial pathways is beneficial for sabinene biosynthesis in engineered Saccharomyces cerevisiae.

Reconstruction and optimization of biosynthetic pathways can help to overproduce target chemicals in microbial cell factories based on genetic engineering. However, the perturbation of biosynthetic pathways on cellular metabolism is not well investigated and profiling the engineered microbes remains challenging. The rapid development of omics tools has the potential to characterize the engineered microbial cell factory. Here, we performed label-free quantitative proteomic analysis and metabolomic analysis of engineered sabinene overproducing Saccharomyces cerevisiae strains. Combined metabolic analysis andproteomic analysis of targeted mevalonate (MVA) pathway showed that co-ordination of cytosolic and mitochondrial pathways had balanced metabolism, and genome integration of biosynthetic genes had higher sabinene production with less MVA enzymes. Furthermore, comparative proteomic analysis showed that compartmentalized mitochondria pathway had perturbation on central cellular metabolism. This study provided an omics analysis example for characterizing engineered cell factory, which can guide future regulation of the cellular metabolism and maintaining optimal protein expression levels for the synthesis of target products.

Predicting the risk of 1-year mortality among patients hospitalized for acute heart failure in China.

BACKGROUND: We aimed to develop and validate a model to predict 1-year mortality risk among patients hospitalized for acute heart failure (AHF), build a risk score and interpret its application in clinical decision making. METHODS: By using data from China Patient-Centred Evaluative Assessment of Cardiac Events Prospective Heart Failure Study, which prospectively enrolled patients hospitalized for AHF in 52 hospitals across 20 provinces, we used multivariate Cox proportional hazard model to develop and validate a model to predict 1-year mortality. RESULTS: There were 4,875 patients included in the study, 857 (17.58%) of them died within 1-year following discharge of index hospitalization. A total of 13 predictors were selected to establish the prediction model, including age, medical history of chronic obstructive pulmonary disease and hypertension, systolic blood pressure, Kansas City Cardiomyopathy Questionnaire-12 score, angiotensin converting enzyme inhibitor or angiotensin receptor blocker at discharge, discharge symptom, N-terminal pro-brain natriuretic peptide, high-sensitivity troponin T, serum creatine, albumin, blood urea nitrogen, and highly sensitive C-reactive protein. The model showed a high performance on discrimination (C-index was 0.759 [95% confidence interval: 0.739, 0.778] in development cohort and 0.761 [95% confidence interval: 0.731, 0.791] in validation cohort), accuracy, calibration, and outperformed than several existed risk scores. A point-based risk score was built to stratify low- (0-12), intermediate- (13-16), and high-risk group (≥17) among patients. CONCLUSIONS: A prediction model using readily available predictors was developed and internal validated to predict 1-year mortality risk among patients hospitalized for AHF. It may serve as a useful tool for individual risk stratification and informing decision making to improve clinical care.

A Cell-Permeable Photosensitizer for Selective Proximity Labeling and Crosslinking of Aggregated Proteome.

Intracellular proteome aggregation is a ubiquitous disease hallmark with its composition associated with pathogenicity. Herein, this work reports on a cell-permeable photosensitizer (P8, Rose Bengal derivative) for selective photo induced proximity labeling and crosslinking of cellular aggregated proteome. Rose Bengal is identified out of common photosensitizer scaffolds for its unique intrinsic binding affinity to various protein aggregates driven by the hydrophobic effect. Further acetylation permeabilizes Rose Bengal to selectively image, label, and crosslink aggregated proteome in live stressed cells. A combination of photo-chemical, tandem mass spectrometry, and protein biochemistry characterizations reveals the complexity in photosensitizing pathways (both Type I & II), modification sites and labeling mechanisms. The diverse labeling sites and reaction types result in highly effective enrichment and identification of aggregated proteome. Finally, aggregated proteomics and interaction analyses thereby reveal extensive entangling of proteostasis network components mediated by HSP70 chaperone (HSPA1B) and active participation of autophagy pathway in combating proteasome inhibition. Overall, this work exemplifies the first photo induced proximity labeling and crosslinking method (namely AggID) to profile intracellular aggregated proteome and analyze its interactions.

Perceived Economic Burden, Mortality, and Health Status in Patients With Heart Failure.

Importance: In the face of an emerging heart failure (HF) epidemic, describing the association between perceived economic burden (PEB) and health care outcomes is an important step toward more equitable and achievable care. Objectives: To examine the association between PEB and risk of 1-year clinical outcomes and HF-specific health status in patients with acute decompensated HF. Design, Setting, and Participants: This prospective, multicenter, hospital-based cohort study prospectively enrolled adult patients hospitalized for acute decompensated HF at 52 hospitals in China from August 2016 to May 2018, with 1-year follow-up. Data were analyzed on June 17, 2022. Exposure: Perceived economic burden, categorized as severe (cannot undertake expenses), moderate (can almost undertake expenses), or little (can easily undertake expenses). Main Outcomes and Measures: The clinical outcomes of the study were 1-year all-cause death and rehospitalization for HF. Heart failure-specific health status was assessed by the 12-Item Kansas City Cardiomyopathy Questionnaire (KCCQ-12). Results: Among 3386 patients, median age was 67 years (IQR, 58-75 years) and 2116 (62.5%) were men. Of these patients, 404 (11.9%) had severe PEB; 2021 (59.7%), moderate PEB; and 961 (28.4%), little PEB. Compared with patients with little PEB, those with severe PEB had increased risk of 1-year mortality (hazard ratio [HR], 1.61; 95% CI, 1.21-2.13; P < .001) but not 1-year HF rehospitalization (HR, 1.21; 95% CI, 0.98-1.49; P = .07). The mean (SD) adjusted KCCQ-12 score was lowest in patients with severe PEB and highest in patients with little PEB at baseline (40.0 [1.7] and 50.2 [1.0] points, respectively; P < .001) and at each visit (eg, 12 months: 61.5 [1.6] and 75.5 [0.9] points respectively; P < .001). Patients reporting severe PEB had a clinically significant lower 1-year KCCQ-12 score compared with those reporting little PEB (mean difference, -11.3 points; 95% CI, -14.9 to -7.6 points; P < .001). Conclusions and Relevance: In this cohort study of patients with acute decompensated HF, greater PEB was associated with higher risk of mortality and poorer health status but not with risk of HF rehospitalization. The findings suggest that PEB may serve as a convenient tool for risk estimation and as a potential target for quality-improvement interventions for patients with HF.

Randomly Layered Superstructure of In2O3 Truncated Nano-Octahedra and Its High-Pressure Behavior.

This study outlines the preparation and characterization of a unique superlattice composed of indium oxide (In2O3) vertex-truncated nano-octahedra, along with an exploration of its response to high-pressure conditions. Transmission electron microscopy and scanning transmission electron microscopy were employed to determine the average circumradius (15.2 nm) of these vertex-truncated building blocks and their planar superstructure. The resilience and response of the superlattice to pressure variations, peaking at 18.01 GPa, were examined using synchrotron-based wide-angle X-ray scattering (WAXS) and small-angle X-ray scattering (SAXS) techniques. The WAXS data revealed no phase transitions, reinforcing the stability of the 2D superlattice composed of random layers in alignment with a p31m planar symmetry as discerned by SAXS. Notably, the SAXS data also unveiled a pressure-induced, irreversible translation of octahedra and ligand interaction occurring within the random layer. Through our examination of these pressure-sensitive behaviors, we identified a distinctive translation model inherent to octahedra and observed modulation of the superlattice cell parameter induced by pressure. This research signifies a noteworthy advancement in deciphering the intricate behaviors of 2D superlattices under a high pressure.

Glycerol Electrooxidation over Precision-Synthesized Gold Nanocrystals with Different Surface Facets.

Electrochemical glycerol oxidation (EGO) emerges as a promising route to valorize glycerol, an underutilized byproduct from biodiesel production, into value-added chemicals. This study employed three types of gold (Au) nanocrystals with controlled shapes to elucidate the facet-dependent electrocatalytic behavior in EGO. Octahedral, rhombic dodecahedral, and cubic Au nanocrystals with {111}, {110}, and {100} facets, respectively, were precisely synthesized with uniform size and shape. Rhombic dodecahedra exhibited the lowest onset potential for EGO due to facile AuOH formation, while octahedra showed enhanced electrochemical activity for glycerol oxidation and resistance to poisoning. In-situ FTIR analysis revealed that Au {111} surfaces selectively favored C2 products, whereas Au {100} surfaces promoted C3 product formation, highlighting the significant effect of facet orientation on EGO performance and informing catalyst design.

Dynamic stability analysis method of anchored rocky slope considering seismic deterioration effect.

The seismic deterioration effects of anchor cables and slope structural planes are often neglected in the dynamic stability analysis of anchored rocky slopes to the extent that the stability of slopes is overestimated. In this paper, a dynamic calculation method for anchored rocky slopes considering the seismic deterioration effect is established, and a stability evaluation method for anchored rocky slopes based on the Gaussian mixture model is proposed. The seismic deterioration effect on the stability of anchored rocky slopes is quantitatively analyzed with an engineering example, and the relationship between seismic intensity and the failure probability of slopes is clarified. The results show that compared with the calculation method without considering the seismic deterioration effect, the minimum safety factor and post-earthquake safety factor obtained by the proposed method in this paper are smaller. The number of seismic deteriorations of the slope is used as the number of components of the Gaussian mixture model to construct the failure probability model of the slope, which can accurately predict the failure probability of anchored rocky slopes. The research results significantly improve the accuracy of the stability calculation of anchored rocky slopes, which can be used to guide the seismic design and safety assessment of anchored rocky slopes.

High remnant cholesterol as a risk factor for developing chronic kidney disease in patients with prediabetes and type 2 diabetes: a cross-sectional study of a US population.

AIMS: To examine any potential links between remnant cholesterol (RC) and comorbid chronic kidney disease (CKD) in individuals with prediabetes and type 2 diabetes mellitus (T2DM). METHODS: We used data from 2709 American people aged > 20 years from the National Health and Nutrition Examination Survey (NHANES) during 2011-2018. Subjects were categorized according to whether they had comorbid CKD. Logistic regression models and smoothed curve fitting methods were employed to assess the association of RC with comorbid CKD in patients with prediabetes and T2DM. RESULTS: The 2709 participants included 1473 patients with T2DM and 1236 with prediabetes [impaired glucose tolerance (IGT) and impaired fasting glucose (IFG)], of whom 744 (27.46%) had comorbid CKD. In multivariate-adjusted analysis, both RC and triglycerides (TG) were significantly associated with an increased risk of comorbid CKD, and a 1 mmol/L elevation of RC increased the risk by 38.1% [OR (95% CI) 1.636 (1.242, 2.156)], which was higher than the risk associated with a 1 mmol/L increase in TG [1.255 (1.106, 1.424)]. Additionally, those in the highest quartile of RC had a 43.6% higher risk of concomitant renal damage than those in the lowest quartile. RC was linearly and positively associated with the incidence of comorbid CKD in this population. CONCLUSIONS: RC is an independent risk factor for comorbid CKD in patients with prediabetes and T2DM. This finding provides a novel insight into the management and early detection of renal disease in patients with impaired glucose metabolism.

Phosphorylated CPI-17 and MLC2 as Biomarkers of Coronary Artery Spasm-Induced Sudden Cardiac Death.

Coronary artery spasm (CAS) plays an important role in the pathogeneses of various ischemic heart diseases and has gradually become a common cause of life-threatening arrhythmia. The specific molecular mechanism of CAS has not been fully elucidated, nor are there any specific diagnostic markers for the condition. Therefore, this study aimed to examine the specific molecular mechanism underlying CAS, and screen for potential diagnostic markers. To this end, we successfully constructed a rat CAS model and achieved in vitro culture of a human coronary-artery smooth-muscle cell (hCASMC) contraction model. Possible molecular mechanisms by which protein kinase C (PKC) regulated CAS through the C kinase-potentiated protein phosphatase 1 inhibitor of 17 kDa (CPI-17)/myosin II regulatory light chain (MLC2) pathway were studied in vivo and in vitro to screen for potential molecular markers of CAS. We performed hematoxylin and eosin staining, myocardial zymogram, and transmission electron microscopy to determine myocardial and coronary artery injury in CAS rats. Then, using immunohistochemical staining, immunofluorescence staining, and Western blotting, we further demonstrated a potential molecular mechanism by which PKC regulated CAS via the CPI-17/MLC2 pathway. The results showed that membrane translocation of PKCα occurred in the coronary arteries of CAS rats. CPI-17/MLC2 signaling was observably activated in coronary arteries undergoing CAS. In addition, in vitro treatment of hCASMCs with angiotensin II (Ang II) increased PKCα membrane translocation while consistently activating CPI-17/MLC2 signaling. Conversely, GF-109203X and calphostin C, specific inhibitors of PKC, inactivated CPI-17/MLC2 signaling. We also collected the coronary artery tissues from deceased subjects suspected to have died of CAS and measured their levels of phosphorylated CPI-17 (p-CPI-17) and MLC2 (p-MLC2). Immunohistochemical staining was positive for p-CPI-17 and p-MLC2 in the tissues of these subjects. These findings suggest that PKCα induced CAS through the CPI-17/MLC2 pathway; therefore, p-CPI-17 and p-MLC2 could be used as potential markers for CAS. Our data provide novel evidence that therapeutic strategies against PKC or CPI-17/MLC2 signaling might be promising in the treatment of CAS.

CFD simulation of cannabidiol delivery through microneedle patches.

This study investigates the efficiency and influence of microneedle parameters, specifically Needle Point Angle (a) and Needle Height (h), on the diffusion of Cannabidiol (CBD) across varying skin depths. Utilizing the Latin Hypercube Sampling method, twelve distinct cases were analyzed. Observations reveal a consistent high concentration of CBD delivered via the microneedle patch, with a notable decrease in concentration as the depth increases, displaying a non-linear trend. Multivariate polynomial regression offers a quantitative relationship between the variables, with the third-order bivariate fitting providing the most accurate representation. Compared to other CBD delivery mechanisms, microneedle patches present enhanced CBD concentrations, circumventing challenges faced by other methods such as dosage inaccuracy, systemic absorption issues, and CBD degradation. The results highlight the potential of microneedle patches as a promising avenue for optimized transdermal drug delivery.

Association of cumulative health status with subsequent mortality in patients with acute heart failure.

OBJECTIVE: We aim to examine the association between long-term cumulative health status and subsequent mortality among patients with acute heart failure (HF). METHODS: Based on a national prospective cohort study of patients hospitalized for HF, we measured health status by Kansas City Cardiomyopathy Questionnaire (KCCQ)-12 at 4 time points, i.e. admission, 1-,6- and 12-month after discharge. Cumulative health status was interpreted by cumulative KCCQ-12 score and cumulative times of good health status. Outcomes included subsequent all-cause and cardiovascular mortality. Multivariable Cox proportional hazard models were performed to examine the association between cumulative health status and subsequent mortality. RESULTS: Totally, 2328 patients (36.7% women and median age 66 [IQR: 56-75] years) were included, the median follow-up was 4.34 (IQR: 3.93-4.96) years. Compared with Quartile 4, the lowest Quartile 1 had the highest HR for all-cause mortality (2.96; 95% CI: 2.26-3.87), followed by Quartile 2 (1.79; 95% CI: 1.37-2.34) and Quartile 3 (1.62; 95% CI: 1.23-2.12). Patients with 0-time of good health status had the highest risk of all-cause mortality (HR: 2.41, 95% CI: 1.69-3.46) compared with patients with 4-times of good health status. Similar associations persisted for cardiovascular mortality. CONCLUSIONS: A greater burden of cumulative health status indicated worse survival among patients hospitalized for HF. Repeated KCCQ measurements could be helpful to monitor long-term health status and identify patients vulnerable to death. Clinical Trial Registration: www.clinicaltrials.gov (NCT02878811).

Progress, Challenges and Opportunities of NMR and XL-MS for Cellular Structural Biology.

The validity of protein structures and interactions, whether determined under ideal laboratory conditions or predicted by AI tools such as Alphafold2, to precisely reflect those found in living cells remains to be examined. Moreover, understanding the changes in protein structures and interactions in response to stimuli within living cells, under both normal and disease conditions, is key to grasping proteins' functionality and cellular processes. Nevertheless, achieving high-resolution identification of these protein structures and interactions within living cells presents a technical challenge. In this Perspective, we summarize the recent advancements in in-cell nuclear magnetic resonance (NMR) and in vivo cross-linking mass spectrometry (XL-MS) for studying protein structures and interactions within a cellular context. Additionally, we discuss the challenges, opportunities, and potential benefits of integrating in-cell NMR and in vivo XL-MS in future research to offer an exhaustive approach to studying proteins in their natural habitat.