Global quantification of newly synthesized proteins reveals cell type- and inhibitor-specific effects on protein synthesis inhibition

Self-Nanoemulsifying Drug Delivery System of Morin: A New Approach for Combating Acute Alcohol Intoxication

Purpose

Acute alcohol intoxication (AAI) is a life-threatening medical condition resulting from excessive alcohol consumption. Our research revealed the potential of morin (MOR) in treating AAI. However, MOR's effectiveness against AAI was hindered by its poor solubility in water and low bioavailability. In this study, our aim was to develop a self-nanoemulsifying drug delivery system (SNEDDS) to enhance MOR's solubility and bioavailability, evaluate its anti-AAI effects, and investigate the underlying mechanism.

Methods

The composition of MOR-loaded self-nanoemulsifying drug delivery system (MOR-SNEDDS) was determined by constructing pseudo-ternary phase diagrams, and its formulation proportion was optimized using the Box-Behnken design. Following characterization of MOR-SNEDDS, we investigated its pharmacokinetics and biodistribution in healthy animals. Additionally, we assessed the anti-AAI effects and gastric mucosal protection of MOR-SNEDDS in an AAI mice model, exploring potential mechanisms.

Results

After breaking down into tiny droplets, the optimized mixture of MOR-SNEDDS showed small droplet size on average, even distribution, strong stability, and permeability. Pharmacokinetic studies indicated that MOR-SNEDDS, compared to a MOR suspension, increased the area under the plasma concentration-time curve (AUC0-t) by 10.43 times. Additionally, studies on how drugs move and are distributed in the body showed that MOR-SNEDDS had an advantage in passively targeting the liver. Moreover, in a mouse model for alcohol addiction, MOR not only decreased alcohol levels by boosting the activity of alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) in the stomach and liver, which counteracted the loss of righting reflex (LORR), but also reduced alcohol-induced damage to the stomach lining by lowering malondialdehyde (MDA) levels and increasing superoxide dismutase (SOD) levels. Furthermore, MOR-SNEDDS notably amplified these effects.

Conclusion

MOR exhibits significant potential as a new medication for treating AAI, and utilizing MOR-SNEDDS with high oral bioavailability represents a promising new strategy in combating AAI.

Systematic Investigation of the Trafficking of Glycoproteins on the Cell Surface

Glycoproteins located on the cell surface play a pivotal role in nearly every extracellular activity. N-glycosylation is one of the most common and important protein modifications in eukaryotic cells, and it often regulates protein folding and trafficking. Glycosylation of cell-surface proteins undergoes meticulous regulation by various enzymes in the endoplasmic reticulum (ER) and the Golgi, ensuring their proper folding and trafficking to the cell surface. However, the impacts of protein N-glycosylation, N-glycan maturity, and protein folding status on the trafficking of cell-surface glycoproteins remain to be explored. In this work, we comprehensively and site-specifically studied the trafficking of cell-surface glycoproteins in human cells. Integrating metabolic labeling, bioorthogonal chemistry, and multiplexed proteomics, we investigated 706 N-glycosylation sites on 396 cell-surface glycoproteins in monocytes, either by inhibiting protein N-glycosylation, disturbing N-glycan maturation, or perturbing protein folding in the ER. The current results reveal their distinct impacts on the trafficking of surface glycoproteins. The inhibition of protein N-glycosylation dramatically suppresses the trafficking of many cell-surface glycoproteins. The N-glycan immaturity has more substantial effects on proteins with high N-glycosylation site densities, while the perturbation of protein folding in the ER exerts a more pronounced impact on surface glycoproteins with larger sizes. Furthermore, for N-glycosylated proteins, their trafficking to the cell surface is related to the secondary structures and adjacent amino acid residues of glycosylation sites. Systematic analysis of surface glycoprotein trafficking advances our understanding of the mechanisms underlying protein secretion and surface presentation.

Mass spectrometry-based methods for investigating the dynamics and organization of the surfaceome: exploring potential clinical implications

INTRODUCTION

Cell-surface proteins are extremely important for many cellular events, such as regulating cell-cell communication and cell-matrix interactions. Aberrant alterations in surface protein expression, modification (especially glycosylation), and interactions are directly related to human diseases. Systematic investigation of surface proteins advances our understanding of protein functions, cellular activities, and disease mechanisms, which will lead to identifying surface proteins as disease biomarkers and drug targets.

AREAS COVERED

In this review, we summarize mass spectrometry (MS)-based proteomics methods for global analysis of cell-surface proteins. Then, investigations of the dynamics of surface proteins are discussed. Furthermore, we summarize the studies for the surfaceome interaction networks. Additionally, biological applications of MS-based surfaceome analysis are included, particularly highlighting the significance in biomarker identification, drug development, and immunotherapies.

EXPERT OPINION

Modern MS-based proteomics provides an opportunity to systematically characterize proteins. However, due to the complexity of cell-surface proteins, the labor-intensive workflow, and the limit of clinical samples, comprehensive characterization of the surfaceome remains extraordinarily challenging, especially in clinical studies. Developing and optimizing surfaceome enrichment methods and utilizing automated sample preparation workflow can expand the applications of surfaceome analysis and deepen our understanding of the functions of cell-surface proteins.