Rational design of near-infrared ratiometric fluorescent probes for real-time tracking of β-galactosidase in vivo

β-galactosidase-activated red fluorescent probe assists in the diagnosis of pancreatitis

Acute pancreatitis (AP) is an acute inflammatory disease resulting from abnormal digestion of itself and surrounding organs by pancreatic enzymes caused by a variety of pathogenic factors. When the tissue of a biological organism is afflicted with pancreatitis and experiences swelling, bleeding, and necrotic injuries, the abnormal expression of β-galactosidase (β-Gal) activity becomes one of the main indicators for assisting in the diagnosis of pancreatitis. In this study, a highly specific red fluorescent probe designed for the detection of β-Gal activity has been developed. β-galactoside is used as the enzyme activating group, and the long-wavelength luminescent water-soluble organic molecule NBDOH is used as the luminophore to construct the fluorescent probe NBD-gal. NBD-gal is activated by abnormally overexpressed β-Gal, releasing a strong red fluorescent signal. The new fluorescent probe developed in this study is used to assist in the diagnosis of pancreatitis by detecting abnormal expression of β-Gal activity in vivo. In in vivo imaging experiments, NBD-gal can effectively differentiate between normal nude mice and pancreatitis nude mice. In addition, NBD-gal can be effectively localized in real-time to the pancreas and intestines, which are rich in β-Gal in nude mice. Therefore, NBD-gal exerts great potential in the early diagnosis, treatment, and prevention of biomedical clinical pancreatitis.

Independent organelle and organelle-organelle interactions: essential mechanisms for malignant gynecological cancer cell survival

Different eukaryotic cell organelles (e.g., mitochondria, endoplasmic reticulum, lysosome) are involved in various cancer processes, by dominating specific cellular activities. Organelles cooperate, such as through contact points, in complex biological activities that help the cell regulate energy metabolism, signal transduction, and membrane dynamics, which influence survival process. Herein, we review the current studies of mechanisms by which mitochondria, endoplasmic reticulum, and lysosome are related to the three major malignant gynecological cancers, and their possible therapeutic interventions and drug targets. We also discuss the similarities and differences of independent organelle and organelle-organelle interactions, and their applications to the respective gynecological cancers; mitochondrial dynamics and energy metabolism, endoplasmic reticulum dysfunction, lysosomal regulation and autophagy, organelle interactions, and organelle regulatory mechanisms of cell death play crucial roles in cancer tumorigenesis, progression, and response to therapy. Finally, we discuss the value of organelle research, its current problems, and its future directions.

Design strategies and biological applications of β-galactosidase fluorescent sensor in ovarian cancer research and beyond

Beta-galactosidase (β-galactosidase), a lysosomal hydrolytic enzyme, plays a critical role in the catalytic hydrolysis of glycosidic bonds, leading to the conversion of lactose into galactose. This hydrolytic enzyme is used as a biomarker in various applications, including enzyme-linked immunosorbent assays (ELISAs), gene expression studies, tuberculosis classification, and in situ hybridization. β-Galactosidase abnormalities are linked to various diseases, such as ganglioside deposition, primary ovarian cancer, and cell senescence. Thus, effective detection of β-galactosidase activity may aid disease diagnoses and treatment. Activatable optical probes with high sensitivity, specificity, and spatiotemporal resolution imaging capabilities have become powerful tools for visualization and real time tracking in vivo in the past decade. This manuscript reviews the sensing mechanism, molecular design strategies, and advances of fluorescence probes in the biological application of β-galactosidase, particularly in the field of ovarian cancer research. Current challenges in tracking β-galactosidase and future directions are also discussed.

Glycosidase-targeting small molecules for biological and therapeutic applications

Glycosidases are ubiquitous enzymes that catalyze the hydrolysis of glycosidic linkages in oligosaccharides and glycoconjugates. These enzymes play a vital role in a wide variety of biological events, such as digestion of nutritional carbohydrates, lysosomal catabolism of glycoconjugates, and posttranslational modifications of glycoproteins. Abnormal glycosidase activities are associated with a variety of diseases, particularly cancer and lysosomal storage disorders. Owing to the physiological and pathological significance of glycosidases, the development of small molecules that target these enzymes is an active area in glycoscience and medicinal chemistry. Research efforts carried out thus far have led to the discovery of numerous glycosidase-targeting small molecules that have been utilized to elucidate biological processes as well as to develop effective chemotherapeutic agents. In this review, we describe the results of research studies reported since 2018, giving particular emphasis to the use of fluorescent probes for detection and imaging of glycosidases, activity-based probes for covalent labelling of these enzymes, glycosidase inhibitors, and glycosidase-activatable prodrugs.