Rabies is a lethal infectious disease caused by rabies virus (RABV). The mortality rate is very high after the appearance of clinical symptoms, with a survival rate of almost 0%. There is presently no cure for rabies. In the present study, we investigated whether the extract of Shougong powder—a calcium powder prepared from gecko that has demonstrated immunomodulatory properties in mice—is an effective treatment for rabies. The antiviral effects of the extract were evaluated both in vitro and in vivo with the cytotoxicity and antiviral assays and by immunofluorescence analysis, quantitative real-time (qRT)-PCR, and western blotting. The results showed that Shougong powder and its extract increased survival rate in RABV-infected mice is up to 60% and 50%, respectively, even in 20 times of LD50, whereas the control groups treated with isoprinosine (IPS) or saline are only 20% and 0% survival (p = .011). qRT-PCR and western blotting analyses showed that the extract strongly inhibited viral mRNA expression and protein synthesis in vitro: expression of the N, P, M, G, and L genes of RABV was decreased by 28.8%-45.0% in the IPS group (p < .05) and by 50.1%-59.0% in the extract group (p < .05) relative to the control group. These results demonstrate that Shougong powder has certain antiviral effects against RABV and can potentially be used for the treatment for rabies.
In three-dimensional (3D) space, an unbiased and systemic view of human specimens between structures and functions is required. However, conventional histological sections from specimens have made only limited progress in exploring intact information about 3D biological tissues. With significant advances in optical physics and chemical engineering, state-of-the-art tissue-clearing methods can revolutionize the intact subcellular level of human tissue histological analysis, from thick human tissues to intact human organs. The present review summarizes the principle of tissue clearing so that a trainee researcher can implement effective human tissue-clearing protocols. Furthermore, this review highlights existing tissue-clearing methods in specific human tissue applications, describes imaging strategies, and presents various efficient computational approaches for processing and visualizing large image data. Finally, potential future directions for developing tissue-clearing methods for human tissues are also discussed.
Cartilage defects resulting from injury or degeneration are a common clinical problem, and due to its avascular nature, articular cartilage has poor self-healing capacity. Three-dimensional (3D) bioprinting has attracted great attention in tissue engineering. Melatonin (MT), a hormone mainly secreted at night, plays an important role in tissue repair. Small extracellular vesicles (sEV) are considered ideal drug delivery vehicles and MT-sEV (sleep-related sEV) have the potential ability to promote cartilage regeneration. Here, biomimetic multilayer scaffolds were fabricated using 3D bioprinting. A double network hydrogel, composed of methacrylated hyaluronic acid and gelatin methacryloyl (HG), was prepared. MT-sEV and HG hydrogel were used to create a cartilage layer. A bone layer was formed using poly(ϵ-caprolactone) and hydroxyapatite ultralong nanowires. Additionally, two bioinks were alternately printed at the interface layer. The results of RNA sequencing revealed the potential regulatory mechanisms. MTsEV showed promotional effects on cell migration, proliferation, chondrogenic differentiation, and extracellular matrix (ECM) deposition. Moreover, MT-sEV altered macrophage polarization and regulated the expression of inflammatory cytokines. In vivo experiments demonstrated that the biomimetic multilayer scaffolds promoted cartilage regeneration. These experiments demonstrated the ability of MT-sEV to regulate the immune microenvironment and promote the secretion of ECM, providing a promising strategy for cartilage regeneration.
Tumor-derived exosomes are crucial for early non-invasive and accurate tumor diagnosis in clinical diagnostics. The development of highly sensitive, simple, and intuitive exosome assays has sparked a research upsurge in clinical diagnostics. Here, we develop a bio-responsive intelligent DNA hydrogel loaded with CRISPR/Cas12a for universal and ultrasensitive detection of the exosomes. The aptamer serves as the target response unit and switch, competitively disintegrating the region of the DNA linkers and then Cas12a/crRNA was released and activated, resulting in a high fluorescent intensity for exosome detection at the detection limit of 119 particles/µL. Moreover, a constructed colorimetric tube is made by loading a colorimetric filter membrane on the tube lid and intelligent DNA hydrogel on the tube bottom, which enables one-pot portable colorimetric detection. Without the need for laboratory instruments and professionals, this strategy allows for naked eye detection with limit of detection as low as 104 particles/µL, and shows great applicability in distinguishing between healthy individuals, pretreatment patients, and post-treatment patients after obtaining a testable analyte. In this study, an ultrasensitive detection platform for exosomes that enables one-step sensing and dual signal output was introduced. The findings here suggest that this platform is a promising tool for the application of liquid biopsy based on exosomes in clinical diagnosis.
Testicular microcirculation is closely related to spermatogenic function and seminiferous tubular function. The diagnosis and monitoring of testicular diseases can be associated with testicular microcirculation; however, there are currently no effective non-invasive methods for super-resolution imaging of testicular microcirculation. In this study, we introduced state-of-the-art graph-based tracking with the Kalman motion model algorithm to non-invasively image human testicular microcirculation for the first time with a regular frame-rate clinical ultrasound imaging system (37 Hz). Two distinct testicular vessels with an 81 µm separation were resolved in the testicular vasculature, surpassing all other imaging modalities. In a retrospective study, we performed contrast-enhanced ultrasound examinations(CEUS) and ultrasound localizationmicroscopy (ULM) processing on the included 76 infertile patients and 15 healthy controls from August 2021 to May 2023 and obtained super-resolution images of testicular microcirculation with sub-diffraction resolution. Through the results of one-way analysis of variance tests and receiver operating characteristic analyses,we found that the ULM-based parameters hold promise as clinical guidance for differentiating between non-obstructive and obstructive male infertility. The mean vessel diameter achieved an area under the curve (AUC) of 0.920 (95%confidence interval [CI]: 0.847–0.994, p < .001) with a cut-off value of 170.9 µm in oligoasthenospermia, and an AUC of 0.952 (95% CI: 0.875–1.000, p < .001) with a cut-off value of 169.9 µm in azoospermia patients, respectively, addressing a significant clinical challenge.
Fluorescent dyes that emit in the second near-infrared (NIR-II, 1000–3000 nm) region have provided significant advances toward real-time and high-resolution imaging of vessel and lymphatic system. However, in vivo NIR-II tracking of the fate of labeled cells still remains challenging. Here, we develop a shielding unit–donor–acceptor–donor–shielding unit (S-D-A-D-S) NIR-II fluorophore (FE-4ZW) with zwitterionic terminal groups for high-efficiency cell labeling without using cell-penetrating peptides, which provides for enhanced noninvasive in vivo determination of the location of cell migration. The tethering terminal sulfoammonium inner salts are featured with its high affinity for cell membranes, thereby enabling the stable labeling even for fixed cells. The fate of transplanted stem cell and the tumor cell migration along lymphatic system in brain or periphery tissues are clearly monitored by the cell-internalized FE-4ZW. We also confirmed that a clinically used surfactant, D-α-tocopheryl polyethylene glycol-1000 succinate, can reduce the liver and spleen uptake of FE-4ZW. The fluorophore design strategy and cell-labeling technology reported here open a new realm in the visualization of cell migration and insight into the relocation process, thereby ultimately providing an opportunity to investigate in greater detail of the underlying mechanisms of stem cell therapy and tumor metastasis.
Periodontitis development is strongly associated with the succession of the oral microbiome. However, the knowledge about the succession of the oral microbiome in the development of periodontitis remains insufficient. In the present study, an analysis was conducted on the succession of tongue back, the saliva (Sal) microbiome, and gingival crevicular fluid (GCF) from healthy individuals and patients with mild (CPL), moderate (CPM), severe chronic (CPH), and generalized aggressive periodontitis (GAgP). The composition and structure of the oral microbiome gradually changed with the increasing severity of periodontitis, among which GCF showed the highest correlation with periodontitis. With an ecological preference, pathogens in the mouth varied with the development of periodontitis. In healthy and CPL patients, Sal-derived microorganisms accounted for a large proportion of GCF but exhibited a decrease in patients with CPM, CPH, and GAgP. Permutation and time course sequencing analysis revealed that a variety of microorganisms changed with the severity of periodontitis. A majority of these microorganisms are closely related to clinical periodontal indices. Ecological analysis suggested that the composition of oral microbial communities at different stages of periodontitis is controlled by random processes. The comparison ofmicrobial interaction networks demonstrated that a series of key microorganisms drive oral health to severe periodontitis. In this study, the relationship between the succession process of the oral microbiota and the development of periodontitis was revealed.