Rational design of a high-affinity fluorescent probe for visualizing monitoring the amyloid ß clearance effect of anti-Alzheimer's disease drug candidates.

Beta-amyloid (Aß), the most pivotal pathological hallmark for Alzheimer's disease (AD) diagnosis and drug evaluation, was recognized by TZ095, a high-affinity fluorescent probe developed by rational molecular design. With a TICT mechanism, TZ095 exhibited remarkable affinity with Aß aggregates (Kd = 81.54 nM for oligomers; Kd = 66.70 nM for fibril) and substantial fluorescence enhancement (F/F0 = 44), enabling real-time monitoring of Aß in live cells and nematodes. Significantly, this work used TZ095 to construct a new protocol that can quickly and conveniently monitor Aß changes at the cellular and nematode levels to evaluate the anti-AD efficacy of candidate compounds, and four reported Aß-lowering drug candidates were administrated for validation. Imaging data demonstrated that TZ095 can visually and quantitatively track the effect of Aß elimination after drug treatment. Furthermore, TZ095 excelled in ex vivo histological staining of 12-month-old APP/PS1 mouse brains, accurately visualizing Aß plaques. Integrating CUBIC technology, TZ095 facilitated whole-brain, 3D imaging of Aß distribution in APP/PS1 mice, enabling high-resolution in situ analysis of Aß plaques. Collectively, these innovative applications of TZ095 offer a promising strategy for rapid, convenient, and real-time monitoring of Aß levels in preclinical therapeutic assessments.

ATF7IP2, a meiosis-specific partner of SETDB1, is required for proper chromosome remodeling and crossover formation during spermatogenesis.

Meiotic crossovers are required for the faithful segregation of homologous chromosomes and to promote genetic diversity. However, it is unclear how crossover formation is regulated, especially on the XY chromosomes, which show a homolog only at the tiny pseudoautosomal region. Here, we show that ATF7IP2 is a meiosis-specific ortholog of ATF7IP and a partner of SETDB1. In the absence of ATF7IP2, autosomes show increased axis length and more crossovers; however, many XY chromosomes lose the obligatory crossover, although the overall XY axis length is also increased. Additionally, meiotic DNA double-strand break formation/repair may also be affected by altered histone modifications. Ultimately, spermatogenesis is blocked, and male mice are infertile. These findings suggest that ATF7IP2 constraints autosomal axis length and crossovers on autosomes; meanwhile, it also modulates XY chromosomes to establish meiotic sex chromosome inactivation for cell-cycle progression and to ensure XY crossover formation during spermatogenesis.

In Silico Analysis of nsSNPs of Human KRAS Gene and Protein Modeling Using Bioinformatic Tools.

The KRAS gene belongs to the RAS family and codes for 188 amino acid residues of KRAS protein, with a molecular mass of 21.6 kD. Non-synonymous single-nucleotide polymorphisms (nsSNPs) have been identified within the coding region in which some are associated with different diseases. However, structural changes are not well defined yet. In this study, we first categorized SNPs in the KRAS coding area and then used computational methods to determine their impact on the protein structure and stability. In addition, the three-dimensional model of KRAS was taken from the Protein Data Bank for structural modeling. Furthermore, genomic data were extracted from a variety of sources, including the 1000 Genome Project, dbSNPs, and ENSEMBLE, and assessed through in silico methods. Based on various tools used in this study, 10 out of 48 missense SNPs with rsIDs were found deleterious. The substitution of alanine for proline at position 146 pushed several residues toward the center of the protein. Arginine instead of leucine has a minor effect on protein structure and stability. In addition, the substitution of proline for leucine at the 34th position disrupted the structure and led to a bigger size than the wild-type protein, hence interrupting the protein interaction. Using the well-intended computational approach and applying several bioinformatic tools, we characterized and identified most damaging nsSNPs and further explored the structural dynamics and stability of KRAS protein.

MEIOK21 regulates oocyte quantity and quality via modulating meiotic recombination.

The reproductive life span of females is largely determined by the number and quality of oocytes. Previously, we identified MEIOK21 as a meiotic recombination regulator required for male fertility. Here, we characterize the important roles of MEIOK21 in regulating female meiosis and oocyte number and quality. MEIOK21 localizes at recombination sites as a component of recombination bridges in oogenesis like in spermatogenesis. Meiok21-/- female mice show subfertility. Consistently, the size of the primordial follicle pool in Meiok21-/- females is only ~40% of wild-type females because a great number of oocytes with defects in meiotic recombination and/or synapsis are eliminated. Furthermore, the numbers of primordial and growing follicles show a more marked decrease in an age-dependent manner compared with wild-type females. Further analysis shows Meiok21-/- oocytes also have reduced rates of germinal vesicle breakdown and the first polar body extrusion when cultured in vitro, indicating poor oocyte quality. Additionally, Meiok21-/- oocytes have more chromosomes bearing a single distally localized crossover (chiasmata), suggesting a possible defect in crossover maturation. Taken together, our findings indicate critical roles for MEIOK21 in ensuring the number and quality of oocytes in the follicles.

Mechanism of action of Panax notoginoside against lung cancer in mice based on response to CTSB gene.

BACKGROUND: This study aimed to investigate the mechanism of action of Panax notoginoside (PNS) against lung cancer and inhibition of lung cancer cell proliferation by the drug at different concentrations in a mouse model, considering the cathepsin B (CTSB) gene as a target. METHODS: The mice were randomly assigned into the following five groups: normal control, tumor-bearing, low-dose Panax notoginoside (TSPN), medium-dose TSPN, and high-dose TSPN. All mice were treated with physiological saline or TSPN at different concentrations for 28 days consecutively by gavage. The tumor size was measured, the tumor growth was observed, and the survival curve was drawn. At different time points, the expression of the CTSB gene was detected using quantitative fluorescent polymerase chain reaction, Western blot analysis, and indirect immunofluorescence. The serum indices, such as carcinoembryonic antigen (CEA), neuron-specific enolase (NSE), and Soluble fragment of cytokeratin 19 (CYFRA21), were detected by enzyme-linked immunosorbent assay. RESULTS: In vivo, PNS could directly inhibit the expression of the CTSB gene in tumors of mice, limit tumor growth, and alter tumor-related indices, such as CEA, NSE, and CYFRA21 levels, in the serum to different extents simultaneously. CONCLUSION: CTSB gene was closely related to the pathogenesis of lung cancer. PNS could act on the CTSB gene, downregulate the expression of CTSB in lung cancer cells, inhibit the proliferation and invasion of tumors, and prolong the survival period.

Royal jelly-derived proteins enhance proliferation and migration of human epidermal keratinocytes in an in vitro scratch wound model.

BACKGROUND: Skin injury is inevitable in daily life. In recent years, with the increasing morbidity of diseases such as diabetes and metabolic disorders, chronic wounds have become a considerable challenge in clinical practice. Royal jelly, reported to have multifarious biological and physiological properties, has been used as a remedy for a variety of wounds since ancient times. However, the active components and mechanisms underlying the wound-healing properties of royal jelly are still largely unknown. METHODS: Water-soluble proteins of royal jelly were fractionated and investigated for the proliferative and migratory effects on human epidermal keratinocytes (HaCaT) in an in vitro wound healing model. The proteins present in bioactive fractions were characterised and quantified using Label-free protein quantification method. The potential functions of these proteins in biological systems were further analysed using bioinformatic tools. RESULTS: A protein fraction, mainly containing major royal jelly proteins 2 (MRJP2), MRJP3 and MRJP7, stimulated proliferative and migratory activities in HaCaT cells without visible cytotoxicity. It exerted the greatest effects on the growth of HaCaT cells in the first 48 h. Furthermore, when treated with this protein fraction, the closure rates of the in vitro scratch wound were significantly increased. Functional analysis indicated that MRJP2, MRJP3 and MRJP7 were associated with carbohydrate transport and metabolism. CONCLUSIONS: We fractionated the water-soluble proteins of royal jelly and identified one fraction (Fraction 2) that induced both proliferative and migratory effects on a human epidermal keratinocyte cell line. Major royal jelly proteins (MRJP2, MRJP3 and/or MRJP7) were speculated to possess potential wound-healing bioactivity. This is the first report that royal jelly may improve wound closure via MRJP-induced cellular proliferation and migration. These proteins may be valuable lead compounds for the development of novel wound healing medications. Our findings would facilitate better understanding of the wound repair mechanisms of royal jelly.

Effects of panax notoginseng saponin on the pathological ultrastructure and serum IL-6 and IL-8 in pulmonary fibrosis in rabbits.

Panax notoginseng saponin (PNS) constitutes the major effective components of Panax notoginseng, which is widely used to treat microcirculatory disturbance associated diseases. In this study, we designed to investigate the effect of PNS on the treatment of pulmonary fibrosis (PF) and further explored its mechanism. A total of 40 healthy Japanese White rabbits were randomly divided into five groups (control group; PF model group; PNS prevention group; PNS treatment group; and western medicine [prednisone acetate] treatment group). Expression of hydroxyproline (HYP), fibronectin (FN), aspartate transaminase (AST), lactate dehydrogenase (LDH), creatine kinase (CK), interleukin-6 (IL-6), and interleukin-8 (IL-8) in serum was detected using corresponding detection kits. Western blot was applied to detect the expression of p50 and p65 in pulmonary tissues. The pathological variations of the cardiac and pulmonary ultrastructure were observed under both the optical and electron microscope. PF models were established successfully. The results showed that compared with the other groups, PNS groups (PNS prevention and treatment group) apparently relieved the cardiopulmonary injury, and reduced IL-6 and IL-8 expression levels in the serum. Furthermore, the PNS groups performed better in relieving cardiopulmonary injurythan other groups. Both the PNS groups and the western medicine treatment group presented an obvious role in relieving PF. We concluded that PNS could reduce the expression of AST, LDH, CK, IL-6, and IL-8 in serum of the rabbits, relieve the pathological ultrastructure of cardiopulmonary injury, alleviate PF. And it might be attributed to the inhibition on the NF-κB signaling pathway.

The effect of royal jelly on the growth of breast cancer in mice.

Due to various pharmacological properties, including antioxidative, anti-inflammatory and antibiotic properties, royal jelly (RJ) has been widely consumed in daily diets in numerous countries. In the present study, the effect of RJ on 4T1-bearing mice was investigated. The study was performed by feeding 4T1-bearing mice with RJ using either the prophylactic-therapeutic (PTRJ) or therapeutic (TRJ) method. The experimental results for the PTRJ group demonstrated that the weight of tumor was significantly reduced (RJ 0.5 and 1.5 g/kg); and in the serum, the levels of interleukin (IL)-2 (RJ 0.5 and 1.5 g/kg), interferon (IFN)-α, superoxide dismutase (SOD) and total antioxidant capacity (T-AOC) were significantly elevated, but the concentrations of IL-4 (RJ 0.5 and 1.5 g/kg) and IL-10 (RJ 1.0 g/kg) were significantly decreased. In addition, the activities of T-AOC and glutathione reductase (GR) were significantly improved in the liver, whereas in the kidney, the activities of T-AOC and GR were significantly increased only under the dose of 0.5 g/kg. For the TRJ group, the antitumor effect of RJ was not significant; the change in IL-2, IFN-α, SOD and T-AOC levels in the serum, and the change in T-AOC and GR in liver were similar to those observed in the PTRJ groups. RJ treatment was demonstrated to reduce the development of breast tumor in mice, and simultaneously improve the antioxidant capacity of the serum, liver and kidney, particularly using the prophylactic-therapeutic method. These results corroborated the efficacy of RJ supplementation in diets. The results of the present study suggest that the antioxidant and immunomodulatory activities of RJ serve an important role on antitumor growth.