Electrospray-assisted cryo-EM sample preparation to mitigate interfacial effects.

Addressing interfacial effects during specimen preparation in cryogenic electron microscopy remains challenging. Here we introduce ESI-cryoPrep, a specimen preparation method based on electrospray ionization in native mass spectrometry, designed to alleviate issues associated with protein denaturation or preferred orientation induced by macromolecule adsorption at interfaces. Through fine-tuning spraying parameters, we optimized protein integrity preservation and achieved the desired ice thickness for analyzing target macromolecules. With ESI-cryoPrep, we prepared high-quality cryo-specimens of five proteins and obtained three-dimensional reconstructions at near-atomic resolution. Our findings demonstrate that ESI-cryoPrep effectively confines macromolecules within the middle of the thin layer of amorphous ice, facilitating the preparation of blotting-free vitreous samples. The protective mechanism, characterized by the uneven distribution of charged biomolecules of varying sizes within charged droplets, prevents the adsorption of target biomolecules at air-water or graphene-water interfaces, thereby avoiding structural damage to the protein particles or the introduction of dominant orientation issues.

[Gene Profile and Clinical Significance of Concomitant Mutations in CN-AML Patients with CEBPA Mutation].

OBJECTIVE: To analyze the occurrence of concomitant gene mutations in cytogenetically normal acute myeloid leukemia (CN-AML) patients with CEBPA mutation and its impact on the clinical characteristics and prognosis of the patients. METHODS: 151 newly diagnosed patients with CN-AML in the Second Hospital of Shanxi Medical University from June 2013 to June 2020 were analyzed retrospectively. 34 common genetic mutations associated with hematologic malignancies were detected by next-generation sequencing technology. The occurrence of concomitant gene mutations in patients with CEBPA positive and negative groups was compared, and the correlation between concomitant mutations in different functional groups and the clinical characteristics and prognosis of CN-AML patients with CEBPA mutation was analyzed. RESULTS: In 151 patients with CN-AML, 55 (36.42%) were positive for CEBPA mutation (including 36 cases of CEBPAdm and 19 cases of CEBPAsm), of which 41 (74.55%) had co-mutations with other genes. The main mutated genes were GATA2 (25.45%, 14/55), TET2 (21.82%, 12/55), FLT3 (20.00%, 11/55), NRAS (12.73%, 7/55) and WT1 (9.09%, 9/55), etc. Some cases had two or more concomitant gene mutations. Grouping the mutant genes according to their functions showed that CEBPA+ group had lower mutation rates of histone methylation (P =0.002) and chromatin modification genes (P =0.002, P =0.033), and higher mutation rates of transcription factors (P =0.037) than CEBPA- group. In 55 patients with CEBPA+ CN-AML, the platelet count at diagnosis in signaling pathway gene mutation-positive group was lower than that in the mutation-negative group (P =0.005), the proportion of bone marrow blasts in transcription factor mutation-positive group was higher than that in the mutation-negative group (P =0.003), and the onset age in DNA methylation gene mutation-positive group and chromatin modifier mutation-positive group was older than that in the mutation-negative group, respectively (P =0.002, P =0.008). DFS of CEBPA+ CN-AML patients in signaling pathway gene mutation group was shorter than that in signaling pathway gene mutation-negative group (median DFS: 12 months vs not reached) (P =0.034). Compared with DNA methylation gene mutation-negative group, CEBPA+ CN-AML patients with DNA methylation gene mutation had lower CR rate (P =0.025) significantly shorter OS and DFS (median OS: 20 months vs not reached, P =0.006; median DFS: 15 months vs not reached, P =0.049). OS in patients with histone methylation gene mutation was significantly shorter than that in the histone methylation gene mutation-negative group (median OS: 12 months vs 40 months) (P =0.008). Multivariate analysis of prognostic factors showed that the proportion of bone marrow blasts (P =0.046), concomitant DNA methylation gene mutation (P =0.006) and histone methylation gene mutation (P =0.036) were independent risk factors affecting the prognosis. CONCLUSION: CN-AML patients with CEBPA mutation have specific concomitant gene profile, and the concomitant mutations of different functional genes have a certain impact on the clinical characteristics and prognosis of the patients.

Telomerase-related advances in hepatocellular carcinoma: A bibliometric and visual analysis.

BACKGROUND: As a critical early event in hepatocellular carcinogenesis, telomerase activation might be a promising and critical biomarker for hepatocellular carcinoma (HCC) patients, and its function in the genesis and treatment of HCC has gained much attention over the past two decades. AIM: To perform a bibliometric analysis to systematically assess the current state of research on HCC-related telomerase. METHODS: The Web of Science Core Collection and PubMed were systematically searched to retrieve publications pertaining to HCC/telomerase limited to "articles" and "reviews" published in English. A total of 873 relevant publications related to HCC and telomerase were identified. We employed the Bibliometrix package in R to extract and analyze the fundamental information of the publications, such as the trends in the publications, citation counts, most prolific or influential writers, and most popular journals; to screen for keywords occurring at high frequency; and to draw collaboration and cluster analysis charts on the basis of coauthorship and co-occurrences. VOSviewer was utilized to compile and visualize the bibliometric data. RESULTS: A surge of 51 publications on HCC/telomerase research occurred in 2016, the most productive year from 1996 to 2023, accompanied by the peak citation count recorded in 2016. Up to December 2023, 35226 citations were made to all publications, an average of 46.6 citations to each paper. The United States received the most citations (n = 13531), followed by China (n = 7427) and Japan (n = 5754). In terms of national cooperation, China presented the highest centrality, its strongest bonds being to the United States and Japan. Among the 20 academic institutions with the most publications, ten came from China and the rest of Asia, though the University of Paris Cité, Public Assistance-Hospitals of Paris, and the National Institute of Health and Medical Research (INSERM) were the most prolific. As for individual contributions, Hisatomi H, Kaneko S, and Ide T were the three most prolific authors. Kaneko S ranked first by H-index, G-index, and overall publication count, while Zucman-Rossi J ranked first in citation count. The five most popular journals were the World Journal of Gastroenterology, Hepatology, Journal of Hepatology, Oncotarget, and Oncogene, while Nature Genetics, Hepatology, and Nature Reviews Disease Primers had the most citations. We extracted 2293 keywords from the publications, 120 of which appeared more than ten times. The most frequent were HCC, telomerase and human telomerase reverse transcriptase (hTERT). Keywords such as mutational landscape, TERT promoter mutations, landscape, risk, and prognosis were among the most common issues in this field in the last three years and may be topics for research in the coming years. CONCLUSION: Our bibliometric analysis provides a comprehensive overview of HCC/telomerase research and insights into promising upcoming research.

Effects of different concentrations of nicotinamide on hematopoietic stem cells cultured in vitro.

BACKGROUND: In vitro expansion to increase numbers of hematopoietic stem cells (HSCs) in cord blood could improve clinical efficacy of this vital resource. Nicotinamide (NAM) can promote HSC expansion ex vivo, but its effect on hematopoietic stem and progenitor cells (HSPCs, CD34+CD38) and functional subtypes of HSCs - short-term repopulating HSCs (ST-HSCs, CD34+CD38CD45RACD49f+) and long-term repopulating HSCs (LT-HSCs, CD34+CD38CD45RACD49f+CD90+) is not yet known. As a sirtuin 1 (SIRT1) inhibitor, NAM participates in regulating cell adhesion, polarity, migration, proliferation, and differentiation. However, SIRT1 exhibits dual effects by promoting or inhibiting differentiation in different tissues or cells. We propose that the concentration of NAM may influence proliferation, differentiation, and SIRT1 signaling of HSCs. AIM: To evaluate the effects and underlying mechanisms of action of different concentrations of NAM on HSC proliferation and differentiation. METHODS: CD34+ cells were purified from umbilical cord blood using MacsCD34 beads, and cultured for 10-12 d in a serum-free medium supplemented with cytokines, with different concentrations of NAM added according to experimental requirements. Flow cytometry was used to detect phenotype, cell cycle distribution, and apoptosis of the cultured cells. Real-time polymerase chain reaction was used to detect the transcription levels of target genes encoding stemness-related factors, chemokines, components of hypoxia pathways, and antioxidant enzymes. Dichloro-dihydro-fluorescein diacetate probes were used to evaluate intracellular production of reactive oxygen species (ROS). Determination of the effect of different culture conditions on the balance of cytokine by cytometric bead array. RESULTS: Compared with the control group, the proportion and expansion folds of HSPCs (CD34+CD38) incubated with 5 mmol/L or 10 mmol/L NAM were significantly increased (all P < 0.05). The ST-HSCs ratio and fold expansion of the 5 mmol/L NAM group were significantly higher than those of the control and 10 mmol/L NAM groups (all P < 0.001), whereas the LT-HSCs ratio and fold expansion of the 10 mmol/L NAM group were significantly higher than those of the other two groups (all P < 0.05). When the NAM concentration was > 10 mmol/L, cell viability significantly decreased. In addition, compared with the 5 mmol/L NAM group, the proportion of apoptotic cells in the 10 mmol/L NAM group increased and the proportion of cells in S and G2 phase decreased. Compared with the 5 mmol/L NAM group, the HSCs incubated with 10 mmol/L NAM exhibited significantly inhibited SIRT1 expression, increased intracellular ROS content, and downregulated expression of genes encoding antioxidant enzymes (superoxide dismutase 1, peroxiredoxin 1). CONCLUSION: Low concentrations (5 mmol/L) of NAM can better regulate the balance between proliferation and differentiation, thereby promoting expansion of HSCs. These findings allow adjustment of NAM concentrations according to expansion needs.

Effect of the defoliant tribufos on the reproductive ability of Japanese quail (Coturnix japonica).

As a cotton defoliator, tribufos (S,S,S-tributyl phosphorotrithioate) is widespread in the environment. It can cause neurotoxicity in chickens, reproductive toxicity in rats, and can also cause headaches and nausea in humans. However, little is known about its impact on the reproduction of birds. Here, by analyzing the differences in reproductive indexs and histopathological characteristics, we investigated the chronic effects of 32 mg a.i./kg, 160 mg a.i./kg and 800 mg a.i./kg tribufos treatment on the reproductive ability of Japanese quail (Coturnix japonica). The results indicated that 32 mg a.i./kg and 160 mg a.i./kg tribufos treatment significantly reduced the food intake of quails, significantly increased the broken egg rate, and had adverse effects on gonads and liver tissue. The 160 mg a.i./kg tribufos treatment also significantly reduced the average egg production. Moreover, 800 mg a.i./kg treatment had significant negative effects on feed intake (FI), body weight (BW), eggshell thickness, egg production (EP), fertilization rate, hatchability and progeny 14-d survival rate, and it also significantly increased the broken egg rate. In addition, tribufos exposure caused lesions in quail gonads and liver tissue. Overall, our results revealed that tribufos had adverse effects on the reproductive ability of Japanese quail, especially at high concentrations.

Efficacy and safety of bipolar fractional radiofrequency vs. 2940-nm Er:YAG ablative fractional laser in striae distensae treatment: A split abdomen study.

BACKGROUND: Striae distensae (SD) is a challenging cosmetic condition. Ablative fractional laser (AFL) is an effective method for treating SD. Recently, fractional radiofrequency (FRF) has been shown to be a promising treatment for SD; however, few studies have shown the differences between FRF and AFL in the treatment of SD. AIMS: This study aimed to evaluate and compare the clinical efficacy and safety of bipolar FRF with 2940-nm erbium yttrium aluminum garnet (Er:YAG) AFL in the treatment of SD. PATIENTS/METHODS: Twenty volunteers with abdominal SD were enrolled in this study. One half of the abdomen was treated with 2940-nm Er:YAG AFL, whereas the other half was treated with bipolar FRF, with three sessions at 4-week intervals. Photographic evaluations of clinical improvement were conducted by two independent investigators before and after treatment, and the patients provided self-assessments. Two participants underwent three punch biopsies, one before treatment and two obtained from bilateral representative skin lesions on the abdomen 3 months following the final treatment. RESULTS: Clinical improvements were observed in SD on both sides of the abdomen after the two treatments. Post-treatment skin biopsies revealed increased thickness in the epidermis and dermis, and higher collagen and elastin density compared to those at the baseline. No statistically significant differences were observed in the clinical outcomes between the two treatment approaches. CONCLUSIONS: The efficacy and safety of bipolar FRF treatment are comparable to those of 2940-nm Er:YAG AFL treatment, providing an alternative and effective treatment for SD.

Phylogenomic analyses sheds new light on the phylogeny and diversification of Corydalis DC. in Himalaya-Hengduan Mountains and adjacent regions.

The Himalaya-Hengduan Mountains (HHM), a renowned biodiversity hotspot of the world, harbors the most extensive habitats for alpine plants with extraordinary high levels of endemism. Although the general evolution pattern has been elucidated, the underlying processes driving spectacular radiations in many species-rich groups remain elusive. Corydalis DC. is widely distributed throughout the Northern Hemisphere containing more than 500 species, with high diversity in HHM and adjacent regions. Using 95 plastid genes, 3,258,640 nuclear single nucleotide polymorphisms (SNPs) and eight single-copy nuclear genes (SCNs) generated from genome skimming data, we reconstructed a robust time-calibrated phylogeny of Corydalis comprising more than 100 species that represented all subgenera and most sections. Molecular dating indicated that all main clades of Corydalis began to diverge in the Eocene, with the majority of extant species in HHM emerged from a diversification burst after the middle Miocene. Global pattern of mean divergence times indicated that species distributed in HHM were considerably younger than those in other regions, particularly for the two most species-rich clades (V and VI) of Corydalis. The early divergence and the recent diversification of Corydalis were most likely promoted by the continuous orogenesis and climate change associated with the uplift of the Qinghai-Tibetan Plateau (QTP). Our study demonstrates the effectivity of phylogenomic analyses with genome skimming data on the phylogeny of species-rich taxa, and sheds lights on how the uplift of QTP has triggered the evolutionary radiations of large plant genera in HHM and adjacent regions.

Graphene sandwich-based biological specimen preparation for cryo-EM analysis.

High-quality specimen preparation plays a crucial role in cryo-electron microscopy (cryo-EM) structural analysis. In this study, we have developed a reliable and convenient technique called the graphene sandwich method for preparing cryo-EM specimens. This method involves using two layers of graphene films that enclose macromolecules on both sides, allowing for an appropriate ice thickness for cryo-EM analysis. The graphene sandwich helps to mitigate beam-induced charging effect and reduce particle motion compared to specimens prepared using the traditional method with graphene support on only one side, therefore improving the cryo-EM data quality. These advancements may open new opportunities to expand the use of graphene in the field of biological electron microscopy.

Inactivation of Mst/Nrf2/Keap1 signaling flexibly mitigates MAPK/NQO-HO1 activation in the reproductive axis of experimental fluorosis.

Fluoride induced reprotoxicity through oxidative stress-mediated reproductive cell death. Hence, the current study evaluated the importance of the MST/Nrf2/MAPK/NQO-HO1 signaling pathway in fluorosis-induced reproductive toxicity. For this purpose, the reproductive toxicity of sodium fluoride (NaF) at physiological, biochemical, and intracellular levels was evaluated. In-vivo, NaF at 100 mg/L instigated physiological dysfunction, morphological, stereological, and structural injuries in the gut-gonadal axis of fluorosis mice through weakening the antioxidant signaling, Nrf2/HO-1/NQO1signaling pathway, causing the gut-gonadal barrier disintegrated via oxidative stress-induced inflammation, mitochondrial damage, apoptosis, and autophagy. Similar trends were also observed in-vitro in the isolated Leydig cells (LCs) challenging with 20 mg/L NaF. Henceforth, activating the cellular antioxidant signaling pathway, Nrf2/HO-1/NQO1, inactivating autophagy and apoptosis, or attenuating lipopolysaccharide (LPS) can be the theoretical basis and valuable therapeutic targets for coping with NaF-induced reproductive toxicity.

The protective effects of icariin against testicular dysfunction in type 1 diabetic mice Via AMPK-mediated Nrf2 activation and NF-κB p65 inhibition.

BACKGROUND: Owing to the early suffering age and the rising incidence of type 1 diabetes (T1D), the resulting male reproductive dysfunction and fertility decline have become a disturbing reality worldwide, with no effective strategy being available. Icariin (ICA), a flavonoid extracted from Herba Epimedium, has been proved its promising application in improving diabetes-related complications including diabetic nephropathy, endothelial dysfunction and erectile dysfunction. Ensuring the future reproductive health of children and adolescents with T1D is crucial to improve global fertility. However, its roles in the treatment of T1D-induced testicular dysfunction and the potential mechanisms remain elusive. PURPOSE: The purpose of this present study was to investigate whether ICA ameliorates T1D-induced testicular dysfunction as well as its potential mechanisms. METHODS: T1D murine model was established by intraperitoneal injection of STZ with or without treated with ICA for eleven weeks. Morphological, pathological and serological experiments were used to determine the efficacy of ICA on male reproductive function of T1D mice. Western blotting, Immunohistochemistry analysis, qRT-PCR and kit determination were performed to investigated the underlying mechanisms. RESULTS: We found that replenishment of ICA alleviated testicular damage, promoted testosterone production and spermatogenesis, ameliorated apoptosis and blood testis barrier impairment in streptozotocin-induced T1D mice. Functionally, ICA treatment triggered adenosine monophosphate protein kinase (AMPK) activation, which in turn inhibited the nuclear translocation of nuclear factor kappa B p65 (NF-κB p65) to reduce inflammatory responses in the testis and activated nuclear factor erythroid 2-related factor 2(Nrf2), thereby enhancing testicular antioxidant capacity. Further studies revealed that supplementation with the AMPK antagonist Compound C or depletion of Nrf2 weakened the beneficial effects of ICA on testicular dysfunction of T1D mice. CONCLUSION: Collectively, these results demonstrate the feasibility of ICA in the treatment of T1D-induced testicular dysfunction, and reveal the important role of AMPK-mediated Nrf2 activation and NF-κB p65 inhibition in ICA-associated testicular protection during T1D.

Pre/postnatal taurine supplementation improves neurodevelopment and brain function in mice offspring: A persistent developmental study from puberty to maturity.

Taurine (TAU) is a sulfur-containing amino acid abundantly found in the human body. Endogenously, TAU is synthesized from cysteine in the liver. However, newborns rely entirely on TAU's dietary supply (milk). There is no investigation on the effect of long-term TAU administration on next-generation neurological development. The current study evaluated the effect of long-term TAU supplementation during the maternal gestational and litter weaning time on several neurological parameters in mice offspring. Moreover, the effects of TAU on mitochondrial function and oxidative stress biomarkers as plausible mechanisms of its action in the whole brain and hippocampus have been evaluated. TAU (0.5 % and 1 % w/v) was dissolved in the drinking water of pregnant mice (Day one of pregnancy), and amino acid supplementation was continued during the weaning time (post-natal day; PND = 21) until litters maturity (PND = 65). It was found that TAU significantly improved cognitive function, memory performance, reflexive motor activity, and emotional behaviors in F1-mice generation. TAU measurement in the brain and hippocampus revealed higher levels of this amino acid. TAU and ATP levels were also significantly higher in the mitochondria isolated from the whole brain and hippocampus. Based on these data, TAU could be suggested as a supplement during pregnancy or in pediatric formula. The effects of TAU on cellular mitochondrial function and energy metabolism might play a fundamental role in the positive effects of this amino acid observed in this investigation.

A new metal ion chelator attenuates human tau accumulation-induced neurodegeneration and memory deficits in mice.

Neuronal neurofibrillary tangles containing Tau hyperphosphorylation proteins are a typical pathological marker of Alzheimer's disease (AD). The level of tangles in neurons correlates positively with severe dementia. However, how Tau induces cognitive dysfunction is still unknown, which leads to a lack of effective treatments for AD. Metal ions deposition occurs with tangles in AD brain autopsy. Reduced metal ion can improve the pathology of AD. To explore whether abnormally phosphorylated Tau causes metal ion deposition, we overexpressed human full-length Tau (hTau) in the hippocampal CA3 area of mice and primary cultured hippocampal neurons (CPHN) and found that Tau accumulation induced iron deposition and activated calcineurin (CaN), which dephosphorylates glycogen synthase kinase 3 beta (GSK3ß), mediating Tau hyperphosphorylation. Simultaneous activation of CaN dephosphorylates cyclic-AMP response binding protein (CREB), leading to synaptic deficits and memory impairment, as shown in our previous study; this seems to be a vicious cycle exacerbating tauopathy. In the current study, we developed a new metal ion chelator that displayed a significant inhibitory effect on Tau phosphorylation and memory impairment by chelating iron ions in vivo and in vitro. These findings provide new insight into the mechanism of memory impairment induced by Tau accumulation and develop a novel potential treatment for tauopathy in AD.

[Three-dimensional comparative study on the stability of bimaxillary simultaneous genioplasty and simple genioplasty].

PURPOSE: To establish a three-dimensional method to evaluate whether there is a difference in stability between bimaxillary simultaneous genioplasty and simple genioplasty. METHODS: This study was a retrospective study. Sixty patients who underwent genioplasty were selected. They were divided into bimaxillary simultaneous genioplasty group (n=30) and simple genioplasty group (n=30). The spiral CT data of patients at 2 months before operation (T0), 7 days after operation (T1) and 12 months after operation (T2) were collected, reconstructed and separated, and the three-dimensional model of maxilla and mandible was obtained. A three-dimensional analysis method of stability was established by 3D-matching. Recurrences in three-dimensional space 12 months after surgery were analyzed in two groups of patients. Statistical analysis of the data was performed with SPSS 26.0 software package. RESULTS: In simple genioplasty, the maximum amount of the chin recurrence was sagittal backward recurrence (0.54±0.38) mm, and the sagittal recurrence rate was 12.27%. In bimaxillary simultaneous genioplasty, the maximum amount of the chin recurrence was sagittal backward recurrence (0.60±0.31) mm, and the sagittal recurrence rate was 12.96%. Rotation occurred in both groups 12 months after operation, which was 1.98±2.70° in the simple genioplasty group and 1.01±1.61° in the bimaxillary simultaneous genioplasty group(P＜0.05). There was no significant difference in the sagittal movement of the chin between the two groups, and in the sagittal recurrence(P＞0.05). CONCLUSIONS: The three-dimensional method established in this study can be used to evaluate the stability after genioplasty. The recurrence after genioplasty mainly occurred in the sagittal direction. The rotation trend of chin after genioplasty is worthy of attention. There was no increased risk for bimaxillary simultaneous genioplasty.

Co-Culture of White Rot Fungi Pleurotus ostreatus P5 and Bacillus amyloliquefaciens B2: A Strategy to Enhance Lipopeptide Production and Suppress of Fusarium Wilt of Cucumber.

Fusarium wilt, caused by Fusarium oxysporum f. sp. cucumerinum (FOC), poses a serious threat to cucumber productivity. Compared to traditional chemical pesticides, biological control strategies have attracted more attention recently owing to their effectiveness against pathogens and their environmental safety. This study investigated the effect of white rot fungi Pleurotus ostreatus P5 on the production of cyclic lipopeptides (CLPs) of Bacillus amyloliquefaciens B2 and the potential co-culture filtrate of strains B2 and P5 to control cucumber Fusarium wilt. A PCR amplification of CLP genes revealed that B. amyloliquefaciens B2 had two antibiotic biosynthesis genes, namely, ituA and srf, which are involved in iturin A and surfactin synthesis. Liquid chromatography with tandem mass spectrometry (LC-MS/MS) revealed that CLPs derived from strain B2 contained two families, iturin A (C14, C15) and surfactin (C12-C17). The co-culture exhibited an enhanced accumulation of iturin A and surfactin compared to the monoculture of strain B2. Furthermore, the gene expressions of ituA and srf were both significantly upregulated when co-cultured with the fungus compared to monocultures. In an in vitro experiment, the co-culture filtrate and monoculture filtrate of B. amyloliquefaciens B2 inhibited mycelial growth by 48.2% and 33.2%, respectively. In a greenhouse experiment, the co-culture filtrate was superior to the monoculture filtrate in controlling cucumber Fusarium wilt disease and in the promotion of plant growth. Co-culture filtrate treatment significantly enhanced the microbial metabolic activity and decreased the abundance of FOC in the rhizosphere soil. These results show that the co-culture of P. ostreatus P5 and B. amyloliquefaciens B2 has great potential in cucumber Fusarium wilt disease prevention by enhancing the production of bacterial CLPs.

Structural insights into the mechanism of GTP initiation of microtubule assembly.

In eukaryotes, the dynamic assembly of microtubules (MT) plays an important role in numerous cellular processes. The underlying mechanism of GTP triggering MT assembly is still unknown. Here, we present cryo-EM structures of tubulin heterodimer at their GTP- and GDP-bound states, intermediate assembly states of GTP-tubulin, and final assembly stages of MT. Both GTP- and GDP-tubulin heterodimers adopt similar curved conformations with subtle flexibility differences. In head-to-tail oligomers of tubulin heterodimers, the inter-dimer interface of GDP-tubulin exhibits greater flexibility, particularly in tangential bending. Cryo-EM of the intermediate assembly states reveals two types of tubulin lateral contacts, "Tube-bond" and "MT-bond". Further, molecular dynamics (MD) simulations show that GTP triggers lateral contact formation in MT assembly in multiple sequential steps, gradually straightening the curved tubulin heterodimers. Therefore, we propose a flexible model of GTP-initiated MT assembly, including the formation of longitudinal and lateral contacts, to explain the nucleation and assembly of MT.

Fluoride-induced osteoporosis via interfering with the RANKL/RANK/OPG pathway in ovariectomized rats: Oophorectomy shifted skeletal fluorosis from osteosclerosis to osteoporosis.

Osteosclerosis and osteoporosis are the two main clinical manifestations of skeletal fluorosis. However, the reasons for the different clinical manifestations are unclear. In this study, we established the fluoride (F) -exposed ovariectomized (OVX) and non-OVX rat models to assess the potential role of ovarian function loss in osteosclerosis and osteoporosis. Micro-CT scanning showed that excessive F significantly induced a high bone mass in non-OVX rats. In contrast, a low bone mass manifestation was presented in OVX F-exposed rats. Also, a prominent feature of increasing trabecular connectivity, collagen area, growth plate thickness, and reduced trabecular space was found by histopathological morphology in non-OVX F-exposed rats; an opposite result was observed in OVX F-exposed. These alterations indicated ovariectomy was a vital factor leading to osteosclerosis or osteoporosis in skeletal fluorosis. Furthermore, levels of bone alkaline phosphatase (BALP) and tartrate-resistant acid phosphatase (TRAP) increased, combined with the increasing osteoclasts number, showing a sign of high bone turnover in both OVX and non-OVX F-exposed rats. Mechanistically, oophorectomy considerably activated the RANKL/RANK/OPG signaling pathway. Meanwhile, it was discovered that upregulated NF-κB positively facilitated the accumulation of nuclear factor of activated T-cells 1 (NFATC1), significantly promoting osteoclast differentiation. To sum up, this study greatly enriched the causes of clinical skeletal fluorosis and provided a new perspective for studying the pathogenesis of skeletal fluorosis.

Fads2b Plays a Dominant Role in ∆6/∆5 Desaturation Activities Compared with Fads2a in Common Carp (Cyprinus carpio).

Highly unsaturated fatty acids (HUFAs) are essential for mammalian health, development and growth. However, most mammals, including humans, are incapable of synthesizing n-6 and n-3 HUFAs. Fish can convert C18 unsaturated fatty acids into n-6 and n-3 HUFAs via fatty acid desaturase (Fads), in which Fads2 is a key enzyme in HUFA biosynthesis. The allo-tetraploid common carp theoretically encode two duplicated fads2 genes. The expression patterns and desaturase functions of these two homologous genes are still unknown. In this study, the full length of the fads2a and fads2b were identified in common carp (Cyprinus carpio). Expression analyses indicate that both genes were mainly expressed in the liver and the expression of fads2b is higher than fads2a at different developmental stages in carp embryos. Heterogenous expression and 3D docking analyses suggested that Fads2b demonstrated stronger ∆6 and ∆5 desaturase activities than Fads2a. The core promotor regions of fads2a and fads2b were characterized and found to have different potential transcriptional binding sites. These results revealed the same desaturase functions, but different activities of two homologues of fasd2 genes in common carp. The data showed that fads2b played a more important role in HUFA synthesis through both expression and functional analyses.

A new pathway for the transformation of AML in MDS: APA mechanism regulated by NUDT21 and RUNX1.

We have identified that NUDT21 plays a vital role in MDS transformations, while the transcription factor RUNX1 is essential for normal hematopoiesis, which is a high expression in acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS), and we aim to explore the linkage between the two genes and new pathways for MDS transformation to AML. Prediction of RUNX1 expression levels and its relationship with NUDT21 in AML and MDS patients was performed using bioinformatics techniques and validated in patients. Using lentiviral packaging technology, NUDT21 knockdown and overexpression models were developed in AML and MDS cell lines. These models were validated using quantitative polymerase chain reaction (qPCR) and western blotting. The cell cycle, apoptosis, differentiation, and cytokines were examined by flow cytometry, CCK-8 analyzed proliferation, and the intracellular localization of NUDT21 and RUNX1 was examined by immunofluorescence. mRNA transcriptome sequencing was performed on THP-1, MUTZ-1, and Dapars analyzed SKM-1 cell lines and the sequencing data to observe the knockdown effect of NUDT21 on RUNX1. qPCR and western blot revealed a positive correlation between NUDT21 and RUNX1; both were located in the nucleus. Overexpression of NUDT21 reduced apoptosis, promoted cell proliferation, and possibly increased the invasive ability of cells. It also altered the APA site in the RUNX1 3'-UTRs region. NUDT21 regulates RUNX1 gene expression and promotes AML transformation in MDS through an APA mechanism.

Controlled Architectures in Supported Photocatalysis: Exploring the Potential of Cold Plasma Discharge, Additive Manufacturing, and Fractal Geometry to Form Hierarchically Immobilized Ni-MOF/BiOI/AgVO3.

Herein, we explore the potential of innovative manufacturing techniques based on green chemistry principles, for the fabrication of convenient, performant, and stable supported photocatalysts to be used for water depollution. After giving some insight into the use of fractal geometry for the fabrication of tunable polymer supports for photocatalysts, we investigated the use of liquid crystal display (LCD) 3D printing to generate the fractal resin substrates to be used for the immobilization of semiconductor photocatalysts. Notably, confocal laser imaging was used as a first attempt for assessing the surface area of the fractal substrate. Immobilization methods based on cold plasma discharge (CPD) were employed to modify the surface of the polymer substrates and permanently anchor three different phases, namely, nickel-based metal-organic framework (Ni-MOF), BiOI, and AgVO3, in a hierarchical configuration. Herein, for the first time, we developed a plasma-initiated condensed in situ complexation-assisted precipitation (c-ISCAP) method that allowed 2D Ni-MOF to be synthesized directly onto the surface of a polymer substrate, in a single step. Not only this MOF coating was found to be strongly bound to the surface of the polymer substrate but also very uniform and fully functional, even when other inorganic phases were immobilized on the top of this layer. This chemical approach opens the way for the fabrication of hybrid materials with complex polymer substrates and MOF coatings that could be used in a range of possible applications, for instance as chemical sensors, electrodes, adsorbents, optical devices, etc. Our hybrid photocatalysts were tested via photodegradation of Rhodamine B (RhB) dye upon visible light activation, with recycling runs to assess their durability. It was found that the hierarchical heterojunction Ni-MOF/BiOI/AgVO3 showed an outstanding ability for the removal of RhB dye, owing to the activity of the Ni-MOF layer in terms of charge transfer, and also partly because of its adsorbing potential. The three photoactive phases demonstrated a strong synergistic effect through coupling. However, more importantly, our findings show that their immobilization itself, regardless of the method used, significantly modified their optoelectronic properties, hence most likely changing the overall mechanism of charge transfer in the heterojunction. The Ni-MOF phase, notably, was found to display a reduced bandgap when obtained by c-ISCAP, which contributed to enhance its activation by visible light irradiation. Finally, it was established that the fractal geometry had a significant impact on the efficiency of the supported catalysts, probably thanks to an increased immobilization ratio of photocatalyst mostly, owing to the larger surface area available.