Extracellular putrescine can augment the epithelial-mesenchymal transition of gastric cancer cells by promoting MAL2 expression by elevating H3K27ac in its promoter region.

Dysregulation of polyamine metabolism has been associated with the development of many cancers. However, little information has been reported about the associations between elevated extracellular putrescine and epithelial-mesenchymal transition (EMT) of gastric cancer (GC) cells. In this study, the influence of extracellular putrescine on the malignant behavior and EMT of the AGS and MKN-28 cells was investigated, followed by RNA sequencing profiling of transcriptomic alterations and CUT&Tag sequencing capturing H3K27ac variations across the global genome using extracellular putrescine. Our results demonstrated that the administration of extracellular putrescine significantly promoted the proliferation, migration, invasion, and expression of N-cadherin in GC cells. We also observed elevated H3K27ac in MKN-28 cells but not in AGS cells when extracellular putrescine was used. A combination of transcriptomic alterations and genome-wide variations of H3K27ac highlighted the upregulated MAL2 and H3K27ac in its promoter region. Knockdown and overexpression of MAL2 were found to inhibit and promote EMT, respectively, in AGS and MKN-28 cells. We demonstrated that extracellular putrescine could upregulate MAL2 expression by elevating H3K27ac in its promoter region, thus triggering augmented EMT in GC cells.

Combination of dexamethasone and dexmedetomidine as adjuvants of transversus abdominis plane block for postoperative analgesia in gastric cancer patients: A double-blinded randomized controlled trial.

STUDY OBJECTIVE: We conducted this double-blinded randomized controlled trial to examine whether the combination of dexamethasone and dexmedetomidine as adjuvants of transversus abdominis plane (TAP) block could improve analgesia efficacy and duration for gastric cancer patients. DESIGN: Randomized controlled trial. SETTING: The preoperative area, operating room, postanesthesia recovery room and bed ward. PATIENTS: A total of 312 adult patients (104 per group) with gastric cancer were included. INTERVENTIONS: Patients received bilateral subcostal TAP block with three different anesthetics (60 ml 0.25% ropivacaine added with 10 mg dexamethasone and 1 µg·kg-1 dexmedetomidine [A] or 10 mg dexamethasone [B] or 1 µg·kg-1 dexmedetomidine [C]). MEASUREMENTS: The primary outcome was the incidence of moderate-to-severe pain 24 h on movement. Secondary outcomes included incidence of moderate-to-severe pain, pain score, opioids use, recovery quality and adverse events. MAIN RESULTS: The incidence of moderate-to-severe pain on movement 24 h postoperatively of group A was significantly lower than group B (45.19% vs 63.46%; RR 0.71; 95% CI, 0.55 to 0.92) and group C (45.19% vs 73.08%, RR 0.62; 95% CI, 0.49 to 0.79). The median moving pain scores decreased significantly at 24 h (3.00 [3.00,5.00] vs 4.00 [3.00,6.00] vs 4.00 [3.00,5.00]; P < 0.001). There were significant differences in the opioids consumption within the first 24 h (27.5 [17.0,37.2] vs 30.0 [20.0,42.0] vs 32.0 [25.0,44.0] mg; P = 0.01) and the duration to first rescue analgesia (65.5 ± 26.7 vs 45.9 ± 34.5 vs 49.2 ± 27.2 h; P = 0.04). CONCLUSIONS: The combination with dexamethasone and dexmedetomidine as adjuvants for TAP block reduced the incidence of moderate-to-severe pain and pain score both on movement and at rest at 24 h with prolonged duration to first rescue analgesia after gastric cancer surgery. TRIAL REGISTRATION NUMBER: ChiCTR2000037981.

Evolutionary divergence of subgenomes in common carp provides insights into speciation and allopolyploid success.

Hybridization and polyploidization have made great contributions to speciation, heterosis, and agricultural production within plants, but there is still limited understanding and utilization in animals. Subgenome structure and expression reorganization and cooperation post hybridization and polyploidization are essential for speciation and allopolyploid success. However, the mechanisms have not yet been comprehensively assessed in animals. Here, we produced a high-fidelity reference genome sequence for common carp, a typical allotetraploid fish species cultured worldwide. This genome enabled in-depth analysis of the evolution of subgenome architecture and expression responses. Most genes were expressed with subgenome biases, with a trend of transition from the expression of subgenome A during the early stages to that of subgenome B during the late stages of embryonic development. While subgenome A evolved more rapidly, subgenome B contributed to a greater level of expression during development and under stressful conditions. Stable dominant patterns for homoeologous gene pairs both during development and under thermal stress suggest a potential fixed heterosis in the allotetraploid genome. Preferentially expressing either copy of a homoeologous gene at higher levels to confer development and response to stress indicates the dominant effect of heterosis. The plasticity of subgenomes and their shifting of dominant expression during early development, and in response to stressful conditions, provide novel insights into the molecular basis of the successful speciation, evolution, and heterosis of the allotetraploid common carp.

Splicing factor hnRNPA1 regulates alternative splicing of LOXL2 to enhance the production of LOXL2Δ13.

Lysyl oxidase-like 2 (LOXL2) is a member of the lysyl oxidase family and has the ability to catalyze the cross-linking of extracellular matrix collagen and elastin. High expression of LOXL2 is related to tumor cell proliferation, invasion, and metastasis. LOXL2 contains 14 exons. Previous studies have found that LOXL2 has abnormal alternative splicing and exon skipping in a variety of tissues and cells, resulting in a new alternatively spliced isoform denoted LOXL2Δ13. LOXL2Δ13 lacks LOXL2WT exon 13, but its encoded protein has greater ability to induce tumor cell proliferation, invasion, and metastasis. However, the molecular events that produce LOXL2Δ13 are still unclear. In this study, we found that overexpression of the splicing factor hnRNPA1 in cells can regulate the alternative splicing of LOXL2 and increase the expression of LOXL2Δ13. The exonic splicing silencer exists at the 3' splice site and 5' splice site of LOXL2 exon 13. HnRNPA1 can bind to the exonic splicing silencer and inhibit the inclusion of exon 13. The RRM domain of hnRNPA1 and phosphorylation of hnRNPA1 at S91 and S95 are important for the regulation of LOXL2 alternative splicing. These results show that hnRNPA1 is a splicing factor that enhances the production of LOXL2Δ13.

scRank infers drug-responsive cell types from untreated scRNA-seq data using a target-perturbed gene regulatory network.

Cells respond divergently to drugs due to the heterogeneity among cell populations. Thus, it is crucial to identify drug-responsive cell populations in order to accurately elucidate the mechanism of drug action, which is still a great challenge. Here, we address this problem with scRank, which employs a target-perturbed gene regulatory network to rank drug-responsive cell populations via in silico drug perturbations using untreated single-cell transcriptomic data. We benchmark scRank on simulated and real datasets, which shows the superior performance of scRank over existing methods. When applied to medulloblastoma and major depressive disorder datasets, scRank identifies drug-responsive cell types that are consistent with the literature. Moreover, scRank accurately uncovers the macrophage subpopulation responsive to tanshinone IIA and its potential targets in myocardial infarction, with experimental validation. In conclusion, scRank enables the inference of drug-responsive cell types using untreated single-cell data, thus providing insights into the cellular-level impacts of therapeutic interventions.

Intelligent near-infrared light-activatable DNA machine with DNA wire nano-scaffold-integrated fast domino-like driving amplification for high-performance imaging in live biological samples.

While there is significant potential for DNA machine-built enzyme-free fluorescence biosensors in the imaging analysis of live biological samples, they persist certain shortcomings. These encompass a deficiency of signal enrichment within a singular interface, uncontrolled premature activation during bio-delivery, and a slow reaction rate due to free nucleic acid collisions. In this contribution, we are committed to resolving the above challenges. Firstly, a single-interface-integrated domino-like driving amplification is constructed. In this conception, a specific target acts as the domino promotor (namely the energy source), initiating a cascading chain reaction that grafts onto a singular interface. Next, an 808 nm near-infrared (NIR) light-excited up-converting luminescence-induced light-activatable biosensing technique is introduced. By locking the target-specific identification segment with a photo-cleavage connector, the up-converted ultraviolet emission can activate target binding in a completely controlled manner. Moreover, a fast reaction rate is achieved by confining nucleic acid collisions within the surface of a DNA wire nano-scaffold, leading to a substantial enhancement in local contact concentration (30.8-fold increase, alongside a 15 times elevation in rate). When a non-coding microRNA (miRNA-221) is positioned as the model low-abundance target for proof-of-concept validation, our intelligent DNA machine demonstrates ultra-high sensitivity (with a limit of detection down to 62.65 fM) and good specificity for this hepatic malignant tumor-associated biomarker in solution detection. Going further, it is worth highlighting that the biosensing system can be employed to carry out high-performance imaging analysis in live bio-samples (ranging from the cellular level to the nude mouse body), thereby propelling the field of DNA machines in disease diagnosis.

Detection of free DNA based on metal-enhanced fluorescence triggered by CRISPR-Cas12a and colorimetric analysis.

The CRISPR-Cas system has been found to be extremely sensitive and there is an urgent demand to extend its potential in bioassays. Herein, we developed a novel nanobiosensor to detect the human papillomavirus 16 genes (HPV-16 DNA), which is triggered by CRISPR-Cas12a to amplify the fluorescence signal by metal-enhanced fluorescence (CAMEF). Along with the changing of the fluorescence signal, the aggregation of the substrate of MEF also leads to a change in the color of the mixture solution, enabling dual signal detection with the fluorescence and the naked eye. Furthermore, the designed CAMEF probe was verified to detect the HPV-16 DNA accurately and reliably in biological samples. Triggered by the CRISPR system, the designed CAMEF probe allows quantitative detection of the HPV-16 DNA in the wide range of 10-500 pM. Owing to the MEF, the fluorescence signal of the CAMEF probe was significantly amplified with the detection limit as low as 1 pM. Besides, we can determine the concentration of HPV-16 DNA simply by the naked eye, which also drastically reduces the possibility of false-positive signals. Theoretically, the target ssDNA could be any strand of DNA obtained by designing the crRNA sequence in the CRISPR-Cas system. We believe that the designed CAMEF sensor can present a reliable approach for the accurate detection of low amounts of target ssDNA in complex biological samples.

Deep Learning Model Coupling Wearable Bioelectric and Mechanical Sensors for Refined Muscle Strength Assessment.

Muscle strength (MS) is related to our neural and muscle systems, essential for clinical diagnosis and rehabilitation evaluation. Although emerging wearable technology seems promising for MS assessment, problems still exist, including inaccuracy, spatiotemporal differences, and analyzing methods. In this study, we propose a wearable device consisting of myoelectric and strain sensors, synchronously acquiring surface electromyography and mechanical signals at the same spot during muscle activities, and then employ a deep learning model based on temporal convolutional network (TCN) + Transformer (Tcnformer), achieving accurate grading and prediction of MS. Moreover, by combining with deep clustering, named Tcnformer deep cluster (TDC), we further obtain a 25-level classification for MS assessment, refining the conventional 5 levels. Quantification and validation showcase a patient's postoperative recovery from level 3.2 to level 3.6 in the first few days after surgery. We anticipate that this system will importantly advance precise MS assessment, potentially improving relevant clinical diagnosis and rehabilitation outcomes.

Risk Factors for Isolated Sphenoid Sinusitis after Endoscopic Endonasal Transsphenoidal Pituitary Surgery.

(1) Background: Transsphenoidal pituitary surgery can be conducted via microscopic or endoscopic approaches, and there has been a growing preference for the latter in recent years. However, the occurrence of rare complications such as postoperative sinusitis remains inadequately documented in the existing literature. (2) Methods: To address this gap, we conducted a comprehensive retrospective analysis of medical records spanning from 2018 to 2023, focusing on patients who underwent transsphenoidal surgery for pituitary neuroendocrine tumors (formerly called pituitary adenoma). Our study encompassed detailed evaluations of pituitary function and MRI imaging pre- and postsurgery, supplemented by transnasal endoscopic follow-up assessments at the otolaryngology outpatient department. Risk factors for sinusitis were compared using univariate and multivariate logistic regression analyses. (3) Results: Out of the 203 patients included in our analysis, a subset of 17 individuals developed isolated sphenoid sinusitis within three months postoperation. Further scrutiny of the data revealed significant associations between certain factors and the occurrence of postoperative sphenoid sinusitis. Specifically, the classification of the primary tumor emerged as a notable risk factor, with patients exhibiting nonfunctioning pituitary neuroendocrine tumors with 3.71 times the odds of developing sinusitis compared to other tumor types. Additionally, postoperative cortisol levels demonstrated a significant inverse relationship, with lower cortisol levels correlating with an increased risk of sphenoid sinusitis postsurgery. (4) Conclusions: In conclusion, our findings underscore the importance of considering tumor classification and postoperative cortisol levels as potential predictors of postoperative sinusitis in patients undergoing transsphenoidal endoscopic pituitary surgery. These insights offer valuable guidance for clinicians in identifying at-risk individuals and implementing tailored preventive and management strategies to mitigate the occurrence and impact of sinusitis complications in this patient population.

Near-Infrared Light-Powered and DNA Nanocage-Confined Catalytic Hairpin Assembly Nanobiosensor with a Nucleic Acid Restriction Behavior and Reinforced Enzymatic Resistance for Robust Imaging Assay in Live Biosystems.

While DNA amplifier-built nanobiosensors featuring a DNA polymerase-free catalytic hairpin assembly (CHA) reaction have shown promise in fluorescence imaging assays within live biosystems, challenges persist due to unsatisfactory precision stemming from premature activation, insufficient sensitivity arising from low reaction kinetics, and poor biostability caused by endonuclease degradation. In this research, we aim to tackle these issues. One aspect involves inserting an analyte-binding unit with a photoinduced cleavage bond to enable a light-powered notion. By utilizing 808 nm near-infrared (NIR) light-excited upconversion luminescence as the ultraviolet source, we achieve entirely a controllable sensing event during the biodelivery phase. Another aspect refers to confining the CHA reaction within the finite space of a DNA self-assembled nanocage. Besides the accelerated kinetics (up to 10-fold enhancement) resulting from the nucleic acid restriction behavior, the DNA nanocage further provides a 3D rigid skeleton to reinforce enzymatic resistance. After selecting a short noncoding microRNA (miRNA-21) as the modeled low-abundance sensing analyte, we have verified that the innovative NIR light-powered and DNA nanocage-confined CHA nanobiosensor possesses remarkably high sensitivity and specificity. More importantly, our sensing system demonstrates a robust imaging capability for this cancer-related universal biomarker in live cells and tumor-bearing mouse bodies, showcasing its potential applications in disease analysis.

First report of cucumber green mottle mosaic virus infecting Cynanchum rostellatum in China.

Cucumber green mottle mosaic virus (CGMMV) was first discovered on cucumber in the United Kingdom in 1935 (Ainsworth, 1935), and has spread worldwide except to Antarctica (Jones, 2021). Given its extensive damage, it is considered an important pathogen on global cucurbit plants and fruit crops. In China, CGMMV was first reported on pumpkin in Guangxi Province in 2003 (Qin et al., 2005), and occurred on 34 plants species across 23 provinces (Liu et al., 2016). Cynanchum rostellatum is a member of the family Apocynaceae. In July 2021, leaves of C. rostellatum exhibiting virus-like symptoms (yellowing, severe crinkling, deformation) were observed and collected in Liaoning Province, China. Aphids were also observed on the leaves and stems (Fig. S1) of the plants and were collected. Total RNA was extracted from diseased leaves following the CTAB method, followed by the depletion of ribosomal RNAs (rRNA) with TIANSeq rRNA Depletion Kit (Tiangen, China). The RNAs were, then processed into a DNBSEQ LncRNA-Seq library, and sequenced on the MGISEQ-2000 platform at BGI Genomics (Wuhan, China). A total of 106.98 M clean reads were obtained after data filtering using SOAPnuke software (BGI, China). The clean reads were assembled into contigs using CLC Genomics Workbench 11 (Qiagen, USA) and Trinity v2.0.6 (Haas et al., 2013). A contig (4,760 reads, average coverage:73.76) of 6,391 nucleotides was found to share the highest sequence identity (99.83%) with CGMMV isolate GDLZ (MK933286), irrespective of other virus-like contigs related to Polerovirus and Totivirus. Based on the genome of GDLZ isolate, seven specific primers (Table S1) were designed to amplify the full viral genomic sequences using a PrimeScriptTM One-Step RT-PCR Kit. Seven expected amplicons were obtained, cloned, and sequenced. The complete genome was determined to be 6,423 nucleotides (GenBank accession number OR854819) in length and designated as LNMJ isolate. LNMJ shared 96.8%-99.7% nucleotide sequence identities with CGMMV isolates from China. Phylogenetic analysis based on the complete genome sequences showed that LNMJ clustered together with CGMMV isolates hn (GenBank accession number KC851866), GDLZ (GenBank accession number MK933286), and JD8 (GenBank accession number KM873784) from China. The specific primers LM-TJ-3F/3R were designed to determine the virus-symptom association for LNMJ, and all twelve symptomatic C. rostellatum plants collected from fields tested positive for LNMJ. Two out of six randomly selected aphids from the diseased plants also tested positive. To further prove its infectivity, LNMJ was inoculated mechanically onto ten healthy Nicotiana benthamiana plants, and the results indicated a high infection rate of 80% (8/10), at 30 days post-inoculation despite no distinct symptoms observed. To our knowledge, this is the first report of the natural infection of C. rostellatum plants with CGMMV. C. rostellatum is a widespread herb in China (Wei et al., 2019) and more surveys are needed to determine the distribution of CGMMV. The habitats of C. rostellatum span diverse agroecological zones, and thus our study underscores the potential spillover of CGMMV to neighboring crops as a significant risk.

Highly Selective Acetylene-to-Ethylene Electroreduction Over Cd-Decorated Cu Catalyst with Efficiently Inhibited Carbon-Carbon Coupling.

Electrochemical acetylene reduction (EAR) employing Cu catalysts represents an environmentally friendly and cost-effective method for ethylene production and purification. However, Cu-based catalysts encounter product selectivity issues stemming from carbon-carbon coupling and other side reactions. We explored the use of secondary metals to modify Cu-based catalysts and identified Cd decoration as particular effective. Cd decoration demonstrated a high ethylene Faradaic efficiency (FE) of 98.38 % with well-inhibited carbon-carbon coupling reactions (0.06 % for butadiene FE at -0.5 V versus reversible hydrogen electrode) in a 5 vol % acetylene gas feed. Notably, ethylene selectivity of 99.99 % was achieved in the crude ethylene feed during prolonged stability tests. Theoretical calculations revealed that Cd metal accelerates the water dissociation on neighboring Cu surfaces allowing more H* to participate in the acetylene semi-hydrogenation, while increasing the energy barrier for carbon-carbon coupling, thereby contributing to a high ethylene semi-hydrogenation efficiency and significant inhibition of carbon-carbon coupling. This study provides a paradigm for a deeper understanding of secondary metals in regulating the product selectivity of EAR electrocatalysts.

Elevated enteric putrescine suppresses differentiation of intestinal germinal center B cells.

The dysregulation of B cell maturation and putrescine metabolism has been implicated in various diseases. However, the causal relationship between them and the underlying mechanisms remain unclear. In this study, we investigated the impact of exogenous putrescine on B cell differentiation in the intestinal microenvironment. Our results demonstrated that administration of exogenous putrescine significantly impaired the proportion of germinal center B (GC B) cells in Peyer's patches (PPs) and lamina propria. Through integration of bulk RNA sequencing and single-cell RNA sequencing (scRNA-seq), we identified putrescine-mediated changes in gene drivers, including those involved in the B cell receptor (BCR) signaling pathway and fatty acid oxidation. Furthermore, putrescine drinking disrupted T-B cell interactions and increased reactive oxygen species (ROS) production in B cells. In vitro activation of B cells confirmed the direct suppression of putrescine on GC B cells differentiation and ROS production. Additionally, we explored the Pearson correlations between putrescine biosynthesis activity and B cell infiltration in pan-cancers, revealing negative correlations in colon adenocarcinoma, stomach adenocarcinoma, and lung adenocarcinoma, but positive correlations in liver hepatocellular carcinoma, and breast invasive carcinoma. Our findings provided novel insights into the suppressive effects of elevated enteric putrescine on intestinal B cells differentiation and highlighted the complex and distinctive immunoregulatory role of putrescine in different microenvironments. These findings expand our understanding of the role of polyamines in B cell immunometabolism and related diseases.

A chaperone-like function of FUS ensures TAZ condensate dynamics and transcriptional activation.

The Hippo pathway has important roles in organ development, tissue homeostasis and tumour growth. Its downstream effector TAZ is a transcriptional coactivator that promotes target gene expression through the formation of biomolecular condensates. However, the mechanisms that regulate the biophysical properties of TAZ condensates to enable Hippo signalling are not well understood. Here using chemical crosslinking combined with an unbiased proteomics approach, we show that FUS associates with TAZ condensates and exerts a chaperone-like effect to maintain their proper liquidity and robust transcriptional activity. Mechanistically, the low complexity sequence domain of FUS targets the coiled-coil domain of TAZ in a phosphorylation-regulated manner, which ensures the liquidity and dynamicity of TAZ condensates. In cells lacking FUS, TAZ condensates transition into gel-like or solid-like assembles with immobilized TAZ, which leads to reduced expression of target genes and inhibition of pro-tumorigenic activity. Thus, our findings identify a chaperone-like function of FUS in Hippo regulation and demonstrate that appropriate biophysical properties of transcriptional condensates are essential for gene activation.

Photoresponsive CHA-Integrated Self-Propelling 3D DNA Walking Amplifier within the Concentration Localization Effect of DNA Molecular Framework Enables Highly Efficient Fluorescence Bioimaging.

While three-dimensional (3D) DNA walking amplifiers hold considerable promise in the construction of advanced DNA-based fluorescent biosensors for bioimaging, they encounter certain difficulties such as inadequate sensitivity, premature activation, the need for exogenous propelling forces, and low reaction rates. In this contribution, a variety of profitable solutions have been explored. First, a catalytic hairpin assembly (CHA)-achieved nonenzymatic isothermal nucleic acid amplification is integrated to enhance sensitivity. Subsequently, one DNA component is simply functionalized with a photocleavage-bond to conduct a photoresponsive manner, whereby the target recognition occurs only when the biosensor is exposed to an external ultraviolet light source, overcoming premature activation during biodelivery. Furthermore, a special self-propelling walking mechanism is implemented by reducing biothiols to MnO2 nanosheets, thereby propelling forces that are self-supplied to a Mn2+-reliant DNAzyme. By carrying the biosensing system with a DNA molecular framework to induce a unique concentration localization effect, the nucleic acid contact reaction rate is notably elevated by 6 times. Following these, an ultrasensitive in vitro detection performance with a limit of detection down to 2.89 fM is verified for a cancer-correlated microRNA biomarker (miRNA-21). Of particular importance, our multiple concepts combined 3D DNA walking amplifier that enables highly efficient fluorescence bioimaging in live cells and even bodies, exhibiting a favorable application prospect in disease analysis.

FSH preserves the viability of hypoxic granulosa cells via activating the HIF-1α-GAS6-Axl-Akt pathway.

The developmental fate of ovarian follicles is primarily determined by the survival status (proliferation or apoptosis) of granulosa cells (GCs). Owing to the avascular environment within follicles, GCs are believed to live in a hypoxic niche. Follicle-stimulating hormone (FSH) has been reported to improve GCs survival by governing hypoxia-inducible factor-1α (HIF-1α)-dependent hypoxia response, but the underlying mechanisms remain poorly understood. Growth arrest-specific gene 6 (GAS6) is a secreted ligand of tyrosine kinase receptors, and has been documented to facilitate tumor growth. Here, we showed that the level of GAS6 was markedly increased in mouse ovarian GCs after the injection of FSH. Specifically, FSH-induced GAS6 expression was accompanied by HIF-1α accumulation under conditions of hypoxia both in vivo and in vitro, whereas inhibition of HIF-1α with small interfering RNAs/antagonist repressed both expression and secretion of GAS6. As such, Luciferase reporter assay and chromatin immunoprecipitation assay showed that HIF-1α directly bound to a hypoxia response element site within the Gas6 promoter and contributed to the regulation of GAS6 expression in response to FSH. Notably, blockage of GAS6 and/or its receptor Axl abrogated the pro-survival effects of FSH under hypoxia. Moreover, phosphorylation of Axl by GAS6 is required for FSH-mediated Akt activation and the resultant pro-survival phenotypes. Finally, the in vitro findings were verified in vivo, which showed that FSH-induced proliferative and antiapoptotic effects in ovarian GCs were diminished after blocking GAS6/Axl using HIF-1α antagonist. These findings highlight a novel function of FSH in preserving GCs viability against hypoxic stress by activating the HIF-1a-GAS6-Axl-Akt pathway.

Genetically engineered virus-like particle-armoured and multibranched DNA scaffold-corbelled ultra-sensitive hierarchical hybridization chain reaction for targeting-enhanced imaging in living biosystems under spatiotemporal light powering.

Although nucleic acids-based fluorescent biosensors, exemplified by the hybridization chain reaction (HCR), have exhibited promise as an imaging tool for detecting disease-related biomolecular makers in living biosystems, they still face certain challenges. These include the need for improved sensitivity, poor bio-targeting capability, the absence of signal enrichment interface and the uncontrollable biosensing initiation. Herein, we present a range of effective solutions. First, a stacking design resembling building blocks is used to construct a special hierarchical HCR (termed H-HCR), for which a hierarchical bridge is employed to graft multiunit HCR products. Furthermore, the H-HCR components are encapsulated into a virus-like particle (VLP) endowed with a naturally peptide-mediated targeting unit through genetic engineering of plasmids, after which the biosensor can specifically identify cancer cytomembranes. By further creating a multibranched DNA scaffold to enrich the H-HCR produced detection signals, the biosensor's analyte recognition module is inserted with a photocleavage-linker, allowing that the biosensing process can be spatiotemporally initiated via a light-powered behavior. Following these innovations, this genetically engineered VLP-armoured and multibranched DNA-scaffold-corbelled H-HCR demonstrates an ultra-sensitive and specific biosensing performance to a cancer-associated microRNA marker (miRNA-155). Beyond the worthy in vitro analysis, our method is also effective in performing imaging assays for such low-abundance analyte in living cells and even bodies, thus providing a roust platform for disease diagnosis.

IGF-I protects porcine granulosa cells from hypoxia-induced apoptosis by promoting homologous recombination repair through the PI3K/AKT/E2F8/RAD51 pathway.

Severe hypoxia induced by vascular compromise (ovarian torsion, surgery), obliteration of vessels (aging, chemotherapy, particularly platinum drugs) can cause massive follicle atresia. On the other hand, hypoxia increases the occurrence of DNA double-strand breaks (DSBs) and triggers cellular damage repair mechanisms; however, if the damage is not promptly repaired, it can also induce the apoptosis program. Insulin-like growth factor-I (IGF-I) is a polypeptide hormone that plays essential roles in stimulating mammalian follicular development. Here, we report a novel role for IGF-I in protecting hypoxic GCs from apoptosis by promoting DNA repair through the homologous recombination (HR) process. Indeed, the hypoxic environment within follicles significantly inhibited the efficiency of HR-directed DNA repair. The presence of IGF-I-induced HR pathway to alleviate hypoxia-induced DNA damage and apoptosis primarily through upregulating the expression of the RAD51 recombinase. Importantly, we identified a new transcriptional regulator of RAD51, namely E2F8, which mediates the protective effects of IGF-I on hypoxic GCs by facilitating the transcriptional activation of RAD51. Furthermore, we demonstrated that the PI3K/AKT pathway is crucial for IGF-I-induced E2F8 expression, resulting in increased RAD51 expression and enhanced HR activity, which mitigates hypoxia-induced DNA damage and thereby protects against GCs apoptosis. Together, these findings define a novel mechanism of IGF-I-mediated GCs protection by activating the HR repair through the PI3K/AKT/E2F8/RAD51 pathway under hypoxia.

Mn-Doped Nano-Hydroxyapatites as Theranostic Agents with Tumor pH-Amplified MRI-Signal Capabilities for Guiding Photothermal Therapy.

Background: The integration of diagnostic and therapeutic functions into a biosafe nanoplatform with intelligent response functions at the tumor microenvironment (TME) is a promising strategy for cancer therapy. Methods: Mn-doped nano-hydroxyapatite (nHAPMn) nanoparticles were successfully prepared via a simple coprecipitation method for magnetic resonance imaging (MRI)-guided photothermal therapy. This study is the first to report on the use of Mn to render biodegradable hydroxyapatite suitable for MRI and effective photothermal therapy (PTT) simultaneously by regulating the pH of nHAPMn during the preparation process. Results: Combined with near-infrared (NIR) laser irradiation, a photothermal conversion efficiency of 26% and effective photothermal lethality in vitro were achieved. Moreover, the degradation of nHAPMn led to the release of Mn ions and amplified the MRI signals in an acidic TME, which confirmed that nHAPMn had a good pH-responsive MRI capacity in solid tumors. In animal experiments, tumors in the nHAPMn5+NIR group completely abated after 14 days of treatment, with no significant recurrence during the experiment. Conclusion: Therefore, nHAPMn is promising as a nanotheranostic agent and can be effective in clinical diagnosis and therapy for treating cancer.