Transcriptome analysis of large yellow croaker (Larimichthys crocea) at different growth rates.

The unsynchronized growth of the large yellow croaker (Larimichthys crocea), which impacts growth efficiency, poses a challenge for aquaculture practitioners. In our study, juvenile stocks of large yellow croaker were sorted by size after being cultured in offshore cages for 4 months. Subsequently, individuals from both the fast-growing (FG) and slow-growing (SG) groups were sampled for analysis. High-throughput RNA-Seq was employed to identify genes and pathways that are differentially expressed during varying growth rates, which could suggest potential physiological mechanisms that influence growth rate. Our transcriptome analysis identified 382 differentially expressed genes (DEGs), comprising 145 upregulated and 237 downregulated genes in comparison to the SG group. GO and KEGG enrichment analyses indicated that these DEGs are predominantly involved in signal transduction and biochemical metabolic pathways. Quantitative PCR (qPCR) results demonstrated that cat, fasn, idh1, pgd, fgf19, igf2, and fads2 exhibited higher expression levels, whereas gadd45b and gadd45g showed lower expression compared to the slow-growing group. In conclusion, the differential growth rates of large yellow croaker are intricately associated with cellular proliferation, metabolic rates of the organism, and immune regulation. These findings offer novel insights into the molecular mechanisms and regulatory aspects of growth in large yellow croaker and enhance our understanding of growth-related genes.

Abnormal Behavior Monitoring Method of Larimichthys crocea in Recirculating Aquaculture System Based on Computer Vision.

It is crucial to monitor the status of aquaculture objects in recirculating aquaculture systems (RASs). Due to their high density and a high degree of intensification, aquaculture objects in such systems need to be monitored for a long time period to prevent losses caused by various factors. Object detection algorithms are gradually being used in the aquaculture industry, but it is difficult to achieve good results for scenes with high density and complex environments. This paper proposes a monitoring method for Larimichthys crocea in a RAS, which includes the detection and tracking of abnormal behavior. The improved YOLOX-S is used to detect Larimichthys crocea with abnormal behavior in real time. Aiming to solve the problems of stacking, deformation, occlusion, and too-small objects in a fishpond, the object detection algorithm used is improved by modifying the CSP module, adding coordinate attention, and modifying the part of the structure of the neck. After improvement, the AP50 reaches 98.4% and AP50:95 is also 16.2% higher than the original algorithm. In terms of tracking, due to the similarity in the fish's appearance, Bytetrack is used to track the detected objects, avoiding the ID switching caused by re-identification using appearance features. In the actual RAS environment, both MOTA and IDF1 can reach more than 95% under the premise of fully meeting real-time tracking, and the ID of the tracked Larimichthys crocea with abnormal behavior can be maintained stably. Our work can identify and track the abnormal behavior of fish efficiently, and this will provide data support for subsequent automatic treatment, thus avoiding loss expansion and improving the production efficiency of RASs.

Effects of transportation on physiological indices and metabolomics of the large yellow croaker Larimichthys crocea.

The aim of this study was to investigate the survival rate, biochemical indices, and metabolome changes of the large yellow croaker after 48 h of live transportation. Two hundred and forty large yellow croakers (body weight: 23.4 ± 5.3 g, total length: 12.2 ± 0.7 cm) were used in this experiment. The transport buckets were filled with fresh seawater and the parameters of the water were a temperature of 16 ± 0.5 °C and a dissolved oxygen content of 6.0-7.2 mg/L. Large yellow crokers were first divided to 0, 10, 20, and 30 mg/L MS-222 groups to observe the 12 h survival rate. The survival rate of 10 mg/L MS-222 group (T1) was the 95%, highest of all, and was further analyzed. The results of liver biochemical indices indicated inhibition of gluconeogenesis and pentose phosphate pathway metabolism. In addition, metabolomics analysis identified significantly differentially expressed metabolites between T1 group and 0 mg/L MS-222 control (C) groups. Furthermore, Kyoto Encyclopedia of Genes and Genomes (KEGG) results revealed that the pathways of amino acid metabolism, especially the lysine, aspartate, and homoserine in the liver were significantly affected. In conclusion, the combination of metabolomics and liver biochemical assays provided a characterization of the response mechanism of L. crocea exposed to live transportation.

CircPDE4B inhibits retinal pathological angiogenesis via promoting degradation of HIF-1α though targeting miR-181c.

Retinopathy of prematurity is a major cause of childhood blindness worldwide. Hence, exploring the proper treatment methods is a must in tacking this disease. qRT-PCR and western blot were used to detect the expression of genes and proteins, respectively. The proliferation of human retinal vascular endothelial cells (HRECs) was ensured by MTT assay. The luciferase activity was measured through luciferase assay. The inverted phase-contrast light microscope was used to observe the formation of a vascular tube. In the present study, our data demonstrated that circPDE4B was downregulated, while hypoxia-inducible factor-1α (HIF-1α) and VEGFA were upregulated in the retinopathy of prematurity model in vitro and in vivo. CircPDE4B increasing remarkably inhibited the expression of HIF-1α and VEGFA in hypoxia-induced HRECs and subsequent repressed cell proliferation and pathological angiogenesis. We further found that miR-181c suppressed the expression of von Hippel-Lindau (VHL), while circPDE4B could promote VHL expression via binding to miR-181c. Finally, our results revealed that circPDE4B inhibited the expression of VEGFA and pathological angiogenesis via facilitating VHL-mediated ubiquitin degradation of HIF-1α. In conclusion, circPDE4B suppressed the expression of VEGFA and pathological angiogenesis via promoting VHL-mediated ubiquitin degradation of HIF-1α through binding to miR-181c. Our study indicated that circPDE4B might be an effective therapeutic target of retinopathy of prematurity.

Molecular cloning, expression analyses and functional characterization of a goose-type lysozyme gene from Bostrychus sinensis (family: Eleotridae).

In this study, we sequenced and characterized the goose-type lysozyme gene, termed as BsLysG, from the Chinese black sleeper (Bostrychus sinensis). The BsLysG encodes 196 amino acids and contains a soluble bacterial lytic transglycosylases domain, three catalytic residues (Glu72, Asp85 and Asp102) and the GLMQ motif (Gly97, Leu98, Met99 and Gln100). No signal peptide was observed in the BsLysG protein. The genomic DNA of BsLysG contains five exons and four introns. The sequence analyses showed that the BsLysG exhibits high similarity with LysG from other fishes. Phylogenetic analyses showed that the BsLysG is clustered together with its counterparts from other teleost fishes. The Real-time PCR analyses showed that the BsLysG was found to be ubiquitously expressed in ten examined organs in Chinese black sleeper, with predominant expression in spleen, followed by head kidney and peripheral blood. Expression analyses showed that the BsLysG was significantly upregulated in vivo after either pathogen Vibrio parahemolyticus infection or poly (I:C) challenge in peripheral blood, head kidney, liver and spleen organs. The purified recombinant BsLysG (rBsLysG) has optimal activity at 35 °C and pH 5.5. The rBsLysG exhibited antimicrobial activity against two Gram-positive bacteria (Micrococcus lysodeikticus and Staphylococcus aureus) and two Gram-negative bacteria (Escherichia coli and V. parahemolyticus). The Scanning electron microscope (SEM) imaging analyses showed that the rBsLysG-treated V. parahemolyticus cells displayed morphological deformation. These results indicate that the BsLysG is involved in host immune defense against bacterial infection.

Transport of Colloidal Particles in Microscopic Porous Medium Analogues with Surface Charge Heterogeneity: Experiments and the Fundamental Role of Single-Bead Deposition.

Understanding colloid transport in subsurface environments is challenging because of complex interactions among colloids, groundwater, and porous media over several length scales. Here, we report a versatile method to assemble bead-based microfluidic porous media analogues with chemical heterogeneities of different configurations. We further study the transport of colloidal particles through a family of porous media analogues that are randomly packed with oppositely charged beads with different mixing ratios. We recorded the dynamics of colloidal particle deposition at the level of single grains. From these, the maximum surface coverage (θmax = 0.051) was measured directly. The surface-blocking function and the deposition coefficient (kpore = 3.56 s-1) were obtained. Using these pore-scale parameters, the transport of colloidal particles was modeled using a one-dimensional advection-dispersion-deposition equation under the assumption of irreversible adsorption between oppositely charged beads and colloids, showing very good agreement with experimental breakthrough curves and retention profiles at the scale of the entire porous medium analogue. This work presents a new approach to fabricate chemically heterogeneous porous media in a microfluidic device that enables the direct measurement of pore-scale colloidal deposition. Compared with the conventional curve-fitting method for deposition constant, our approach allows quantitative prediction of colloidal breakthrough and retention via coupling of direct pore-scale measurements and an advection-dispersion-deposition model.

Interfacial CO2-mediated nanoscale oil transport: from impediment to enhancement.

CO2-based enhanced oil recovery is widely practiced. The current understanding of its mechanisms largely focuses on bulk phenomena such as achieving miscibility or reducing oil density and viscosity. Using molecular dynamics simulations, we show that CO2 adsorption on calcite surfaces impedes decane transport at moderate adsorption density but enhances decane transport when CO2 adsorption approaches surface saturation. These effects change the decane permeability through 8 nm-wide pores by up to 30% and become negligible only in pores wider than several tens of nanometers. The strongly nonlinear, non-monotonic dependence of decane permeability on CO2 adsorption is traced to CO2's modulation of interfacial structure of long-chain hydrocarbons, and thus the slippage between interfacial hydrocarbon layers and between interfacial CO2 and hydrocarbon layers. These results highlight a new and critical role of CO2-induced interfacial effects in influencing oil recovery from unconventional reservoirs, whose porosity is dominated by nanopores.

Hypoxia-induced lncRNA ANRIL promotes cisplatin resistance in retinoblastoma cells through regulating ABCG2 expression.

Cisplatin (DDP) resistance limits its efficacy for retinoblastoma (Rb). Hypoxia-inducible factor-1α (HIF-1α) has been shown to contribute to chemotherapy resistance in tumours under hypoxic conditions. This study was designed to explore the role and mechanism of long non-coding RNA (lncRNA) antisense non-coding RNA in the INK4 locus (ANRIL) in regulating DDP resistance in Rb cells under hypoxia and to validate whether HIF-1α was involved in this process. The interaction between HIF-1α and the promoter of ANRIL was analyzed using ChIP assay. Cell proliferation and apoptosis, as well as protein levels of drug resistance-related proteins (ABCG2 and MDR1) were examined to evaluate DDP resistance in Rb cells. The interactions between miR-328 and ANRIL as well as miR-328 and ABCG2 were analyzed using dual-luciferase reporter assays. Upon hypoxia, HIF-1α directly bound to the ANRIL promoter region to transcriptionally activate ANRIL. The hypoxia-induced ANRIL promoted Rb cell resistance to DDP, as evidenced by facilitation of cell proliferation, inhibition of cell apoptosis and upregulation of ABCG2 and MDR1. Mechanistically, ANRIL promoted Rb cell resistance to DDP by acting as a sponge of miR-328 to upregulate expression of ABCG2, which was confirmed as a direct target of miR-328. Collectively, hypoxia-induced ANRIL promotes DDP resistance in Rb cells by sponging miR-328 to upregulate ABCG2 expression.

PRC1 gene silencing inhibits proliferation, invasion, and angiogenesis of retinoblastoma cells through the inhibition of the Wnt/ß-catenin signaling pathway.

Retinoblastoma is an ocular malignancy occurring in childhood. The current study evaluates the ability of silenced PRC1 on retinoblastoma cell proliferation, and angiogenesis via the Wnt/ß-catenin signaling pathway. A total of 36 cases of retinoblastoma tissues (n = 36) and normal retinal tissues (n = 10) were selected in the current study. Retinoblastoma cells presenting with the high PRC1 messenger RNA (mRNA) expression were selected among the WERI-Rb-1, HXO-RB44, Y79, SO-Rb50, and SO-Rb70 cells lines, and were transfected with siRNA-PRC1 and LiCl (the activator of the Wnt/ß-catenin pathway). The expressions of PRC1, VEGF, Wnt1, ß-catenin, CyclinD1, extent of ß-catenin, and GSK-3ß phosphorylation were evaluated. Cell proliferation, cell-cycle distribution, and cell invasion of retinoblastoma cells were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, flow cytometry, and Transwell assay. The angiogenesis of retinoblastoma cells was detected by tube formation assay. HXO-RB44 and WERI-Rb-1 cells were selected owing to the highest PRC1 mRNA expression. Meanwhile, PRC2 gene silencing presented lower expression levels of PRC1, VEGF, Wnt1, ß-catenin, CyclinD1, extent of ß-catenin and GSK-3ß phosphorylation, decreased proliferation and invasion abilities, extended G0/G1 phase, and shortened S and G2/M phases of HXO-RB44 and WERI-Rb-1 cells, suggesting the silenced PRC2 inactivated Wnt/ß-catenin pathway, so as to further restrain the retinoblastoma cell proliferation, invasion, and angiogenesis. These results support the view that PRC1 gene silencing could suppress the proliferation, and angiogenesis of retinoblastoma cells by repressing the Wnt/ß-catenin pathway.

Mesenchymal stem cells promote endothelial progenitor cell migration, vascularization, and bone repair in tissue-engineered constructs via activating CXCR2-Src-PKL/Vav2-Rac1.

Tissue-engineered constructs (TECs) hold great promise for treating large bone defects. Incorporated mesenchymal stem cells (MSCs) can facilitate the vascularization of TECs. Nevertheless, the underlying mechanism remains ambiguous. Here we analyzed the roles of C-X-C chemokine receptor 2 (CXCR2) and its downstream signal pathways in MSC-induced endothelial progenitor cell (EPC) migration. Transwell assays and immunofluorescence staining were performed for cell migration analysis in vitro and in vivo, respectively. A series of signal inhibitors and short hairpin RNA was used for screening essential signaling molecules. We found that blockade of CXCR2 abolished the migration of EPCs toward MSCs as well as subsequent vascularization and bone repair in TECs. Moreover, screening results suggested that steroid receptor coactivator (Src) acted as a predominant downstream effector of CXCR2. Further molecular biologic and histomorphological experiments revealed that the action of Src required the phosphorylation of ras-related C3 botulinum toxin substrate 1 (Rac1), which was pivotal for the development of lamellipodia and filopodia. The phosphorylation and colocalization of paxillin kinase linker (PKL) and vav guanine nucleotide exchange factor 2 (Vav2) were essential for the activation of Rac1. Therefore, we demonstrated that MSCs promoted EPC migration via activating CXCR2 and its downstream Src-PKL/Vav2-Rac1 signaling pathway. These findings unveiled the molecular mechanism in the vascularization of TECs and were expected to provide novel targets for efficacy improvement.-Li, Z., Yang, A., Yin, X., Dong, S., Luo, F., Dou, C., Lan, X., Xie, Z., Hou, T., Xu, J., Xing, J. Mesenchymal stem cells promote endothelial progenitor cell migration, vascularization, and bone repair in tissue-engineered constructs via activating CXCR2-Src-PKL/Vav2-Rac1.

Immunity-associated long non-coding RNA and expression in response to bacterial infection in large yellow croaker (Larimichthys crocea).

Long non-coding RNA refers to an RNA transcript of a non-coding protein with a sequence length greater than 200 bp. More and more reports indicated that lncRNA was involved in the regulation of gene expression as a signalling molecule, an inducing molecule, a leader molecule and a scaffold molecule. Previous studies have sequenced the draft genome and several transcriptome data sets for protein-coding genes of the large yellow croaker (Larimichthys crocea), but little is known about the expression and function of lncRNAs in this species. In order to obtain a catalogue of lncRNAs for this croaker, Vibrio parahaemolyticus infection challenge experiment was conducted and long non-coding RNA sequences were obtained. Using high-throughput sequencing of lncRNA, a total of 73,233 high-confidence transcripts were reconstructed in 32,726 loci, recovering most of the expressed reference transcripts, and 6473 novel expressed loci were identified. The tissue expression profile revealed that most lacunas were specifically enriched in distinct tissues. A set of 163 lncRNAs were identified as being specifically expressed in the spleen and may be involved in the immune response. It is the first time to identify specific lncRNAs in the L. crocea systematically in this croaker, aiming to benefit the future genomic study of this species.

Gray matter reduction related to decreased serum creatinine and increased triglyceride, Hemoglobin A1C, and low-density lipoprotein in subjects with obesity.

PURPOSE: Altered brain volume and metabolic variables have been found in subjects with obesity. However, the role of metabolic parameters in gray matter volume (GMV) has been poorly investigated. This study aimed to investigate the relationship between the metabolic parameters and brain volume in subjects with obesity. METHODS: Thirty-seven subjects with obesity and 39 age and sex matched normal-weight controls were included in this study. Eighteen of the 37 participants who underwent sleeve gastrectomy were included in the longitudinal analysis. Blood samples and high-resolution 3T T1-weighted magnetic resonance images were collected. Metabolic parameters in plasma and GMV were measured. RESULTS: Multiple linear regression analysis showed that gray matter reduction in several cognition-related cortices including right angular gyrus, superior occipital cortex, superior parietal cortex, and cerebellum was related to decreased creatinine, as well as increased triglyceride, HbA1c, and low-density lipoprotein in plasma in subjects with obesity. Weight loss after the surgery induced significant recovery of altered metabolic parameters and decreased gray matter volume. Furthermore, changes in the four metabolic parameters before and after the surgery were associated with changes in gray matter volume. CONCLUSION: Our results suggest that the gray matter reduction is related to decreased creatinine as well as increased triglyceride, HbA1c, and low-density lipoprotein in plasma in subjects with obesity.

IL-8 Enhances Therapeutic Effects of BMSCs on Bone Regeneration via CXCR2-Mediated PI3k/Akt Signaling Pathway.

BACKGROUND/AIMS: Tissue engineering bone transplantation with bone marrow mesenchymal stem cells (BMSCs) is an effective technology to treat massive bone loss, while molecular regulation of the bone regeneration processes remains poorly understood. Here, we aimed to assess the role of interleukin-8 (IL-8) in the recruitment of host cells by seeded BMSCs and in the bone regeneration. METHODS: A transwell assay was performed to examine the role of IL-8/CXCR1/CXCR2/PI3k/Akt on the migration potential of hBMSCs. The in vitro chondrogenic differentiation of hBMSCs was assessed by examination of 2 chondrogenic markers, Sox9 and type 2 collagen (COL2). mBMSCs were used in tissue engineered bone (TEB) with/without IL-8 implanted into bone defect area with CXCR2 or Akt inhibitors. Density and Masson staining of the regenerated bone were assessed. The chondrogenesis was assessed by expression levels of associated proteins, Sox9 and COL2, by RT-qPCR and by immunohistochemistry. RESULTS: IL-8 may trigger in vitro migration of hBMSCs via CXCR2-mediated PI3k/Akt signaling pathway. IL-8 enhances osteogenesis in the TEB-implanted bone defect in mice. IL-8 induces chondrogenic differentiation of hBMSCs via CXCR2-mediated PI3k/Akt signaling pathway in vitro and in vivo. CONCLUSIONS: IL-8 enhances therapeutic effects of MSCs on bone regeneration via CXCR2-mediated PI3k/Akt signaling pathway.

Bitter peptides from enzymatically hydrolyzed protein increase the number of leucocytes and lysozyme activity of large yellow croaker (Larimichthys crocea).

The large yellow croakers (Larimichthys crocea) are mainly present in the Chinese coast and near seas with high economic importance, but vulnerable to many diseases, especially in the breeding and aquaculture. The purpose of this research was to boost the innate immune system of the large yellow croaker by administering bitter peptides into their peritoneal cavity. Total 120 Juvenile of large yellow croakers in very even weight of 60 g were divided into 4 different groups in 200/300 L of water tank, respectively. Fish growth were observed for 3 months before and after different treatments. The bitter peptides from pepsin hydrolysis were applied because they possess the highest bitter sensory scores. The blood of fish from the different groups was collected and tested for different immune parameters to evaluate the effectiveness of bitter peptides as immune stimulants after administration for 8 weeks. The average ratio of leukocytes/total blood cells (%) for control was found at 14.6%, for the low dose of bitter peptides 0.6 mg/fish was at 29.3%, for middle dose of 1.2 mg/fish was at 35%, and high dose of 2.4 mg/fish was at 30%. The lysozyme assay showed that the OD (optical density) units of relative progress lysis activity at 60 min were 0.17, 0.101, 0.307 and 0.198, respectively. Similarly in the same order as in phagocyte assay, most importantly the middle dose (1.2mg/fish) gave the highest survival rate throughout the assay. The results showed that bitter peptides can be used as immune boosters for the yellow croakers and the optimum dose was 1.2 mg/fish due to both leukocytes and lysozyme activity in the treated samples increased significantly compared with the control group. According to the results obtained, we suggest that the incorporation of middle dose of bitter peptides into fish feeds may reduce the fish diseases in aquaculture, at least for large yellow croakers.

Hybrid Newton-Successive Substitution Method for Multiphase Rachford-Rice Equations.

In multiphase (≥3) equilibrium calculations, when the Newton method is used to solve the material balance (Rachford-Rice) equations, poorly conditioned Jacobian can lead to false convergence. We present a robust successive substitution method that solves the multiphase Rachford-Rice equations sequentially using the method of bi-section while considering the monotonicity of the equations and the locations of singular hyperplanes. Although this method is slower than Newton solution, as it does not rely on Jacobians that can become poorly conditioned, it can be inserted into Newton iterations upon the detection of a poorly conditioned Jacobian. Testing shows that embedded successive substitution steps effectively improved the robustness. The benefit of the Newton method in the speed of convergence is maintained.

Bead-Based Microfluidic Sediment Analogues: Fabrication and Colloid Transport.

Mobile colloids can act as carriers for low-solubility contaminants in the environment. However, the dominant mechanism for this colloid-facilitated transport of chemicals is unclear. Therefore, we developed a bead-based microfluidic platform of sediment analogues and measured both single and population transport of model colloids. The porous medium is assembled through a bead-by-bead injection method. This approach has the versatility to build both electrostatically homogeneous and heterogeneous media at the pore scale. A T-junction at the exit also allowed for encapsulation and enumeration of colloids effluent at single particle resolution to give population dynamics. Tortuosity calculated from pore-scale trajectory analysis and its comparison with lattice Boltzmann simulations revealed that transport of colloids was influenced by the size exclusion effect. The porous media packed by positively and negatively charged beads into two layers showed distinctive colloidal particle retention and significant remobilization and re-adsorption of particles during water flushing. We demonstrated the potential of our method to fabricate porous media with surface heterogeneities at the pore scale. With both single and population dynamics measurement, our platform has the potential to connect pore-scale and macroscale colloid transport on a lab scale and to quantify the impact of grain surface heterogeneities that are natural in the subsurface environment.

Pulmonary arterial hypertension in HIV infection: a concise review.

Pulmonary arterial hypertension (PAH) is an infrequent but nevertheless serious life threatening severe complication of human immunodeficiency virus (HIV) infection. In today's era of antiretroviral therapy (ART), the mortality of HIV patients has greatly reduced due to improved immune function and fewer opportunistic infections. However, these patients have an increased incidence of PAH. In this review, we will mainly discuss HIV-related pulmonary arterial hypertension (HRPH) in terms of the epidemiology, pathogenesis, clinical characteristics and treatment.

Synthesis of Au@Ag core-shell nanocubes with finely tuned shell thicknesses for surface-enhanced Raman spectroscopic detection.

In this work, we describe a facile method for generating monodisperse Au@Ag core-shell nanocubes with well-controlled size and fine-tuned Ag shell thicknesses. In this synthesis method, Au nanocubes were prepared via the seed-mediated growth method. Then, Au@Ag nanocubes with the core-shell structure were prepared separately by reducing AgNO3 with AA using as-prepared Au nanocubes as seeds. The thickness of Ag shells could be finely tuned from 3.6 nm to 10.0 nm by varying the concentration of the AgNO3 precursor. By investigating the localized surface plasmon resonance (LSPR) properties of Au@Ag nanocubes in relation to the thickness of the Ag shell, we found that the intensity of the characteristic peak of Ag gradually increases and that of Au gradually decreases as the thickness of the Ag shell increases. Additionally, surface-enhanced Raman scattering (SERS) properties of Au@Ag core-shell nanocubes were evaluated using rhodamine 6G (R6G) as the probe molecule. Interestingly, Au@Ag nanocubes exhibit efficient SERS intensities compared to the Au nanocubes, and Ag shell with a thickness of about 8.4 nm exhibits the optimal SERS activity. In addition, our results also demonstrated that Au@Ag nanocubes with an Ag shell thickness of 8.4 nm exhibited high SERS sensitivity and are capable of probing the analyte down to 10-12 M. The results obtained here suggest that Au@Ag core-shell nanocubes might serve as a nanoprobe for SERS-based analytical and biosensing applications.

Brain network hierarchy reorganization in subthreshold depression.

BACKGROUND: Hierarchy is the organizing principle of human brain network. How network hierarchy changes in subthreshold depression (StD) is unclear. The aim of this study was to investigate the altered brain network hierarchy and its clinical significance in patients with StD. METHODS: A total of 43 patients with StD and 43 healthy controls matched for age, gender and years of education participated in this study. Alterations in the hierarchy of StD brain networks were depicted by connectome gradient analysis. We assessed changes in network hierarchy by comparing gradient scores in each network in patients with StD and healthy controls. The study compared different brain subdivisions if there was a different network. Finally, we analysed the relationship between the altered gradient scores and clinical characteristics. RESULTS: Patients with StD had contracted network hierarchy and suppressed cortical range gradients. In the principal gradient, the gradient scores of default mode network were significantly reduced in patients with StD compared to controls. In the default network, the subdivisions of reduced gradient scores were mainly located in the precuneus, superior temporal gyrus, and anterior and posterior cingulate gyrus. Reduced gradient scores in the default mode network, the anterior and posterior cingulate gyrus were correlated with severity of depression. CONCLUSIONS: The network hierarchy of the StD changed and was significantly correlated with depressive symptoms and severity. These results provided new insights into further understanding of the neural mechanisms of StD.