DISC1 inhibits GSK3β activity to prevent tau hyperphosphorylation under diabetic encephalopathy

Diabetic encephalopathy (DE) is a common complication of type 2 diabetes (T2D), especially in those patients with long T2D history. Persistent high glucose (HG) stimulation leads to neuron damage and manifests like Alzheimer's disease's pathological features such as neurofilament tangle. However, the precise mechanism of high-glucose-induced tau hyperphosphorylation is not fully revealed. We here gave evidence that Disrupted in schizophrenia 1 protein (DISC1) could interact with glycogen synthase kinase 3β (GSK3β) and inhibit its activity to prevent tau hyperphosphorylation. By using DB/DB mice as animal model and HG-treated N2a cell as cell model, we found that DISC1 was downregulated both in vivo and in vitro, complicated with Tau hyperphosphorylation and GSK3β activation. Further, we identified DISC1 interacted with GSK3β by its 198th-237th amino acid residues. Overexpression of full length DISC1 but not mutated DISC1 lacking this domain could prevent HG induced tau hyperphosphorylation. Taken together, our work revealed DISC1 could be an important negative modulators of tau phosphorylation, and suggested that preservation of DISC1 could prevent HG induced neuron damage.

Occurrence and Characteristics of Microplastics Contamination in Different Intensive Aquaculture Systems Nearby the Yangtze Estuary, China

Microplastics (MPs) pollution has been extensively investigated in natural fishery waters, but studies on intensive aquaculture systems are scarce. Here, the occurrence and properties of MPs were investigated and compared between four different aquaculture systems nearby the Yangtze Estuary. The average MPs concentration was in order of recirculating aquaculture system (RAS, 1.67 particles/L) < aquarium (2.47 particles/L) < cement pond (10.09 particles/L) < earthen pond (13.81 particles/L). Compared to fragment MPs, fiber was the more abundant shape in aquarium (85.88%), RAS (77.61%) and earthen pond (68.13%). A total of six colors were found in four systems. The black MPs accounted for 56.86% and 47.45% in aquarium and RAS system, respectively. The high proportion of blue MPs was found in cement pond (37.65%) and earthen pond (40%). The most MPs sizes observed in the four systems were 43% of 50-300 μm MPs in aquarium; 44% and 30.19% of 300-1000 μm MPs in RAS and cement pond, respectively; and 30.19% of 3000-5000 μm MPs in earthen pond. For polymers, polypropylene occupied 47.83% in aquarium and RAS, 41.46% in cement pond and 27.79% in earthen pond. Proportion of rayon was highest in RAS (60.87%) and 34.04% of nylon was found in earthen pond. These results could provide scientific reference for further traceability and removal of MPs in different aquaculture systems.

Microplastics drive nitrification by enriching functional microorganisms in aquaculture pond waters

The plastisphere refers to biofilm formation on the microplastic (MP) surface, but its subsequent functions, especially driving the nitrogen biogeochemical cycle, are rarely studied. Here, MPs were incubated in the pelagic water and benthic water-sediment interface of an aquaculture pond, and the two corresponding microcosms amended with incubated plastisphere were simulated. The results showed decreased ammonia concentrations and increased nitrification rates in microcosms with either pelagic or benthic plastispheres. To uncover the possible mechanisms, the community structure and function of the plastisphere were investigated. As clarified by 16S rRNA, the community diversity of the pelagic plastisphere was significantly higher than that of the corresponding hydrosphere. Plastisphere communities, especially those incubated in pelagic water, were separated from the hydrosphere. Moreover, the abundance of Proteobacteria increased while the abundance of Cyanobacteria decreased in both plastispheres. Metagenome further revealed that the abundance of amoA and annotated Nitrososphaeraceae_archaeon and hao and affiliated Nitrosomonas_europaea, which contributed to ammonia oxidation to nitrite, was higher in the benthic plastisphere. Comparing the pelagic plastisphere with the corresponding hydrosphere, however, the abundance of nxrA and annotated Nitrobacter hamburgensis and nxrB and the affiliated Nitrospira moscoviensis, which are involved in nitrite oxidation, was more abundant in the plastisphere. These findings suggest that the plastisphere might selectively enrich functional microorganisms and genes in a habitat-dependent manner to promote nitrification in aquaculture ponds.

Modified Sijunzi granule decreases post-weaning diarrhea in Rex rabbits via promoting intestinal development

Traditional Chinese medicine (TCM) formulas can be adjusted on the basis of TCM basic theory to achieve the best curative effect, especially for diseases with complex pathogenesis, such as post-weaning diarrhea (PWD). Shugan Jianwei Sijunzi decoction (SJ-SJZD) can be recognized as modified Sijunzi Decoction (SJZD) supplemented with Astragalus mongholicus Bunge, Bupleurum chinense DC, Citrus × aurantium L., and Crataegus pinnatifida Bunge (fruit) in a fixed dosage ratio. The inactive ingredients were subsequently added to make granule, which was Shugan Jianwei Sijunzi granule (SJ-SJZG). Previous studies have confirmed the antagonism of SJ-SJZG to PWD. However, the mechanism of SJ-SJZG protective effects on small intestine in weaned Rex rabbits remained unclear. Animals were randomly divided into negative control (NC), low dose (LD), medium dose (MD), high dose (HD), and positive control (PC). SJ-SJZG significantly increased the intestinal length and the jejunum villi length. The SIgA level was statistically increased in duodenum and jejunum with the ELISA. Immunohistochemical detection showed that SIgA protein expression was also increased significantly in jejunum. Meanwhile, the relative expression of Zo1 in duodenum and jejunum of SJ-SJZG group increased significantly. SJ-SJZG significantly increased the relative expression of occludin in duodenum and jejunum as well. Moreover, real-time PCR results showed a significant increase in GLUT2 and SGLT1 relative expression in ileum. SJ-SJZG could also obviously enhance the expression of GLUT2 in jejunum and the expression of SGLT1 in duodenum. In conclusion, SJ-SJZG had been proven to be effective in promoting the development of small intestine and improving the immunity of small intestine. Moreover, SJ-SJZG could ensure the integrity of mucosal barrier and increase the ability of intestine to absorb glucose in small intestine.

Self-Effected Allosteric Coupling and Cooperativity in Hypoxic Response Regulation with Disordered Proteins

Hypersensitive regulation of cellular hypoxic response relies on cooperative displacement of one disordered protein (HIF-1α) by another disordered protein (CITED2) from the target in a negative feedback loop. Considering the weak intramolecule coupling in disordered proteins, the molecular mechanism of high cooperativity in the molecular displacement event remains elusive. Herein, we show that disordered proteins utilize a "self-effected allostery" mechanism to achieve high binding cooperativity. Different from the conventional allostery mechanisms shown by many structured or disordered proteins, this mechanism utilizes one part of the disordered protein as the effector to trigger the allosteric coupling and enhance the binding of the remaining part of the same disordered protein, contributing to high cooperativity of the displacement event. The conserved charge motif of CITED2 is the key determinant of the molecular displacement event by serving as the effector of allosteric coupling. Such self-effected allostery provides an efficient strategy to achieve high cooperativity in the molecular events involving disordered proteins.

NBL1 Mediates Endothelial-to-Mesenchymal Transition in Pulmonary Arterial Hypertension Related to Congenital Heart Disease

Endothelial-to-mesenchymal transition (EndMT) plays a critical role in the flow-induced vascular remodeling process, such as pulmonary artery hypertension related to congenital heart disease (CHD-PAH). Neuroblastoma suppressor of tumorigenicity 1 (NBL1) is a secreted glycoprotein and has been implicated in CHD-PAH by aggravating the phenotypic transformation of smooth muscle cell (SMC). However, the underlying mechanisms regarding the interplay between NBL1 and endothelial cell (EC) in CHD-PAH remains to be fully elucidated. Thus, we aimed to identify the potential effect of NBL1 on EndMT by a novel flow-associated PAH model with Nbl1 knockout rats. The phenotype of EndMT was detected by RNA-seq and further examined by western blotting and immunostaining of pulmonary arteries. Our observation demonstrated that the novel strategy of Nbl1 knockout effectively attenuated flow-associated PAH through downregulation of EndMT to some extent. Mechanistic experiments were established on human pulmonary artery endothelial cells (HPAECs) to confirm that EndMT was induced by NBL1 in vitro. After 7 days stimulation with NBL1, levels of EndMT-related biomarkers and downstream transcription factors were quantified by RNA-seq, western blotting and immunocytochemistry. Both in vitro and in vivo experiments supported the imbalance of increased TGF-β and dysregulation of BMP signaling by NBL1. Blocking the canonical TGF-β pathway efficiently preserved endothelial function upon NBL1 stimulation. These data suggested that NBL1 aggravated flow-associated PAH by inducing EndMT via the TGF-β/BMP signaling pathway. Thus, antagonizing NBL1 and rebalancing TGF-β/BMP signaling may be a suitable therapeutic target for CHD-PAH.

Alcohol promotes epithelial mesenchymal transformation-mediated premetastatic niche formation of colorectal cancer by activating interaction between laminin-γ2 and integrin-β1

BACKGROUND

Colorectal cancer (CRC) is a common malignant tumor. Alcohol consumption is positively correlated with CRC malignant metastasis; however, the mechanism is unclear. The interaction between laminin-γ2 (LAMC2) and integrin-β1 (ITGB1) plays a role in premetastatic niche signaling, which may induce epithelial mesenchymal transformation (EMT) and lead to metastasis.

AIM

To investigate the effects of alcohol on CRC metastasis from the molecular mechanism of the premetastatic niche.

METHODS

The interaction between LAMC2 and ITGB1 was measured by Duolink assay, and the expression levels of LAMC2, ITGB1 and focal adhesion kinase (FAK), snail, fibronectin, N-cadherin and special AT-rich sequence binding protein 1 (SATB1) were measured by quantitative real-time polymerase chain reaction, immunohistochemistry and western blotting. Interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α) and IL-6 levels were measured via enzyme-linked immunosorbent assay, histopathological assessment via hematoxylin eosin staining, and determination of aberrant crypt foci via methylene blue.

RESULTS

The lymph node metastasis rate was higher in the alcohol group than non-alcohol group. There was a significant increase in interaction signals between LAMC2 and ITGB1, and an increase in phosphorylate-FAK/FAK, snail, fibronectin, N-cadherin and SATB1, whereas E-cadherin was reduced in the alcohol group compared to the non-alcohol group in both animal and clinical samples. Serum IL-1β, TNF-α and IL-6 were higher in alcohol group than in non-alcohol group. Alcohol may promote CRC metastasis by influencing the molecular mechanism of the premetastatic niche.

CONCLUSION

Our study suggests that alcohol promotes EMT-mediated premetastatic niche formation of CRC by activating the early interaction between LAMC2 and ITGB1 and lead to CRC metastasis.

Bacterial Toxin-Responsive Biomimetic Nanobubbles for Precision Photodynamic Therapy against Bacterial Infections

With few options available for the effective treatment of multidrug-resistant bacteria, photodynamic therapy (PDT) has emerged as a promising therapeutic strategy that does not promote the development of antibiotic resistance. Unfortunately, the beneficial bactericidal effect of PDT is oftentimes accompanied by the uncontrollable production of reactive oxygen species. To overcome this issue, a pore-forming toxin (PFT)-responsive biomimetic nanobubble is designed, which is constructed by co-encapsulating a perfluorocarbon nanoemulsion and a photosensitizer within the red blood cell membrane. It is shown that PFTs derived from three pathogens, including methicillin-resistant Staphylococcus aureus (MRSA), group A Streptococcus (GAS), and Listeria monocytogenes (LM), can be effectively absorbed by the nanobubble. Upon toxin absorption, the formation of pores on the nanobubble surface allows the accelerated release of oxygen dissolved inside the nanoemulsion along with the photosensitizer, thus resulting in enhanced PDT and bactericidal efficacy. In three skin infection models, treatment with the nanobubbles results in significantly decreased lesion formation and reduced inflammation. In addition to oxygen, the platform can be used to deliver nitric oxide in a bacterial toxin-dependent manner. Overall, biomimetic nanobubbles may work as a broad gas delivery system that is capable of responding to a variety of PFT-based stimuli for precision PDT.

Surgical Management of 48 Patients with Retrosternal Goiter and Tracheal Stenosis: A Retrospective Clinical Study from a Single Surgical Center

Background

Benign retrosternal thyroid goiters can become large enough to compress the trachea and result in tracheomalacia and stenosis. This retrospective study from a single surgical center aimed to study the surgical management of 48 patients with retrosternal goiter and tracheal stenosis diagnosed and treated from January 2017 to December 2021.

Material/Methods

All preoperative contrast-enhanced CT scans showed retrosternal goiter and tracheal stenosis. RG was classified into type I in 28 patients, type II in 12 patients, and type III in 8 patients. TS was classified into grade I in 31 patients, grade II in 11 patients, and grade III in 6 patients. All patients were referred for surgery. Clinicopathologic features and surgical outcomes were recorded.

Results

All operations were successfully performed. There were 41 patients with transcervical incision, 4 with cervical incision+sternotomy, 2 with cervical incision and thoracoscopic surgery, and 1 with cervical incision and surgery via the subxiphoid approach. Two patients presented recurrent laryngeal nerve injury. One patient showed short-term hand and foot numbness. The patients were pathologically diagnosed as simple nodular goiter (n=27), nodular goiter combined with cystic change (n=6), adenomatous nodular goiter (n=10), and thyroid adenoma (n=5). There was no prominent tumor recurrence or gradual TS remission.

Conclusions

This study has highlighted that patients with retrosternal goiter and tracheal stenosis may have comorbidities and require a multidisciplinary approach to management. The choice of anesthesia, surgical approach, and maintenance of the airway during and after surgery should be individualized.

Financial Crisis in Management Stress: From the Perspective of Crisis Anxiety of Others

The crisis anxiety of others is a phenomenon that goes hand in hand with the spread of the occupational health pandemic. It is becoming increasingly important to better understand its emergence process, especially in the era of greater uncertainty. This study aims to examine the impact of the external financial crisis on managerial stress among financial employees. The sample consists of 347 senior managers and financial employees from companies in China. The empirical analysis shows that external financial crises have significant effects on anxiety levels, especially external corporate crisis, debt crisis and growth crisis both have mediating effect on the relationship between anxiety level and pressure management and the relationship between external financial crisis and pressure management. This study explores the rules for the emergence of anxiety among corporate managers and expands the scope of environmental factors that need to be discussed in the study of corporate financial management. This study provides theoretical implications for the psychological study of Financial Management and practical implications for corporate financial management.

Natural djurleite with refined composition Cu61.39S32 revealing disorder of some Cu sites

A djurleite crystal was discovered from a natural sample originally labelled as chalcocite. The djurleite crystal under investigation has a refined composition of Cu61.39S32, thus revealing a Cu deficiency compared to the originally reported Cu62S32 phase [Evans (1979). Z. Kristallogr. 150, 299-320], where all atomic sites are reported to be fully occupied. In addition, the current refinement revealed a splitting of eight of the Cu sites into pairs.

Salidroside Ameliorates Ischemia-Induced Neuronal Injury through AMPK Dependent and Independent Pathways to Maintain Mitochondrial Quality Control

Salidroside, an active ingredient in Rhodiola rosea, has potent protective activity against cerebral ischemia. However, the mechanisms underlying its pharmacological actions are poorly understood. In this study, we employed a mouse middle cerebral artery occlusion (MCAO) and cellular oxygen and glucose deprivation (OGD) models to test the hypothesis that salidroside may restore mitochondrial quality control in neurons by modulating the relevant signaling. The results indicated that salidroside mitigated almost 40% the ischemia-induced brain infarct volumes in mice and the OGD-decreased viability of neurons to ameliorate the mitochondrial functions. Furthermore, salidroside treatment alleviated the OGD- or ischemia-induced imbalance of mitochondrial fission and fusion, mitophagy and promoted mitochondrial biogenesis in neurons by attenuating the AMPK activity. Moreover, salidroside alleviated 50% the OGD-promoted mitochondrial calcium fluorescence intensity and 5% mitochondria-associated membrane (MAM) area by down-regulating GRP75 expression independent of the AMPK signaling. Finally, similar findings were achieved in primary mouse neurons. Collectively, these data indicate that salidroside effectively restores the mitochondria dynamics, facilitates mitochondrial biogenesis by attenuating the AMPK signaling, and maintains calcium homeostasis in neurons independent of the AMPK activity.

A single amino acid residue tunes the stability of the fully reduced flavin cofactor and photorepair activity in photolyases

The ultraviolet-induced DNA lesions, cyclobutane pyrimidine dimers (CPDs) and pyrimidine (6-4) pyrimidone photoproducts (6-4 photoproducts), can be directly photorepaired by CPD photolyases and 6-4 photolyases, respectively. The fully reduced flavin (hydroquinone, HQ) cofactor is required for the catalysis of both types of these photolyases. On the other hand, flavin cofactor in the semi-reduced state, semiquinone (SQ), can be utilized by photolyase homologs, the cryptochromes. However, the evolutionary process of the transition of the functional states of` flavin cofactors in photolyases and cryptochromes remains mysterious. In this work, we investigated three representative photolyases (Escherichia coli CPD photolyase, Microcystis aeruginosa DASH, and Phaeodactylum tricornutum 6-4 photolyase). We show that the residue at a single site adjacent to the flavin cofactor (corresponding to Ala377 in E. coli CPD photolyase, hereafter referred to as site 377) can fine-tune the stability of the HQ cofactor. We found that, in the presence of a polar residue (such as Ser or Asn) at site 377, HQ was stabilized against oxidation. Furthermore, this polar residue enhanced the photorepair activity of these photolyases both in vitro and in vivo. In constrast, substitution of hydrophobic residues, such as Ile, at site 377 in these photolyases adversely affected the stability of HQ. We speculate that these differential residue preferences at site 377 in photolyase proteins might reflect an important evolutionary event that altered the stability of HQ on the timeline from expression of photolyases to that of cryptochromes.

GSK-J4, a Specific Histone Lysine Demethylase 6A Inhibitor, Ameliorates Lipotoxicity to Cardiomyocytes via Preserving H3K27 Methylation and Reducing Ferroptosis

Changes in modern lifestyle provoke a series of metabolic stresses such as hyperlipidemia. Excessive free fatty acids induce cardiomyocyte metabolic reprogramming and rearrangement of the lipid content of cardiomyocyte and promote oxidative stress. As a newly defined lipid peroxidation-related cell death pathway, the role of ferroptosis in metabolic stress-induced cardiomyocyte injury is poorly revealed. Our work indicates that GSK-J4, a histone lysine demethylase 6A/6B dual inhibitor, can alleviate palmitic acid (PA)-induced hypersensitivity to ferroptosis by suppressing H3K27 demethylation. Mechanistically, PA stimulation reduces the H3K27me3 level and hence promotes the expression of ACSL4, a key lipid modulator of ferroptosis. GSK-J4 pretreatment significantly preserves the H3K27me3 level and reduces the ACSL4 level. GSK-J4 also reduces reactive oxygen species to alleviate oxidative stress, which further decreases lipid peroxidation. Taken together, our data suggest that cardiomyocyte undergoes epigenetic reprogramming under metabolic challenges, rearranging lipid content, and sensitizing to ferroptosis. GSK-J4 can be a potential drug for treating hyperlipidemia-induced cardiomyocyte injury by targeting epigenetic modulations.

Gut microbiota communities of reciprocal hybrids from koi (Cyprinus carpio) and goldfish (Carassius auratus) are more similar to koi than goldfish

AIMS

To investigate the gut microbiota communities of reciprocal hybrids and inbred lines of koi (Cyprinus carpio) and goldfish (Carassius auratus), as well as the genetic effect of intestinal microbiota between hybrids and parents.

METHODS AND RESULTS

The reciprocal hybrids and inbred lines derived from the parents, koi and goldfish, were established. Then the bacterial 16S rRNA gene of intestinal contents was sequenced using Illumina Miseq PE300. Alpha diversity in the two types of hybrids was lower than inbred lines of koi or goldfish and was highest in goldfish, followed by koi. For beta diversity, microbial samples presented clear clusters and the two types of hybrids were more similar to koi than goldfish, indicating the gut microbiota of the reciprocal hybrids was more affected by koi. The dominant phyla were Proteobacteria, Actinobacteria and Firmicutes in koi, and Proteobacteria, Fusobacteria and Actinobacteria in goldfish, and Proteobacteria, Fusobacteria and Firmicutes in the reciprocal hybrids. In the case of Proteobacteria, the dominant classes were Alphaproteobacteria and Gammaproteobacteria in four fish. The dominant genera were norank_f_Rhizobiales_Incertae_Sedis and Plesiomonas in koi, Cetobacterium in goldfish, and Cetobacterium and ZOR0006 in the reciprocal hybrids. PICRUSt1 predictive function analysis showed that the reciprocal hybrids had lower abundance in the most functional categories than koi and goldfish.

CONCLUSIONS

The gut microbiota of reciprocal hybrids was more affected by koi. Two types of hybrids possessed the same dominated phyla and were different from the inbred lines of koi and goldfish.

SIGNIFICANCE AND IMPACT OF THE STUDY

It enhanced our understanding of gut microbiota of hybrid lines of goldfish and koi and provided a new perspective for the selective breeding of gut microbiota traits.