Dietary intakes of vitamin D promote growth performance and disease resistance in juvenile grass carp (Ctenopharyngodon idella).

Vitamin D3 (VD3) is an essential nutrient for fish and participates in a variety of physiological activities. Notably, both insufficient and excessive supplementation of VD3 severely impede fish growth, and the requirements of VD3 for fish vary considerably in different species and growth periods. The present study aimed to evaluate the appropriate requirements of VD3 for juvenile grass carp (Ctenopharyngodon idella) according to growth performance and disease prevention capacity. In this study, diets containing six supplemental levels of VD3 (0, 300, 600, 1200, 2400, and 4800 IU/kg diet) were formulated to investigate the effect(s) of VD3 on the growth performance, antioxidant enzyme activities, and antimicrobial ability in juvenile grass carp. Compared with the VD3 deficiency group (0 IU/kg), the supplementation of 300-2400 IU/kg VD3 significantly enhanced growth performance and increased antioxidant enzyme activities in the fish liver. Moreover, dietary supplementation of VD3 significantly improved the intestinal health by manipulating the composition of intestinal microbiota in juvenile grass carp. In agreement with this notion, the mortality of juvenile grass carp fed with dietary VD3 was much lower than that in VD3 deficient group upon infection with Aeromonas hydrophila. Meanwhile, dietary supplementation of 300-2400 IU/kg VD3 reduced bacterial load in the spleen and head kidney of the infected fish, and 1200 IU/kg VD3 supplementation could decrease enteritis morbidity and increase lysozyme activities in the intestine. These findings strengthened the essential role of dietary VD3 in managing fish growth and antimicrobial capacity. Additionally, based on weight gain ratio and lysozyme activities, the appropriate VD3 requirements for juvenile grass carp were estimated to be 1994.80 and 2321.80 IU/kg diet, respectively.

MethylRAD Sequencing Technology Reveals DNA Methylation Characteristics of Apostichopus japonicus of Different Ages.

The A. japonicus industry has expanded significantly, but no research has focused on determining the age of A. japonicus during farming. Correctly estimating the age of A. japonicus can provide a decision-making basis for the breeding process and data for the protection of A. japonicus aquatic germplasm resources. DNA methylation levels in the body wall of Apostichopus japonicus at 4 months, 1 year, 2 years, and 3 years old were determined using MethylRAD-Seq, and differentially methylated genes were screened. A total of 441 and 966 differentially methylated genes were detected at the CCGG and CCWGG sites, respectively. Aspartate aminotransferase, succinate semialdehyde dehydrogenase, isocitrate dehydrogenase, the histone H2AX, heat shock protein Hsp90, aminopeptidase N, cell division cycle CDC6, Ras GTPase activating protein (RasGAP), slit guidance ligand slit1, integrin-linked kinase ILK, mechanistic target of rapamycin kinase Mtor, protein kinase A Pka, and autophagy-related 3 atg3 genes may play key roles in the growth and aging process of A. japonicus. This study provides valuable information regarding age-related genes for future research, and these candidate genes can be used to create an "epigenetic clock".

Engineered exosomes reprogram Gli1+ cells in vivo to prevent calcification of vascular grafts and autologous pathological vessels.

Calcification of autologous pathological vessels and tissue engineering blood vessels (TEBVs) is a thorny problem in clinic. However, there is no effective and noninvasive treatment that is available against the calcification of TEBVs and autologous pathological vessels. Gli1+ cells are progenitors of smooth muscle cells (SMCs) and can differentiate into osteoblast-like cells, leading to vascular calcification. Our results showed that the spatiotemporal distribution of Gli1+ cells in TEBVs was positively correlated with the degree of TEBV calcification. An anticalcification approach was designed consisting of exosomes derived from mesenchymal stem cells delivering lncRNA-ANCR to construct the engineered exosome-Ancr/E7-EXO. The results showed that Ancr/E7-EXO effectively targeted Gli1+ cells, promoting rapid SMC reconstruction and markedly inhibiting Gli1+ cell differentiation into osteoblast-like cells. Moreover, Ancr/E7-EXO significantly inhibited vascular calcification caused by chronic kidney disease. Therefore, Ancr/E7-EXO reprogrammed Gli1+ cells to prevent calcification of vascular graft and autologous pathological vessel, providing unique insights for an effective anticalcification.

Programming of Regulatory T Cells In Situ for Nerve Regeneration and Long-Term Patency of Vascular Grafts.

Rapid integration into the host tissue is critical for long-term patency after small diameter tissue engineering vascular grafts (sdTEVGs) transplantation. Neural recognition may be required for host integration and functionalization of the graft. However, immune rejection and inflammation hinder nerve regeneration of sdTEVGs. Here, a CRISPR/dCas9-nanocarrier was used for targeted programming of regulatory T cells (Treg cells) in situ to promote nerve regeneration of sdTEVGs by preventing excessive inflammation. Treg cells and (C-C chemokine receptor) CCR2+ macrophage recruitment occurred after transplantation. The nanodelivery system upregulated ten eleven translocation (TET2) in Treg cells in vitro. Reprogrammed Treg cells upregulated anti-inflammatory cytokines and decreased the proportion of CCR2+ macrophages. IL-6 concentrations decreased to the levels required for nerve regeneration. Implantation of CRISPR/dCas9 nanodelivery system-modified sdTEVGs in rats resulted in Treg cell editing, control of excessive inflammation, and promoted nerve regeneration. After 3 months, nerve regeneration was similar to that observed in normal blood vessels; good immune homeostasis, consistency of hemodynamics, and matrix regeneration were observed. Neural recognition promotes further integration of the graft into the host, with unobstructed blood vessels without intimal hyperplasia. Our findings provide new insights into vascular implant functionalization by the host.

Frequency-Dependent Plasticity in the Temporal Association Cortex Originates from the Primary Auditory Cortex, and Is Modified by the Secondary Auditory Cortex and the Medial Geniculate Body.

The brain areas that mediate the formation of auditory threat memory and perceptual decisions remain uncertain to date. Candidates include the primary (A1) and secondary (A2) auditory cortex, the medial division of the medial geniculate body (MGm), amygdala, and the temporal association cortex. We used chemogenetic and optogenetic manipulations with in vivo and in vitro patch-clamp recordings to assess the roles of these brain regions in threat memory learning in female mice. We found that conditioned sound (CS) frequency-dependent plasticity resulted in the formation of auditory threat memory in the temporal association cortex. This neural correlated auditory threat memory depended on CS frequency information from A1 glutamatergic subthreshold monosynaptic inputs, CS lateral inhibition from A2 glutamatergic disynaptic inputs, and non-frequency-specific facilitation from MGm glutamatergic monosynaptic inputs. These results indicate that the A2 and MGm work together in an inhibitory-facilitative role.SIGNIFICANCE STATEMENT: The ability to recognize specific sounds to avoid predators or seek prey is a useful survival tool. Improving this ability through experiential learning is an added advantage requiring neural plasticity. As an example, humans must learn to distinguish the sound of a car horn, and thus avoid oncoming traffic. Our research discovered that the temporal association cortex can encode this kind of auditory information through tonal receptive field plasticity. In addition, the results revealed the underlying synaptic mechanisms of this process. These results extended our understanding of how meaningful auditory information is processed in an animal's brain.

The activated synaptic terminals beyond the light illumination range affect the results of optogenetics.

OBJECTIVES: Optogenetics is widely applied to study complex brain networks. However, recent studies have found that light alone can produce effects that are unrelated to optogenetics, and it is still unclear whether this can affect the results of optogenetic experiments. METHODS: We explored the characteristics of projection of interneurons to excitatory neurons in the auditory cortex with optogenetics, transgenic mice and patch-clamp recording. RESULTS: We discovered that postsynaptic responses can be induced when we stimulated a blank area adjacent to the edge of brain slice. Similar results can be observed after blocking the polysynaptic responses by drugs. Together with the results of control experiments, we found that the false response is caused by activating the synaptic terminals beyond the range of the blue light (470 nm). Also, there was a linear relationship between the response and the stimulus distance for all data, which suggested that these false responses may be related to other factors, such as light scattering. CONCLUSIONS: The LED-light-evoked response cannot reflect microcircuit of the recorded neuron and the activated neurons within the illumination range accurately. Together, these results confirm that light alone can affect neural activity, but this can be unrelated to the genuine 'optogenetic effect'.

Synthesis and Biological Evaluation of Novel Triazine Derivatives as Positive Allosteric Modulators of α7 Nicotinic Acetylcholine Receptors.

Enhancing neuronal α7 nicotinic acetylcholine receptor (α7 nAChR) function can alleviate cognitive deficits. Here, we report the design, synthesis, and evaluation of N-(4-(trifluoromethoxy)phenyl)-1,3,5-triazin-2-amine derivatives 8-10 as a series of novel α7 nAChR positive allosteric modulators (PAMs). The representative compound 10e functions as a type I PAM with an EC50 of 3.0 µM and approximately 38-fold enhancement of α7 current in the presence of agonist acetylcholine (100 µM). It specifically enhances α7 current with high selectivity. Compound 10e shows good pharmacokinetic property in mice. Intraperitoneal injection of 10e (3 mg/kg) exhibits sufficient blood-brain barrier penetration in mice. Furthermore, 10e can also rescue the auditory gating deficit in mice with schizophrenia-like behavior. Molecular docking of 10e with homopentameric α7 nAChR reveals a new mode of action. These results support the potential of 10e for treatment for schizophrenia and Alzheimer's disease.

Review on the Vascularization of Organoids and Organoids-on-a-Chip.

The use of human cells for the construction of 3D organ models in vitro based on cell self-assembly and engineering design has recently increased in popularity in the field of biological science. Although the organoids are able to simulate the structures and functions of organs in vitro, the 3D models have difficulty in forming a complex vascular network that can recreate the interaction between tissue and vascular systems. Therefore, organoids are unable to survive, due to the lack of oxygen and nutrients, as well as the accumulation of metabolic waste. Organoids-on-a-chip provides a more controllable and favorable design platform for co-culture of different cells and tissue types in organoid systems, overcoming some of the limitations present in organoid culture. However, the majority of them has vascular networks that are not adequately elaborate to simulate signal communications between bionic microenvironment (e.g., fluid shear force) and multiple organs. Here, we will review the technological progress of the vascularization in organoids and organoids-on-a-chip and the development of intravital 3D and 4D bioprinting as a new way for vascularization, which can aid in further study on tissue or organ development, disease research and regenerative medicine.

Using 24-h Heart Rate Variability to Investigate the Sleep Quality and Depression Symptoms of Medical Students.

There have been numerous studies on the relationship between sleep and depression, as well as the relationship between sleep and depression, and heart rate variability (HRV), respectively. Even so, few studies have combined 24-h HRV analysis to study sleep quality and depressive symptoms. The purpose of this cross-sectional study was to investigate the relationship between depressed symptoms, sleep quality, and 24-h HRV in medical students. The particiants were all students at a medical university in Guangdong province, China. A total of 74 college students participated. They were asked to complete a questionnaire that included the Pittsburgh Sleep Quality Index (PSQI), the Beck Depression Inventory-II (BDI-II), the Positive and Negative Affect Scale (PANAS), and 24-h ECG monitoring. The results showed that 41.7% of the medical students had poor sleep quality, with higher levels of depressive symptoms and more negative emotions, and there was no difference in 24-h HRV indices between the low PSQI group and the high one. Correlation analysis showed that there was a significant relationship between sleep quality and depressive symptoms (r = 0.617), but the relationship between 24-h HRV indices and PSQI global scores, BDI scores were not significant. However, the correlation analysis of PSQI components and 24-h HRV showed that sleep disturbance was significantly negatively correlated with SDNN and LF in waking period (r = -0.285, -0.235), and with SDNN in sleeping period (r = -0.317). In general, the sleep disturbance in PSQI components can sensitively reflect the relationship between sleep quality and 24-h HRV of medical students. Individuals with higher sleep disturance may have lower SDNN during awake period and bedtime period, and lower LF in awake period. Twenty-four hour HRV has certain application value in clinical sleep quality monitoring, and its sensitivity and specificity in clinical application and daily life are still worth further investigation.