In vitro modeling of skeletal muscle ischemia-reperfusion injury based on sphere differentiation culture from human pluripotent stem cells.

Skeletal muscle ischemia-reperfusion (IR) injury poses significant challenges due to its local and systemic complications. Traditional studies relying on two-dimensional (2D) cell culture or animal models often fall short of faithfully replicating the human in vivo environment, thereby impeding the translational process from animal research to clinical applications. Three-dimensional (3D) constructs, such as skeletal muscle spheroids with enhanced cell-cell interactions from human pluripotent stem cells (hPSCs) offer a promising alternative by partially mimicking human physiological cellular environment in vivo processes. This study aims to establish an innovative in vitro model, human skeletal muscle spheroids based on sphere differentiation from hPSCs, to investigate human skeletal muscle developmental processes and IR mechanisms within a controlled laboratory setting. By eticulously recapitulating embryonic myogenesis through paraxial mesodermal differentiation of neuro-mesodermal progenitors, we successfully established 3D skeletal muscle spheroids that mirror the dynamic colonization observed during human skeletal muscle development. Co-culturing human skeletal muscle spheroids with spinal cord spheroids facilitated the formation of neuromuscular junctions, providing functional relevance to skeletal muscle spheroids. Furthermore, through oxygen-glucose deprivation/re-oxygenation treatment, 3D skeletal muscle spheroids provide insights into the molecular events and pathogenesis of IR injury. The findings presented in this study significantly contribute to our understanding of skeletal muscle development and offer a robust platform for in vitro studies on skeletal muscle IR injury, holding potential applications in drug testing, therapeutic development, and personalized medicine within the realm of skeletal muscle-related pathologies.

Profiling Chromatin Accessibility Responses in Goat Bronchial Epithelial Cells Infected with Pasteurella multocida.

Pasteurella multocida can cause goat hemorrhagic sepsis and endemic pneumonia. Respiratory epithelial cells are the first line of defense in the lungs during P. multocida infection. These cells act as a mechanical barrier and activate immune response to protect against invading pathogenic microorganisms. Upon infection, P. multocida adheres to the cells and causes changes in cell morphology and transcriptome. ATAC-seq was conducted to determine the changes in the chromatin open region of P. multocida-infected goat bronchial epithelial cells based on transcriptional regulation. A total of 13,079 and 28,722 peaks were identified in the control (CK) and treatment (T) groups (P. multocida infection group), respectively. The peaks significantly increased after P. multocida infection. The specific peaks for the CK and T groups were annotated to 545 and 6632 genes, respectively. KEGG pathway enrichment analysis revealed that the specific peak-related genes in the T group were enriched in immune reaction-related pathways, such as Fc gamma R-mediated phagocytosis, MAPK signaling pathway, bacterial invasion of epithelial cells, endocytosis, and autophagy pathways. Other cellular component pathways were also enriched, including the regulation of actin cytoskeleton, adherent junction, tight junction, and focal adhesion. The differential peaks between the two groups were subsequently analyzed. Compared to those in the CK group, 863 and 11 peaks were upregulated and downregulated, respectively, after the P. multocida infection. Fifty-six known transcription factor motifs were revealed in upregulated peaks in the P. multocida-infected group. By integrating ATAC-seq and RNA-seq, some candidate genes (SETBP1, RASGEF1B, CREB5, IRF5, TNF, CD70) that might be involved in the goat bronchial epithelial cell immune reaction to P. multocida infection were identified. Overall, P. multocida infection changed the structure of the cell and caused chromatin open regions to be upregulated. In addition, P. multocida infection actively mobilized the host immune response with the inflammatory phenotype. The findings provide valuable information for understanding the regulatory mechanisms of P. multocida-infected goat bronchial epithelial cells.

Bovine skin fibroblasts mediated immune responses to defend against bovine Acinetobacter baumannii infection.

Acinetobacter baumannii (A. baumannii) is an opportunistic pathogen which can cause pneumonia, sepsis and infections of skin and soft tissue. The host mostly relies on innate immune responses to defend against the infection of A. baumannii. Currently, it has been confirmed that fibroblasts involved in innate immune responses. Therefore, to explore how bovine skin fibroblasts mediated immune responses to defend against A. baumannii infection, we analyzed the differential transcripts data of bovine skin fibroblasts infected with bovine A. baumannii by RNA-sequencing (RNA-seq). We found that there were 3014 differentially expressed genes (DEGs) at 14h with bovine A. baumannii infection, including 1940 up-regulated genes and 1074 down-regulated genes. Gene Ontology (GO) enrichment showed that ubiquitin protein ligase binding, IL-6 receptor complex, ERK1 and ERK2 cascade terms were mainly enriched. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment showed that innate immune pathways were significantly enriched, such as TNF, IL-17, NLR, MAPK, NF-κB, endocytosis, apoptosis and HIF-1 signaling pathways. Furthermore, Gene Set Enrichment Analysis (GSEA) revealed that GO terms such as chemokine receptor binding and Th17 cell differentiation and KEGG pathways such as TLR and cytokine-cytokine receptor interaction pathways were up-regulated. In addition, CASP3 and JUN were the core functional genes of apoptosis, while IL-6, ERBB2, EGFR, CHUK and MAPK8 were the core functional genes of immunity by Protein-Protein Interaction (PPI) analysis. Our study provided an in-depth understanding of the molecular mechanisms of fibroblasts against A. baumannii infection. It also lays the foundation for the development of new therapeutic targets for the diseases caused by A. baumannii infection and formulates effective therapeutic strategies for the prevention and control of the diseases caused by A. baumannii.

Tanshinone IIA improves contextual fear- and anxiety-like behaviors in mice via the CREB/BDNF/TrkB signaling pathway.

Posttraumatic stress disorder (PTSD) is one of the most common psychiatric diseases, which is characterized by the typical symptoms such as re-experience, avoidance, and hyperarousal. However, there are few drugs for PTSD treatment. In this study, conditioned fear and single-prolonged stress were employed to establish PTSD mouse model, and we investigated the effects of Tanshinone IIA (TanIIA), a natural product isolated from traditional Chinese herbal Salvia miltiorrhiza, as well as the underlying mechanisms in mice. The results showed that the double stress exposure induced obvious PTSD-like symptoms, and TanIIA administration significantly decreased freezing time in contextual fear test and relieved anxiety-like behavior in open field and elevated plus maze tests. Moreover, TanIIA increased the spine density and upregulated synaptic plasticity-related proteins as well as activated CREB/BDNF/TrkB signaling pathway in the hippocampus. Blockage of CREB remarkably abolished the effects of TanIIA in PTSD model mice and reversed the upregulations of p-CREB, BDNF, TrkB, and synaptic plasticity-related protein induced by TanIIA. The molecular docking simulation indicated that TanIIA could interact with the CREB-binding protein. These findings indicate that TanIIA ameliorates PTSD-like behaviors in mice by activating the CREB/BDNF/TrkB pathway, which provides a basis for PTSD treatment.

Paeonol ameliorates CFA-induced inflammatory pain by inhibiting HMGB1/TLR4/NF-κB p65 pathway.

The enhanced release of inflammatory cytokines mediated by high mobility group box1 (HMGB1) leads to pain sensation, and has been implicated in the etiology of inflammatory pain. Paeonol (PAE), a major active phenolic component in Cortex Moutan, provides neuroprotective efficacy via exerting anti-inflammatory effect. However, the role and mechanism of PAE in inflammatory pain remain to be fully clarified. In this study, we showed that PAE treatment significantly ameliorated mechanical and thermal hyperalgesia of mice induced by complete Freund's adjuvant (CFA). The analgesic effect of PAE administration was associated with suppressing the enhanced expression of HMGB1 as well as the downstream signaling molecules including toll-like receptor 4 (TLR4), the nuclear NF-κB p65, TNF-α and IL-1ß after CFA insult in the anterior cingulate cortex (ACC), a key brain region responsible for pain processing. Furthermore, inhibition of HMGB1 activity by glycyrrhizin (GLY), an HMGB1 inhibitor, alleviated CFA-induced pain and also facilitated PAE-mediated analgesic effect in mice along with the decreased expression of TLR4, NF-κB p65, TNF-α and IL-1ß upon CFA injury. Collectively, we showed PAE exerted analgesic effect through inhibiting the HMGB1/TLR4/NF-κB p65 pathway and subsequent generation of cytokines TNF-α and IL-1ß in the ACC.

FMRP acts as a key messenger for visceral pain modulation.

Visceral pain is a common clinical symptom, which is caused by mechanical stretch, spasm, ischemia and inflammation. Fragile X syndrome (FXS) with lack of fragile X mental retardation protein (FMRP) protein is an inherited disorder that is characterized by moderate or severe intellectual and developmental disabilities. Previous studies reported that FXS patients have self-injurious behavior, which may be associated with deficits in nociceptive sensitization. However, the role of FMRP in visceral pain is still unclear. In this study, the FMR1 knock out (KO) mice and SH-SY5Y cell line were employed to demonstrate the role of FMRP in the regulation of visceral pain. The data showed that FMR1 KO mice were insensitive to zymosan treatment. Recording in the anterior cingulate cortex (ACC), a structure involved in pain process, showed less presynaptic glutamate release and postsynaptic responses in the FMR1 KO mice as compared to the wild type (WT) mice after zymosan injection. Zymosan treatment caused enhancements of adenylyl cyclase 1 (AC1), a pain-related enzyme, and NMDA GluN2B receptor in the ACC. However, these up-regulations were attenuated in the ACC of FMR1 KO mice. Last, we found that zymosan treatment led to increase of FMRP levels in the ACC. These results were further confirmed in SH-SY5Y cells in vitro. Our findings demonstrate that FMRP is required for NMDA GluN2B and AC1 upregulation, and GluN2B/AC1/FMRP forms a positive feedback loop to modulate visceral pain.

Estrogen-like neuroprotection of isopsoralen against spinal cord injury through estrogen receptor ERα.

Isopsoralen is a type of furocoumarin that exhibits estrogen-like activities. The aim of this study was to determine the estrogen-like neuroprotection of isopsoralen in an animal model of spinal cord injury (SCI). Results indicated that isopsoralen (intraperitoneal injection of 5 and 10 mg/kg per day for two weeks) significantly enhanced the hindlimb locomotor functions of mice with SCI, as revealed in the BMS score and angle of inclined plane tests. Morphological data showed that isopsoralen significantly attenuated the injury of the gray matter of spinal cord and induced the up-regulation of ERα levels. The neuroprotective effects of isopsolaren were blocked by the ERα antagonist MPP (0.3 mg/kg), but not by the ERß receptor antagonist PHTPP (0.3 mg/kg). Isopsolaren treatment increased phosphorylated PI3K and AKT (P-PI3K and P-AKT) in the spinal cord of SCI mice and showed a significant anti-apoptotic activity. These results suggest that isopsoralen performs estrogen-like neuroprotection against SCI-induced apoptosis by activating ERα and regulating the PI3K/AKT pathway.

Anxiolytic effects of sesamin in mice with chronic inflammatory pain.

OBJECTIVE: Sesamin is known for its role in antioxidant, antiproliferative, antihypertensive, and neuroprotective activities. However, little is known about the role of sesamin in the development of emotional disorders. Here we investigated persistent inflammatory pain hypersensitivity and anxiety-like behaviors in the mouse suffering chronic pain. METHODS: Chronic inflammatory pain was induced by hind paw injection of complete Freund's adjuvant (CFA). Levels of protein were detected by Western blot. RESULTS: Administration of sesamin could induce anxiolytic activities but had no effect on analgesia. In the basolateral amygdala, a structure involving the anxiety development, sesamin attenuated the up-regulation of NR2B-containing N-methyl-d-aspartate receptors, GluR1 subunit of the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor as well as phosphorylation of GluR1 at Ser831 (p-GluR1-Ser831), and Ca(2+)/calmodulin-dependent protein kinase II (CaMKII-alpha) in the hind paw CFA-injected mice. In the same model, we found that the sesamin blocked the down-regulation of gamma-aminobutyric acid A (GABAA-alpha-2) receptors. CONCLUSION: Our findings show that sesamin reduces anxiety-like behaviors induced by chronic pain at least partially through regulating the GABAergic and glutamatergic transmission in the amygdala of mice.

A novel translocator protein 18 kDa ligand, ZBD-2, exerts neuroprotective effects against acute spinal cord injury.

Traumatic spinal cord injury (SCI) happens accidently and often leads to motor dysfunction due to a series of biochemical and pathological events and damage, either temporarily or permanently. Translocator protein 18 (TSPO) has been found to be involved in the synthesis of endogenous neurosteroids which have multiple effects on neurons, but the internal mechanisms are not clear. N-benzyl-N-ethyl-2-(7,8-oxo-2-phenyl-9H-purin-9-yl) acetamide (ZBD-2), a newly reported ligand of TSPO, shows some neuroprotective effect against focal cerebral ischemia in vivo and NMDA-induced neurotoxicity in vitro. The present study aims to examine the role of ZBD-2 in SCI mice and elucidate the underlying molecular mechanisms. The SCI model was established by crushing spinal cord. ZBD-2 (10 mg/kg) significantly enhanced the hindlimb locomotor functions after SCI and decreased the tissue damage and conserved the white matter of the spinal cord. High-dose ZBD-2 alleviated the oxidative stress induced by SCI and regulated the imbalance between NR2B-containing NMDA and GABA receptors by increasing the levels of GAD67 in the spinal cord of SCI mice. Additionally, ZBD-2 (10 mg/kg) increased phosphorylated Akt (p-Akt) and decreased the ratio of Bax/Bcl-2. These results demonstrate that ZBD-2 performs neuroprotection against SCI through regulating the synaptic transmission and the PI3K/AKT signaling pathway.

Anxiolytic-like effects of translocator protein (TSPO) ligand ZBD-2 in an animal model of chronic pain.

The activation of Translocator protein (18 kDa) (TSPO) has been demonstrated to mediate rapid anxiolytic efficacy in stress response and stress-related disorders. This protein is involved in the synthesis of endogenous neurosteroids that promote γ-aminobutyric acid (GABA)-mediated neurotransmission in the central neural system. However, little is known about the functions and the underlying mechanisms of TSPO in chronic pain-induced anxiety-like behaviors. The novel TSPO ligand N-benzyl-N-ethyl-2-(7,8-dihydro-7-benzyl-8-oxo-2-phenyl-9H-purin-9-yl) acetamide (ZBD-2) was used in the present study. We found that ZBD-2 (0.15 or 1.5 mg/kg) significantly attenuated anxiety-like behaviors in mice with chronic inflammatory pain induced by hindpaw injection of complete Freund's adjuvant (CFA). However, the treatment did not alter the nociceptive threshold or inflammation in the hindpaw. Hindpaw injection of CFA induced the upregulation of TSPO, GluR1-containing α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors, and NR2B-containing N-methyl-D-aspartate (NMDA) receptors in the basolateral amygdala (BLA). ZBD-2 administration reversed the alterations of the abovementioned proteins in the BLA of the CFA-injected mice. Electrophysiological recording revealed that ZBD-2 could prevent an imbalance between excitatory and inhibitory transmissions in the BLA synapses of CFA-injected mice. Therefore, as the novel ligand of TSPO, ZBD-2 induced anxiolytic effects, but did not affect the nociceptive threshold of mice under chronic pain. The anxiolytic effects of ZBD-2 were related to the regulation of the balance between excitatory and inhibitory transmissions in the BLA.

Neuroprotective effects of a novel translocator protein (18 kDa) ligand, ZBD-2, against focal cerebral ischemia and NMDA-induced neurotoxicity.

Ligands of the translocator protein (18 kDa) (TSPO) have demonstrated rapid anxiolytic efficacy in stress responses and stress-related disorders. This protein is involved in the synthesis of endogenous neurosteroids including pregnenolone, dehydroepiandrosterone, and progesterone. These neurosteroids promote γ-aminobutyric acid-mediated neurotransmission in the central neural system (CNS). A TSPO ligand, N-benzyl-N-ethyl-2-(7,8-dihydro-7-benzyl-8-oxo-2-phenyl-9H-purin-9-yl) acetamide (ZBD-2) was recently synthesized. The purpose of the present study was to investigate the neuroprotective effects of ZBD-2 and. In cultured cortical neurons, treatment with ZBD-2 attenuated excitotoxicity induced by N-methyl-d-aspartate (NMDA) exposure. It significantly decreased the number of apoptotic cells by downregulating GluN2B-containing NMDA receptors (NMDARs), the ratio of Bax/Bcl-2, and levels of pro-caspase-3. Systemic treatment of ZBD-2 provided significant neuroprotection in mice subjected to middle cerebral artery occlusion. These findings provide direct evidence that neuroprotection by ZBD-2 is partially mediated by inhibiting GluN2B-containing NMDA receptor-mediated excitotoxicity.

In-Plane Radiation of Surface Plasmon Polaritons Excited by Free Electrons.

Surface plasmon polaritons (SPPs) have become a research hotspot due to their high intensity and subwavelength localization. Through free-electron excitation, a portion of the momentum of moving electrons can be converted into SPPs. Converting highly localized SPPs into a radiated field is an approach with the potential to aid in the development of a light radiation source. Reducing losses of SPPs is currently a critical challenge that needs to be addressed. The lifetime of SPPs in metal films is longer than that in metal blocks. Traditional optical gratings can transform SPPs into radiation to avoid the decay of SPPs in metal; however, they are created by etching metal films, so they tend to alter the dispersion characteristics of these films and will emit radiation in the direction perpendicular to the metal surface. This paper proposes an approach to converting the SPPs of a metal film excited by free electrons into a radiation field via lateral grating and obtaining in-plane radiation. We investigate the properties of SPP lateral radiation. The study of lateral radiation from metal films holds significant importance for SPP radiation sources and SPP on-chip circuit development.

Unraveling radiation-induced skeletal muscle damage: Insights from a 3D human skeletal muscle organoid model.

BACKGROUND: Three-dimensional (3D) organoids derived from human pluripotent stem cells (hPSCs) have revolutionized in vitro tissue modeling, offering a unique opportunity to replicate physiological tissue organization and functionality. This study investigates the impact of radiation on skeletal muscle response using an innovative in vitro human 3D skeletal muscle organoids (hSMOs) model derived from hPSCs. METHODS: The hSMOs model was established through a differentiation protocol faithfully recapitulating embryonic myogenesis and maturation via paraxial mesodermal differentiation of hPSCs. Key skeletal muscle characteristics were confirmed using immunofluorescent staining and RT-qPCR. Subsequently, the hSMOs were exposed to a clinically relevant dose of 2 Gy of radiation, and their response was analyzed using immunofluorescent staining and RNA-seq. RESULTS: The hSMO model faithfully recapitulated embryonic myogenesis and maturation, maintaining key skeletal muscle characteristics. Following exposure to 2 Gy of radiation, histopathological analysis revealed deficits in hSMOs expansion, differentiation, and repair response across various cell types at early (30 min) and intermediate (18 h) time points post-radiation. Immunofluorescent staining targeting γH2AX and 53BP1 demonstrated elevated levels of foci per cell, particularly in PAX7+ cells, during early and intermediate time points, with a distinct kinetic pattern showing a decrease at 72 h. RNA-seq data provided comprehensive insights into the DNA damage response within the hSMOs. CONCLUSIONS: Our findings highlight deficits in expansion, differentiation, and repair response in hSMOs following radiation exposure, enhancing our understanding of radiation effects on skeletal muscle and contributing to strategies for mitigating radiation-induced damage in this context.

TOM40 mediates the effect of TSPO on postpartum depression partially through regulating calcium homeostasis in microglia.

AIMS: To assess the effect of the translocator protein 18 kDa (TSPO) on postpartum depression and explore its mechanism. METHODS: Postpartum depression (PPD) mouse model was established, and flow cytometry, immunofluorescence, Western blot analysis, real-time quantitative PCR, adeno-associated virus (AAV), co-immunoprecipitation-mass spectrometry and immunofluorescence co-staining were used to detect the effect of TSPO ligand ZBD-2 on PPD mice. RESULTS: ZBD-2 inhibits the overactivation of microglia in the hippocampus and amygdala of PPD model mice. ZBD-2 not only inhibited the inflammation but also repressed the burst of reactive oxygen species (ROS) and mitochondrial ROS (mtROS). Meanwhile, ZBD-2 protects mitochondria from LPS-induced damages through inhibiting the influx of calcium. ZBD-2 modulated the calcium influx by increasing the level of translocase of the outer mitochondrial membrane 40 (TOM40) and reducing the interaction of TSPO and TOM40. In addition, the effect of ZBD-2 was partially dependent on anti-oxidative process. Knockdown of TOM40 by adeno-associated virus (AAV) in the hippocampus or amygdala dramatically reduced the effect of ZBD-2 on PPD, indicating that TOM40 mediates the effect of ZBD-2 on PPD. CONCLUSIONS: TOM40 is required for the effect of ZBD-2 on treating anxiety and depression in PPD mice. This study reveals the role of microglia TSPO in PPD development and provides the new therapeutic strategy for PPD.

L-Cysteine: A promising nutritional supplement for alleviating anxiety disorders.

Anxiety disorders are prevalent chronic psychological disease with complex pathogenic mechanisms. Current anxiolytics have limited efficacy and numerous side effects in many anxiety patients, highlighting the urgent need for new therapies. Recent research has been focusing on nutritional supplements, particularly amino acids, as potential therapies for anxiety disorders. Among these, L-Cysteine plays a crucial role in various biological processes. L-Cysteine exhibits antioxidant properties that can enhance the antioxidant functions of the central nervous system (CNS). Furthermore, metabolites of L-cysteine, such as glutathione and hydrogen sulfide have been shown to alleviate anxiety through distinct molecular mechanisms. Long-term administration of L-Cysteine has anxiolytic, antidepressant, and memory-improving effects. L-Cysteine depletion can lead to increased oxidative stress in the brain. This review delves into the potential mechanisms of L-Cysteine and its main products, glutathione (GSH) and hydrogen sulfide (H2S) in the management of anxiety and related diseases.

Experimental Investigation of Tool Wear and Machining Quality of BTA Deep-Hole Drilling in Low-Carbon Alloy Steel SA-5083.

Nuclear power tube plates are made from the high-strength, low-carbon alloy steel SA-5083, which has high values of toughness and plasticity, though it is forged with poor consistency and entails serious work hardening. It requires a large number of deep holes with a high machining accuracy and high surface quality to be processed. However, the quality of the processed holes is often not up to the standard of the Boring and Trepanning Association (BTA) for the deep-hole drilling of tube plates; this has led to deep-hole processing becoming a bottleneck in the manufacture of steam generators for the main equipment of nuclear power islands. The variation laws of the diameter, roundness, perpendicularity, roughness, microhardness, and residual stress in relation to the feed, speed, and drilling depth are explored in the macro- and micro-dimensions; also explored is the wear morphology of BTA drills. The internal influence mechanisms between them are revealed in order to provide a scientific basis for the control of surface quality and machining accuracy as well as the optimization of process parameters. Our research results indicate that the guide block wear is mainly concentrated at the top 1-2 mm and that the drilling depth and feed have a great influence on the machining diameter. The hole wall roughness is between 0.3 and 0.6 µm, the maximum microhardness is about 2.15 times the hardness of the matrix material, and the residual stress is compressive stress. With increases in the feed and drilling depth, the hole diameter and the roughness increase. With an increase in the speed, the roughness decreases and the compressive stress of the BTA deep-hole drilling wall increases.

[A preliminary study of the hemodynamics of concealed perforator flap in animal model with ultrasonic Doppler technique].

Objective: To study the hemodynamic characteristics of concealed perforator flap in mini-pigs by ultrasonic Doppler technique. Methods: Seven 7-month-old mini-pigs, weighing 20-25 kg, were included in the study. The saphenous artery perforator flap (group A, n=4), saphenous artery concealed perforator flap (group B, n=5), and saphenous artery concealed perforator flap combined with sarcolemma (group C, n=5) models were established randomly on both hind limbs of pigs. The pigs and flap survival conditions were observed after operation. The percentage of flap survival area was calculated by Photoshop CS5 software at 5 days after operation. Ultrasonic Doppler technique was performed on the flaps before operation and at immediate, 3 days, and 5 days after operation to record the hemodynamic changes of the flaps. The hemodynamic indicators of saphenous artery (inner diameter, peak systoli velocity, resistance index, and blood flow) and saphenous vein (inner diameter, maximum velocity, and blood flow) were recorded. Results: At 1 day after operation, 1 pig died of infection, and the rest survived until the experiment was completed. Finally, the 3 flaps of group A, 4 of group B, and 5 of group C were included in the study. The flaps of the 3 groups all showed swelling after operation, which was most significant at 3 days. At 3 days after operation, the flaps in group B showed partial bruising and necrosis. At 5 days after operation, the flaps in groups A and C were basically alive, and the necrosis area of flap in group B increased further. The percentage of flap survival area in groups A, B, and C were 99.7%±0.5%, 74.8%±26.4%, and 100%, respectively. The percentage of flap was significantly lower in group B than in groups A and C (P<0.05). There was no significant difference between groups A and C (P>0.05). There were significant differences in the hemodynamic indicators of saphenous artery and vein between different time points in 3 groups (P<0.05). There was no significant difference in each indicator between groups at each time point (P>0.05). Conclusion: Both the saphenous artery concealed perforator flap and the flap combined with sarcolemma have stable blood flow, but the survival area of the latter was better than the former.

Activation of MyD88-Dependent TLR Signaling Modulates Immune Response of the Mouse Heart during Pasteurella multocida Infection.

Pasteurella multocida (P. multocida) is an important zoonotic pathogen. In addition to lung lesions, necropsies have revealed macroscopic lesions in the heart in clinical cases. However, most previous studies focused on lung lesions while ignoring heart lesions. Therefore, to investigate the immune response of the P. multocida-infected heart, two murine infection models were established by using P. multocida serotype A (Pm HN02) and D (Pm HN01) strains. Histopathological examination revealed heterogeneous inflammatory responses, including immune cell infiltration in the epicardial and myocardial areas of the heart. Transcriptome sequencing was performed on infected cardiac tissues. To explore the traits of immune responses, we performed the functional enrichment analysis of differentially expressed genes, gene set enrichment analysis and gene set variation analysis. The results showed that the innate immune pathways were significantly regulated in both groups, including the NOD-like receptor signaling pathway, the complement and coagulation cascade and cytokine-cytokine receptor interaction. The Toll-like receptor signaling pathway was only significantly activated in the Pm HN02 group. For the Pm HN02 group, immunohistochemistry analysis further verified the significant upregulation of the hub component MyD88 at the protein level. In conclusion, this study reveals critical pathways for host heart recognition and defense against P. multocida serotypes A and D. Moreover, MyD88 was upregulated by P. multocida serotype A in the heart, providing a theoretical basis for future prevention, diagnosis and treatment research.

PJA1 mediates the effects of astrocytic GPR30 on learning and memory in female mice.

Hormone replacement therapy (HRT) is not recommended for treating learning and memory decline in menopausal women because it exerts adverse effects by activating classic estrogen receptors ERα and ERß. The membrane estrogen receptor G protein-coupled receptor 30 (GPR30) has been reported to be involved in memory modulation; however, the underlying mechanisms are poorly understood. Here, we found that GPR30 deletion in astrocytes, but not in neurons, impaired learning and memory in female mice. Astrocytic GPR30 depletion induced A1 phenotype transition, impairing neuronal function. Further exploration revealed that Praja1 (PJA1), a RING ubiquitin ligase, mediated the effects of astrocytic GPR30 on learning and memory by binding to Serpina3n, which is a molecular marker of neuroinflammation in astrocytes. GPR30 positively modulated PJA1 expression through the CREB signaling pathway in cultured murine and human astrocytes. Additionally, the mRNA levels of GPR30 and PJA1 were reduced in exosomes isolated from postmenopausal women while Serpina3n levels were increased in the plasma. Together, our findings suggest a key role for astrocytic GPR30 in the learning and memory abilities of female mice and identify GPR30/PJA1/Serpina3n as potential therapeutic targets for learning and memory loss in peri- and postmenopausal women.

Analytical Model of Hole Diameter and Self-Guiding Machining Mechanism of BTA Deep Hole Drilling.

The goal of this study was to explore the self-guided machining mechanism of boring and trepanning association (BTA) deep hole drilling and realize precise control of the machining quality. The motion analysis method was used to analyze the center motion trajectory of the drill during the entrance, and the self-guiding mechanism and hole-forming mechanism of BTA deep hole drilling were revealed. Considering the bending deformation of the drilling tube and the tool structure parameters, according to the elastic-plastic deformation theory and Hertzian contact theory, a novel analytical model of the extrusion contact between the guide pads and the hole wall of the BTA deep hole drilling was established for the theoretical prediction of the extrusion deformation and the machining hole diameter. Combined with the finite element method (FEM) simulation model, the variation law of the contact inclination angle, contact stress, and extrusion deformation of the guide pads and the hole wall with the drilling conditions were studied. The total extrusion deformation between the guide pad and the hole wall was between 10 and 50 µm. The maximum error between the FEM simulation results and the test results was 18.1%, and the maximum error between the analytical model results and the test results was 23.6%. The simulation and experimental results showed that the established extrusion contact model could accurately predict the extrusion deformation of the hole wall and the machining hole diameter.