Opportunistic use of chest low-dose computed tomography (LDCT) imaging for low bone mineral density and osteoporosis screening: cutoff thresholds for the attenuation values of the lower thoracic and upper lumbar vertebrae.

Background: Osteoporosis remains substantially underdiagnosed and undertreated worldwide. Chest low-dose computed tomography (LDCT) may provide a valuable and popular opportunity for osteoporosis screening. This study sought to evaluate the feasibility of the screening of low bone mineral density (BMD) and osteoporosis with mean attenuation values of the lower thoracic compared to upper lumbar vertebrae. The cutoff thresholds of the mean attenuation values in Hounsfield units (HU) were derived to facilitate implementation of opportunistic screening using chest LDCT. Methods: The participants aged 30 years or older who underwent chest LDCT and quantitative computed tomography (QCT) examinations from August 2018 to October 2020 in our hospital were consecutively included in this retrospective study. A region of interest (ROI) was placed in the trabecular bone of each vertebral body to measure the HU values. The correlations of mean HU values of lower thoracic (T11-T12) and upper lumbar (L1-L2) vertebrae with age and lumbar BMD obtained with QCT were performed using the Pearson correlation coefficient, respectively. The area under the curve (AUC) of the receiver operator characteristic (ROC) curve was generated to determine the cutoff thresholds for distinguishing low BMD from normal and osteoporosis from non-osteoporosis. Results: A total of 1,112 participants were included in the final study cohort (743 men and 369 women, mean age 58.2±8.9 years; range, 32-88 years). The mean HU values of T11-T12 and L1-L2 were significantly different among 3 QCT-defined BMD categories of osteoporosis, osteopenia, and normal (P<0.001). The differences in HU values between T11-T12 and L1-L2 in each category of bone status were statistically significant (P<0.001). The mean HU values of T11-T12 (r=-0.453, P<0.001) and L1-L2 (r=-0.498, P<0.001) had negative correlations with age. Positive correlations were observed between the mean HU values of T11-T12 (r=0.872, P<0.001) and L1-L2 (r=0.899, P<0.001) with BMD. The optimal cutoff thresholds for distinguishing low BMD from normal were average T11-T12 ≤157 HU [AUC =0.941, 95% confidence interval (CI): 0.925-0.954, P<0.001] and L1-L2 ≤138 HU (AUC =0.950, 95% CI: 0.935-0.962, P<0.001), as well as distinguishing osteoporosis from non-osteoporosis were average T11-T12 ≤125 HU (AUC =0.960, 95% CI: 0.947-0.971, P<0.001) and L1-L2 ≤107 HU (AUC =0.961, 95% CI: 0.948-0.972, P<0.001). There was no significant difference between the AUC values of T11-T12 and L1-L2 for low BMD (P=0.07) and osteoporosis (P=0.92) screening. Conclusions: We have conducted a study on low BMD and osteoporosis screening using mean attenuation values of lower thoracic and upper lumbar vertebrae. Assessment of mean attenuation values of T11-T12 and L1-L2 can be used interchangeably for low BMD and osteoporosis screening using chest LDCT, and their cutoff thresholds were established.

Promoter of Cassava MeAHL31 Responds to Diverse Abiotic Stresses and Hormone Signals in Transgenic Arabidopsis.

The AT-hook motif nuclear-localized (AHL) family is pivotal for the abiotic stress response in plants. However, the function of the cassava AHL genes has not been elucidated. Promoters, as important regulatory elements of gene expression, play a crucial role in stress resistance. In this study, the promoter of the cassava MeAHL31 gene was cloned. The MeAHL31 protein was localized to the cytoplasm and the nucleus. qRT-PCR analysis revealed that the MeAHL31 gene was expressed in almost all tissues tested, and the expression in tuber roots was 321.3 times higher than that in petioles. Promoter analysis showed that the MeAHL31 promoter contains drought, methyl jasmonate (MeJA), abscisic acid (ABA), and gibberellin (GA) cis-acting elements. Expression analysis indicated that the MeAHL31 gene is dramatically affected by treatments with salt, drought, MeJA, ABA, and GA3. Histochemical staining in the proMeAHL31-GUS transgenic Arabidopsis corroborated that the GUS staining was found in most tissues and organs, excluding seeds. Beta-glucuronidase (GUS) activity assays showed that the activities in the proMeAHL31-GUS transgenic Arabidopsis were enhanced by different concentrations of NaCl, mannitol (for simulating drought), and MeJA treatments. The integrated findings suggest that the MeAHL31 promoter responds to the abiotic stresses of salt and drought, and its activity is regulated by the MeJA hormone signal.

Single-cell analysis of Crohn's disease: Unveiling heterogeneity and evaluating ustekinumab outcomes.

BACKGROUND: The present study aimed to dissect the cellular complexity of Crohn's disease (CD) using single-cell RNA sequencing, focusing on identifying key cell populations and their transcriptional profiles in inflamed tissue. METHODS: We applied scRNA-sequencing to compare the cellular composition of CD patients with healthy controls, utilizing Seurat for clustering and annotation. Differential gene expression analysis and protein-protein interaction networks were constructed to identify crucial genes and pathways. RESULTS: Our study identified eight distinct cell types in CD, highlighting crucial fibroblast and T cell interactions. The analysis revealed key cellular communications and identified significant genes and pathways involved in the disease's pathology. The role of fibroblasts was underscored by elevated expression in diseased samples, offering insights into disease mechanisms and potential therapeutic targets, including responses to ustekinumab treatment, thus enriching our understanding of CD at a molecular level. CONCLUSIONS: Our findings highlight the complex cellular and molecular interplay in CD, suggesting new biomarkers and therapeutic targets, offering insights into disease mechanisms and treatment implications.

[Stellera chamaejasme against multidrug resistance of triple-negative breast cancer MDA-MB-231 cell through Nrf2].

This study aims to investigate the effect and mechanism of Stellera chamaejasme extract(SCL) on multidrug resistance(MDR) in breast cancer. Human triple-negative breast cancer cell line MDA-MB-231 and its adriamycin-resistant cell line MDA-MB-231/ADR were used in the experiment. Cell viability was detected by methyl thiazolyl tetrazolium(MTT) assay, and cell apoptosis was detected by DAPI staining and Annexin-V/Pi double staining. Western blot(WB) was used to detect the expression levels of Keap1, Nrf2, HO-1, Bcl-2, Bax, caspase-9, and caspase-3. Immunofluorescence staining was used to observe the distribution of Nrf2 in the cell, and flow cytometry was used to detect the level of reactive oxygen species(ROS) in the cell. The results showed that the resis-tance factor of SCL was 0.69, and that of adriamycin and paclitaxel was 8.40 and 16.36, respectively. DAPI staining showed that SCL could cause nuclear shrinkage and fragmentation of breast cancer cells. Annexin-V/Pi double staining showed that the average apoptosis rate of the drug-resistant cells was 32.64% and 50.29%, respectively under medium and high doses of SCL. WB results showed that SCL could significantly reduce the expression levels of anti-apoptotic proteins Bcl-2, caspase-9, and caspase-3 and significantly increase the expression level of pro-apoptotic protein Bax. Further studies showed that SCL could significantly promote the expression of Keap1, significantly inhibit the expression of Nrf2 and HO-1, and significantly reduce the expression level of Nrf2 in the nucleus. Correspondingly, flow cytometry showed that the intracellular ROS level was significantly increased. In conclusion, SCL can significantly inhibit the proliferation of MDA-MB-231 multidrug-resistant cells of triple-negative breast cancer and cause cell apoptosis, and the mechanism is related to inhibiting Keap1/Nrf2 signaling pathway, leading to ROS accumulation in drug-resistant cells and increasing the expression of apoptosis-related proteins.

Functional Characterization of the MeSSIII-1 Gene and Its Promoter from Cassava.

Soluble starch synthases (SSs) play important roles in the synthesis of cassava starch. However, the expression characteristics of the cassava SSs genes have not been elucidated. In this study, the MeSSIII-1 gene and its promoter, from SC8 cassava cultivars, were respectively isolated by PCR amplification. MeSSIII-1 protein was localized to the chloroplasts. qRT-PCR analysis revealed that the MeSSIII-1 gene was expressed in almost all tissues tested, and the expression in mature leaves was 18.9 times more than that in tuber roots. MeSSIII-1 expression was induced by methyljasmonate (MeJA), abscisic acid (ABA), and ethylene (ET) hormones in cassava. MeSSIII-1 expression patterns were further confirmed in proMeSSIII-1 transgenic cassava. The promoter deletion analysis showed that the -264 bp to -1 bp MeSSIII-1 promoter has basal activity. The range from -1228 bp to -987 bp and -488 bp to -264 bp significantly enhance promoter activity. The regions from -987 bp to -747 bp and -747 bp to -488 bp have repressive activity. These findings will provide an important reference for research on the potential function and transcriptional regulation mechanisms of the MeSSIII-1 gene and for further in-depth exploration of the regulatory network of its internal functional elements.

Hepatic kynurenic acid mediates phosphorylation of Nogo-A in the medial prefrontal cortex to regulate chronic stress-induced anxiety-like behaviors in mice.

Exercise training effectively relieves anxiety disorders via modulating specific brain networks. The role of post-translational modification of proteins in this process, however, has been underappreciated. Here we performed a mouse study in which chronic restraint stress-induced anxiety-like behaviors can be attenuated by 14-day persistent treadmill exercise, in association with dramatic changes of protein phosphorylation patterns in the medial prefrontal cortex (mPFC). In particular, exercise was proposed to modulate the phosphorylation of Nogo-A protein, which drives the ras homolog family member A (RhoA)/ Rho-associated coiled-coil-containing protein kinases 1(ROCK1) signaling cascade. Further mechanistic studies found that liver-derived kynurenic acid (KYNA) can affect the kynurenine metabolism within the mPFC, to modulate this RhoA/ROCK1 pathway for conferring stress resilience. In sum, we proposed that circulating KYNA might mediate stress-induced anxiety-like behaviors via protein phosphorylation modification within the mPFC, and these findings shed more insights for the liver-brain communications in responding to both stress and physical exercise.

Serotonin receptor 2B induces visceral hyperalgesia in rat model and patients with diarrhea-predominant irritable bowel syndrome.

BACKGROUND: Serotonin receptor 2B (5-HT2B receptor) plays a critical role in many chronic pain conditions. The possible involvement of the 5-HT2B receptor in the altered gut sensation of irritable bowel syndrome with diarrhea (IBS-D) was investigated in the present study. AIM: To investigate the possible involvement of 5-HT2B receptor in the altered gut sensation in rat model and patients with IBS-D. METHODS: Rectosigmoid biopsies were collected from 18 patients with IBS-D and 10 patients with irritable bowel syndrome with constipation who fulfilled the Rome IV criteria and 15 healthy controls. The expression level of the 5-HT2B receptor in colon tissue was measured using an enzyme-linked immunosorbent assay and correlated with abdominal pain scores. The IBS-D rat model was induced by intracolonic instillation of acetic acid and wrap restraint. Alterations in visceral sensitivity and 5-HT2B receptor and transient receptor potential vanilloid type 1 (TRPV1) expression were examined following 5-HT2B receptor antagonist administration. Changes in visceral sensitivity after administration of the TRPV1 antagonist were recorded. RESULTS: Here, we observed greater expression of the 5-HT2B receptor in the colonic mucosa of patients with IBS-D than in that of controls, which was correlated with abdominal pain scores. Intracolonic instillation of acetic acid and wrap restraint induced obvious chronic visceral hypersensitivity and increased fecal weight and fecal water content. Exogenous 5-HT2B receptor agonist administration increased visceral hypersensitivity, which was alleviated by successive administration of a TRPV1 antagonist. IBS-D rats receiving the 5-HT2B receptor antagonist exhibited inhibited visceral hyperalgesia.Moreover, the percentage of 5-HT2B receptor-immunoreactive (IR) cells surrounded by TRPV1-positive cells (5-HT2B receptor I+) and total 5-HT2B receptor IR cells (5-HT2B receptor IT) in IBS-D rats was significantly reduced by the administration of a 5-HT2B receptor antagonist. CONCLUSION: Our finding that increased expression of the 5-HT2B receptor contributes to visceral hyperalgesia by inducing TRPV1 expression in IBS-D patients provides important insights into the potential mechanisms underlying IBS-D-associated visceral hyperalgesia.

[Pathogenesis and Therapeutic Prospects of Chronic Graft-Versus-Host Disease --Review].

Chronic graft-versus-host disease (cGVHD) is one of a major complication that affecting the long-term survival and living quality of patients after allogeneic hematopoietic stem cell transplantation, with the incidence of 30%-70%. Unlike acute GVHD, cGVHD involves a large number of immune cells and cytokines in addition to T cell, which is activated abnormally by the donor, and cytokine storms, which characterized by infiltration of donor lymphocytes and damage to host target organ. Recent studies have further made progress in targeting related immune cells and cytokines. In this review, the pathogenesis and therapeutic prospects of cGVHD were summarized from the perspectives of classical innate and adaptive immunity.

N-Heterocyclic Carbene-Catalyzed Formal Intramolecular [3 + 2] Annulations of Cyclohexadienone-Tethered Ynals.

A formal [3 + 2] annulation of cyclohexadienone-tethered ynals is enabled by an N-heterocyclic carbene (NHC) catalyst, affording a tricyclo[6.2.1.04,11]undecane framework. This study represents the first demonstration of using C═C double bonds as the reaction partner in the NHC-catalyzed annulation of ynals. This strategy is characterized by mild reaction conditions and 100% atom economy as well as high catalytic performance and efficiency.

Effect of Body Weight Support Training on Lower Extremity Motor Function in Patients With Spinal Cord Injury: A Systematic Review and Meta-analysis.

OBJECTIVES: The aims of the study are to systematically evaluate the effect of body weight support training on lower extremity motor function(s) in patients with spinal cord injury and to compare the effect differences among three body weight support training methods. DESIGN: PubMed, Web of Science, Cochrane Library, Embase, CNKI, CBM, China Scientific Journal, and Wan Fang databases were searched until December 31, 2022. Meta-analysis and network meta-analysis were conducted using RevMan 5.4 and ADDIS 1.16.8. RESULTS: Nineteen randomized controlled trials involving 864 patients were included. The meta-analysis showed that body weight support training could improve lower extremity motor scores according to the International Standards for Neurological Classification of Spinal Cord Injury standard (mean difference = 6.38, 95% confidence interval = 3.96-8.80, P < 0.05), walking speed (standard mean difference = 0.77, 95% confidence interval = 0.52-1.02, P < 0.05), and modified Barthel Index scores (mean difference = 9.85, 95% confidence interval = 8.39-11.30, P < 0.05). The network meta-analysis showed no significant difference among the three body weight support training methods for improving lower extremity motor scores in patients with spinal cord injury. The best probability ranking of the body weight support training methods for improving lower extremity motor scores in patients with spinal cord injury was robot-assisted gait training ( P = 0.60), followed by aquatic exercise ( P = 0.21) and body weight support training ( P = 0.19). CONCLUSIONS: Body weight support training can improve lower extremity motor score in patients with spinal cord injury. No significant difference was observed among the three body weight support training methods, but robot-assisted gait training may produce the best effect.

Halogen bonding-driven chiral amplification of a bimetallic gold-copper cluster through hierarchical assembly.

Understanding the fundamentals and applications of chirality relies substantially on the amplification of chirality through hierarchical assemblies involving various weak interactions. However, a notable challenge remains for metal clusters chiral assembly driven by halogen bonding, despite their promising applications in lighting, catalysis, and biomedicine. Here, we used halogen bonding-driven assembly to achieve a hierarchical degree of achiral emissive Au2Cu2 clusters. From single crystals to one-dimensional ribbons and then to helixes, the morphologies were primarily modulated by intermolecular halogen bonding that evoked by achiral or/and chiral iodofluorobenzene (IFBs) molecules. Concomitantly, the luminescence and circularly polarized luminescence (CPL) changed a lot, ultimately leading to a substantial increase in the luminescence dissymmetry g-factor (glum) of 0.036 in the supramolecular helix. This work opens an avenue for hierarchical assemblies using predesigned metal clusters as building blocks though directional halogen bonding. This achievement marks a noteworthy advancement in the field of nanosized inorganic functional blocks.

A Preliminary Study of Brain Functional Magnetic Resonance Imaging in Text Reading and Comprehension.

BACKGROUND: Few studies have focused on the changes in human brain function activities caused by reading Chinese characters with different intelligibility and whether it can reflect the understanding and cognitive ability of the human brain. OBJECTIVE: Task-fMRI based on Chinese character reading tasks with different intelligibility was used to explore activated brain regions and their cognitive changes. METHODS: Volunteers were randomly recruited using advertisements. Forty volunteers were recruited based on strict inclusion and exclusion criteria, and 40 volunteers were recruited. Brain function data of 40 healthy right-handed volunteers in fuzzy/clear Chinese reading tasks were collected using a Siemens Skyra 3.0T magnetic resonance scanner. Data were preprocessed and statistically analyzed using the statistical software SPM12.0 to observe the activation of the cortex and analyze its characteristics and possible changes in cognitive function. RESULTS: Task-fMRI analysis: (1) The main brain regions activated in fuzzy/clear reading tasks were located in the occipital visual cortex (P < 0.001); (2) a paired sample t-test suggested that there was a significant difference in BOLD signals in the brain regions activated by fuzzy/clear reading tasks (P < 0.001, equiv Z = 4.25). Compared with the fuzzy reading task, the brain regions more strongly activated in the clear reading task were mainly located in the right superior frontal gyrus and the bilateral temporal lobe. Compared with the clear reading task, the brain region that was more strongly activated in the fuzzy reading task was mainly located in the right fusiform gyrus. CONCLUSION: Clear Chinese character information mainly activates the dorsal stream of the visual-spatial network. This reflects the information transmission of the brain after understanding the text content and is responsible for guiding and controlling attention. Fuzzy words that cannot provide clear text content activate the fusiform gyrus of the ventral stream of the visual-spatial network, strengthening the function of orthographic processing.

[Expression and Prognostic Value of Cytokines in Patients with Newly Diagnosed Diffuse Large B-Cell Lymphoma].

OBJECTIVE: To investigate the expression and prognostic value of cytokines in patients with newly diagnosed diffuse large B-cell lymphoma (DLBCL). METHODS: Clinical data of 62 patients diagnosed with DLBCL in the First People's Hospital of Yunnan Province from June 2017 to November 2018 were collected. The differences in expression levels of 14 serum cytokines [interleukin (IL)-1ß, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12p70, IL-17A, IL-17F, IL-22, interferon (IFN)-γ, tumor necrosis factor (TNF)-α, TNF-ß] in patients with different survival outcomes, and the impact of the cytokines on 3-year progression-free survival (PFS) and 3-year overall survival (OS) of patients with DLBCL were analyzed retrospectively. RESULTS: Among the 14 cytokines, only the expression of IL-10 was significantly different in patients with different survival outcomes (P =0.007). According to the receiver operating characteristic (ROC) curve, the optimal cut-off value for IL-10 was 11.74 pg/ml. Serum IL-10 was positively correlated with infection markers procalcitonin (PCT) (r =0.321, P =0.029), C-reactive protein (CRP) (r =0.320, P =0.013) and tumor burden index lactate dehydrogenase (LDH) (r =0.439, P <0.001) in newly diagnosed DLBCL patients. The level of IL-10 in patients with pulmonary infection was significantly higher than that in patients without pulmonary infection (P =0.012). However, there was no statistically significant difference on the 3-year survival outcomes between patients with or without pulmonary infection. There was no significant difference in IL-10 level in patients with different Ann Arbor stages (P >0.05). Patients with high IL-10 level (IL-10>11.74 pg/ml) had significantly higher LDH level than those with low IL-10 level (IL-10≤11.74 pg/ml) (P <0.001). The 3-year PFS rate and 3-year OS rate of DLBCL patients with high IL-10 level were significantly lower than those of low IL-10 level group [(44.4±11.7)% vs (81.8±5.8)%, P <0.001; (61.6±11.5)% vs (93.2±3.8)%, P =0.001]. CONCLUSION: Serum IL-10 level in newly diagnosed DLBCL patients can reflect the inflammatory state of the body, which may be related to tumor load. Newly diagnosed DLBCL patients with serum IL-10>11.74 pg/ml have higher early mortality and worse prognosis.

Comparative study on inhibitory effects of ginsenosides on human pancreatic lipase and porcine pancreatic lipase: structure-activity relationships and inhibitory mechanism.

The inhibitory effects of twenty-six ginsenosides on human pancreatic lipase (hPL) and porcine pancreatic lipase (pPL) were studied. Study reveals that nine ginsenosides have moderate inhibitory effects against hPL, and good selectivity over pPL. By contrast, (S)-Rh2 showed good inhibitory effects on pPL over hPL. SAR analysis indicated that introduction of the O-glycosyl group(s) at C-3/C-7 site is unbeneficial for hPL inhibition, ginsenosides with A-skeleton is more beneficial than ginsenosides with B-/C-skeleton. Inhibition kinetic analysis indicated that Rg3 and (S)-Rh2 inhibited hPL-catalyzed DDAO-ol hydrolysis in a mixed manner. Molecular docking studies have confirmed that Rg3 and (S)-Rh2 inhibit hPL via many Pi-hydrogen interactions and hydrogen bonds with catalytic residues of hPL. These results indicated that pPL as an enzyme source could not fully represent the inhibitory effect of the tested compounds on hPL, and hPL should be used as far as possible to evaluate the inhibitory effect of PL.

[Stellera chamaejasme extract against multidrug resistance of breast cancer cell line MCF-7].

This study explored the effect and underlying mechanism of Stellera chamaejasme extract(SCE) on multidrug resistance of breast cancer. The chemotherapy-sensitive breast cancer cell line MCF-7 and adriamycin(ADR)-resistant cell line MCF-7/ADR were used as experimental subjects. MTT assay was used to detect cell proliferation activity. Pi staining was used to detect the cell cycle. 4',6-Diamidino-2-phenylindole, dihydrochloride(DAPI) staining and flow cytometry were used to detect apoptosis. Dansylcadaverine(MDC) staining and GFP-LC3B-Mcherry adenovirus transfection were used to detect autophagy. The protein expression of Bcl-2, Bax, caspase-9, caspase-3, LC3B, p62, and Beclin-1 was detected by Western blot. The results showed that SCE could significantly inhibit the proliferation of both sensitive and resistant breast cancer cell lines. The drug resistance factor was 0.53, which was significantly lower than 59 of ADR. Meanwhile, the proportion of sensitive/resistant cells in the G_0/G_1 phase increased significantly after SCE treatment. In addition, DAPI staining showed that a series of apoptosis phenomena such as nuclear pyknosis, staining deepening, and nuclear fragmentation appeared in sensitive/resistant cell lines after SCE administration. Moreover, the results of flow cytometry double staining showed that the proportion of apoptotic cells in sensitive/resistant cell lines increased significantly after SCE administration. Besides, Western blot showed that the protein expression levels of caspase-3, caspase-9, and Bcl-2 significantly decreased and the expression level of Bax protein significantly increased in both breast cancer cell lines after SCE administration. Furthermore, SCE could also increase the positive fluorescent spots after MDC staining and yellow fluorescent spots after GFP-LC3B-mcherry transfection, and up-regulate the expression levels of autophagy-related proteins LC3B-Ⅱ, p62, and Beclin-1 in breast cancer cells. In summary, SCE may play the role of anti-multidrug resistance by blocking the cell cycle of breast cancer multidrug-resistant cells, blocking autophagy flow, and ultimately interfering with the apoptosis resistance of drug-resistant cells.

Metallophilic Interactions Drive Supramolecular Chirality Evolution and Amplify Circularly Polarized Luminescence.

Metallophilic interactions, which are ubiquitous among d10 metal complexes with linear coordination geometries, can direct one-dimensional assembly. However, the ability of these interactions to manipulate chirality at the hierarchical level largely remains unknown. In this work, we unveiled the role of Au···Cu metallophilic interactions in directing the chirality of multicomponent assemblies. N-heterocyclic carbene-Au(I) complexes bearing amino acid residues formed chiral co-assemblies with [CuI2]- anions via Au···Cu interactions. These metallophilic interactions changed the molecular packing modes of the co-assembled nanoarchitectures from lamellar to columnar chiral packing. This transformation initiated the emergence, inversion, and evolution of supramolecular chirality, thereby affording helical superstructures, depending on the geometry of building units. In addition, the Au···Cu interactions altered the luminescence properties and induced the emergence and amplification of circularly polarized luminescence. This work, for the first time, revealed the role of Au···Cu metallophilic interactions in modulating supramolecular chirality, paving the way for the construction of functional chiroptical materials based on d10 metal complexes.

Shenlian extract decreases mitochondrial autophagy to regulate mitochondrial function in microvascular to alleviate coronary artery no-reflow.

Shenlian (SL) extract has been proven to be effective in the prevention and treatment of atherosclerosis and myocardial ischemia. However, the function and molecular mechanisms of SL on coronary artery no-reflow have not been fully elucidated. This study was designed to investigate the contribution of SL extract in repressing excessive mitochondrial autophagy to protect the mitochondrial function and prevent coronary artery no-reflow. The improvement of SL on coronary artery no-reflow was observed in vivo experiments and the molecular mechanisms were further explored through vitro experiments. First, a coronary artery no-reflow rat model was built by ligating the left anterior descending coronary artery for 2 hr of ischemia, followed by 24 hr of reperfusion. Thioflavin S (6%, 1 ml/kg) was injected into the inferior vena cava to mark the no-reflow area. Transmission electron microscopy was performed to observe the cellular structure, mitochondrial structure, and mitochondrial autophagy of the endothelial cells. Immunofluorescence was used to observe the microvascular barrier function and microvascular inflammation. Cardiac microvascular endothelial cells (CMECs) were isolated from rats. The CMECs were deprived of oxygen-glucose deprivation (OGD) for 2 hr and reoxygenated for 4 hr to mimic the Myocardial ischemia-reperfusion (MI/R) injury-induced coronary artery no-reflow in vitro. Mitochondrial membrane potential was assessed using JC-1 dye. Intracellular adenosine triphosphate (ATP) levels were determined using an ATP assay kit. The cell total reactive oxygen species (ROS) levels and cell apoptosis rate were analyzed by flow cytometry. Colocalization of mitochondria and lysosomes indirectly indicated mitophagy. The representative ultrastructural morphologies of the autophagosomes and autolysosomes were also observed under transmission electron microscopy. The mitochondrial autophagy-related proteins (LC3II/I, P62, PINK, and Parkin) were analyzed using Western blot analysis. In vivo, results showed that, compared with the model group, SL could reduce the no-reflow area from 37.04 ± 9.67% to 18.31 ± 4.01% (1.08 g·kg-1 SL), 13.79 ± 4.77% (2.16 g·kg-1 SL), and 12.67 ± 2.47% (4.32 g·kg-1 SL). The extract also significantly increased the left ventricular ejection fraction (EF) and left ventricular fractional shortening (FS) (p < 0.05 or p < 0.01). The fluorescence intensities of VE-cadherin, which is a junctional protein that preserves the microvascular barrier function, decreased to ~74.05% of the baseline levels in the no-reflow rats and increased to 89.87%(1.08 g·kg-1 SL), 82.23% (2.16 g·kg-1 SL), and 89.69% (4.32 g·kg-1 SL) of the baseline levels by SL treatment. SL administration repressed the neutrophil migration into the myocardium. The oxygen-glucose deprivation/reoxygenation (OGD/R) model was induced in vitro to mimic microvascular ischemia-reperfusion injury. The impaired mitochondrial function after OGD/R injury led to decreased ATP production, calcium overload, the excessive opening of the Mitochondrial Permeability Transition Pore, decreased mitochondrial membrane potential, and reduced ROS scavenging ability (p < 0.05 or p < 0.01). The normal autophagosomes (double-membrane vacuoles with autophagic content) in the sham group were rarely found. The large morphology and autophagosomes were frequently observed in the model group. By contrast, SL inhibited the excessive activation of mitochondrial autophagy. The mitochondrial autophagy regulated by the PINK/Parkin pathway was excessively activated. However, administration of SL prevented the activation of the PINK/Parkin pathway and inhibited excessive mitochondrial autophagy to regulate mitochondrial dysfunction. Results also demonstrated that mitochondrial dysfunction stimulated endothelial cell barrier dysfunction, but Evans blue transmission was significantly decreased and transmembrane resistance was increased significantly by SL treatment (p < 0.05 or p < 0.01). Carbonylcyanide-3-chlorophenylhydrazone (CCCP) could activate the PINK/Parkin pathway. CCCP reversed the regulation of SL on mitochondrial autophagy and mitochondrial function. SL could alleviate coronary artery no-reflow by protecting the microvasculature by regulating mitochondrial function. The underlying mechanism was related to decreased mitochondrial autophagy by the PINK/Parkin pathway.

A Highly Enantioselective Homoenolate Michael Addition/Esterification Sequence of Cyclohexadienone-Tethered Enals via NHC Catalysis.

Reported here is a highly enantioselective homoenolate Michael addition/esterification sequence of cyclohexadienone-tethered enals via N-heterocyclic carbene (NHC) catalysis, affording the enantiopure cis-hydrobenzofurans, cis-hydroindoles, and cis-hydroindenes. The NHC catalyst bearing a nitro group greatly enhances the stereocontrol, and a bulky N-aryl substituent of the triazolium salt in the catalyst is helpful for inhibiting the further aldol condensation after homoenolate Michael addition. The utility of this protocol is highlighted by a gram-scale experiment and versatile downstream transformations.