Metallaphotoredox deuteroalkylation utilizing thianthrenium salts.

Deuterium labeling compounds play a crucial role in organic and pharmaceutical chemistry. The synthesis of such compounds typically involves deuterated building blocks, allowing for the incorporation of deuterium atoms and functional groups into a target molecule in a single step. Unfortunately, the limited availability of synthetic approaches to deuterated synthons has impeded progress in this field. Here, we present an approach utilizing alkyl-substituted thianthrenium salts that efficiently and selectively introduce deuterium at the α position of alkyl chains through a pH-dependent HIE process, using D2O as the deuterium source. The resulting α-deuterated alkyl thianthrenium salts, which bear two deuterium atoms, exhibit excellent selectivity and deuterium incorporation in electrophilic substitution reactions. Through in situ formation of isotopically labelled alkyl halides, these thianthrenium salts demonstrate excellent compatibility in a series of metallaphotoredox cross-electrophile coupling with (hetero)aryl, alkenyl, alkyl bromides, and other alkyl thianthrenium salts. Our technique allows for a wide range of substrates, high deuterium incorporation, and precise control over the site of deuterium insertion within a molecule such as the benzyl position, allylic position, or any alkyl chain in between, as well as neighboring heteroatoms. This makes it invaluable for synthesizing various deuterium-labeled compounds, especially those with pharmaceutical significance.

Hydrodeuteroalkylation of Unactivated Olefins Using Thianthrenium Salts.

Isotopically labeled alkanes play a crucial role in organic and pharmaceutical chemistry. While some deuterated methylating agents are readily available, the limited accessibility of other deuteroalkyl reagents has hindered the synthesis of corresponding products. In this study, we introduce a nickel-catalyzed system that facilitates the synthesis of various deuterium-labeled alkanes through the hydrodeuteroalkylation of d2-labeled alkyl TT salts with unactivated alkenes. Diverging from traditional deuterated alkyl reagents, alkyl thianthrenium (TT) salts can effectively and selectively introduce deuterium at α position of alkyl chains using D2O as the deuterium source via a single-step pH-dependent hydrogen isotope exchange (HIE). Our method allows for high deuterium incorporation, and offers precise control over the site of deuterium insertion within an alkyl chain. This technique proves to be invaluable for the synthesis of various deuterium-labeled compounds, especially those of pharmaceutical relevance.

Identifying of immune-associated genes for assessing the obesity-associated risk to the offspring in maternal obesity: A bioinformatics and machine learning.

BACKGROUND: Perinatal exposure to maternal obesity predisposes offspring to develop obesity later in life. Immune dysregulation in the hypothalamus, the brain center governing energy homeostasis, is pivotal in obesity development. This study aimed to identify key candidate genes associated with the risk of offspring obesity in maternal obesity. METHODS: We obtained obesity-related datasets from the Gene Expression Omnibus (GEO) database. GSE135830 comprises gene expression data from the hypothalamus of mouse offspring in a maternal obesity model induced by a high-fat diet model (maternal high-fat diet (mHFD) group and maternal chow (mChow) group), while GSE127056 consists of hypothalamus microarray data from young adult mice with obesity (high-fat diet (HFD) and Chow groups). We identified differentially expressed genes (DEGs) and module genes using Limma and weighted gene co-expression network analysis (WGCNA), conducted functional enrichment analysis, and employed a machine learning algorithm (least absolute shrinkage and selection operator (LASSO) regression) to pinpoint candidate hub genes for diagnosing obesity-associated risk in offspring of maternal obesity. We constructed a nomogram receiver operating characteristic (ROC) curve to evaluate the diagnostic value. Additionally, we analyzed immune cell infiltration to investigate immune cell dysregulation in maternal obesity. Furthermore, we verified the expression of the candidate hub genes both in vivo and in vitro. RESULTS: The GSE135830 dataset revealed 2868 DEGs between the mHFD offspring and the mChow group and 2627 WGCNA module genes related to maternal obesity. The overlap of DEGs and module genes in the offspring with maternal obesity in GSE135830 primarily enriched in neurodevelopment and immune regulation. In the GSE127056 dataset, 133 DEGs were identified in the hypothalamus of HFD-induced adult obese individuals. A total of 13 genes intersected between the GSE127056 adult obesity DEGs and the GSE135830 maternal obesity module genes that were primarily enriched in neurodevelopment and the immune response. Following machine learning, two candidate hub genes were chosen for nomogram construction. Diagnostic value evaluation by ROC analysis determined Sytl4 and Kncn2 as hub genes for maternal obesity in the offspring. A gene regulatory network with transcription factor-miRNA interactions was established. Dysregulated immune cells were observed in the hypothalamus of offspring with maternal obesity. Expression of Sytl4 and Kncn2 was validated in a mouse model of hypothalamic inflammation and a palmitic acid-stimulated microglial inflammation model. CONCLUSION: Two candidate hub genes (Sytl4 and Kcnc2) were identified and a nomogram was developed to predict obesity risk in offspring with maternal obesity. These findings offer potential diagnostic candidate genes for identifying obesity-associated risks in the offspring of obese mothers.

Non-linear association of years of experience and burnout among nursing staff: a restricted cubic spline analysis.

Background: Occupational burnout is intricately linked to a spectrum of physical disorders encompassing respiratory, cardiovascular, and gastrointestinal conditions, as well as manifestations such as headaches, type 2 diabetes, elevated cholesterol levels, chronic fatigue, and muscle pain. Despite this association, there remains a paucity of research on the specific risk factors contributing to burnout among nurses in China. Methods: This cross-sectional study utilized convenience sampling to recruit participants, with data analyzed from 1,774 nurse staffs. Psychosocial traits were assessed using the Three-Item Loneliness Scale for loneliness, the Generalized Anxiety Disorder 7-item scale (GAD-7) for anxiety symptoms, the 9-item Patient Health Questionnaire (PHQ-9) for depressive symptoms, the Connor Davidson Resilience Scale-10 item (CDRISC-10) for resilience, and the Maslach Burnout Inventory-Human Service Survey (MBI-HSS) for burn out. Restrictive cubic spline analysis to investigate the dose-response relationship between years of experience and burn out. Multivariate linear regression was employed to investigate the relationship between burnout and various risk factors. Results: After controlling for basic demographic variables, good sleep quality was associated with a reduction in emotional exhaustion (ß = -0.307, p < 0.001), while loneliness (ß = 1.334, p < 0.001), depressive symptoms (ß = 0.896, p < 0.001), and anxiety symptoms (ß = 0.504, p < 0.001) were significantly associated with increased emotional exhaustion. Moreover, higher levels of resilience were positively associated with personal accomplishment (ß = 0.635, p < 0.001). Regarding depersonalization, loneliness (ß = 0.577, p < 0.001), depressive symptoms (ß = 0.429, p < 0.001), and anxiety symptoms (ß = 0.152, p < 0.01) were found to increase its level. Conversely, good resilience was associated with a decrease in depersonalization (ß = -0.069, p < 0.001). The non-liner association between year of experience and emotional exhaustion was significantly (p < 0.05). Conclusion: Our findings revealed that significant risk factors contributing to burnout among nursing staff including bad sleep quality, loneliness, lower level of resilience, anxiety symptoms, depressive symptoms. Moreover, a nonlinear correlation between years of experience and the likelihood of experiencing emotional exhaustion was exist.

The protective influence of family support on anxiety, depressive symptoms, and suicidal ideation among elderly Chinese nursing home residents: A study of serial mediation.

In light of the aging demographic in China, heightened attention is warranted for the mental well-being of elderly individuals. Nevertheless, the prevalence of suicidal ideation among older residents in Chinese nursing homes and the nuanced impact of family support on this phenomenon, mediated by anxiety and depressive symptoms, remain unclear. A cohort of 506 Chinese elderly adults participated in the study. Psychosocial traits were assessed using the Perceived Social Support from Family scale (PSS-Fa) for family support, the 7-item Generalized Anxiety Disorder scale (GAD-7) for anxiety symptoms, the 9-item Patient Health Questionnaire (PHQ-9) for depressive symptoms, and suicidal ideation. A structural equation model (SEM) was employed to execute a serial mediation model. The analysis of 506 elderly adults revealed that 8.1% reported varying levels of suicidal ideation within Chinese nursing homes. The pathway from family support to anxiety symptoms (standardized beta = -0.025, P = .241), family support to depressive symptoms (standardized beta = -0.072, P < .05), and family support to suicidal ideation (standardized beta = -0.082, P < .05) were explored. Additionally, pathways from anxiety symptoms to suicidal ideation (standardized beta = 0.364, P < .001), anxiety symptoms to depressive symptoms (standardized beta = 0.647, P < .001), and depressive symptoms to suicidal ideation (standardized beta = 0.369, P < .001) were examined. This study elucidated the underlying mechanisms connecting family support to suicidal ideation, with depressive symptoms partially mediating this association. Additionally, our discoveries shed light on the partial mediation of anxiety symptoms by depressive factors when it came to the realm of suicidal ideation.

Spinal interleukin-24 contributes to neuropathic pain after peripheral nerve injury through interleukin-20 receptor2 in mice.

Neuroinflammation is critically involved in nerve injury-induced neuropathic pain, characterized by local and systemic increased levels of proinflammatory cytokines. Interleukin-24 (IL-24), a key member of the IL-10 family, has been extensively studied for its therapeutic potential in various diseases, including cancer, autoimmune disorders, and bacterial infections, but whether it is involved in the regulation of neuropathic pain caused by peripheral nerve injury (PNI) has not been well established. In this study, we reported that spared nerve injury (SNI) induced a significant upregulation of IL-24 in fibroblasts, neurons, and oligodendrocyte precursor cells (OPCs, also called NG2-glia) in the affected spinal dorsal horns (SDHs), as well as dorsal root ganglions (DRGs). We also found that tumor necrosis factor α (TNF-α) induced the transcriptional expression of IL-24 in cultured fibroblasts, neurons, and NG2-glia; in addition, astrocytes, microglia, and NG2-glia treated with TNF-α exhibited a prominent increase in interleukin-20 receptor 2 (IL-20R2) expression. Furthermore, we evaluated the ability of IL-24 and IL-20R2 to attenuate pain in preclinical models of neuropathic pain. Intrathecal (i.t.) injection of IL-24 neutralizing antibody or IL-20R2 neutralizing antibody could effectively alleviate mechanical allodynia and thermal hyperalgesia after PNI. Similarly, intrathecal injection of IL-24 siRNA or IL-20R2 siRNA also alleviated mechanical allodynia after SNI. The inhibition of IL-24 reduced SNI-induced proinflammatory cytokine (IL-1ß and TNF-α) production and increased anti-inflammatory cytokine (IL-10) production. Meanwhile, the inhibition of IL-20R2 also decreased IL-1ß mRNA expression after SNI. Collectively, our findings revealed that IL-24/IL-20R might contribute to neuropathic pain through inflammatory response. Therefore, targeting IL-24 could be a promising strategy for treating neuropathic pain induced by PNI.

Nickel-Catalyzed Asymmetric Propargyl-Aryl Cross-Electrophile Coupling.

Performing asymmetric cross-coupling reactions between propargylic electrophiles and aryl nucleophiles is a well-established method to build enantioenriched benzylic alkynes. Here, a catalytic enantioselective propargyl-aryl cross-coupling between two electrophiles was achieved for the first time in a stereoconvergent manner. Propargylic chlorides were treated with aryl iodides as well as heteroaryl iodides in the presence of a chiral nickel complex, and manganese metal was used as a stoichiometric reductant, allowing for the construction of a propargyl C-aryl bond under mild conditions. An alternative dual nickel/photoredox catalytic protocol was also developed for this cross-electrophile coupling in the absence of a metal reductant. The potential utility of this conversion is demonstrated in the facile construction of stereoenriched bioactive molecule derivatives and medicinal compounds based on the diversity of acetylenic chemistry. Detailed experimental studies have revealed the key mechanistic features of this transformation.

Causes of low mercury levels in fish from the Three Gorges Reservoir, China.

Previous studies have suggested that growth dilution may be an important factor contributing to the low fish Hg levels in China. To evaluate the impact of growth rate to MeHg bioaccumulation in fish in the Three Gorges Reservoir (TGR), this study used two fish species, Aristichthys nobilis (A. nobilis) and Coilia nasus (C. nasus), which differ significantly in their growth rates. A combined bioenergetic-toxicokinetic model was used to simulate methylmercury (MeHg) concentrations in these two species. The model simulations were compared with the field data and showed good fits. It explained 44.0% and 46.5% of the variation in MeHg concentrations in A. nobilis and C. nasus, respectively. Sensitivity analysis revealed that growth rate accounted for 50.9% and 16.0% of MeHg concentrations in A. nobilis and C. nasus, respectively. This indicated that growth rate was the most critical factor affecting MeHg concentrations in fast-growing fish, such as A. nobilis. However, in species with low growth rate, such as C. nasus, the effect of growth rate was not as prominent as that in fast-growing fish. As a result, MeHg elimination rates and diet MeHg levels could offset the effect of growth, and become the decisive factors for MeHg concentrations in slow-growing fish.

Synthesis of dienes from pyrrolidines using skeletal modification.

Saturated N-heterocyclic pyrrolidines are common in natural products, medicinal compounds and agrochemicals. However, reconstruction of their skeletal structures creating new chemical space is a challenging task, and limited methods exist for this purpose. In this study, we report a skeletal modification strategy for conversion of polar cyclic pyrrolidines into nonpolar linear dienes through a N-atom removal and deconstruction process. This involves N-sulfonylazidonation followed by rearrangement of the resulting sulfamoyl azide intermediates. This can be an energetically unfavorable process, which involves the formation of active C-C π bonds, the consumption of inert C-N and C-C σ bonds and the destruction of stable five-membered rings, but we have used it here to produce versatile conjugated and nonconjugated dienes with links of varying lengths. We also studied the application of this method in late-stage skeletal modification of bioactive compounds, formal traceless C(sp2)-H functionalization and formal N-atom deletion.

Relationship of widowhood with pulse pressure, fasting blood glucose, and mental health in older adults: a propensity matching score analysis.

Background: Transitioning from marriage to widowhood presents inevitable and significant challenges for many older adults. This study explored the impact of widowhood on a range of mental health outcomes, including pulse pressure and fasting blood glucose levels, among older adults in nursing homes. Methods: This cross-sectional study utilized cluster random sampling to recruit participants, with data analyzed from 388 older Chinese adults. Psychosocial traits were assessed using the Perceived Social Support from Family scale (PSS-Fa) for family support, the Generalized Anxiety Disorder 7-item scale (GAD-7) for anxiety symptoms, and the 9-item Patient Health Questionnaire (PHQ-9) for depressive symptoms and suicidal ideation. Propensity score matching (PSM) was employed to control for confounding factors. A multivariate linear regression analysis was performed to explore the relationship between widowhood, mental health outcomes, pulse pressure, and fasting blood glucose levels. Results: After applying PSM, the sample size was refined to 268 (N = 134 for both married and widowed groups) from the initial 388, excluding 120 unmatched cases. Widowed older adults were found to have notably lower family support (ß = -0.81, p = 0.002), increased depressive symptoms (ß = 1.04, p = 0.043), elevated pulse pressure (ß = 8.90, p < 0.001), and higher fasting blood glucose levels (ß = 3.22, p = 0.027). These associations exhibited greater beta values compared to pre-matching analysis. Conclusion: Our findings revealed that widowed participants had reduced family support, an increased risk of depressive symptoms, heightened pulse pressure, and elevated fasting blood glucose in comparison to their married counterparts. Interventions focusing on social support, mental health, and cardiovascular well-being could be advantageous for this at-risk group.

HSC-derived exosomal miR-199a-5p promotes HSC activation and hepatocyte EMT via targeting SIRT1 in hepatic fibrosis.

Exosomes have been implicated in inflammation-related diseases, such as hepatic fibrosis (HF) and renal fibrosis, via transferring bioactive cargoes to recipient cells. This study aimed to investigate the possible effect of hepatic stellate cell (HSC)-derived exosomes on the initiation and development of HF by delivering microRNA (miR)-199a-5p. In HF rats with cholestasis induced by ligating the common bile duct, miR-199a-5p was upregulated while SIRT1 was downregulated in liver tissues from bile duct ligation (BDL) rats compared with that of sham rats. Furthermore, miR-199a-5p expression was upregulated, but the mRNA and protein expression levels of SIRT1 were downregulated in TGF-ß1-activated LX-2. miR-199a-5p promoted the proliferation and further activation of LX-2 and enhanced the expression levels of the HF markers COL1A1 and α-SMA. Subsequently, the binding of miR-199a-5p to the 3'UTR of SIRT1 mRNA was predicted by bioinformatics websites and evidenced by fluorescent reporter assay. Knocking down SIRT1 enhanced the abilities of LX-2 cell proliferation, migration, and colony formation and increased the expression levels of the HF markers α-SMA and COL1A1. LX-2-derived exosomal miR-199a-5p transferred to LX-2 and THLE-2, inhibited the proliferation of THLE-2, and promoted the epithelial mesenchymal transition (EMT) and senescence of THLE-2. Furthermore, in vivo results suggested that miR-199a-5p overexpression aggravated HF in BDL rats; increased miR-199a-5p, α-SMA, and COL1A1 expression levels; and significantly upregulated the serum ALT, AST, TBA, and TBIL levels. However, reverse results were obtained with inhibited miR-199a-5p expression. In conclusion, HSC-derived exosomal miR-199a-5p may promote HF by accelerating HSC activation and hepatocyte EMT by targeting SIRT1, suggesting that miR-199a-5p and SIRT1 may serve as potential therapeutic targets for HF.

Hg bioaccumulation in the aquatic food web from tributaries of the Three Gorges Reservoir, China and potential consumption advisories.

The Three Gorges Reservoir (TGR) holds the distinction of being China's largest reservoir, and the presence of pollutants in the fish from the reservoir have a direct impact on the health of local residents. Thus, 349 fish specimens of 21 species and 1 benthos (Bellamya aeruginosas) were collected from four typical tributaries of the TGR from 2019 to 2020. These specimens were analyzed for the concentrations of total mercury (THg) and methylmercury (MeHg), and some representative samples were tested for δ13C and δ15N values to reveal the characteristics of bioaccumulation and biomagnification. The maximum safe daily consumption was estimated based on the oral reference dose (0.1 µg kg-1 bw/day according to US-EPA, 2017). The results showed that the mean THg and MeHg concentrations in fish from the TGR tributaries were 73.18 ± 49.21 ng g-1 and 48.42 ± 40.66 ng g-1, respectively, with the trophic magnification factors (TMFs) of THg and MeHg being 0.066 and 0.060, respectively. Among all the fish species in the tributaries, the highest daily maximum safe consumption amount was 1253.89 g for S. asotus consumed by adults, while the lowest was 62.88 g for C. nasus consumed by children.

DMAP Catalyzed One-Pot Curtius Rearrangement Using 1,1-Dimethyl-2,2,2-trichloroethoxycarbonyl Azide.

We report our development of a controllable, base-free, one-pot Curtius rearrangement using 1,1-dimethyl-2,2,2-trichloroethoxycarbonyl azide (DMTN3) with 4-(dimethylamino)pyridine (DMAP) as a catalyst. The scope of this catalytic process covers a range of primary, secondary, and tertiary alkyl and aryl carboxylic acids that allow the efficient stereospecific construction of alkyl or aryl isocyanates. Examples are reported of late-stage decarboxylative isocyanation of natural products and drug molecules, the rapid synthesis of several drugs, and the utilization of in situ generated DMTN3. Detailed studies of the mechanism indicate that the reaction rate depends on the concentration of the DMAP catalyst, and this ensures that the reaction is a mild and controllable process.

A miR-340/SPP1 axis inhibits the activation and proliferation of hepatic stellate cells by inhibiting the TGF-ß1/Smads pathway.

BACKGROUND: Hepatic fibrosis (HF) is a common pathological complication of liver cirrhosis which affects human health. It is well established that microRNAs (miRNAs) regulate the proliferation, activation and apoptosis of hepatic stellate cells (HSCs). OBJECTIVES: To determine the function and molecular mechanism of miR-340-5p/secreted phosphoprotein 1 (SPP1) axis in HF and identify potential therapeutic targets. MATERIAL AND METHODS: The HF model in cholestatic rats was induced by ligating the common bile duct. The histological sections of the liver tissues were stained with hematoxylin and eosin (H&E), Masson's trichrome or Sirius Red. The differential expression of mRNAs in the liver tissues was examined using the microarray analysis. The expression levels of miR-340-5p, SPP1, alpha-smooth muscle actin (α-SMA), Collagen I, phosphorylated Smad2 (p-Smad2), and p-Smad3 were determined using quantitative real-time polymerase chain reaction (qRT-PCR) or western blot. Cell proliferation was quantified using cell counting kit-8 (CCK-8) assays. The regulatory effect of miR-340-5p on SPP1 was determined with fluorescent reporter assay. RESULTS: The bile duct ligation (BDL) rat model was successfully induced, and SPP1 was upregulated in liver tissue from the BDL group compared to that of the sham group. The expression level of miR-340-5p was decreased in activated human primary normal fibroblasts (NFs) and activated LX-2 cells, and the mRNA and protein expression levels of SPP1 were increased in activated LX-2 cells. The SPP1 was the target of miR-340-5p, and the overexpression of SPP1 increased the proliferation of LX-2 cells, the expression of HF markers α-SMA and Collagen I, and key factors p-Smad2 and p-Smad3 (all p < 0.05). However, reverse results were obtained with the overexpression of miR-340-5p in LX-2 cells. CONCLUSIONS: Our findings provide evidence that SPP1 targeted by miR-340-5p promotes LX-2 cell proliferation and activation through the TGF-ß1/Smads signaling pathway. Therefore, miR-340-5p and SPP1 may be possible therapeutic targets for HF.

NCOR1 maintains the homeostasis of vascular smooth muscle cells and protects against aortic aneurysm.

Phenotypic modulation of vascular smooth muscle cells (VSMCs) plays critical roles in the pathogenesis of aortic aneurysm (AA). The function of nuclear receptor corepressor1 (NCOR1) in regulation of VSMC phenotype and AA is unclear. Herein, using smooth muscle NCOR1 knockout mice, we demonstrated that smooth muscle NCOR1 deficiency decreased both mRNA and protein levels of contractile genes, impaired stress fibers formation and RhoA pathway activation, reduced synthesis of elastin and collagens, and induced the expression and activity of MMPs, manifesting a switch from contractile to degradative phenotype of VSMCs. NCOR1 modulated VSMC phenotype through 3 different mechanisms. First, NCOR1 deficiency increased acetylated FOXO3a to inhibit the expression of Myocd, which downregulated contractile genes. Second, deletion of NCOR1 derepressed NFAT5 to induce the expression of Rgs1, thus impeding RhoA activation. Third, NCOR1 deficiency increased the expression of Mmp12 and Mmp13 by derepressing ATF3. Finally, a mouse model combined apoE knockout mice with angiotensin II was used to study the role of smooth muscle NCOR1 in the development of AA. The results showed that smooth muscle NCOR1 deficiency increased the incidence of aortic aneurysms and exacerbated medial degeneration in angiotensin II-induced AA mouse model. Collectively, our data illustrated that NCOR1 interacts with FOXO3a, NFAT5, and ATF3 to maintain contractile phenotype of VSMCs and suppress AA development. Manipulation of smooth muscle NCOR1 may be a potential approach for AA treatment.

Carbonyl-Assisted Iridium-Catalyzed C-H Amination Using 2,2,2-Trichloroethoxycarbonyl Azide.

The carbonyl-directed, mono C-H amination of arenes has been achieved using [Cp*Ir(III)Cl2]2 as the catalyst and 2,2,2-trichloroethoxycarbonyl (Troc) azide as an aminating reagent. The amination proceeds smoothly with a variety of arylcarbonyl compounds, including alkyl and vinyl arylketones, secondary and tertiary aryl amides, and acetyl indoles. The resulting ortho-TrocNH arylcarbonyl compounds are easily transformed to the corresponding free arylamines, aryl carbamates, or aryl ureas. Taking advantage of the electrophilic nature of both Troc and carbonyl groups in ortho-TrocNH arylcarbonyl compounds, the subsequent cyclization with dinucleophilic reagents has also been demonstrated. This provides an efficient strategy for the construction of aryl-fused N-heterocycles.

Sodium butyrate reduces overnutrition-induced microglial activation and hypothalamic inflammation.

Overnutrition-induced hypothalamic inflammation greatly disturbs feeding behavior and energy homeostasis as well as the pathogenesis of obesity. Butyrate, a short-chain fatty acid, reportedly participates in the regulation of the immune response and energy metabolism in the body. However, the role of butyrate in overnutrition-induced microglial activation and hypothalamic inflammation remains unclear. In the present study, we established a high-fat diet (HFD)-induced hypothalamic inflammation model in mice. Oral supplementation with sodium butyrate (NaB) significantly reduced HFD-induced microgliosis, inflammatory cytokine expression, endoplasmic reticulum (ER) stress, neuronal apoptosis, and neuropeptide Y (NPY) expression in the mouse hypothalamus. Utilizing a high-glucose (HG)-stimulated microglial activation model in vitro, we found that NaB inhibited the HG-induced expression of the inflammatory factor IL-1ß. Moreover, NaB exerted an antioxidant effect by balancing HO-1 and NOX4 expression, thus preventing reactive oxygen species (ROS) production in HG-treated microglia. Interestingly, NaB treatment promoted microglial process formation and extension via the Akt/Cdc42 pathway under both normal and HG-stimulated conditions, indicating a resting morphology of microglia. Taken together, our study revealed for the first time the anti-inflammatory and antioxidant effects of NaB in overnutrition-induced microglial activation and hypothalamic inflammation, which might become a potential therapeutic option for obesity prevention and treatment.

MiR-22-3p and miR-29a-3p synergistically inhibit hepatic stellate cell activation by targeting AKT3.

Hepatic fibrosis (HF) is a worldwide health problem for which there is no medically effective drug treatment at present, and which is characterized by activation of hepatic stellate cells (HSCs) and excessive extracellular matrix (ECM) deposition. The HF model in cholestatic rats by ligating the common bile duct was induced and the differentially expressed miRNAs in the liver tissues were analyzed by microarray, which showed that miR-22-3p and miR-29a-3p were significantly downregulated in bile-duct ligation (BDL) rat liver compared with the sham control. The synergistic anti-HF activity and molecular mechanism of miR-22-3p and miR-29a-3p by targeting AKT serine/threonine kinase 3 (AKT3) in HSCs were explored. The expression levels of miR-22-3p and miR-29a-3p were downregulated in activated LX-2 and human primary normal hepatic fibroblasts (NFs), whereas AKT3 was found to be upregulated in BDL rat liver and activated LX-2 cells. The proliferation, colony-forming, and migration ability of LX-2 were inhibited synergistically by miR-22-3p and miR-29a-3p. In addition, cellular senescence was induced and the expressions of the LX-2 fibrosis markers COL1A1 and α-SMA were inhibited by miR-22-3p and miR-29a-3p synergistically. Subsequently, these two miRNAs binding to the 3'UTR of AKT3 mRNA was predicted and evidenced by the luciferase reporter assay. Furthermore, the proliferation, migration, colony-forming ability, and the expression levels of COL1A1 and α-SMA were promoted and cellular senescence was inhibited by AKT3 in LX-2 cells. Thus, miR-22-3p/miR-29a-3p/AKT3 regulates the activation of HSCs, providing a new avenue in the study and treatment of HF.

PDCD4 Simultaneously Promotes Microglia Activation via PDCD4-MAPK-NF-κB Positive Loop and Facilitates Neuron Apoptosis During Neuroinflammation.

Neuroinflammation and neuron injury are common features of the central nervous system (CNS) diseases. It is of great significance to identify their shared key regulatory molecules and thus explore the potential therapeutic targets. Programmed cell death factor 4 (PDCD4), an apoptosis-related molecule, extensively participates in tumorigenesis and inflammatory diseases, but its expression and biological function during CNS neuroinflammation remain unclear. In the present study, utilizing the lipopolysaccharide (LPS)-induced neuroinflammation model in mice, we reported an elevated expression of PDCD4 both in injured neurons and activated microglia of the inflamed brain. A similar change in PDCD4 expression was observed in vitro in the microglial activation model. Silencing PDCD4 by shRNA significantly inhibited the phosphorylation of MAPKs (p38, ERK, and JNK), prevented the phosphorylation and nuclear translocation of NF-κB p65, and thus attenuated the LPS-induced microglial inflammatory activation. Interestingly, LPS also required the MAPK/NF-κB signaling activation to boost PDCD4 expression in microglia, indicating the presence of a positive loop. Moreover, a persistent elevation of PDCD4 expression was detected in the H2O2-induced neuronal oxidative damage model. Knocking down PDCD4 significantly inhibited the expression of pro-apoptotic proteins BAX and Cleaved-PARP, suggesting the proapoptotic activity of PDCD4 in neurons. Taken together, our data indicated that PDCD4 may serve as a hub regulatory molecule that simultaneously promotes the microglial inflammatory activation and the oxidative stress-induced neuronal apoptosis within CNS. The microglial PDCD4-MAPK-NF-κB positive feedback loop may act as pivotal signaling for neuroinflammation which subsequently exaggerates neuronal injury, and thus may become a potential therapeutic target for neuroinflammatory diseases.

Pyruvate kinase M2 (PKM2) interacts with activating transcription factor 2 (ATF2) to bridge glycolysis and pyroptosis in microglia.

Pyruvate kinase M2 (PKM2), a glycolytic rate-limiting enzyme, reportedly plays an important role in tumorigenesis and the inflammatory response by regulating the metabolic reprogramming. However, its contribution to microglial activation during neuroinflammation is still unknown. In this study, we observed an enhanced glycolysis level in the lipopolysaccharide (LPS)-activated microglia. Utilizing the glycolysis inhibitor 2-DG, we proved that LPS requires glycolysis to induce microglial pyroptosis. Moreover, the protein expression, dimer/monomer formation, phosphorylation and nuclear translocation of PKM2 were all increased by LPS. Silencing PKM2 or preventing its nuclear translocation by TEPP-46 significantly alleviated the LPS-induced inflammatory response and pyroptosis in microglia. Employing biological mass spectrometry combined with immunoprecipitation technology, we identified for the first time that PKM2 interacts with activating transcription factor 2 (ATF2) in microglia. Inhibition of glycolysis or preventing PKM2 nuclear aggregation significantly reduced the phosphorylation and activation of ATF2. Furthermore, knocking down ATF2 reduced the LPS-induced pyroptosis of microglia. In vivo, we showed the LPS-induced pyroptosis in the cerebral cortex tissues of mice, and first found that an increased PKM2 expression was co-localized with ATF2 in the inflamed mice brain. Collectively, our data suggested for the first time that PKM2, a key rate-limiting enzyme of the Warburg effect, directly interacts with the pro-inflammatory transcription factor ATF2 to bridge glycolysis and pyroptosis in microglia, which might be a pivotal crosstalk between metabolic reprogramming and neuroinflammation in the CNS.