Unveiling the Significance of Peroxiredoxin 6 in Central Nervous System Disorders

Peroxiredoxin 6 (Prdx6), a unique 1-Cys member of the peroxiredoxin family, exhibits peroxidase activity, phospholipase activity, and lysophosphatidylcholine acyltransferase (LPCAT) activity. Prdx6 has been known to be an important enzyme for the maintenance of lipid peroxidation repair, cellular metabolism, inflammatory signaling, and antioxidant damage. Growing research has demonstrated that the altered activity of this enzyme is linked with various pathological processes including central nervous system (CNS) disorders. This review discusses the distinctive structure, enzyme activity, and function of Prdx6 in different CNS disorders, as well as emphasizing the significance of Prdx6 in neurological disorders.

Deletion of mesencephalic astrocyte-derived neurotrophic factor delays and damages the development of white pulp in spleen

Mesencephalic astrocyte-derived neurotrophic factor (MANF) is an endoplasmic reticulum (ER) stress-induced protein, and it has been reported that ER stress and unfolded protein response (UPR) are closely related to the immune system. The spleen is an important immune organ and we have shown in our previous research that MANF is expressed in human spleen tissues. However, there have been limited studies about the effect of MANF on spleen development. In this study, we detected MANF expression in spleen tissues and found that MANF was expressed in the red pulp and marginal zone. Additionally, MANF was localized in the CD68+ and CD138+ cells of adult rat spleen tissues, but not in the CD3+ cells. We performed immunohistochemical staining to detect MANF expression in the spleen tissues of rats that were different ages, and we found that MANF+ cells were localized together in the spleen tissues of rats that were 1-4 weeks old. MANF was also expressed in CD68+ cells in the spleen tissues of rats and mice. Furthermore, we found that MANF deficiency inhibited white pulp development in MANF knockout mice, thus indicating that MANF played an important role in the white pulp development of rodent spleen tissues.

Interplay between SUMO1-related SUMOylation and phosphorylation of p65 promotes hepatocellular carcinoma progression

The nuclear factor kappaB (NF-κB) subunit p65, plays an important role in the progression of hepatocellular carcinoma (HCC). Phosphorylation of p65 is considered as an important mechanism for the positive regulation of NF-κB activity. According to our previous data, p65 can be SUMOylated by small ubiquitin-related modifier 1 (SUMO1) protein, and SUMO1 promotes p65 nuclear import and HCC progression. However, the effect of SUMO1-related p65 SUMOylation on NF-κB transcriptional activity and the relationship between phosphorylation and SUMOylation of p65 remain obscure. Here, we found that phosphorylated p65 level was increased in cancer tissues of HCC patients, and similar phenomenon was found for SUMO1 expression but not for SUMO2/3. Further clinical data showed a positive correlation between SUMO1 and phosphorylated p65. We also verified that overexpression of SUMO1 upregulated phosphorylated p65 levels. Next, we verified SUMO1-related p65 SUMOylation with in vitro SUMOylation assay, constructed mutants of p65 SUMOylation and phosphorylation, and found that SUMO1-related p65 SUMOylation promoted p65 nuclear import and increased NF-κB activity. Both SUMO1-related p65 SUMOylation and p65 phosphorylation (especially at S276 site) increased the viability and invasion of hepatoma cells, and decreased the apoptosis of hepatoma cells. At last, we found that the phosphorylation of p65 promoted the level of SUMO1-related p65 SUMOylation, and SUMO1-related p65 SUMOylation upregulated phosphorylated p65 (at S276 site). Our study contributes to the exploration of the oncogenic mechanism of p65, which is the important protein in HCC.

NIR Light-Activated and RGD-Conjugated Ultrasmall Fe/PPy Nanopolymers for Enhanced Tumor Photothermal Ferrotherapy and MR Imaging

Iron-based nanomaterials have shown great promise for tumor ferrotherapy in recent years. However, nanoparticle-induced ferroptosis has low therapeutic efficacy owing to unsatisfactory Fenton reaction activity in a typical tumor microenvironment. In this study, NIR light-activated Fe/PPy-RGD nanopolymers were developed to combine photothermal therapy and ferrotherapy and achieve enhanced antitumor activity. Importantly, Fe/PPy-RGD exhibited excellent therapeutic performance under NIR light activation both in vitro and in vivo. Under irradiation with NIR light, the heat generated by Fe/PPy-RGD not only induced a therapeutic photothermal effect but also enhanced the release of iron ions and the Fenton reaction by inducing ferroptosis. Additionally, by virtue of RGD conjugation and its ultrasmall size, Fe/PPy-RGD could effectively accumulate at tumor sites in living mice after systemic administration and could be monitored via MR imaging. Hence, this study provides a promising approach for integrating ferrotherapy with photothermal therapy to achieve enhanced tumor treatment.

Molecular Engineering Design of Enhanced Donor-Acceptor Therapeutic Reagent for Efficient Image-Guided Photodynamic Therapy

The greatest barrier to the further development and clinical application of tumor image-guided photodynamic therapy (PDT), is the inconsistency between the fluorescence intensity and singlet oxygen generation yield of the photosensitizer under light excitation. Herein, a novel donor-acceptor (D-A) system is designed from the point of molecular selection by wrapping a classical porphyrin molecule (5,10,15,20-tetraphenylphorphyrin, H2 TPP) as an acceptor into conjugated polymer (Poly[N,N'-bis(4-butylpheny)-N,N'-bis(phenyl)benzidine], ADS254BE) as a donor through fluorescence resonance energy transfer (FRET) mechanism, which exhibits bright red emission centered at 650 nm (quantum yield, 0.12), relatively large Stoke shift of 276 nm, enhanced singlet oxygen generation rate of 0.73, and excellent photostability. The investigations on distribution and killing effect of nanomaterials in cancer cells reveal that ADS254BE/H2 TPP NPs can accumulate in the cytoplasm for imaging while simultaneously producing a large amount of singlet oxygen to remarkably kill cancer cells, which can be used for real-time image-guided PDT. In the xenograft tumor model, real-time imaging and long-term tracing in tumor tissue with ADS254BE/H2 TPP NPs disclose that the growth of lung cancer in mice can be effectively inhibited during in situ imaging. From the standpoint of molecular engineering design, this work provides a feasible strategy for novel D-A systems to improve the development of image-guided PDT.

Construction and validation of a immune-related prognostic gene DHRS1 in hepatocellular carcinoma based on bioinformatic analysis

A member of the short-chain dehydrogenase/reductase superfamily (DHRS1, SDR19C1) is a member of the short-chain dehydrogenase/reductase superfamily and a potential predictor of hepatocellular carcinoma (HCC). However, the role of DHRS1 in HCC immunity remains unclear. We systematically analyzed the association between DHRS1 and HCC immunity with transcriptional and clinical data from the Tumor Immune Estimation Resource, an integrated repository portal for tumor immune system interactions, and cBioPortal databases. Six DHRS1-associated immunomodulators strongly correlated with survival and were uncovered by exploiting univariate and multivariate Cox analyses. We created a risk score for each patient by adding the points from each immunomodulator and then classified them into high and low risk categories. Survival analysis were used to compare the overall survival between the 2 groups, and the receiver operating characteristic curve was applied to assess the accuracy of the risk score. Data from our center were adopted as the external validation set, the risk score was calculated using the risk coefficient of the 6 genes in the training cohort, and survival analysis were executed to verify the experimental group results. A nomogram was ultimately constructed with the R package. Our data revealed a correlation between the levels of immune cell infiltration and either the DHRS1 gene copy numbers or mRNA levels in HCC. Second, we generated a signature based on the 6 DHRS1-related immunomodulators (KDR, TNFRSF4, CD276, TNFSF4, SLAMF6, and SIGLEC9). We postulate that the generated risk scores would serve as an independent indicator of HCC prognosis, with an area under the receiver operating characteristic curve for the risk score of 0.743. We further established external validation sets to reconfirm the predictive validity of the risk score. Finally, a prognostic nomogram and calibration curve were created. The DHRS1 gene may exert an impact on HCC immunity. We posit that the nominated immune signature based on DHRS1-associated immunomodulators could constitute a promising prognostic biomarker in HCC.

MANF brakes TLR4 signaling by competitively binding S100A8 with S100A9 to regulate macrophage phenotypes in hepatic fibrosis

The mesencephalic astrocyte-derived neurotrophic factor (MANF) has been recently identified as a neurotrophic factor, but its role in hepatic fibrosis is unknown. Here, we found that MANF was upregulated in the fibrotic liver tissues of the patients with chronic liver diseases and of mice treated with CCl4. MANF deficiency in either hepatocytes or hepatic mono-macrophages, particularly in hepatic mono-macrophages, clearly exacerbated hepatic fibrosis. Myeloid-specific MANF knockout increased the population of hepatic Ly6Chigh macrophages and promoted HSCs activation. Furthermore, MANF-sufficient macrophages (from WT mice) transfusion ameliorated CCl4-induced hepatic fibrosis in myeloid cells-specific MANF knockout (MKO) mice. Mechanistically, MANF interacted with S100A8 to competitively block S100A8/A9 heterodimer formation and inhibited S100A8/A9-mediated TLR4-NF-κB signal activation. Pharmacologically, systemic administration of recombinant human MANF significantly alleviated CCl4-induced hepatic fibrosis in both WT and hepatocytes-specific MANF knockout (HKO) mice. This study reveals a mechanism by which MANF targets S100A8/A9-TLR4 as a "brake" on the upstream of NF-κB pathway, which exerts an impact on macrophage differentiation and shed light on hepatic fibrosis treatment.

PRDX6 Promotes Fatty Acid Oxidation via PLA2-Dependent PPARα Activation in Rats Fed High-Fat Diet

Aims: Nonalcoholic fatty liver disease (NAFLD) is becoming the most common chronic liver disease globally, which is defined as an excess accumulation of fat caused by the imbalance of lipogenesis and lipid catabolism. Recently, increasing evidence suggests that peroxiredoxin 6 (PRDX6) is involved in the pathogenesis and progression of NAFLD. However, little is known regarding its role in liver lipid catabolism. Results: We found that PRDX6 level was significantly increased in liver tissues after high-fat diet (HFD) treatment. PRDX6 knockout (KO) exacerbated HFD-induced hepatic steatosis. PRDX6 KO did not affect messenger RNA (mRNA) and protein levels of peroxisome proliferator-activated receptor alpha (PPARα). However, PRDX6 KO decreased the mRNA and protein levels of carnitine palmitoyltransferase-1alpha (CPT-1α) and acyl-CoA oxidase 1 (ACOX1), the target genes of PPARα. PRDX6 KO also did not activate AMP-activated protein kinase (AMPK)α/proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α), the upstream signal of PPARα. However, PRDX6 KO reduces the levels of PPARα activators, the oxidized fatty acids (9- and 13-hydroxyoctadecadienoic acid) in HFD rats. More interestingly, PRDX6 promoted the production of oxidized fatty acids by hydrolyzing oxidized low-density lipoprotein (Ox-LDL), which depends on its phospholipase A2 (PLA2) activity. PRDX6 mutation on its PLA2 and its competitive phospholipase inhibitor inhibited the production of the oxidized fatty acids as well as the activation of PPARα. Furthermore, PRDX6 overexpression enhanced the transcriptional activation of PPARα. Innovation and Conclusion: This study elucidates for the first time the role of PLA2 enzyme activity of PRDX6 in fatty acid oxidation and reveals a novel mechanism of PRDX6 involved in liver steatosis.

MAGED4B Promotes Glioma Progression via Inactivation of the TNF-α-induced Apoptotic Pathway by Down-regulating TRIM27 Expression

MAGED4B belongs to the melanoma-associated antigen family; originally found in melanoma, it is expressed in various types of cancer, and is especially enriched in glioblastoma. However, the functional role and molecular mechanisms of MAGED4B in glioma are still unclear. In this study, we found that the MAGED4B level was higher in glioma tissue than that in non-cancer tissue, and the level was positively correlated with glioma grade, tumor diameter, Ki-67 level, and patient age. The patients with higher levels had a worse prognosis than those with lower MAGED4B levels. In glioma cells, MAGED4B overexpression promoted proliferation, invasion, and migration, as well as decreasing apoptosis and the chemosensitivity to cisplatin and temozolomide. On the contrary, MAGED4B knockdown in glioma cells inhibited proliferation, invasion, and migration, as well as increasing apoptosis and the chemosensitivity to cisplatin and temozolomide. MAGED4B knockdown also inhibited the growth of gliomas implanted into the rat brain. The interaction between MAGED4B and tripartite motif-containing 27 (TRIM27) in glioma cells was detected by co-immunoprecipitation assay, which showed that MAGED4B was co-localized with TRIM27. In addition, MAGED4B overexpression down-regulated the TRIM27 protein level, and this was blocked by carbobenzoxyl-L-leucyl-L-leucyl-L-leucine (MG132), an inhibitor of the proteasome. On the contrary, MAGED4B knockdown up-regulated the TRIM27 level. Furthermore, MAGED4B overexpression increased TRIM27 ubiquitination in the presence of MG132. Accordingly, MAGED4B down-regulated the protein levels of genes downstream of ubiquitin-specific protease 7 (USP7) involved in the tumor necrosis factor-alpha (TNF-α)-induced apoptotic pathway. These findings indicate that MAGED4B promotes glioma growth via a TRIM27/USP7/receptor-interacting serine/threonine-protein kinase 1 (RIP1)-dependent TNF-α-induced apoptotic pathway, which suggests that MAGED4B is a potential target for glioma diagnosis and treatment.

Xanthatin suppresses proliferation and tumorigenicity of glioma cells through autophagy inhibition via activation of the PI3K-Akt-mTOR pathway

Glioma is the most common and aggressive primary brain tumor in adults with high morbidity and mortality. Rapid proliferation and diffuse migration are the main obstacles to successful glioma treatment. Xanthatin, a sesquiterpene lactone purified from Xanthium strumarium L., possesses a significant antitumor role in several malignant tumors. In this study, we report that xanthatin suppressed glioma cells proliferation and induced apoptosis in a time- and concentration-dependent manner, and was accompanied by autophagy inhibition displaying a significantly reduced LC3 punctate fluorescence and LC3II/I ratio, decreased level of Beclin 1, while increased accumulation of p62. Notably, treating glioma cells with xanthatin resulted in obvious activation of the PI3K-Akt-mTOR signaling pathway, as indicated by increased mTOR and Akt phosphorylation, decreased ULK1 phosphorylation, which is important in modulating autophagy. Furthermore, xanthatin-mediated pro-apoptosis in glioma cells was significantly reversed by autophagy inducers (rapamycin or Torin1), or PI3K-mTOR inhibitor NVP-BEZ235. Taken together, these findings indicate that anti-proliferation and pro-apoptosis effects of xanthatin in glioma are most likely by inhibiting autophagy via activation of PI3K-Akt-mTOR pathway, suggesting a potential therapeutic strategy against glioma.

Neoadjuvant chemoradiotherapy versus neoadjuvant chemotherapy followed by minimally invasive esophagectomy for locally advanced esophageal squamous cell carcinoma: a prospective multicenter randomized clinical trial

BACKGROUND

Neoadjuvant therapy is recommended for locally advanced esophageal cancer, but the optimal strategy remains unclear. We aimed to evaluate the safety and efficacy of neoadjuvant chemoradiotherapy (nCRT) versus neoadjuvant chemotherapy (nCT) followed by minimally invasive esophagectomy (MIE) for locally advanced esophageal squamous cell carcinoma (ESCC).

PATIENTS AND METHODS

Eligible patients staged as cT3-4aN0-1M0 ESCC were randomly assigned (1 : 1) to the nCRT or nCT group stratified by age, cN stage, and centers. The chemotherapy, based on paclitaxel and cisplatin, was administered to both groups, while concurrent radiotherapy was added for the nCRT group; then MIE was carried out. The primary endpoint was 3-year overall survival. This study is registered with ClinicalTrials.gov (NCT03001596).

RESULTS

A total of 264 patients were eligible for the intention-to-treat analysis. By 30 November 2021, 121 deaths had occurred. The median follow-up was 43.9 months (interquartile range 36.6-49.3 months). The overall survival in the intention-to-treat population was comparable between the nCRT and nCT strategies [hazard ratio (HR) 0.82, 95% confidence interval (CI) 0.58-1.18; P = 0.28], with a 3-year survival rate of 64.1% (95% CI 56.4% to 72.9%) versus 54.9% (95% CI 47.0% to 64.2%), respectively. There were also no differences in progression-free survival (HR 0.83, 95% CI 0.59-1.16; P = 0.27) and recurrence-free survival (HR 1.07, 95% CI 0.71-1.60; P = 0.75), although the pathological complete response in the nCRT group (31/112, 27.7%) was significantly higher than that in the nCT group (3/104, 2.9%; P < 0.001). Besides, a trend of lower risk of recurrence was observed in the nCRT group (P = 0.063), while the recurrence pattern was similar (P = 0.802).

CONCLUSIONS

NCRT followed by MIE was not associated with significantly better overall survival than nCT among patients with cT3-4aN0-1M0 ESCC. The results underscore the pending issue of the best strategy of neoadjuvant therapy for locally advanced bulky ESCC.

A non-immersive virtual reality-based intervention to enhance lower-extremity motor function and gait in patients with subacute cerebral infarction: A pilot randomized controlled trial with 1-year follow-up

Introduction

This study was conducted to evaluate whether a non-immersive virtual reality (VR)-based intervention can enhance lower extremity movement in patients with cerebral infarction and whether it has greater short-term and long-term effectiveness than conventional therapies (CTs).

Materials and methods

This was a single-blinded, randomized clinical controlled trial. Forty-four patients with subacute cerebral infarction were randomly allocated to the VR or CT group. All intervention sessions were delivered in the inpatient unit for 3 weeks. Outcomes were measured before (baseline) and after the interventions and at 3-month, 6-month and 1-year follow-ups. The outcomes included clinical assessments of movement and balance function using the Fugl–Meyer Assessment of Lower Extremity (FMA-LE) and Berg Balance Scale (BBS), and gait parameters in the sagittal plane.

Results

In the VR group, the walking speed after intervention, at 3-month, 6-month, and 1-year follow-ups were significantly greater than baseline (p = 0.01, <0.001, 0.007, and <0.001, respectively). Compared with baseline, BBS scores after intervention, at 3-month, 6-month, and 1-year follow-ups were significantly greater in both the VR group (p = 0.006, 0.002, <0.001, and <0.001, respectively) and CT group (p = <0.001, 0.002, 0.001, and <0.001, respectively), while FMA-LE scores after intervention, at 3-month, 6-month, and 1-year follow-ups were significant increased in the VR group (p = 0.03, <0.001, 0.003, and <0.001, respectively), and at 3-month, 6-month, and 1-year follow-ups in the CT group (p = 0.02, 0.004 and <0.001, respectively). In the VR group, the maximum knee joint angle in the sagittal plane enhanced significantly at 6-month follow-up from that at baseline (p = 0.04).

Conclusion

The effectiveness of the non-immersive VR-based intervention in our study was observed after the intervention and at the follow-ups, but it was not significantly different from that of CTs. In sum, our results suggest that non-immersive VR-based interventions may thus be a valuable addition to conventional physical therapies to enhance treatment efficacy.

Clinical trial registration

http://www.chictr.org.cn/showproj.aspx?proj=10541, ChiCTR-IOC-15006064.

NADPH oxidase 4 contributes to TRPV4-mediated endothelium-dependent vasodilation in human arterioles by regulating protein phosphorylation of TRPV4 channels

Impaired endothelium-dependent vasodilation has been suggested to be a key component of coronary microvascular dysfunction (CMD). A better understanding of endothelial pathways involved in vasodilation in human arterioles may provide new insight into the mechanisms of CMD. The goal of this study is to investigate the role of TRPV4, NOX4, and their interaction in human arterioles and examine the underlying mechanisms. Arterioles were freshly isolated from adipose and heart tissues obtained from 71 patients without coronary artery disease, and vascular reactivity was studied by videomicroscopy. In human adipose arterioles (HAA), ACh-induced dilation was significantly reduced by TRPV4 inhibitor HC067047 and by NOX 1/4 inhibitor GKT137831, but GKT137831 did not further affect the dilation in the presence of TRPV4 inhibitors. GKT137831 also inhibited TRPV4 agonist GSK1016790A-induced dilation in HAA and human coronary arterioles (HCA). NOX4 transcripts and proteins were detected in endothelial cells of HAA and HCA. Using fura-2 imaging, GKT137831 significantly reduced GSK1016790A-induced Ca²⁺ influx in the primary culture of endothelial cells and TRPV4-WT-overexpressing human coronary artery endothelial cells (HCAEC). However, GKT137831 did not affect TRPV4-mediated Ca²⁺ influx in non-phosphorylatable TRPV4-S823A/S824A-overexpressing HCAEC. In addition, treatment of HCAEC with GKT137831 decreased the phosphorylation level of Ser824 in TRPV4. Finally, proximity ligation assay (PLA) revealed co-localization of NOX4 and TRPV4 proteins. In conclusion, both TRPV4 and NOX4 contribute to ACh-induced dilation in human arterioles from patients without coronary artery disease. NOX4 increases TRPV4 phosphorylation in endothelial cells, which in turn enhances TRPV4-mediated Ca²⁺ entry and subsequent endothelium-dependent dilation in human arterioles.

Respiratory Mucosal Immunity: Kinetics of Secretory Immunoglobulin A in Sputum and Throat Swabs From COVID-19 Patients and Vaccine Recipients

While IgM and IgG response to SARS-CoV-2 has been extensively studied, relatively little is known about secretory IgA (sIgA) response in respiratory mucosa. Here we report IgA response to the SARS-CoV-2 in sputum, throat swabs, and serum with nucleocapsid protein (NP) enzyme-linked immunosorbent assays (ELISA) in a cohort of 28 COVID-19 patients and 55 vaccine recipients. The assays showed sIgA in respiratory mucosa could be detected on the first day after illness onset (AIO), and the median conversion time for sIgA in sputum, throat swabs, and serum was 3, 4, and 10 days, respectively. The positive rates of sIgA first week AIO were 100% (24/28) and 85.7% (24/28) in sputum and throat swabs, respectively, and were both 100% during the mid-onset (2–3 weeks AIO). During the recovery period, sIgA positive rates in sputum and throat swabs gradually decreased from 60.7% (17/28) and 57.1% (16/28) 1 month AIO and the sIgA antibodies were all undetectable 6 months AIO. However, serum IgA positive rate was still 100% at 4 months and 53.6% (15/28) at 6 months. Throat swabs obtained from volunteers who received inactivated SARS-CoV-2 vaccines by intramuscular delivery all showed negative results in IgA ELISA. These findings will likely improve our understanding of respiratory mucosal immunity of this emerging disease and help in containing the pandemic and developing vaccines.

Dynamic tracking of p21 mRNA in living cells by sticky-flares for the visual evaluation of the tumor treatment effect

Monitoring the expression level of the intracellular tumor suppressor gene p21 mRNA is essential to reveal the progress and prognosis of a tumor. Methods widely reported for the detection of p21 mRNA are the real-time polymerase chain reaction and Northern blot. However, these methods only detect mRNA in vitro and cannot realize the in situ monitoring of the p21 mRNA expression level in living cells. Additionally, the sensor for the real-time tracking and monitoring of the p21 mRNA location without the help of a transfection reagent in living cells is still limited. Herein, a novel sticky-flare was constructed for the dynamic monitoring of the temporal and spatial variations of p21 mRNA in living cells. The nanoprobe consists of AuNP, a recognition sequence modified with Cy5, and a thiol-modified DNA sequence. The thiol oligonucleotide strand could act partially complementary to the Cy5-modified oligonucleotide strand to form a double-stranded DNA linked to AuNP, resulting in the fluorescence quenching of Cy5 due to the energy transfer from Cy5 to the gold sphere. In the presence of p21 mRNA, the Cy5-modified recognition nucleic acid specifically bound to p21 mRNA to form a more stable double chain and escaped from the gold sphere, leading to the recovery of red fluorescence. Our method is better than other methods in its ability to quantify the spatial distribution and expression level of p21 mRNA in living cells and discriminate various tumor cell lines with different p21 mRNA expression levels by the naked eye. Particularly, the sticky-flare probe used in this assay could allow the visual evaluation of the tumor treatment effect and the determination of the tumor progression stage by enabling monitoring of the relative expression level of p21 mRNA in tumor cells after cisplatin treatment. The method reported here is accurate, reliable and needs no auxiliary tools (transfection reagent), and thereby provides a promising route for the prognostic evaluation and drug development of cancer treatment in the future.

Incidence and Prevalence of Poststroke Shoulder Pain Among Different Regions of the World: A Systematic Review and Meta-Analysis

Objectives: Poststroke shoulder pain (PSSP) is a common complication after stroke. This review aimed to provide updated information on the epidemiological characteristics of PSSP, reveal their trends over time and region. Study Design and Setting: We searched the PubMed, Embase, Cochrane Library and Web of Science databases from inception until Dec 31, 2020. Data were extracted from the eligible studies, and their quality was assessed. The pooled incidence and prevalence estimates of PSSP and their 95% confidence intervals (CIs) were calculated. We analyzed the incidence and prevalence of PSSP by different geographical regions and countries and separately calculated the annual incidence and prevalence (and 95% CIs) of PSSP. Results: A total of 21 studies were eligible for the meta-analysis. Eleven cohort studies were included to analyze the incidence of PSSP, and the estimated pooled incidence in 3,496 stroke patients was 0.29 (95% CI 0.21-0.36). Ten cross-sectional studies were included to analyze the prevalence of PSSP, and the pooled prevalence in 3,701 stroke patients was 0.33 (95% CI 0.22-0.43). In addition, we found that there were significant differences in the incidence and prevalence of PSSP between different geographical regions and different countries. Additionally, the incidence of PSSP fluctuated around 30%, and the prevalence had a downward trend over time. Conclusions: Current evidence suggests that the incidence and prevalence of PSSP are high and may be influenced by geographical region and time.

Dexmedetomidine and Phosphocreatine Post-treatment Provides Protection against Focal Cerebral Ischemia-reperfusion Injury in Rats

In this study we investigated the neuroprotective efficacy of dexmedetomidine (Dex) and phosphocreatine (PCr) alone or in combination in a rat model of focal cerebral ischemia-reperfusion injury (I/R). I/R was induced by intraluminal middle cerebral artery occlusion (MCAO) and reperfusion. Male Sprague-Dawley rats were randomly allocated to the Sham group and I/R group, and the I/R group was further divided into three subgroups: Dex (9 μg.kg⁻¹ Dex), PCr (180 mg.kg⁻¹ PCr) and Dex + PCr (9 μg.kg⁻¹ Dex + 180 mg.kg⁻¹ PCr). All treatments were given intravenously at the onset of reperfusion. After 24 hr of reperfusion, the neurological deficit score (NDS) was determined and a magnetic resonance imaging (MRI) scan was performed. Serum concentrations of malonaldehyde (MDA) and 4-hydroxynonenal (4-HNE) were measured and cerebral infarct volume was estimated by triphenyl tetrazolium chloride (TTC) staining. Blood brain barrier, neuronal and mitochondrial damage was assessed by optical and electron microscopy. Neuronal injury was further assessed using double cleaved caspase-3 and NeuN immunofluorescent staining. Compared with group I/R, Dex and PCr significantly reduced the neurological deficit score (P < 0.01), infarct volume (P < 0.01), and brain blood barrier, neuronal and mitochondrial damage. The level of oxidative stress (P < 0.001) and neuronal injury (P < 0.001) also decreased and surviving neurons increased (P < 0.001). Compared with Dex or PCr alone, the combination treatment had overall greater effects (P < 0.05). These results indicate that posttreatment with Dex or PCr decreases focal cerebral I/R injury and that these agents in combination have greater protective effects than each alone.

Hepatocyte-derived MANF alleviates hepatic ischaemia-reperfusion injury via regulating endoplasmic reticulum stress-induced apoptosis in mice

BACKGROUND

Endoplasmic reticulum (ER) perturbations are novel subcellular effectors involved in the ischaemia-reperfusion injury. As an ER stress-inducible protein, mesencephalic astrocyte-derived neurotrophic factor (MANF) has been proven to be increased during ischaemic brain injury. However, the role of MANF in liver ischaemia reperfusion (I/R) injury has not yet been studied.

METHODS

To investigate the role of MANF in the process of liver ischaemia-reperfusion, Hepatocyte-specific MANF knockout (MANF^hep-/- ) mice and their wild-type (WT) littermates were used in our research. Mice partial (70%) warm hepatic I/R model was established by vascular occlusion. We detected the serum levels of MANF in both liver transplant patients and WT mice before and after liver I/R injury. Recombinant human MANF (rhMANF) was injected into the tail vein before 1 hour occlusion. AST, ALT and Suzuki score were used to evaluate the extent of I/R injury. OGD/R test was performed on primary hepatocytes to simulate IRI in vitro. RNA sequence and RT-PCR were used to detect the cellular signal pathway activation while MANF knockout.

RESULTS

We found that MANF expression and secretion are dramatically up-regulated during hepatic I/R. Hepatocyte-specific MANF knockout aggravates the I/R injury through the over-activated ER stress. The systemic administration of rhMANF before ischaemia has the potential to ameliorate I/R-triggered UPR and liver injury. Further study showed that MANF deficiency activated ATF4/CHOP and JNK/c-JUN/CHOP pathways, and rhMANF inhibited the activation of the two proapoptotic pathways caused by MANF deletion.

CONCLUSION

Collectively, our study unravels a previously unknown relationship among MANF, UPR and hepatic I/R injury.

Retinal Imaging Techniques Based on Machine Learning Models in Recognition and Prediction of Mild Cognitive Impairment

BACKGROUND AND PURPOSE

Mild Cognitive Impairment (MCI) is thought to be the signal of many progressive diseases but is easily ignored. Therefore, a simple and easy screening method for recognizing and predicting MCI is urgently needed. The study aimed to establish machine learning models of retinal vascular features to categorize and predict MCI.

PATIENTS AND METHODS

Subjects enrolled underwent cognitive function assessment and were divided into a normal group, an MCI group, and a dementia group, and fundus photography was performed. MATLAB 2019b was used for fundus image preprocessing and vascular segmentation. Via the Green channel, adaptive histogram equalization (AHE), image binarization, and median filtering, we obtained the original and segmentation retinal vessel images. Afterwards, the histogram of oriented gradient (HOG) was used for image feature extraction. Support vector machine (SVM) and extreme learning machine (ELM) were selected for training models in the fundus original images and fundus vascular segmentation images, respectively. Among the three cognitive groups, sensitivity, specificity, the receiver operating characteristic (ROC) curves, and the area under the curve (AUC) were used to evaluate and compare the predictive performance of the two models in the fundus original and vascular segmentation images, respectively.

RESULTS

A total of 86 eligible subjects were enrolled in the study. After a clinical cognitive assessment, the participants were divided into the normal group (N = 38), the MCI group (N = 26), and the dementia group (N = 22). A total of 332 qualified fundus images were adopted after screening. Comparing the models among the three groups showed that the SVM model had more advantages than the ELM model in the fundus original images and vascular segmentation images. Meanwhile, we found that the original images performed better than the segmentation images in the same prediction model. Among the three groups, the SVM model of the fundus original images had the best performance.

CONCLUSION

The establishment of a predictive model based on vascular-related feature extraction from fundus images has high recognition and prediction abilities for cognitive function and can be used as a screening method for MCI.

CLINICAL TRIAL REGISTRATION

ChiCTR.org.cn (ChiCTR1900027404), Registered on Nov 12, 2019.

Hepatocyte-derived MANF is protective for rifampicin-induced cholestatic hepatic injury via inhibiting ATF4-CHOP signal activation

Rifampicin (RFP) has been known to be potentially hepatotoxic and often used as an inducer of cholestatic hepatic injury. Here we found that mesencephalic astrocyte-derived neurotrophic factor (MANF), an endoplasmic reticulum (ER) stress inducible protein, is a protector in RFP-induced liver injury. In cholestatic hepatic injury mice induced by RFP, the liver/body ratio and the levels of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), total bile acid (TBA), total bilirubin (TBIL), and direct bilirubin (DBIL) were significantly increased. Meanwhile, the protein and mRNA levels of MANF were remarkably elevated in the liver injury mice. In hepatocyte-specific MANF knockout (HKO) mice, an extra increase in the liver/body ratio and serum ALT, AST, ALP, TBA, TBIL, and DBIL levels was detected after treatment with RFP. In addition, recombinant human MANF (rhMANF) treatment efficiently reduced the liver/body ratio and serum ALT, AST, ALP, TBA, TBIL, and DBIL levels in RFP-induced liver injury mice. Furthermore, we found there is an increase in the number of the apoptotic cells, detected by TUNEL staining in the liver tissues of HKO mice. Meanwhile, the protein levels of C/EBP-homologous protein (CHOP), Ki67, and the proliferating cell nuclear antigen (PCNA), as well as the mRNA level of Ki67 were elevated after treated with RFP, and these parameters were increased more significantly in HKO mice than that in wild type (WT) controls in RFP-induced liver injury. The rhMANF treatment can rescue the cell apoptosis and reduce the protein and mRNA levels of CHOP, Ki67, and PCNA elevated by MANF deletion and RFP. In HKO mice, immunoglobulin heavy chain binding protein (BIP) and activating transcription factor 4 (ATF4) were predominantly increased after treatment with RFP, which were reduced by rhMANF treatment. Therefore, we conclude that hepatocyte-derived MANF is protective for RFP-induced cholestatic hepatic injury via inhibiting ATF4-CHOP signal activation and subsequent cell apoptosis.

Advances in Exosome-Based Drug Delivery and Tumor Targeting: From Tissue Distribution to Intracellular Fate

Exosomes or small extracellular vesicles are considered a new generation of bioinspired-nanoscale drug delivery system (DDS). Endogenous exosomes function as signalosomes since they convey signals via ligands or adhesion molecules located on the exosomal membrane, or packaged inside the exosome. Recently, exosome membrane modification, therapeutic payloads encapsulation, and modulation of in vivo disposition of exosomes have been extensively investigated, among which significant advances have been made to optimize exosome-mediated delivery to solid tumors. Exosomes, specifically tumor cell-derived exosomes, are presumed to have tumor-preferential delivery due to the homotypic features. However, quality attributes that dictate the tissue distribution, cell type-selective uptake, and intracellular payload release of the administered exosomes, as well as the spatiotemporal information regarding exosome fate in vivo, remain to be further investigated. This review summarizes recent advances in developing exosomes as drug delivery platforms with a focus on tumor targeting. The pharmacokinetic features of naive exosomes and factors influencing their intracellular fate are summarized. Recent strategies to improve tumor targeting of exosomes are also reviewed in the context of the biological features of tumor and tumor microenvironment (TME). Selected approaches to augment tumor tissue deposition of exosomes, as well as methods to enhance intracellular payload delivery, are summarized with emphasis on the underlying mechanisms (eg, passive or active targeting, endosomal escape, etc.). In conclusion, this review highlights recently reported tumor-targeting strategies of exosome-based drug delivery, and it's in the hope that multiple approaches might be employed in a synergistic combination in the development of exosome-based cancer therapy.

Mono-macrophage-Derived MANF Protects Against Lipopolysaccharide-Induced Acute Kidney Injury via Inhibiting Inflammation and Renal M1 Macrophages

The outburst of renal inflammatory response has been found to be a crucial cause of acute kidney injury (AKI). Attenuating the renal inflammation is an effective way for AKI treatment. Mesencephalic astrocyte-derived neurotrophic factor (MANF) has been proven to be an anti-inflammatory factor. However, the effect of MANF on renal inflammation induced by AKI is unknown. In this study, we have investigated the effect of mono-macrophage-derived MANF on AKI. We constructed the mono-macrophage-specific MANF knockout (Mø MANF^-/-) mouse and used lipopolysaccharide (LPS) to induce AKI in wild-type (WT) and Mø MANF^-/- mice. With mono-macrophage-specific MANF deficiency, Mø MANF^-/- mice had a lower survival rate, more severe renal injury, and higher serum level of pro-inflammatory TNF-α after AKI was induced by LPS. Also, compared with WT mice, there were more M1 macrophages in renal tissues of Mø MANF^-/- mice with LPS treatment, which might be attributed to the enhanced NF-κB activation in the renal microenvironment. Our study indicates the immunoregulatory role of mono-macrophage-derived MANF in the pathophysiological process of AKI, as well as the potential clinical application of MANF for AKI treatment.

The momentous role of N6-methyladenosine in lung cancer

Lung cancer is the leading cause of cancer death worldwide. Although diagnostic methods and targeted drugs have been rapidly developed in recent years, the underlying molecular mechanisms in the pathogenesis of lung cancer remain enigmatic. The N6-methyladenosine (m⁶ A) modification is the most common modification of messenger RNA in eukaryotes and plays critical roles in many diseases, especially cancers. Ectopic m⁶ A modification is associated with human carcinogenesis, including lung cancer. The m⁶ A modification is mediated by methyltransferases (writers) and demethylases (erasers) and indirectly affects biological processes through the recruitment of specific reader proteins (readers). Many studies have shown that m⁶ A writers, erasers, and readers serve as specific and sensitive biomarkers for lung cancer diagnosis, prognosis, and therapy. This review summarizes recent studies on the biological functions of the m⁶ A modification in lung cancer and discusses the potential application of m⁶ A regulators in lung cancer diagnosis and therapeutics.

[Neutralization of interleukin-6 alleviates acute liver injury in mice]

Objective: To study the role of interleukin 6 (IL-6) in the occurrence and development of acute liver injury. Methods: Twelve C57BL/6 male mice without specific pathogens were randomly divided into a control group and an acute liver injury model group, with six mice in each group. Control and model group were injected with an equal volume (dosage of 10 mg/kg) of phosphate-buffered saline (PBS) and concanavalin A (ConA) into the tail vein, respectively. Samples were collected at 6 h for liver HE staining. Transaminase assay was used to determine the success of the induction model. The expression of IL-6, IL-17, IL-1β, interferon (IFN) γ and tumor necrosis factor α were screened by quantitative fluorescence PCR (qPCR). The expressional condition of IL-6 and IFNγ were measured by enzyme-linked immunosorbent assay (ELISA). Subsequently, three control groups and three IL-6 neutralizing antibody groups were established for acute liver injury, respectively. Equal volumes of PBS or IL-6 neutralizing antibody (100 μg/body) were injected prior 30 minutes, followed by injection of ConA (10 mg/kg) into the tail vein. Blood sampled from eye and liver tissue were fetched at 6 h. Liver tissues were stained with HE and serum alanine aminotransferase (ALT) was determined. An independent sample T-test was used for data comparison. Results: Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) of the model group was significantly higher than control group [ALT: (2 618.99 ± 188.08) U/L and (43.34 ± 5.02) U/L, t = -13.69, P = 0.001; AST: (942.48 ± 150.44) U/L and (57.80 ± 4.84) U/L, t = -5.878, P = 0.01]. Liver HE staining showed that the structure of hepatocyte cord was disordered, the cytoplasm of hepatocyte was lightly stained, and large necrotic foci were gradually formed, accompanied by lymphocyte infiltration, and then a mouse model of acute liver injury was successfully established. Protein levels of IL-6 and IFN, and mRNA of the model group were significantly up-regulated, as compared to control group. IL-6 mRNA expression of the model group was increased 73.7 times that of the control group (t =-6.218, P < 0.001), and the serum IL-6 expression level was also higher than that of the control group (18 537.02 ± 92.57) pg/ml (t = -199.782, P < 0.001). IFNγ mRNA was 108.4 times higher than that of the control the group (t = -4.413, P = 0.003), and serum IFNγ concentration of the model group was also higher than the control group (12 068.30 ± 288.43) pg/ml (t = -41.748, P < 0.001). Among them, IL-6 level was obviously increased, suggesting that it could participate in the occurrence and development of liver injury. IL-6 neutralizing antibody was injected into the tail vein. ALT level of IL-6 neutralizing antibody was significantly lower than acute liver injury control group [(167.41 ± 47.80) U/L and (1 520.34 ± 190.21) U/L, t = 6.899, P = 0.015]. Liver tissue HE staining showed that hepatocyte necrosis and the number of necrotic foci was significantly alleviated after blocking serum IL-6.Immunohistochemical results showed that the expression of activated caspase3 and hepatocyte apoptosis in the IL-6 neutralizing antibody group was decreased. Conclusion: Neutralizing IL-6 can significantly reduce acute liver injury caused by concanavalin A.

Mesencephalic Astrocyte-Derived Neurotrophic Factor Inhibits Liver Cancer Through Small Ubiquitin-Related Modifier (SUMO)ylation-Related Suppression of NF-κB/Snail Signaling Pathway and Epithelial-Mesenchymal Transition

BACKGROUND AND AIMS

Endoplasmic reticulum (ER) stress is associated with liver inflammation and hepatocellular carcinoma (HCC). However, how ER stress links inflammation and HCC remains obscure. Mesencephalic astrocyte-derived neurotrophic factor (MANF) is an ER stress-inducible secretion protein that inhibits inflammation by interacting with the key subunit of nuclear factor kappa light chain enhancer of activated B cells (NF-κB) p65. We hypothesized that MANF may play a key role in linking ER stress and inflammation in HCC.

APPROACH AND RESULTS

Here, we found that MANF mRNA and protein levels were lower in HCC tissues versus adjacent noncancer tissues. Patients with high levels of MANF had better relapse-free survival and overall survival rates than those with low levels. MANF levels were also associated with the status of liver cirrhosis, advanced tumor-node-metastasis (TNM) stage, and tumor size. In vitro experiments revealed that MANF suppressed the migration and invasion of hepatoma cells. Hepatocyte-specific deletion of MANF accelerated N-nitrosodiethylamine (DEN)-induced HCC by up-regulating Snail1+2 levels and promoting epithelial-mesenchymal transition (EMT). MANF appeared in the nuclei and was colocalized with p65 in HCC tissues and in tumor necrosis factor alpha (TNF-α)-treated hepatoma cells. The interaction of p65 and MANF was also confirmed by coimmunoprecipitation experiments. Consistently, knockdown of MANF up-regulated NF-κB downstream target genes TNF-α, interleukin (IL)-6 and IL-1α expression in vitro and in vivo. Finally, small ubiquitin-related modifier 1 (SUMO1) promoted MANF nuclear translocation and enhanced the interaction of MANF and p65. Mutation of p65 motifs for SUMOylation abolished the interaction of p65 and MANF.

CONCLUSIONS

MANF plays an important role in linking ER stress and liver inflammation by inhibiting the NF-κB/Snail signal pathway in EMT and HCC progression. Therefore, MANF may be a cancer suppressor and a potential therapeutic target for HCC.

Xanthatin induces glioma cell apoptosis and inhibits tumor growth via activating endoplasmic reticulum stress-dependent CHOP pathway

Xanthatin is a natural sesquiterpene lactone purified from Xanthium strumarium L., which has shown prominent antitumor activity against a variety of cancer cells. In the current study, we investigated the effect of xanthatin on the growth of glioma cells in vitro and in vivo, and elucidated the underlying mechanisms. In both rat glioma C6 and human glioma U251 cell lines, xanthatin (1–15 μM) dose-dependently inhibited cell viability without apparent effect on the cell cycle. Furthermore, xanthatin treatment dose-dependently induced glioma cell apoptosis. In nude mice bearing C6 glioma tumor xenografts, administration of xanthatin (10, 20, 40 mg·kg⁻¹·d⁻¹, ip, for 2 weeks) dose-dependently inhibited the tumor growth, but did not affect the body weight. More importantly, xanthatin treatment markedly increased the expression levels of the endoplasmic reticulum (ER) stress-related markers in both the glioma cell lines as well as in C6 xenografts, including glucose-regulated protein 78, C/EBP-homologous protein (CHOP), activating factor 4, activating transcription factor 6, spliced X-box binding protein-1, phosphorylated protein kinase R-like endoplasmic reticulum kinase, and phosphorylated eukaryotic initiation factor 2a. Pretreatment of C6 glioma cells with the ER stress inhibitor 4-phenylbutyric acid (4-PBA, 7 mM) or knockdown of CHOP using small interfering RNA significantly attenuated xanthatin-induced cell apoptosis and increase of proapoptotic caspase-3. These results demonstrate that xanthatin induces glioma cell apoptosis and inhibits tumor growth via activating the ER stress-related unfolded protein response pathway involving CHOP induction. Xanthatin may serve as a promising agent in the treatment of human glioma.

BAF45D Downregulation in Spinal Cord Ependymal Cells Following Spinal Cord Injury in Adult Rats and Its Potential Role in the Development of Neuronal Lesions

The endogenous spinal cord ependymal cells (SCECs), which form the central canal (CC), are critically involved in proliferation, differentiation and migration after spinal cord injury (SCI) and represents a repair cell source in treating SCI. Previously, we reported that BAF45D is expressed in the SCECs and the spinal cord neurons in adult mice and knockdown of BAF45D fail to induce expression of PAX6, a neurogenic fate determinant, during early neural differentiation of human embryonic stem cells. However, the effects of SCI on expression of BAF45D have not been reported. The aim of this study is to explore the expression and potential role of BAF45D in rat SCI model. In this study, adult rats were randomly divided into intact, sham, and SCI groups. We first explored expression of BAF45D in the SCECs in intact adult rats. We then explored SCI-induced loss of motor neurons and lesion of neurites in the anterior horns induced by the SCI. We also investigated whether the SCI-induced lesions in SCECs are accompanied by the motor neuron lesions. Finally, we examined the effect of BAF45D knockdown on cell growth in neuro2a cells. Our data showed that BAF45D is expressed in SCECs, neurons, and oligodendrocytes but not astrocytes in the spinal cords of intact adult rats. After SCI, the structure of CC was disrupted and the BAF45D-positive SCEC-derivatives were decreased. During the early stages of SCI, when shape of CC was affected but there was no disruption in circular structure of the SCECs, it was evident that there was a significant reduction in the number of neurites and motor neurons in the anterior horns compared with those of intact rats. In comparison, a complete loss of SCECs accompanied by further loss of motor neurons but not neurites was observed at the later stage. BAF45D knockdown was also found to inhibit cell growth in neuro2a cells. These results highlight the decreased expression of BAF45D in SCI-injured SCECs and the potential role of BAF45D downregulation in development of neuronal lesion after SCI in adult rats.

Microglial proliferation and monocyte infiltration contribute to microgliosis following status epilepticus

Microglial activation has been recognized as a major contributor to inflammation of the epileptic brain. Seizures are commonly accompanied by remarkable microgliosis and loss of neurons. In this study, we utilize the CX3CR1^GFP/+ CCR2^RFP/+ genetic mouse model, in which CX3CR1⁺ resident microglia and CCR2⁺ monocytes are labeled with GFP and RFP, respectively. Using a combination of time-lapse two-photon imaging and whole-cell patch clamp recording, we determined the distinct morphological, dynamic, and electrophysiological characteristics of infiltrated monocytes and resident microglia, and the evolution of their behavior at different time points following kainic acid-induced seizures. Seizure activated microglia presented enlarged somas with less ramified processes, whereas, infiltrated monocytes were smaller, highly motile cells that lacked processes. Moreover, resident microglia, but not infiltrated monocytes, proliferate locally in the hippocampus after seizure. Microglial proliferation was dependent on the colony-stimulating factor 1 receptor (CSF-1R) pathway. Pharmacological inhibition of CSF-1R reduced seizure-induced microglial proliferation, which correlated with attenuation of neuronal death without altering acute seizure behaviors. Taken together, we demonstrated that proliferation of activated resident microglia contributes to neuronal death in the hippocampus via CSF-1R after status epilepticus, providing potential therapeutic targets for neuroprotection in epilepsy.

Mesencephalic astrocyte-derived neurotrophic factor (MANF) protects against Aβ toxicity via attenuating Aβ-induced endoplasmic reticulum stress

BACKGROUND

Extracellular accumulation of amyloid β-peptide (Aβ) is one of pathological hallmarks of Alzheimer's disease (AD) and contributes to the neuronal loss. Mesencephalic astrocyte-derived neurotrophic factor (MANF) is an endoplasmic reticulum (ER) stress-inducible neurotrophic factor. Many groups, including ours, have proved that MANF rescues neuronal loss in several neurological disorders, such as Parkinson's disease and cerebral ischemia. However, whether MANF exerts its protective effect against Aβ neurotoxicity in AD remains unknown.

METHODS

In the present study, the characteristic expressions of MANF in Aβ_1-42-treated neuronal cells as well as in the brains of APP/PS1 transgenic mice were analyzed by immunofluorescence staining, qPCR, and Western blot. The effects of MANF overexpression, MANF knockdown, or recombination human MANF protein (rhMANF) on neuron viability, apoptosis, and the expression of ER stress-related proteins following Aβ_1-42 exposure were also investigated.

RESULTS

The results showed the increased expressions of MANF, as well as ER stress markers immunoglobulin-binding protein (BiP) and C/EBP homologous protein (CHOP), in the brains of the APP/PS1 transgenic mice and Aβ_1-42-treated neuronal cells. MANF overexpression or rhMANF treatment partially protected against Aβ_1-42-induced neuronal cell death, associated with marked decrease of cleaved caspase-3, whereas MANF knockdown with siRNA aggravated Aβ_1-42 cytotoxicity including caspase-3 activation. Further study demonstrated that the expressions of BiP, ATF6, phosphorylated-IRE1, XBP1s, phosphorylated-eIF2α, ATF4, and CHOP were significantly downregulated by MANF overexpression or rhMANF treatment in neuronal cells following Aβ_1-42 exposure, whereas knockdown of MANF has the opposite effect.

CONCLUSIONS

These findings demonstrate that MANF may exert neuroprotective effects against Aβ-induced neurotoxicity through attenuating ER stress, suggesting that an applicability of MANF as a therapeutic candidate for AD.

pH-Responsive polyelectrolyte coated gadolinium oxide-doped mesoporous silica nanoparticles (Gd2O3@MSNs) for synergistic drug delivery and magnetic resonance imaging enhancement

Theranostic platforms that combine therapeutic and imaging modalities have received increasing interest.

[Changes and clinical significance of γδT cells in peripheral blood of patients with chronic hepatitis B during pegylated interferon α-2a treatment]

Objective: To observe the changes of γδT cells in the peripheral blood of patients with chronic hepatitis B (CHB) during pegylated interferon α-2a treatment, and to analyze the correlation between clinical indicators and curative effects. Methods: Peripheral blood of hepatitis B e antigen (HBeAg)-positive CHB patients were collected at different time points of Peg-IFNα-2a treatment, including 17 patients at 0 weeks, 20 patients at 12 weeks, 20 patients at 24 weeks, and 16 patients at 48 weeks. From these 11 patients, blood samples were frequently observed at 0, 12, 24, and 48 weeks of treatment. The frequencies of γδT and its subpopulation cells Vδ1T, Vδ2T, effector memory γδT (γδTem), central memory γδT (γδTcm), initial γδT (γδTnaive) and terminal differentiation effect γδT (γδTeff) cells in peripheral blood were detected by flow cytometry. Liver function, serum HBV markers and HBV DNA levels were measured simultaneously. SPSS 23.0 statistical software was used to analyze the differences in cell proportions at each treatment time point, and the correlation between cell proportions and alanine aminotransferase (ALT), HBsAg, HBeAg or HBV DNA levels. In addition, the correlation between the proportions of γδT and its subpopulation cells and the response to Peg-IFNα-2a treatment in the 11 patients with continuous follow-up were analyzed. Results: The percentage of γδT and Vδ2T cells in peripheral blood of patients with CHB decreased gradually during the period of 0-48 weeks of Peg-IFNα-2a treatment. The percentages of γδT cells and Vδ2T cells at 48 weeks were 6.89% (5%, 8.15%), 4.61% (2.16%, 6.50%), respectively; significantly lower than the 0 week [12.5% ​​(7.73%, 19%), 6.59% (3.86%, 13.62%)], the differences were statistically significant (P < 0.05). The proportions of Vδ1T, γδTem, γδTcm, γδTnaive, or γδTeff subpopulations were not statistically different at each time points (all P > 0.05). At the same time, the levels of ALT, HBsAg, HBeAg or HBV DNA were positively correlated with the ratio of γδT or Vδ2T cells (P < 0.05). Among the 11 patients with continuous followed- up, the proportion of γδTem cells in responders was significantly lower than that of non-responders at each time points, and the difference was statistically significant (P < 0.05). There was no statistically significant difference between the two groups (all P > 0.05). Conclusion: The proportion of γδT cells in the course of CHB treatment with Peg-IFNα-2a reduces the liver inflammation by decreasing the replication of HBV virus. Chronic hepatitis B patients with a lower proportion of effector memory (γδTem) cells may be more likely to get better response with Peg-IFNα-2a.

Mitochondrial oxidation of the carbohydrate fuel is required for neural precursor/stem cell function and postnatal cerebellar development

While deregulation of mitochondrial metabolism and cytosolic glycolysis has been well recognized in tumor cells, the role of coordinated mitochondrial oxidation and cytosolic fermentation of pyruvate, a key metabolite derived from glucose, in physiological processes is not well understood. Here, we report that knockout of PTPMT1, a mitochondrial phosphoinositide phosphatase, completely blocked postnatal cerebellar development. Proliferation of granule cell progenitors, the most actively replicating cells in the developing cerebellum, was only moderately decreased, and proliferation of Purkinje cell progenitors did not seem to be affected in knockout mice. In contrast, generation of functional Bergmann glia from multipotent precursor cells (radial glia), which is essential for cerebellar corticogenesis, was totally disrupted. Moreover, despite a low turnover rate, neural stem cells were impaired in self-renewal in knockout mice. Mechanistically, loss of PTPMT1 decreased mitochondrial aerobic metabolism by limiting utilization of pyruvate, which resulted in bioenergetic stress in neural precursor/stem cells but not in progenitor or mature cells, leading to cell cycle arrest through activation of the AMPK-p19/p21 pathway. This study suggests that mitochondrial oxidation of the carbohydrate fuel is required for postnatal cerebellar development, and identifies a bioenergetic stress-induced cell cycle checkpoint in neural precursor/stem cells.

XBP1 activation enhances MANF expression via binding to endoplasmic reticulum stress response elements within MANF promoter region in hepatitis B

As an endoplasmic reticulum (ER) stress-related protein, mesencephalic astrocyte-derived neurotrophic factor (MANF) is involved in inflammatory diseases, such as rheumatoid arthritis. However, the mechanisms of the transcriptional regulation of MANF is still undefined. Here, we showed that MANF expression was upregulated in hepatitis B tissues and hepatoma cells, and positively correlated with the spliced X-box binding protein-1 (XBP1s). Both overexpression of XBP1s and tunicamycin treatment were able to enhance MANF transcription. On the contrary, inhibition of XBP1 splicing by IRE1α endonuclease inhibitor or knockdown of XBP1s with siRNA attenuated MANF expression. Two ER stress-responsive elements (ERSE) were found in the promoter region of MANF (ERSE I and ERSE II). The chromatin immunoprecipitation and reporter gene assay showed that XBP1s mainly binds to ERSE I to promote MANF transcription. Moreover, MANF was found to interact with XBP1s to enhance its own expression. Our findings uncover a new mechanism of ERSE-dependent transcriptional regulation of MANF, as well as a key role of XBP1s in promoting the MANF expression.

Small ubiquitin-related modifier 1 is involved in hepatocellular carcinoma progression via mediating p65 nuclear translocation

Small ubiquitin-related modifier (SUMO) proteins participate in a post-translational modification called SUMOylation and regulate a variety of intracellular processes, such as targeting proteins for nuclear import. The nuclear transport of p65 results in the activation of NF-κB, and p65 contains several SUMO interacting motifs (SIMs). However, the relationship between p65 and SUMO1 in hepatocellular carcinoma (HCC) remains unclear. In this study, we demonstrated the potential roles of SUMO1 in HCC via the regulation of p65 subcellular localization. We found that either SUMO1- or p65-positive immunoreactivity was remarkably increased in the nuclei of tumor tissues in HCC patients compared with non-tumor tissues, and further analysis suggested a correlation between SUMO1- and nuclear p65-positive immunoreactivities (R = 0.851, P = 0.002). We also verified the interaction between p65 and SUMO1 in HCC by co-immunoprecipitation. TNF-α and hypoxia increased SUMO1 protein levels and enhanced SUMO1-modified p65 SUMOylation. Moreover, the knockdown of SUMO1 decreased p65 nuclear translocation and inhibited NF-κB transcriptional activity. Further the results of this study revealed that the knockdown of SUMO1 suppressed the proliferation and migration of hepatoma cells. These results suggest that SUMO1 contributes to HCC progression by promoting p65 nuclear translocation and regulating NF-κB activity.

The BAF45D Protein Is Preferentially Expressed in Adult Neurogenic Zones and in Neurons and May Be Required for Retinoid Acid Induced PAX6 Expression

Adult neurogenesis is important for the development of regenerative therapies for human diseases of the central nervous system (CNS) through the recruitment of adult neural stem cells (NSCs). NSCs are characterized by the capacity to generate neurons, astrocytes, and oligodendrocytes. To identify key factors involved in manipulating the adult NSC neurogenic fate thus has crucial implications for the clinical application. Here, we report that BAF45D is expressed in the subgranular zone (SGZ) of the dentate gyrus, the subventricular zone (SVZ) of the lateral ventricle, and the central canal (CC) of the adult spinal cord. Coexpression of BAF45D with glial fibrillary acidic protein (GFAP), a radial glial like cell marker protein, was identified in the SGZ, the SVZ and the adult spinal cord CC. Quantitative analysis data indicate that BAF45D is preferentially expressed in the neurogenic zone of the LV and the neurons of the adult CNS. Furthermore, during the neuroectoderm differentiation of H9 cells, BAF45D is required for the expression of PAX6, a neuroectoderm determinant that is also known to regulate the self-renewal and neuronal fate specification of adult neural stem/progenitor cells. Together, our results may shed new light on the expression of BAF45D in the adult neurogenic zones and the contribution of BAF45D to early neural development.

Rifampicin-induced injury in HepG2 cells is alleviated by TUDCA via increasing bile acid transporters expression and enhancing the Nrf2-mediated adaptive response

Bile acid transporters and the nuclear factor erythroid 2-related factor (Nrf-2)-mediated adaptive response play important roles in the development of drug-induced liver injury (DILI). However, little is known about the contribution of the adaptive response to rifampicin (RFP)-induced cell injury. In this study, we found RFP decreased the survival rate of HepG2 cells and increased the levels of lactate dehydrogenase (LDH), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (AKP), γ-glutamyl-transferase (γ-GT), total bilirubin (TBIL), direct bilirubin (DBIL), indirect bilirubin (IBIL), total bile acid (TBA) and adenosine triphosphate (ATP) in the cell culture supernatants in both a concentration- and a time-dependent manner. RFP increased the expression levels of bile acid transporter proteins and mRNAs, such as bile salt export pump (BSEP), multidrug resistance protein 1 (MDR1), multidrug resistance-associated protein 2 (MRP2), Na+/taurocholate cotransporter (NTCP), organic anion transporting protein 2 (OATP2), organic solute transporter β (OSTβ) and Nrf2. Following the transient knockdown of Nrf2 and treatment with RFP, the expression levels of the BSEP, MDR1, MRP2, NTCP, OATP2 and OSTβ proteins and mRNAs were decreased to different degrees. Moreover, the cell survival was decreased, whereas the LDH level in the cell culture supernatant was increased. Overexpression of the Nrf2 gene produced the opposite effects. Treatment with tauroursodeoxycholic acid (TUDCA) increased the expression levels of the bile acid transporters and Nrf2, decreased the expression levels of glucose-regulated protein 78 (GRP78), PKR-like ER kinase (PERK), activating transcription factor 4 (ATF4), and C/EBP-homologous protein (CHOP), and inhibited RFP-induced oxidative stress. Moreover, TUDCA reduced cell apoptosis, increased cell survival and decreased the levels of LDH, ALT, AST, AKP, γ-GT, TBIL, DBIL, IBIL, TBA and ATP in the cell culture supernatant. Therefore, TUDCA alleviates RFP-induced injury in HepG2 cells by enhancing bile acid transporters expression and the Nrf2-mediated adaptive response.

1α,25-Dihydroxyvitamin D3 up-regulates IL-34 expression in SH-SY5Y neural cells

Vitamin D supplementation is regarded as a novel approach to treat Alzheimer’s disease, but the underlying mechanism remains elusive. The cytokine IL-34 provides strong neuroprotective and survival signals in brain injury and neurodegeneration and could be an immunological mediator for the vitamin D-induced protection. The aim of this study was to investigate whether human IL-34 is up-regulated in neuronal cells by the hormonally active form of vitamin D, 1α,25-dihydroxyvitamin D3 [1α,25(OH)2D3]. We found that IL-34 was detectable in a variety of cell lines and its expression was strongly induced in SH-SY5Y neural cells in a dose- and time-dependent manner by 1α,25(OH)2D3 through the vitamin D receptor (VDR). Furthermore, we identified the core promoter of IL-34 gene and a VDR binding site (CGCCCT) that was required for 1α,25(OH)2D3-induced IL-34 expression. These findings suggest that the induction of IL-34 expression by 1α,25(OH)2D3 may constitute a mechanism that explains the protective function of vitamin D in Alzheimer’s disease.

Roles of SAMHD1 in antiviral defense, autoimmunity and cancer

The enzyme, sterile α motif and histidine-aspartic acid domain-containing protein 1 (SAMHD1) diminishes infection of human immunodeficiency virus type 1 (HIV-1) by hydrolyzing intracellular deoxynucleotide triphosphates (dNTPs) in myeloid cells and resting CD4+ T cells. This dNTP degradation reduces the dNTP concentration to a level insufficient for viral cDNA synthesis, thereby inhibiting retroviral replication. This antiviral enzymatic activity can be inhibited by viral protein X (Vpx). The HIV-2/SIV Vpx causes degradation of SAMHD1, thus interfering with the SAMHD1-mediated restriction of retroviral replication. Recently, SAMHD1 has been suggested to restrict HIV-1 infection by directly digesting genomic HIV-1 RNA through a still controversial RNase activity. Here, we summarize the current knowledge about structure, antiviral mechanisms, intracellular localization, interferon-regulated expression of SAMHD1. We also describe SAMHD1-deficient animal models and an antiviral drug on the basis of disrupting proteasomal degradation of SAMHD1. In addition, the possible roles of SAMHD1 in regulating innate immune sensing, Aicardi-Goutières syndrome and cancer are discussed in this review.

Ubiquitin ligase SYVN1/HRD1 facilitates degradation of the SERPINA1 Z variant/α-1-antitrypsin Z variant via SQSTM1/p62-dependent selective autophagy

SERPINA1/AAT/α-1-antitrypsin (serpin family A member 1) deficiency (SERPINA1/ AAT-D) is an autosomal recessive disorder characterized by the retention of misfolded SERPINA1/AAT in the endoplasmic reticulum (ER) of hepatocytes and a significant reduction of serum SERPINA1/AAT level. The Z variant of SERPINA1/AAT, containing a Glu342Lys (E342K) mutation (SERPINA1^E342K/ATZ), the most common form of SERPINA1/AAT-D, is prone to misfolding and polymerization, which retains it in the ER of hepatocytes and leads to liver injury. Both proteasome and macroautophagy/autophagy pathways are responsible for disposal of SERPINA1^E342K/ATZ after it accumulates in the ER. However, the mechanisms by which SERPINA1^E342K/ATZ is selectively degraded by autophagy remain unknown. Here, we showed that ER membrane-spanning ubiquitin ligase (E3) SYVN1/HRD1 enhances the degradation of SERPINA1^E342K/ATZ through the autophagy-lysosome pathway. We found that SYVN1 promoted SERPINA1^E342K/ATZ, especially Triton X 100-insoluble SERPINA1^E342K/ATZ clearance. However, the effect of SYVN1 in SERPINA1^E342K/ATZ clearance was impaired after autophagy inhibition, as well as in autophagy-related 5 (atg5) knockout cells. On the contrary, autophagy induction enhanced SYVN1-mediated SERPINA1^E342K/ATZ degradation. Further study showed that SYVN1 mediated SERPINA1^E342K/ATZ ubiquitination, which is required for autophagic degradation of SERPINA1^E342K/ATZ by promoting the interaction between SERPINA1^E342K/ATZ and SQSTM1/p62 for formation of the autophagy complex. Interestingly, SYVN1-mediated lysine 48 (K48)-linked polyubiquitin chains that conjugated onto SERPINA1^E342K/ATZ might predominantly bind to the ubiquitin-associated (UBA) domain of SQSTM1 and couple the ubiquitinated SERPINA1^E342K/ATZ to the lysosome for degradation. In addition, autophagy inhibition attenuated the suppressive effect of SYVN1 on SERPINA1^E342K/ATZ cytotoxicity, and the autophagy inducer rapamycin enhanced the suppressive effect of SYVN1 on SERPINA1^E342K/ATZ-induced cell apoptosis. Therefore, this study proved that SYVN1 enhances SERPINA1^E342K/ATZ degradation through SQSTM1-dependent autophagy and attenuates SERPINA1^E342K/ATZ cytotoxicity.

[Oxidative stress and antioxitant therapy of chronic periodontitis]

Chronic periodontitis is a progressive, infectious inflammation disease, caused by the dysbiosis of oral resident flora, leading to the destruction of periodontium. The onset of pathogenic microorganisms is the etiological factor of periodontitis, while the immuno-inflammatory response affects the progression of the disease. Under chronic periodontitis, oxidative stress occurs when excessive reactive oxygen species are produced and exceed the compensative capacity of the organism. Oxidative stress leads to the destruction of periodontium, in a direct way(damaging the biomolecule) or an indirect way(enhancing the produce of inflammatory cytokine and destructive enzymes). Therefore, as the antagonist of the reactive oxygen species, antioxidants may be helpful to treat the chronic periodontitis. This paper reviewed relevant literatures about the destructive role of excessive reactive oxygen species and protective role of antioxidants in chronic periodontitis.

[Body mass index, waist circumference and waist-to-height ratio associated with the incidence of type 2 diabetes mellitus: a cohort study]

OBJECTIVE

To investigate the association between body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR), and the incidence risk of type 2 diabetes mellitus (T2DM).

METHODS

In total, 20 194 participants ≥18 years old were selected randomly by cluster sampling from two township (town) of the county in Henan province from July to August of 2007 and July to August of 2008 and the investigation included questionnaires, anthropometric measurements, fasting plasma glucose, and lipid profile examination were performed at baseline; 17 236 participants were enrolled in this cohort study. 14 720 (85.4%) were followed up from July to August 2013 and July to October 2014. Finally, 11 643 participants (4 301 males and 7 342 females) were included in this study. Incidence density and Cox proportional hazards regression models were used to evaluate the risk of T2DM associated with baseline BMI, WC, WHtR, and their dynamic changes.

RESULTS

After average of 6.01 years following up for 11 643 participants, 613 developed T2DM and the incidence density was 0.89 per 100 person-years. After adjusted for baseline sex, age, smoking, drinking, family history of diabetes, as well as the difference of fasting plasma-glucose (FPG), total cholesterol (TC), triglyceride (TG), high density lipoprotein cholesterol (HDL-C), systolic blood pressure (SBP), diastolic blood pressure (DBP) between baseline and follow-up, Cox Proportional-Hazards regression analysis indicated that T2DM risk of baseline BMI overweight group, BMI obesity group, abnormal WC group and abnormal WHtR group were significantly higher than that of the corresponding baseline normal groups , and the incidence risk of T2DM reached the highest for those whose baseline BMI, WC and WHtR were all abnormal, the corresponding HR (95%CI) were 2.05 (1.62-2.59), 3.01 (2.33-3.90), 2.34 (1.89-2.90), 2.88 (2.21-3.74), 3.32 (2.50-4.40), respectively. Whether baseline BMI/WC was normal or not, T2DM risk increased if baseline WHtR was abnormal, and the HR (95%CI) of baseline normal BMI/abnormal WHtR group, baseline abnormal BMI/abnormal WHtR group, baseline normal WC/abnormal WHtR group, baseline abnormal WC/abnormal WHtR group were 1.88 (1.29-2.74), 3.08 (2.34-4.05), 2.15(1.53-3.00), 3.22 (2.45-4.23), respectively. The analysis for dynamic changes of BMI, WC, and WHtR indicated that in baseline normal WC or WHtR group, T2DM risk increased when baseline normal WC or WHtR developed abnormal at follow-up, and the corresponding HR (95%CI) were 1.79 (1.26-2.55), 2.12(1.32-3.39), respectively. In baseline abnormal WC or WHtR group, T2DM risk decresed when baseline abnormal WC or WHtR reversed to normal at follow-up, and the corresponding HR (95%CI) were 2.16 (1.42-3.29), 2.62 (1.63-4.20), respectively.

CONCLUSION

BMI, WC, and WHtR were associated with increased T2DM risk. The more abnormal aggregation of BMI, WC, and WHtR presents, the higher T2DM risk was. T2DM risk could be decreased when abnormal WC or WHtR reversed to normal.

Facile synthesis of tunable plasmonic silver core/magnetic Fe3O4 shell nanoparticles for rapid capture and effective photothermal ablation of bacterial pathogens

Multifunctional Ag@Fe₃O₄–PEI nanoparticles have been developed for simultaneously capturing and photothermal killing bacteria in contaminated source.

Small differences make a big impact: Structural insights into the differential function of the 2 Atg8 homologs in C. elegans

The 2 C. elegans homologs of Atg8, LGG-1 and LGG-2, show differential function in the degradation of protein aggregates during embryogenesis. LGG-1 is essential for the degradation of various protein aggregates, while LGG-2 has cargo-specific and developmental stage-specific roles. LGG-1 and LGG-2 differentially interact with autophagy substrates and ATG proteins. LGG-1 and LGG-2 possess 2 hydrophobic pockets, the W-site and the L-site, which recognize the LIR motif in Atg8-binding proteins. The plasticity of the W-site and the size and shape of the L-site differ between LGG-1 and LGG-2, thus determining their preferences for distinct LIR motifs. The N-terminal tails of LGG-1 and LGG-2 adopt unique closed and open conformations, respectively, which may result in distinct membrane tethering and fusion activities. LGG-1 and LGG-2 have different affinities for ATG-7 and ATG-3, and lipidation of LGG-2 is regulated by levels of lipidated LGG-1. Taken together, the structural differences between LGG-1 and LGG-2 provide insights into their differential functions in the aggrephagy pathway.

Preparation of amino-functionalized magnetic nanoparticles for enhancement of bacterial capture efficiency

PEI-MNPs were successfully fabricated, which showed higher bacterial capture ability than the triaminopropylalkoxysilane directly modified NH-MNPs at low concentration.

ER stress-inducible protein MANF selectively expresses in human spleen

Mesencephalic astrocyte-derived neurotrophic factor (MANF; also known as arginine-rich, mutated in early tumors; ARMET), is an ER stress-inducible protein, and widely expressed in mammalian tissues. In this study, we are interested in the profile of MANF expression in human splenocytes. Three patients with spleen trauma were enrolled in this study. Immunohistochemistry and immunofluorescence were used to detect MANF expression in the four types of cells, including T cells, B cells, plasma cells, and macrophages in spleens by using the specific antibodies of anti-CD3, anti-CD20, anti-CD138, and anti-CD68, respectively. We found that MANF-positive cells extensively distributed in the red pulp and marginal-zone of spleen, and MANF was almost localized in the cytoplasm of splenocytes. Double immunofluorescent staining results showed that MANF localized mainly in the plasma cells and macrophages, but not in T and B cells. Meanwhile, we found that some MANF-positive cells expressed ER stress-related proteins, including ATF6, XBP1s, BiP, and CHOP. These results suggest that the selective expression of MANF in splenocytes may be involved in plasma cell differentiation and immune regulation.