Deciphering the potential role of PGRN in regulating CD8+ T cell antitumor immunity.

A key factor contributing to resistance in immune checkpoint blockade (ICB) therapies is CD8+ T-cell tolerance in the tumor microenvironment (TME), partly resulting from upregulating coinhibitory receptors. Here, we describe the role of PGRN as a coinhibitory molecule that modulates the antitumor response of CD8+ T cells, thus presenting a novel immunosuppressive target for lung cancer. The in vivo subcutaneous transplanted lung cancer model showed that PGRN expression was elevated on CD8+ T cells that infiltrated transplanted lung cancers. Furthermore, PGRN deficiency was found to specifically encourage the infiltration of CD8+ T cells, enhance their proliferation, migration, and activation, and resist apoptosis, ultimately inhibiting tumor growth. This was achieved by PGRN knockout, increasing the production of T cell chemokine CCL3, which boosts the antitumor immune response induced by CD8+ T cells. Critically, the PD-L1 inhibitor exhibited a synergistic effect in enhancing the antitumor response in PGRN-/- mice. In summary, our findings highlight the significance of PGRN as a novel target for boosting CD8+ T cells antitumor immunity and its potential to overcome the resistance in ICB therapy.

Dynasore Alleviates LPS-Induced Acute Lung Injury by Inhibiting NLRP3 Inflammasome-Mediated Pyroptosis.

Background: Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are clinically severe respiratory disorders without available pharmacological therapies. Dynasore is a cell-permeable molecule that inhibits GTPase activity and exerts protective effects in several disease models. However, whether dynasore can alleviate lipopolysaccharide (LPS)-induced ALI is unknown. This study investigated the effect of dynasore on macrophage activation and explored its potential mechanisms in LPS-induced ALI in vitro and in vivo. Methods: Bone marrow-derived macrophages (BMDMs) were activated classically with LPS or subjected to NLRP3 inflammasome activation with LPS+ATP. A mouse ALI model was established by the intratracheal instillation (i.t.) of LPS. The expression of PYD domains-containing protein 3 (NLRP3), caspase-1, and gasdermin D (GSDMD) protein was detected by Western blots. Inflammatory mediators were analyzed in the cell supernatant, in serum and bronchoalveolar lavage fluid (BALF) by enzyme-linked immunosorbent assays. Morphological changes in lung tissues were evaluated by hematoxylin and eosin staining. F4/80, Caspase-1 and GSDMD distribution in lung tissue was detected by immunofluorescence. Results: Dynasore downregulated nuclear factor (NF)-κB signaling and reduced proinflammatory cytokine production in vitro and inhibited the production and release of interleukin (IL)-1ß, NLRP3 inflammasome activation, and macrophage pyroptosis through the Drp1/ROS/NLRP3 axis. Dynasore significantly reduced lung injury scores and proinflammatory cytokine levels in both BALF and serum in vivo, including IL-1ß and IL-6. Dynasore also downregulated the co-expression of F4/80, caspase-1 and GSDMD in lung tissue. Conclusion: Collectively, these findings demonstrated that dynasore could alleviate LPS-induced ALI by regulating macrophage pyroptosis, which might provide a new therapeutic strategy for ALI/ARDS.

Role of placental barrier on trace element transfer in maternal fetal system and hypertensive disorders complicating pregnancy and gestational diabetes mellitus.

BACKGROUND: Hypertensive disorders complicating pregnancy (HDCP) and gestational diabetes mellitus (GDM) can affect the placental barrier function to varying degrees. However, current studies show that the transfer and distribution characteristics of trace elements in the maternal-fetal system are still unclear. This study investigated the effect of the placental barrier on the transfer of trace elements from mother to fetus and its relationship with HDCP and GDM. METHODS: A case-control method was used in this study. 140 pairs of samples were collected; 60 were from healthy pregnant women, and 80 were from patients with pregnancy complications. The contents of trace elements in paired samples were determined by inductively coupled plasma-mass spectrometry (ICP-MS). SPSS software was used to analyze the differences in trace element levels in matched samples of each group. The correlations were analyzed based on Pearson's correlation factor (r). RESULTS: The distribution characteristics of Fe content in the pathological group (HDCP group and GDM group) were the same as those in the normal group (umbilical cord blood > maternal blood > placenta), but there was no significant difference in the iron content in maternal blood and cord blood of pathological group. The distribution characteristics of Mn content in the pathological group (placenta > umbilical cord blood > maternal blood) were changed compared with those in the normal group (placenta > maternal blood > umbilical cord blood). In addition, the placental Cr content and cord blood Cr and Ni content of the pathological group were higher than those of the normal group. HDCP placental Cr and GDM placental Fe levels were significantly correlated with the Apgar score. CONCLUSIONS: The transfer of Fe and Mn and the placental barrier function of Cr and Ni in the maternal-fetal system of HDCP and GDM are significantly altered, which directly or indirectly increases the maternal and fetal health risk.

LINC00491 Facilitates Tumor Progression of Lung Adenocarcinoma via Wnt/ß-Catenin-Signaling Pathway by Regulating MTSS1 Ubiquitination.

Background: Long non-coding RNAs have been reported to be involved in tumorigenesis and progression through different regulatory mechanisms. It has been reported that aberrantly expressed long non-coding RNA LINC00491 promotes malignancy in multiple tumors, while the role of LINC00491 in lung adenocarcinoma (LUAD) is little reported and the mechanism for regulating tumor progression has not been elucidated. Methods: RNA sequencing and the TCGA database were combined to screen differentially expressed lncRNAs that facilitate tumor progression. The expression level of LINC00491 was examined in LUAD clinical samples and in cell lines using RT-qPCR. In vitro experiments including colony formation assay, EdU assay, cell migration and invasion assay and wound healing assay, and in vivo experiments including xenografting subcutaneous tumors and lung metastasis models were performed to investigate the function of LINC00491 in LUAD tumor progressions. RNA pull-down, mass spectrometry, RIP assays and truncation experiments were carried out to explore the proteins binding to LINC00491 and the specific interactions between the RNA-protein complex. Results: Our results showed that LINC0491 was significantly upregulated in LUAD and positively correlated with poor survival. High LINC00491 expression promoted proliferation, migration and invasion, and resulted in a high metastatic burden in LUAD. Using pull-down assay and mass spectrometry, MTSS1 was found binding to LINC00491, and the conducted experiments verified the direct interaction between LINC00491 and MTSS1. Meanwhile, LINC00491 was found to regulate MTSS1 degradation by promoting the MTSS1 ubiquitination level and then activating the Wnt/ß-catenin-signaling pathway. LINC00491/MTSS1/ß-catenin may act as a complex to facilitate tumor progression. Conclusions: In summary, our results found a novel mechanism in which LINC00491 directly interacts with MTSS1 by affecting its ubiquitination modification to promote LUAD proliferation, migration and invasion, then activating the Wnt/ß-catenin-signaling pathway, demonstrating its significant role in tumor progression and suggesting that the LINC00491/MTSS1/Wnt/ß-catenin-signaling pathway could serve as a potential therapeutic target for lung adenocarcinoma in the future.

2D Co-MOF nanosheet-based nanozyme with ultrahigh peroxidase catalytic activity for detection of biomolecules in human serum samples.

A two-dimensional (2D) Co-MOF nanosheet-based nanozyme was developed for colorimetric detection of disease-related biomolecules. The prepared 2D Co-MOFs exhibited ultrahigh peroxidase catalytic activity. 2D Co-MOFs can catalyze the oxidation of colorless 3,3',5,5'-tetramethylbenzidine (TMB) to the blue product oxTMB, accompanying an obvious change of absorption value at 652 nm. However, alkaline phosphatase can catalyze the hydrolysis of L-ascorbic acid-2-phosphate to produce ascorbic acid which can reduce the oxTMB to TMB, resulting in an obvious color fading. Therefore, by recording the change of absorption value at 652 nm, the 2D Co-MOF nanosheets were used to detect ascorbic acid (AA) and alkaline phosphatase (ALP). The limit of detection for AA and ALP was 0.47 µM and 0.33 U L-1, respectively. The limit of quantification for AA and ALP was 1.56 µM and 1.1 U L-1, respectively. The developed nanozyme was successfully used to determine alkaline phosphatase in clinical human serum samples and the results were consistent with those provided by the hospital. Furthermore, by integrating 2D Co-MOF nanosheets with image recognition and data processing function fixed on a smartphone, a portable test of ascorbic acid was reached. Schematic presentation of the preparation of two-dimensional Co-MOF nanosheet-based nanozyme and their application in portable detection of biomolecules.

Hydrogen-rich water attenuates the radiotoxicity induced by tritium exposure in vitro and in vivo.

Radionuclide tritium is widely used in the nuclear energy production industry and creates a threat to human health through radiation exposure. Herein, the radioactive elimination and radioprotective effect of hydrogen-rich water (HRW), a potential antioxidant with various medical applications, on tritiated water (HTO) exposure, was studied in vitro and in vivo. Results showed that intragastric administration of HRW effectively promoted the elimination of urinary tritium, decreased the level of serum tritium and tissue-bound tritium (OBT), and attenuated the genetic damage of blood cells in mice exposed to HTO (18.5 MBq/kg). Pretreatment with HRW effectively reduces tritium accumulation in HTO-treated human blood B lymphocyte AHH-1 cells. In addition, the anti-oxidative properties of HRW could attenuate the increased intracellular ROS (such as O2•-, •OH and ONOO-), resulting in reversing the exhaustion of cellular endogenous antioxidants (reduced GSH and SOD), decreasing lipid peroxidation (MDA), relieving DNA oxidative damage, and depressing cell apoptosis and cytotoxicity induced by HTO exposure. In conclusion, HRW is expected to be an effective radioactive elimination agent through the competition effect of isotope exchange or a radioprotective agent by scavenging free radicals induced by HTO exposure.

Hypolipidemia is associated with the severity of COVID-19.

BACKGROUND: Many patients with coronavirus disease 2019 (COVID-19) suffer multiple organ dysfunctions. However, whether patients develop dyslipidemia is unknown. OBJECTIVE: In this study, we aimed to investigate the pathological alterations of low-density lipoprotein cholesterol (LDL-c), high-density lipoprotein cholesterol (HDL-c), and total cholesterol (TC) in COVID-19 patients and their relationships with the disease severity. METHODS: A retrospective study was performed to examine serum levels of LDL-c, HDL-c, and TC on 597 COVID-19 patients (mild: 394; severe, 171; critical: 32) who were hospitalized in our center between February 1 and March 3, 2020. Age- and gender-matched normal subjects (n = 50) who had routine laboratory lipid tests between October 1 and November 1, 2019 in our center were included as the control group. RESULTS: LDL-c and TC levels were significantly lower in COVID-19 patients as compared with normal subjects (P < .001). There were significant and gradual decreases in levels of LDL-c (median (IQR) in mg/dL, mild: 91 (76, 104); severe: 86 (69, 102); critical: 69 (48, 81); P < .02) and TC (mild: 173 (148, 203); severe: 167 (138, 197); critical: 125 (95, 162); P < .05) across all three groups. HDL-c levels only decreased significantly in critical cases as compared with levels in mild and severe cases. LDL-c and TC levels inversely correlated with C-reactive protein and interleukin-6, and positively correlated with the number of lymphocytes in patients. CONCLUSIONS: Development of hypolipidemia begins in patients with mild symptoms. It progressively becomes worse in an association with the disease severity.

Elevations of serum cancer biomarkers correlate with severity of COVID-19.

In this retrospective study, we evaluated the levels of a series of serum biomarkers in coronavirus disease 2019 (COVID-19) patients (mild: 131; severe: 98; critical: 23). We found that there were significant increases in levels of human epididymis protein 4 (HE4) (73.6 ± 38.3 vs 46.5 ± 14.7 pmol/L; P < .001), cytokeratin-19 fragment (CYFRA21-1) (2.2 ± 0.9 vs 1.9 ± 0.8 µg/L; P < .001), carcinoembryonic antigen (CEA) (3.4 ± 2.2 vs 2.1 ± 1.2 µg/L; P < .001), carbohydrate antigens (CA) 125 (18.1 ± 13.5 vs 10.5 ± 4.6 µg/L; P < .001), and 153 (14.4 ± 8.9 vs 10.1 ± 4.4 µg/L; P < .001) in COVID-19 mild cases as compared to normal control subjects; their levels showed continuous and significant increases in severe and critical cases (HE4, CYFRA21-1, and CA125: P < .001; CEA and CA153: P < .01). Squamous cell carcinoma antigen (SCC) and CA199 increased significantly only in critical cases of COVID-19 as compared with mild and severe cases and normal controls (P < .01). There were positive associations between levels of C-reactive protein and levels of HE4 (R = .631; P < .001), CYFRA21-1 (R = .431; P < .001), CEA (R = .316; P < .001), SCC (R = .351; P < .001), CA153 (R = .359; P < .001) and CA125 (R = .223; P = .031). We concluded that elevations of serum cancer biomarkers positively correlated with the pathological progressions of COVID-19, demonstrating diffuse and acute pathophysiological injuries in COVID-19.

dTMP-GH Fusion Protein Therapy Improves Survival after Radiation Injury Combined with Skin-Burn Trauma in Mice.

Exposure to ionizing radiation combined with traumatic tissue injury is an important life-threatening condition found in the civilian populations after nuclear and radiological events. The significance feature of radiation combined injury (RCI) is the severe combined effect, which makes the injury more complicated. At present, there are limited measures available to treat RCI. Here we show that a chimeric protein dTMP-GH, fusing human growth hormone (hGH) with a tandem dimer of thrombopoietin mimetic peptide (dTMP), could be an effective therapy agent for RCI in a mice model. In this study, using a RCI mouse model exposed to 60Co γ-ray photons (6.0 Gy, 0.3 Gy/min) followed by a 20% total-body-surface-area burns (henceforth called: RB-CI) was established. Administration of dTMP-GH (200 ug/kg) for 10 consecutive days beginning at 24 h after injury improved survival rate during a 30-day observation period compared with the control vehicle group. dTMP-GH treatment also showed enhanced bone marrow hematopoiesis recovery determined by peripheral blood analysis and bone marrow histopathology. Meanwhile, dTMP-GH treatment accelerated skin wound closure and mitigated ileum injury in the RCI model. These results suggest that dTMP-GH may prove to be an effective therapeutic drug for RCI.

pT305-CaMKII stabilizes a learning-induced increase in AMPA receptors for ongoing memory consolidation after classical conditioning.

The role of CaMKII in learning-induced activation and trafficking of AMPA receptors (AMPARs) is well established. However, the link between the phosphorylation state of CaMKII and the agonist-triggered proteasomal degradation of AMPARs during memory consolidation remains unknown. Here we describe a novel CaMKII-dependent mechanism by which a learning-induced increase in AMPAR levels is stabilized for consolidation of associative long-term memory. Six hours after classical conditioning the levels of both autophosphorylated pT305-CaMKII and GluA1 type AMPAR subunits are significantly elevated in the ganglia containing the learning circuits of the snail Lymnaea stagnalis. CaMKIINtide treatment significantly reduces the learning-induced elevation of both pT305-CaMKII and GluA1 levels and impairs associative long-term memory. Inhibition of proteasomal activity offsets the deleterious effects of CaMKIINtide on both GluA1 levels and long-term memory. These findings suggest that increased levels of pT305-CaMKII play a role in AMPAR-dependent memory consolidation by reducing proteasomal degradation of GluA1 receptor subunits.

Role of pigment epithelium-derived factor in stem/progenitor cell-associated neovascularization.

Pigment epithelium-derived factor (PEDF) was first identified in retinal pigment epithelium cells. It is an endogenously produced protein that is widely expressed throughout the human body such as in the eyes, liver, heart, and adipose tissue; it exhibits multiple and varied biological activities. PEDF is a multifunctional protein with antiangiogenic, antitumorigenic, antioxidant, anti-inflammatory, antithrombotic, neurotrophic, and neuroprotective properties. More recently, PEDF has been shown to be the most potent inhibitor of stem/progenitor cell-associated neovascularization. Neovascularization is a complex process regulated by a large, interacting network of molecules from stem/progenitor cells. PEDF is also involved in the pathogenesis of angiogenic eye disease, tumor growth, and cardiovascular disease. Novel antiangiogenic agents with tolerable side effects are desired for the treatment of patients with various diseases. Here, we review the value of PEDF as an important endogenous antiangiogenic molecule; we focus on the recently identified role of PEDF as a possible new target molecule to influence stem/progenitor cell-related neovascularization.

Delayed intrinsic activation of an NMDA-independent CaM-kinase II in a critical time window is necessary for late consolidation of an associative memory.

Calcium/calmodulin-dependent kinases (CaM-kinases) are central to various forms of long-term memory (LTM) in a number of evolutionarily diverse organisms. However, it is still largely unknown what contributions specific CaM-kinases make to different phases of the same specific type of memory, such as acquisition, or early, intermediate, and late consolidation of associative LTM after classical conditioning. Here, we investigated the involvement of CaM-kinase II (CaMKII) in different phases of associative LTM induced by single-trial reward classical conditioning in Lymnaea, a well established invertebrate experimental system for studying molecular mechanisms of learning and memory. First, by using a general CaM-kinase inhibitor, KN-62, we found that CaM-kinase activation was necessary for acquisition and late consolidation, but not early or intermediate consolidation or retrieval of LTM. Then, we used Western blot-based phosphorylation assays and treatment with CaMKIINtide to identify CaMKII as the main CaM-kinase, the intrinsic activation of which, in a critical time window ( approximately 24 h after learning), is central to late consolidation of LTM. Additionally, using MK-801 and CaMKIINtide we found that acquisition was dependent on both NMDA receptor and CaMKII activation. However, unlike acquisition, CaMKII-dependent late memory consolidation does not require the activation of NMDA receptors. Our new findings support the notion that even apparently stable memory traces may undergo further molecular changes and identify NMDA-independent intrinsic activation of CaMKII as a mechanism underlying this "lingering consolidation." This process may facilitate the preservation of LTM in the face of protein turnover or active molecular processes that underlie forgetting.