Mangiferin alleviates diabetic pulmonary fibrosis in mice via inhibiting endothelial-mesenchymal transition through AMPK/FoxO3/SIRT3 axis

Diabetes mellitus results in numerous complications. Diabetic pulmonary fibrosis (DPF), a late pulmonary complication of diabetes, has not attracted as much attention as diabetic nephropathy and cardiomyopathy. Mangiferin (MF) is a natural small molecular compound that exhibits a variety of pharmacological effects including anti-inflammatory, anti-cancer, anti-diabetes, and anti-fibrosis effects. In this study, we investigated whether long-term diabetes shock induces DPF, and explored whether MF had a protective effect against DPF. We first examined the lung tissues and sections of 20 diabetic patients obtained from discarded lung surgical resection specimens and found that pulmonary fibrosis mainly accumulated around the pulmonary vessels, accompanied by significantly enhanced endothelial-mesenchymal transition (EndMT). We established a mouse model of DPF by STZ injections. Ten days after the final STZ injection, the mice were administered MF (20, 60 mg/kg, i.g.) every 3 days for 4 weeks, and kept feeding until 16 weeks and euthanized. We showed that pulmonary fibrotic lesions were developed in the diabetic mice, which began around the pulmonary vessels, while MF administration did not affect long-term blood glucose levels, but dose-dependently alleviated diabetes-induced pulmonary fibrosis. In human umbilical vein endothelial cells (HUVECs), exposure to high glucose (33.3 mM) induced EndMT, which was dose-dependently inhibited by treatment with MF (10, 50 μM). Furthermore, MF treatment promoted SIRT3 expression in high glucose-exposed HUVECs by directly binding to AMPK to enhance the activity of FoxO3, which finally reversed diabetes-induced EndMT. We conclude that MF attenuates DPF by inhibiting EndMT through the AMPK/FoxO3/SIRT3 axis. MF could be a potential candidate for the early prevention and treatment of DPF.

Tectorigenin protects against cardiac fibrosis in diabetic mice heart via activating the adiponectin receptor 1-mediated AMPK pathway

Diabetic cardiomyopathy (DCM) is a common severe complication of diabetes that occurs independently of hypertension, coronary artery disease, and valvular cardiomyopathy, eventually leading to heart failure. Previous studies have reported that Tectorigenin (TEC) possesses extensive anti-inflammatory and anti-oxidative stress properties. In this present study, the impact of TEC on diabetic cardiomyopathy was examined. The model of DCM in mice was established with the combination of a high-fat diet and STZ treatment. Remarkably, TEC treatment significantly attenuated cardiac fibrosis and improved cardiac dysfunction. Concurrently, TEC was also found to mitigate hyperglycemia and hyperlipidemia in the DCM mouse. At the molecular level, TEC is involved in the activation of AMPK, both in vitro and in vivo, by enhancing its phosphorylation. This is achieved through the regulation of endothelial-mesenchymal transition via the AMPK/TGFβ/Smad3 pathway. Furthermore, it was demonstrated that the level of ubiquitination of the adiponectin receptor 1 (AdipoR1) protein is associated with TEC-mediated improvement of cardiac dysfunction in DCM mice. Notably the substantial reduction of myocardial fibrosis. In conclusion, TEC improves cardiac fibrosis in DCM mice by modulating the AdipoR1/AMPK signaling pathway. These findings suggest that TEC could be an effective therapeutic agent for the treatment of diabetic cardiomyopathy.

Macrod1 suppresses diabetic cardiomyopathy via regulating PARP1-NAD+-SIRT3 pathway

Diabetic cardiomyopathy (DCM), one of the most serious long-term consequences of diabetes, is closely associated with oxidative stress, inflammation and apoptosis in the heart. MACRO domain containing 1 (Macrod1) is an ADP-ribosylhydrolase 1 that is highly enriched in mitochondria, participating in the pathogenesis of cardiovascular diseases. In this study, we investigated the role of Macrod1 in DCM. A mice model was established by feeding a high-fat diet (HFD) and intraperitoneal injection of streptozotocin (STZ). We showed that Macrod1 expression levels were significantly downregulated in cardiac tissue of DCM mice. Reduced expression of Macrod1 was also observed in neonatal rat cardiomyocytes (NRCMs) treated with palmitic acid (PA, 400 μM) in vitro. Knockout of Macrod1 in DCM mice not only worsened glycemic control, but also aggravated cardiac remodeling, mitochondrial dysfunction, NAD+ consumption and oxidative stress, whereas cardiac-specific overexpression of Macrod1 partially reversed these pathological processes. In PA-treated NRCMs, overexpression of Macrod1 significantly inhibited PARP1 expression and restored NAD+ levels, activating SIRT3 to resist oxidative stress. Supplementation with the NAD+ precursor Niacin (50 μM) alleviated oxidative stress in PA-stimulated cardiomyocytes. We revealed that Macrod1 reduced NAD+ consumption by inhibiting PARP1 expression, thereby activating SIRT3 and anti-oxidative stress signaling. This study identifies Macrod1 as a novel target for DCM treatment. Targeting the PARP1-NAD+-SIRT3 axis may open a novel avenue to development of new intervention strategies in DCM. Schematic illustration of macrod1 ameliorating diabetic cardiomyopathy oxidative stress via PARP1-NAD+-SIRT3 axis.

ADP-ribosylation: An emerging direction for disease treatment

ADP-ribosylation (ADPr) is a dynamically reversible post-translational modification (PTM) driven primarily by ADP-ribosyltransferases (ADPRTs or ARTs), which have ADP-ribosyl transfer activity. ADPr modification is involved in signaling pathways, DNA damage repair, metabolism, immunity, and inflammation. In recent years, several studies have revealed that new targets or treatments for tumors, cardiovascular diseases, neuromuscular diseases and infectious diseases can be explored by regulating ADPr. Here, we review the recent research progress on ART-mediated ADP-ribosylation and the latest findings in the diagnosis and treatment of related diseases.

[Clinicopathologic characteristics and prognostic analysis of testicular diffuse large B-cell lymphoma]

Objective: To analyze the clinicopathologic characteristics and prognosis of testicular diffuse large B-cell lymphoma (DLBCL) . Methods: A retrospective analysis was performed on 68 patients with testicular DLBCL admitted to Ruijin Hospital affiliated to Shanghai Jiao Tong University School of Medicine from October 2001 to April 2020. The gene mutation profile was evaluated by targeted sequencing (55 lymphoma-related genes) , and prognostic factors were analyzed. Results: A total of 68 patients were included, of whom 45 (66.2% ) had primary testicular DLBCL and 23 (33.8% ) had secondary testicular DLBCL. The proportion of secondary testicular DLBCL patients with Ann Arbor stage Ⅲ-Ⅳ (P<0.001) , elevated LDH (P<0.001) , ECOG score ≥ 2 points (P=0.005) , and IPI score 3-5 points (P<0.001) is higher than that of primary testicular DLBCL patients. Sixty-two (91% ) patients received rituximab in combination with cyclophosphamide, adriamycin, vincristine, and prednisone (R-CHOP) -based first-line regimen, whereas 54 cases (79% ) underwent orchiectomy prior to chemotherapy. Patients with secondary testicular DLBCL had a lower estimated 5-year progression-free survival (PFS) rate (16.5% vs 68.1% , P<0.001) and 5-year overall survival (OS) rate (63.4% vs 74.9% , P=0.008) than those with primary testicular DLBCL, and their complete remission rate (57% vs 91% , P=0.003) was also lower than that of primary testicular DLBCL. The ECOG scores of ≥2 (PFS: P=0.018; OS: P<0.001) , Ann Arbor stages Ⅲ-Ⅳ (PFS: P<0.001; OS: P=0.018) , increased LDH levels (PFS: P=0.015; OS: P=0.006) , and multiple extra-nodal involvements (PFS: P<0.001; OS: P=0.013) were poor prognostic factors in testicular DLBCL. Targeted sequencing data in 20 patients with testicular DLBCL showed that the mutation frequencies of ≥20% were PIM1 (12 cases, 60% ) , MYD88 (11 cases, 55% ) , CD79B (9 cases, 45% ) , CREBBP (5 cases, 25% ) , KMT2D (5 cases, 25% ) , ATM (4 cases, 20% ) , and BTG2 (4 cases, 20% ) . The frequency of mutations in KMT2D in patients with secondary testicular DLBCL was higher than that in patients with primary testicular DLBCL (66.7% vs 7.1% , P=0.014) and was associated with a lower 5-year PFS rate in patients with testicular DLBCL (P=0.019) . Conclusion: Patients with secondary testicular DLBCL had worse PFS and OS than those with primary testicular DLBCL. The ECOG scores of ≥2, Ann Arbor stages Ⅲ-Ⅳ, increased LDH levels, and multiple extra-nodal involvements were poor prognostic factors in testicular DLBCL. PIM1, MYD88, CD79B, CREBBP, KMT2D, ATM, and BTG2 were commonly mutated genes in testicular DLBCL, and the prognosis of patients with KMT2D mutations was poor.

Limonin stabilises SIRT6 by activating USP10 in cardiac hypertrophy

BACKGROUND AND PURPOSE

Limonin, a natural tetracyclic triterpenoid extract, exerts extensive pharmacological effects; however, its role in cardiac hypertrophy remains to be elucidated. We investigated the beneficial effects of limonin on cardiac hypertrophy and explored the potential mechanisms.

EXPERIMENTAL APPROACH

C57/BL6 male mice were subjected to aortic banding (AB) surgery and neonatal rat cardiac myocytes (NRCMs) were stimulated with phenylephrine (PE) to evaluate the effects of limonin on cardiac hypertrophy.

KEY RESULTS

Limonin markedly improved the cardiac function and heart weight in AB operation mice. In addition, limonin-treated mice and NRCMs produced fewer cardiac hypertrophy markers than those treated with the vehicle in hypertrophic groups. Sustained AB- or PE-stimulation impaired cardiac sirtuin 6 (SIRT6) protein levels, which were partially rescued by limonin and subsequently enhanced the activity of PPARα, and Sirt6 siRNA inhibited the anti-hypertrophic effects of limonin in vitro. Interestingly, limonin did not influence Sirt6 mRNA levels, but controlled its ubiquitin levels. Thus, the protein biosynthesis inhibitor, cycloheximide (CHX), and proteasome inhibitor, MG-132, were used to determine SIRT6 protein expression levels. Under PE stimulation, limonin increased SIRT6 protein levels in the presence of CHX, but it didn't influence SIRT6 expression in the presence of MG-132, suggesting that limonin promotes SIRT6 abundance by inhibiting its ubiquitination degradation. Furthermore, limonin inhibited the degradation of SIRT6 by activating ubiquitin-specific peptidase (Cuspidi et al.)-10, while USP10 siRNA abrogated the beneficial effects of limonin.

CONCLUSION AND IMPLICATIONS

Limonin mediates the ubiquitination and degradation of SIRT6 by activating USP10, providing an attractive therapeutic target for cardiac hypertrophy.

[Peripheral small airway dysfunction differences between idiopathic pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension]

Objective: To investigate the peripheral small airway dysfunction differences between idiopathic pulmonary arterial hypertension (IPAH) and chronic thromboembolic pulmonary hypertension (CTEPH). Methods: Impulse oscillmetory system testing (IOS) and pulmonary function testing (PFT) were performed in IPAH and CTEPH patients and 30 healthy control group. We also carried out a subgroup analysis depending on their medical history of airway diseases. Results: We included 42 IPAH and 47 CTEPH patients (with or without airways disease: 8 vs. 34 and 17 vs. 34, respectively). Compared with CTEPH patients, IPAH patients were younger but had more serious pulmonary vessel resistance and mean pulmonary arterial resistance. Compared with IPAH patients, CTEPH patients had significant impaired peripheral small airway dysfunction with decreased of MEF(50) (% pred), MMEF(75/25) evaluated by PFT and R5-R20, Δ R5-R20 and AX measured by IOS [10.6(2.0, 33.0) vs. 2.5(-5.0, 16.5); 22.1(14.0, 32.6) vs. 15.5 (7.0, 23.2); 7.64(4, 18.6) vs. 6(3, 11) respectively, all P<0.05]. Subgroup analysis revealed there were no significant peripheral small dysfunction differences in IPAH patients with or without airway diseases. CTEPH patients had a higher proportion of airway diseases and more serious peripheral dysfunction than IPAH patients with airway diseases. Compared with control healthy group, peripheral airway dysfunction was more obvious even in IPAH and CTEPH patients without airway diseases. Conclusion: Compared with IPAH, CTEPH patients were older, but had better hemodynamics and a higher proportion of airway diseases. The peripheral airway dysfunction were more serious in CTEPH patients without airway diseases than IPAH patients without airway diseases and healthy controls group.

Effects of dietary Lactobacillus rhamnosus CF supplementation on growth, meat quality, and microenvironment in specific pathogen-free chickens

The probiotic effects of Lactobacillus rhamnosus strain CF (Chen Fu) on growth performance, meat quality, and microenvironment in specific pathogen-free (SPF) chickens were investigated and compared with Enterococcus faecium. One-hundred-eighty 7-day-old SPF chickens were randomly assigned into 3 groups with 3 replicate pens of 20 chickens each. Group 1 served as a control that was fed a basal diet without probiotics supplementation. Groups 2 and 3 were fed the basal diet supplemented with L. rhamnosus CF and E. faecium, respectively. On d 12 and 24, BW, ADG, feed conversion ratio (FCR), dressing percentage (DP), and apparent digestibility of crude protein (AD-CP) were calculated. Meat color, fat content, shear force, water content, and pH value of breast and thigh muscles; ammonia, urea nitrogen, and uric acid content in plasma; pH value, Enterococcus, Lactobacillus, and E. coli in ceca; and ammonia emission were determined. Compared with group 1, group 2 exhibited higher BW, ADG, AD-CP, DP, cecal Lactobacilli, and muscle fat content (P < 0.05) as well as lower FCR, muscle water content, plasma ammonia, pH value, E. coli, and Enterococcus in ceca, and ammonia emission (P < 0.05), and group 3 exhibited higher BW, ADG, AD-CP, DP, and muscle fat content (P < 0.05), as well as lower FCR, meat color, plasma ammonia, E. coli and Enterococcus in ceca, and ammonia emission (d 24) (P < 0.05). Compared with group 3, group 2 exhibited lower plasma ammonia level, E. coli, and pH value in ceca and ammonia emission (P < 0.05) and higher AD-CP, meat color, pH value in thigh muscles, fat content in breast muscles, and number of Lactobacillus in ceca (P < 0.05). Thus, L. rhamnosus CF improves growth performance, meat quality, and microenvironment and is a potential probiotic additive in chickens.

[Clinical and imaging features of pulmonary veno-occlusive disease and pulmonary capillary hemangioma]

Objective: To improve the diagnosis and treatment of the pulmonary veno-occlusive disease (PVOD) and pulmonary capillary hemangioma (PCH). Methods: The clinical features, radiological findings, laboratory testing and treatment in 8 cases of PVOD/PCH which was diagnosed from 2013 to 2017 were described. Results: PVOD/PCH was rare. The clinical symptoms were easily confused with IPAH, but the decrease of hypoxemia, clubbing, D(L)CO were more obvious, and the imaging features of HRCT were helpful for PVOD/PCH diagnosis. Combined with gene testing, it was helpful to diagnose PVOD/PCH and avoid the risk of surgical biopsy. Conclusion: PVOD and PCH are rare type of pulmonary vascular diseases. According to clinical manifestations, physical examination, pulmonary function test results, HRCT imaging, CPET and gene detection results, PVOD or PCH can be diagnosed.

Effect of cyclosporin A particles of varying diameters on gastric cancer cell apoptosis

Human health is significantly threatened by gastric cancer, which is the most common malignant tumor; although drastic, surgery is currently the only way to cure it. However, high recurrence rates and low survival rates are associated with the disease. Therefore, to improve the effectiveness of gastric cancer treatment and to increase the clinical cure rate, we investigated the effect of cyclosporin A particles of varying diameter on gastric cancer cell apoptosis. Flow cytometry was used to detect apoptosis induced by Annexin V-fluorescein isothiocyanate/propidium iodide-double labeling. We also determined the content of reactive oxygen species and the expression level of P-glycoprotein in cells after treatment with cyclosporin A. The results indicated that increases in the concentration and action time of cyclosporin A were associated with statistically significant increases in the apoptosis rate of gastric cancer cells when the experimental and control groups were compared (P < 0.05 and P < 0.01, respectively). In conclusion, during a certain action time and concentration range, cyclosporin A inhibits the proliferation of human gastric cancer cells and can induce their apoptosis.

Expression and preliminary characterization of recombinant human tissue kallikrein in egg white of laying hens

Human tissue kallikrein (hK1) plays an important role in regulation of blood pressure, electrolyte and glucose transport, and renal function. To evaluate the feasibility of expression of recombinant human tissue kallikrein (rhK1) in the egg whites of laying hens, human tissue kallikrein gene (hKLK1) cDNA was subcloned into the chicken oviduct-specific expression vector (pOV3), and the resultant recombinant vector pOV3K was injected into laying hens via wing vein after mixing with polyethyleneimine. Following injection twice with the recombinant vector, the enzymatic activity at a maximal level of 59 U/mL was detected in the egg whites, which lasted for more than 7 d. The expression level of rhK1 in the egg whites in the 3-mg group was relatively higher than that in the 2-mg group, but the significant differences were identified on d 7 and 8 (P < 0.05). Ten days after the primary injection, the hens were reinjected with the same dose of the vector, and even higher enzymatic activity was detected in their egg whites. Two different breeds of hen were tested with no difference in expression level found (P > 0.05). Western blot analysis of the egg whites from vector-injected hens showed the rhK1 was recognized by a polyclonal antibody specific for hK1 with molecular weights of 37 and 43 kDa, which probably corresponded to the mature and preenzyme, respectively. Biochemical studies showed that the recombinant enzyme had a similar thermostability, optimal pH, hypotensive effect, and sensitivity to different ions to the natural enzymes in human and porcine tissues. These data indicate that the chicken oviduct-specific transient expression system can produce relatively high level and authentic recombinant enzyme with a potential for further development for therapeutic use.

Specific regional transcription of apolipoprotein E in human brain neurons

In central nervous system injury and disease, apolipoprotein E (APOE, gene; apoE, protein) might be involved in neuronal injury and death indirectly through extracellular effects and/or more directly through intracellular effects on neuronal metabolism. Although intracellular effects could clearly be mediated by neuronal uptake of extracellular apoE, recent experiments in injury models in normal rodents and in mice transgenic for the human APOE gene suggest the additional possibility of intraneuronal synthesis. To examine whether APOE might be synthesized by human neurons, we performed in situ hybridization on paraffin-embedded and frozen brain sections from three nondemented controls and five Alzheimer's disease (AD) patients using digoxigenin-labeled antisense and sense cRNA probes to human APOE. Using the antisense APOE probes, we found the expected strong hybridization signal in glial cells as well as a generally fainter signal in selected neurons in cerebral cortex and hippocampus. In hippocampus, many APOE mRNA-containing neurons were observed in sectors CA1 to CA4 and the granule cell layer of the dentate gyrus. In these regions, APOE mRNA containing neurons could be observed adjacent to nonhybridizing neurons of the same cell class. APOE mRNA transcription in neurons is regionally specific. In cerebellar cortex, APOE mRNA was seen only in Bergmann glial cells and scattered astrocytes but not in Purkinje cells or granule cell neurons. ApoE immunocytochemical localization in semi-adjacent sections supported the selectivity of APOE transcription. These results demonstrate the expected result that APOE mRNA is transcribed and expressed in glial cells in human brain. The important new finding is that APOE mRNA is also transcribed and expressed in many neurons in frontal cortex and human hippocampus but not in neurons of cerebellar cortex from the same brains. This regionally specific human APOE gene expression suggests that synthesis of apoE might play a role in regional vulnerability of neurons in AD. These results also provide a direct anatomical context for hypotheses proposing a role for apoE isoforms on neuronal cytoskeletal stability and metabolism.

Sialylated human apolipoprotein E (apoEs) is preferentially associated with neuron-enriched cultures from APOE transgenic mice

Mice transgenic for human APOE2, E3, and E4 alleles express native 34-kDa human apoE and two sialylated apoE isoproteins with approximate molecular weights of 37 kDa (apoEs) and 39 kDa (apoEs2) in brain. These multiple apoE/apoEs/apoEs2 band patterns on Western blot are also observed in human brain, but are not seen in wild-type mouse brain. Both the 37-kDa apoEs and 39-kDa apoEs2 are coprecipitated with native 34-kDa apoE by antibody to human apoE. Neuraminidase digestion eliminates the 37- and 39-kDa forms and results in a downward shift in the bands to the position of the 34-kDa native form. These sialylated apoE isoproteins are found preferentially associated with neurons and contribute significantly (50-60%) to the total neuronal apoE in neuronal cultures from transgenic mice, while only 5-10% of total apoE is sialylated in cultures enriched in glial cells. In situ hybridization and immunocytochemistry demonstrate apoE mRNA and apoE immunoreactivity are predominantly located in cell soma of neurons, not in neuronal processes.

Regionally specific neuronal expression of human APOE gene in transgenic mice

Apolipoprotein E (APOE, gene; apoE, protein) is a susceptibility gene for late-onset Alzheimer's disease (AD). To examine whether neurons can synthesize apoE, we performed in situ hybridization on brain tissue of transgenic mice carrying genomic constructs for the three major human APOE alleles. We find human APOE mRNA in glial cells of cerebellum, striatum and cerebral cortex and also in neurons of cerebral cortex, corresponding to apoE localization in humans. Synthesis of apoE by neurons implies that models of AD may need to consider intrinsic apoE production in addition to uptake. Inclusion of human regulatory sequences may result in more realistic transgenic models of human disease.

Human apolipoprotein E2, E3, and E4 isoform-specific transgenic mice: human-like pattern of glial and neuronal immunoreactivity in central nervous system not observed in wild-type mice

Apolipoprotein E (apoE) and its three major alleles (APOE2, E3, and E4) have been implicated in Alzheimer's disease and other neurological disorders. Little is known of the role apoE plays in normal brain function and pathology. To create a model to study apoE in brain, we have generated APOE transgenic mice using microinjection of allele-specific human genomic fragments to establish founders which were then bred to APOE knockout mice lacking a functional mouse apoE protein. This allows the study of apoE without interference from the endogenous mouse APOE gene. Results demonstrate that transgenic lines have been established that transcribe and express apoE appropriately in brain, liver, and other tissues. High cholesterol levels found in APOE knockout mice are substantially corrected in the APOE transgenic lines. ApoE immunoreactivity has been detected in glial cells and selected classes of neurons in all three isoform-specific transgenics. This pattern of immunoreactivity is similar to that observed in nonhuman primates and man, and contrasts with the strictly glial staining pattern of normal rodents.

Antigenic difference between viral strains causing classical and mild types of epidemic hemorrhagic fever with renal syndrome in China

The antigenic relationship between viral isolates from Apodemus and Rattus that appear to cause the classical and mild types of epidemic hemorrhagic fever (EHF) in China was studied by cross-immunofluorescence, cross-neutralization, immunofluorescence blocking tests, and cross-enzyme-linked immunosorbent assay (ELISA). Obvious antigenic diversity between the isolates was demonstrated by cross-neutralization, immunofluorescence blocking tests, and cross-ELISA. Antisera from patients with classical EHF neutralized viruses of both types to a similar degree, but antisera from patients with mild EHF showed little neutralization of apodemus virus. Similarly, antisera from classical EHF blocked immunofluorescence by monoclonal antibody (25-1 McAb) derived from apodemus virus to both viral antigens, but antisera from mild EHF gave only low-grade blocking against apodemus viral antigen. Direct antigenic titrations of both viral strains by cross-ELISA yielded similar results. That distinct antigenic differences exist between viral strains causing these two types of EHF might be of great importance to the serological differentiation of the viruses and the study of EHF vaccine.