ITGAM-mediated macrophages contribute to basement membrane damage in diabetic nephropathy and atherosclerosis.

BACKGROUND: Diabetic nephropathy (DN) and atherosclerosis (AS) are prevalent and severe complications associated with diabetes, exhibiting lesions in the basement membrane, an essential component found within the glomerulus, tubules, and arteries. These lesions contribute significantly to the progression of both diseases, however, the precise underlying mechanisms, as well as any potential shared pathogenic processes between them, remain elusive. METHODS: Our study analyzed transcriptomic profiles from DN and AS patients, sourced from the Gene Expression Omnibus database. A combination of integrated bioinformatics approaches and machine learning models were deployed to identify crucial genes connected to basement membrane lesions in both conditions. The role of integrin subunit alpha M (ITGAM) was further explored using immune infiltration analysis and genetic correlation studies. Single-cell sequencing analysis was employed to delineate the expression of ITGAM across different cell types within DN and AS tissues. RESULTS: Our analyses identified ITGAM as a key gene involved in basement membrane alterations and revealed its primary expression within macrophages in both DN and AS. ITGAM was significantly correlated with tissue immune infiltration within these diseases. Furthermore, the expression of genes encoding core components of the basement membrane was influenced by the expression level of ITGAM. CONCLUSION: Our findings suggest that macrophages may contribute to basement membrane lesions in DN and AS through the action of ITGAM. Moreover, therapeutic strategies that target ITGAM may offer potential avenues to mitigate basement membrane lesions in these two diabetes-related complications.

Fisetin treatment alleviates kidney injury in mice with diabetes-exacerbated atherosclerosis through inhibiting CD36/fibrosis pathway.

Diabetes-related vascular complications include diabetic cardiovascular diseases (CVD), diabetic nephropathy (DN) and diabetic retinopathy, etc. DN can promote the process of end-stage renal disease. On the other hand, atherosclerosis accelerates kidney damage. It is really an urge to explore the mechanisms of diabetes-exacerbated atherosclerosis as well as new agents for treatment of diabetes-exacerbated atherosclerosis and the complications. In this study we investigated the therapeutic effects of fisetin, a natural flavonoid from fruits and vegetables, on kidney injury caused by streptozotocin (STZ)-induced diabetic atherosclerosis in low density lipoprotein receptor deficient (LDLR-/-) mice. Diabetes was induced in LDLR-/- mice by injecting STZ, and the mice were fed high-fat diet (HFD) containing fisetin for 12 weeks. We found that fisetin treatment effectively attenuated diabetes-exacerbated atherosclerosis. Furthermore, we showed that fisetin treatment significantly ameliorated atherosclerosis-enhanced diabetic kidney injury, evidenced by regulating uric acid, urea and creatinine levels in urine and serum, and ameliorating morphological damages and fibrosis in the kidney. In addition, we found that the improvement of glomerular function by fisetin was mediated by reducing the production of reactive oxygen species (ROS), advanced glycosylation end products (AGEs) and inflammatory cytokines. Furthermore, fisetin treatment reduced accumulation of extracellular matrix (ECM) in the kidney by inhibiting the expression of vascular endothelial growth factor A (VEGFA), fibronectin and collagens, while enhancing matrix metalloproteinases 2 (MMP2) and MMP9, which was mainly mediated by inactivating transforming growth factor ß (TGFß)/SMAD family member 2/3 (Smad2/3) pathways. In both in vivo and in vitro experiments, we demonstrated that the therapeutic effects of fisetin on kidney fibrosis resulted from inhibiting CD36 expression. In conclusion, our results suggest that fisetin is a promising natural agent for the treatment of renal injury caused by diabetes and atherosclerosis. We reveal that fisetin is an inhibitor of CD36 for reducing the progression of kidney fibrosis, and fisetin-regulated CD36 may be a therapeutic target for the treatment of renal fibrosis.

A Class of Disulfide Compounds Suppresses Ferroptosis by Stabilizing GPX4.

Ferroptosis is a nonapoptotic form of cell death characterized by iron-dependent lipid peroxidation and has been implicated in multiple pathological conditions. Glutathione peroxidase 4 (GPX4) plays an essential role in inhibiting ferroptosis by eliminating lipid peroxide using glutathione (GSH) as a reductant. In this study, we found Ellman's reagent DTNB and a series of disulfide compounds, including disulfiram (DSF), an FDA-approved drug, which protect cells from erastin-induced ferroptosis. Mechanistically, DTNB or DSF is conjugated to multiple cysteine residues in GPX4 and disrupts GPX4 interaction with HSC70, an adaptor protein for chaperone mediated autophagy, thus preventing GPX4 degradation induced by erastin. In addition, DSF ameliorates concanavalin A induced acute liver injury by suppressing ferroptosis in a mouse model. Our work reveals a novel regulatory mechanism for GPX4 protein stability control. We also discover disulfide compounds as a new class of ferroptosis inhibitors and suggest therapeutic repurposing of DSF in treating ferroptosis-related diseases.

The oncometabolite 2-hydroxyglutarate produced by mutant IDH1 sensitizes cells to ferroptosis.

Ferroptosis is a non-apoptotic form of cell death characterized by the iron-dependent lipid peroxidation and is implicated in several human pathologies, such as tissue ischemia, neurodegeneration, and cancer. Ferroptosis appears to be high cell-context dependent and the regulation of ferroptosis by physiological or pathological conditions are unclear. Here, we report that tumor-derived IDH1 mutation sensitizes cells to ferroptosis. Deletion of the mutant IDH1 allele in IDH1 heterozygous tumor cells or pharmacological inhibition of mutant IDH1 to produce the oncometabolite D-2-hydroxyglutarate (D-2-HG) confers resistance to erastin-induced ferroptosis. Conversely, ectopic expression of mutant IDH1 or treatment of cells with cell-permeable D-2-HG promotes the accumulation of lipid reactive oxygen species (ROS) and subsequently ferroptosis. Mechanistically, mutant IDH1 reduces the protein level of the glutathione peroxidase 4 (GPX4), a key enzyme in removing lipid ROS and ferroptosis, and promotes depletion of glutathione. Our results uncover a new role of mutant IDH1 and 2-HG in ferroptosis.

Antitumor effect of a short peptide on p53-null SKOV3 ovarian cancer cells.

Fibroblast growth factor-2 (FGF2) is a protein ligand, which exerts essential roles in development, angiogenesis, and tumor progression via activation of the downstream signaling cascades. Accumulating evidence has demonstrated that FGF2 is involved in the progression of ovarian cancer, providing a novel potential target for ovarian cancer therapy. In this study, we showed that FGF2 is significantly increased in ovarian tumors, and is negatively associated with the overall survival of ovarian cancer by database analysis. A short peptide obtained from a heptapeptide phage display library suppressed FGF2-induced proliferation, migration, and invasion of the p53-null epithelial ovarian cancer (EOC) cells. Further investigations revealed that the short peptide antagonized the effects of FGF2 on G0/G1 to S cell phase promotion, cyclin D1 expression, and MAPK and Akt signaling activation, which might contribute to the mechanism underlying the inhibitory effects of the short peptide on the aggressive phenotype of the ovarian cancer cells triggered by FGF2. Moreover, the short peptide might have the potentials of reversing FGF2-induced resistance to the doxorubicin via downregulation of the antiapoptotic proteins and counteracting of the antiapoptotic effects of FGF2 on p53-null EOC cells. Taken together, the short peptide targeting FGF2 may provide a novel strategy for improving the therapeutic efficiency in a subset of EOC.

Cisplatin induces chemoresistance through the PTGS2-mediated anti-apoptosis in gastric cancer.

It has been proposed that the aberrant expressions of the classical apoptosis-related genes and the subsequent decrease of apoptosis contribute to the development of cisplatin resistance in gastric cancer. However, little is known about the correlation and the molecular regulation mechanisms of cisplatin and the apoptosis-related gene expressions. Herein, we first identified the expressions of the anti-apoptotic BCL2 and the prostaglandin-endoperoxide synthase-2 (PTGS2) genes, which were abundant in the gastric carcinoma and associated with poor patient survival, were closely related with the resistance against cisplatin. Further investigations revealed that PTGS2 served as an essential mediator involved in the developing process of the resistance against cisplatin via mediating the inhibition effects of cisplatin on BCL2 expression. Mechanistically, cisplatin induced PTGS2 expression through ROS/NF-κB pathway. In addition, PTGS2 mediated cisplatin-induced BCL2 expression and subsequent resistance to apoptosis via PGE2/EP4/MAPKs (ERK1/2, P38) axis. Analysis of the clinical specimens demonstrated that PTGS2 and BCL2 were positively correlated in human gastric cancer. Moreover, in the xenograft models, inhibition of PTGS2 by celecoxib significantly augmented the cytotoxic efficacy of cisplatin in the resistant gastric cancer via suppression of PTGS2 and BCL2 expressions regulated by ERK1/2 and P38 signal axis, suggesting PTGS2 might be employed as an adjunctive therapeutic target for reversal of the chemoresistance in a subset of cisplatin resistant gastric cancer.

Identification of a crucial amino acid responsible for the loss of specifying FGFR1-KLB affinity of the iodinated FGF21.

Previous studies suggest that specific binding to the complex consisting of fibroblast growth factor receptor-1 (FGFR1) and the coreceptor beta-Klotho (KLB) is the premise for human FGF19 and FGF21 activating the downstream signaling cascades, and regulating the metabolic homeostasis. However, it was found that human FGF21 loses its ability to bind to FGFR1-KLB after iodination with Na125 I and chloramine T, whereas human FGF19 retained its affinity for FGFR1-KLB even after iodination. The molecular mechanisms underlying these differences remained elusive. In this study, we first demonstrated that an intramolecular disulfide bond was formed between cysteine-102 and cysteine-121 in FGF21, implying that the oxidation of the cysteine to cysteic acid, which may interfere with the active conformation of FGF21, did not occur during the iodination procedures, and thus ruled out the possibility of the two conserved cysteine residues mediating the loss of FGF21 binding affinity to FGFR1-KLB upon iodination. Site-directed mutagenesis and molecular modeling were further applied to determine the residue(s) responsible for the loss of FGFR1-KLB affinity. The results showed that mutation of a single tyrosine-207, but not the other five tyrosine residues in FGF21, to a phenylalanine retained the FGFR1-KLB affinity of FGF21 even after iodination, whereas replacing the corresponding phenylalanine residue with tyrosine in FGF19 did not alter its binding affinity to FGFR1-KLB, but decreased the receptor binding ability of the iodinated protein, suggesting that tyrosine-207 is the crucial amino acid responsible for the loss of specifying FGFR1-KLB affinity of the iodinated FGF21.

[Expression and significance of pericytes and TGF-ß in infantile parotid hemangioma].

PURPOSE: To study the expression and significance of pericytes and TGF-ß in infantile parotid hemangioma. METHODS: The expressions of pericytes and TGF-ß at protein level were examined in 76 cases of infant parotid hemangioma by strep avidin-biotin complex (SABC) immunohistochemical technique. All statistical analysis were performed using SPSS 13.0 statistical package. The relationship between the expression of pericytes and TGF-ß and clinical phase of hemangioma was analyzed by using Chi-square test. Kappa test was used to determine the relationship between pericytes and TGF-ß expression. RESULTS: The rates of positive expression of pericytes were 86.7%(13/15), 45.5%(10/22) and 51.3%(20/39) in early, middle and advanced stage of hemangioma, respectively. The rates of positive expression of TGF-ß were 33.3%(5/15), 40.9%(9/22) and 76.9%(30/39) in early, middle and advanced stage of hemangioma, respectively. There was significantly close correlation between the level of pericytes and clinical phase of hemangioma, as well as between TGF-ß expression and clinical phase of hemangioma(P<0.05). CONCLUSION: Pericytes and TGF-ß may significantly contribute to the proliferation of infantile parotid hemangioma.

[Expression of ERK and nm23-H1 in tongue squamous cell carcinoma and its relation with invasion and metastasis].

PURPOSE: To reveal the relations between expression of extracellular signal-regulated kinase (ERK) and nm23-H1 and tumor invasion and metastasis in tongue squamous cell carcinoma (TSCC). METHODS: The expression of ERK and nm23-H1 at protein level was examined in 74 cases of TSCC by strep avidin-biotin complex (SABC) immunohistochemical technique. SPSS10.0 software package was used for data analysis. RESULTS: The expression of ERK was positively related to TNM clinical stage and cervical lymph node metastasis. The expression of nm23-H1 was negatively related to TNM clinical stage and cervical lymph node metastasis. The expression of ERK had a negative correlation with the expression of nm23-H1. TSCC cases with ERK(+)/nm23-H1(-) revealed significant higher tendency to cervical lymph node metastasis than those with ERK(-)/nm23-H1(+). CONCLUSION: The expression of ERK and nm23-H1 is correlated with invasion and cervical lymph node metastasis in TSCC.

BRAFV600E mutation and X-linked inhibitor of apoptosis expression in papillary thyroid carcinoma.

BACKGROUND: The BRAF mutation V600E (BRAF(V600E)) is the most common genetic alteration in papillary thyroid carcinoma (PTC), while overexpression of X-linked inhibitor of apoptosis (XIAP) has been found in various tumors. Both of these events are implicated in carcinogenesis, tumor progression, recurrence, etc. There are few reports, however, of the BRAF(V600E) mutation and XIAP overexpression in PTC patients. The aim of this study was to investigate the frequency of the BRAF(V600E) mutation in PTC and its relationship to clinicopathological parameters and the expression of XIAP. METHODS: Genomic DNA was extracted from 123 paraffin-embedded PTC tumor tissue samples and amplified for analysis of the V600E mutation in exon 15 of the BRAF gene by polymerase chain reaction. XIAP expression was examined by immunohistochemical methods in 46 PTCs, 18 benign nodular goiters, and 10 Hashimoto's thyroiditis samples. RESULTS: The BRAF(V600E) mutation was found in 34.1% of PTC, and was especially prevalent in the classic type. BRAF(V600E) was significantly correlated with younger age at diagnosis (p = 0.026), tumor size (p = 0.009), and histological variants (p = 0.024). There was a trend towards association with extrathyroidal invasion (p = 0.067). By logistic regression analysis, a significant relationship was found between tumor size and the BRAF(V600E) mutation (p = 0.03). XIAP was expressed in 82.6% of PTCs, which was a higher percentage than observed in the group of benign thyroid disorders (35.7%, p < 0.001). Neither the intensity (p = 0.611) nor the extent (p = 0.723) of XIAP staining was correlated with the presence of BRAF(V600E) in PTC patients. CONCLUSIONS: These data indicate that BRAF(V600E) is associated some of the aggressive clinicopathological features of PTC including younger age at diagnosis, larger tumor size, and classic histological type, as well as also extrathyroidal invasion. XIAP-positive staining was more prevalent in PTCs than in the benign thyroid disorders. Although BRAF(V600E) and XIAP expression are commonly seen in PTC, their presence together seems unrelated.

[The expression and significance of ERK1, ERK2 gene in tongue squamous cell carcinoma].

PURPOSE: The aim of this study is to investigate the relationship between ERK1, ERK2 gene expression and tumor behavior such as invasion, metastasis in tongue squamous cell carcinoma (TSCC). METHODS: The expressions of ERK1, ERK2 at gene level were examined in 45 cases of TSCC by reverse transcriptase polymerase chain reaction(RT-PCR). Student's t test was used for data analysis using SPSS 12.0 software package. RESULTS: No correlation between the expression intensity of ERK gene and tumor pathological degree of TSCC.A significant relationship was observed between the expression intensity of ERK gene and T stage of TSCC. A significant relationship was observed between the expression intensity of ERK gene and lymphnode metastasis of TSCC. CONCLUSIONS: Activation of ERK gene may play a strong role in cervical lymph node metastasis of TSCC. Intensive expression of ERK may be an important presage marker in TSCC patient. Supported by Key Science and Technology Research Project of Liaoning Province (Grant No.2005225013-2).

[Expression and significance of PTEN protein in tongue squamous cell carcinoma].

PURPOSE: To study the expressions and clinical significance of PTEN protein in tongue squamous cell carcinoma (TSCC). METHODS: The expressions of PTEN at protein level was investigated in 74 cases of TSCC and 15 cases of normal peripheral tissues around cancer (as control) by strep avidin-biotin complex (SABC) immunohistochemical technique. Mann-Whitney U-test, Pearson's Chi-square test and Fisher exact test were used to analyze the data. RESULTS: The rates of the positive expression in normal tissue and TSCC of PTEN were 100% and 66.2% respectively (P<0.05). Pathological grade and T stage were not significantly related with the level of PTEN expression (P>0.05). There was significant correlation between the level of PTEN expression and cervical lymph node status (P<0.05). CONCLUSION: Expressions of PTEN is correlated with cervical lymphnode metastasis in tongue squamous cell carcinoma.

[Expressions and clinical significance of urokinase-type plasminogen activator (uPA) and uPA receptor (uPAR) in tongue squamous cell carcinoma].

PURPOSE: To study the expressions and clinical significance of urokinase-type plasminogen activator (uPA) and uPA receptor (uPAR) in tongue squamous cell carcinoma (TSCC). METHODS: The expressions of uPA and uPAR at protein level were examined in 74 cases of TSCC and 15 cases of normal peripheral tissues around cancer (as control) by strep avidin-biotin complex (SABC) immunohistochemical technique. The relationship between the expressions of uPA and uPAR was evaluated by the Spearman's rank correlation test. Mann-Whitney U-test was used to examine the association of these factors with conventional clinical pathological factors. Pearson's Chi-square test was used to analyze the relationship between uPA, uPAR and cervical lymph node status. RESULTS: The rates of the positive expression in TSCC of uPA and uPAR were 71.6% and 64.8% respectively, and a positive relationship between expression of uPA and uPAR was found (P<0.05). There was significant correlation between the level of uPA expression and TNM stage or cervical lymph node status, either between the level of uPAR expression and cervical lymph node status. Pathological grade was not significantly related to the level of uPA expression. Pathological grade and TNM stage were not significantly related to the level of uPAR expression. TSCC cases with concurrent positive expression of these proteins revealed significant higher tendency of cervical lymph node metastasis than those with concourse negative expression (P<0.05). CONCLUSIONS: The expression of uPA and uPAR increased in TSCC, and uPA, uPAR may contribute significantly to TSCC invasion and metastasis.