SPI1 activates TGF-β1/PI3K/Akt signaling through transcriptional upregulation of FKBP12 to support the mesenchymal phenotype of glioma stem cells

Glioma stem cells (GSCs) exhibit diverse molecular subtypes with the mesenchymal (MES) population representing the most malignant variant. The oncogenic potential of Salmonella pathogenicity island 1 (SPI1), an oncogenic transcription factor, has been established across various human malignancies. In this study, we explored the association between the SPI1 pathway and the MES GSC phenotype. Through comprehensive analysis of the Cancer Genome Atlas and Chinese Glioma Genome Atlas glioma databases, along with patient-derived GSC cultures, we analyzed SPI1 expression. Using genetic knockdown and overexpression techniques, we assessed the functional impact of SPI1 on GSC MES marker expression, invasion, proliferation, self-renewal, and sensitivity to radiation in vitro, as well as its influence on tumor formation in vivo. Additionally, we investigated the downstream signaling cascades activated by SPI1. Our findings revealed a positive correlation between elevated SPI1 expression and the MES phenotype, which in turn, correlated with poor survival. SPI1 enhanced GSC MES differentiation, self-renewal, and radioresistance in vitro, promoting tumorigenicity in vivo. Mechanistically, SPI1 augmented the transcriptional activity of both TGF-β1 and FKBP12 while activating the non-canonical PI3K/Akt pathway. Notably, inhibition of TGF-β1/PI3K/Akt signaling partially attenuated SPI1-induced GSC MES differentiation and its associated malignant phenotype. Collectively, our results underscore SPI1's role in activating TGF-β1/PI3K/Akt signaling through transcriptional upregulation of FKBP12, thereby supporting the aggressive MES phenotype of GSCs. Therefore, SPI1 emerges as a potential therapeutic target in glioma treatment.

The multifaceted role of macrophage mitophagy in SiO2-induced pulmonary fibrosis: A brief review

Prolonged exposure to environments with high concentrations of crystalline silica (CS) can lead to silicosis. Macrophages play a crucial role in the pathogenesis of silicosis. In the process of silicosis, silica (SiO2) invades alveolar macrophages (AMs) and induces mitophagy which usually exists in three states: normal, excessive, and/or deficiency. Different mitophagy states lead to corresponding toxic responses, including successful macrophage repair, injury, necrosis, apoptosis, and even pulmonary fibrosis. This is a complex process accompanied by various cytokines. Unfortunately, the details have not been fully systematically summarized. Therefore, it is necessary to elucidate the role of macrophage mitophagy in SiO2-induced pulmonary fibrosis by systematic analysis on the literature reports. In this review, we first summarized the current data on the macrophage mitophagy in the development of SiO2-induced pulmonary fibrosis. Then, we introduce the molecular mechanism on how SiO2-induced mitophagy causes pulmonary fibrosis. Finally, we focus on introducing new therapies based on newly developed mitophagy-inducing strategies. We conclude that macrophage mitophagy plays a multifaceted role in the progression of SiO2-induced pulmonary fibrosis, and reprogramming the macrophage mitophagy state accordingly may be a potential means of preventing and treating pulmonary fibrosis.

Arsenic exposure induced renal fibrosis via regulation of mitochondrial dynamics and the NLRP3-TGF-β1/SMAD signaling pathway

Environmental arsenic exposure is one of the major global public health problems. Studies have shown that arsenic exposure can cause renal fibrosis, but the underlying mechanism is still unclear. Integrating the in vivo and in vitro models, this study investigated the potential molecular pathways for arsenic-induced renal fibrosis. In this study, SD rats were treated with 0, 5, 25, 50, and 100 mg/L NaAsO2 for 8 weeks via drinking water, and HK2 cells were treated with different doses of NaAsO2 for 48 h. The in vivo results showed that arsenic content in the rats' kidneys increased as the dose increased. Body weight decreased and kidney coefficient increased at 100 mg/L. As a response to the elevated NaAsO2 dose, inflammatory cell infiltration, renal tubular injury, glomerular atrophy, tubulointerstitial hemorrhage, and fibrosis became more obvious indicated by HE and Masson staining. The kidney transcriptome profiles further supported the protein-protein interactions involved in NaAsO2-induced renal fibrosis. The in vivo results, in together with the in vitro experiments, have revealed that exposure to NaAsO2 disturbed mitochondrial dynamics, promoted mitophagy, activated inflammation and the TGF-β1/SMAD signaling pathway, and finally resulted in fibrosis. In summary, arsenic exposure contributed to renal fibrosis via regulating the mitochondrial dynamics and the NLRP3-TGF-β1/SMAD signaling axis. This study presented an adverse outcome pathway for the development of renal fibrosis due to arsenic exposure through drinking water.

Forkhead box O6 (FoxO6) promotes cardiac pathological remodeling and dysfunction by activating Kif15-TGF-β1 under aggravated afterload

Pathological cardiac hypertrophy exhibits complex and abnormal gene expression patterns and progresses to heart failure. Forkhead box protein O6 (FoxO6) is a key transcription factor involved in many biological processes. This study aimed to explore the role of FoxO6 in cardiac hypertrophy. Three groups of mice were established: wild-type, FoxO6 knockout, and FoxO6-overexpressing. The mice received daily administration of angiotensin-II (Ang-II) or saline for 4 weeks, after which they were examined for cardiac hypertrophy, fibrosis, and function. Elevated cardiac expression of FoxO6 was observed in Ang-II-treated mice. FoxO6 deficiency attenuated contractile dysfunction and cardiac remodeling, including cardiomyocyte hypertrophy and fibroblast proliferation and differentiation. Conversely, FoxO6 overexpression aggravated the cardiomyopathy and heart dysfunction. Further studies identified kinesin family member 15 (Kif15) as downstream molecule of FoxO6. Kif15 inhibition attenuated the aggravating effect of FoxO6 overexpression. In vitro, FoxO6 overexpression increased Kif15 expression in cardiomyocytes and elevated the concentration of transforming growth factor-β1 (TGF-β1) in the medium where fibroblasts were grown, exhibiting increased proliferation and differentiation, while FoxO6 knockdown attenuated this effect. Cardiac-derived FoxO6 promoted pathological cardiac remodeling induced by aggravated afterload largely by activating the Kif15/TGF-β1 axis. This result further complements the mechanisms of communication among different cells in the heart, providing novel therapeutic targets for heart failure.

Cytokine TGF-β1, TNF-α, IFN-γ and IL-6 Gene Polymorphisms and Localization of Premalignant Gastric Lesions in Immunohistochemically H. pylori-negative Patients

Background: Cytokines and their gene variants are proven to play a role in pathogenic gastritis and carcinogenesis. The study assesses associations of the cytokine gene polymorphisms with extension of atrophic gastritis/intestinal metaplasia (AGIM) in patients without Helicobacter pylori infection on immunohistochemistry study. Methods: 224 adult consecutive patients undergoing an upper digestive endoscopy were included and grouped according to localization of AGIM: 37 patients with antrum-limited AGIM, 21 corpus-limited AGIM, 15 extended-AGIM (antrum and corpus) and 151 patients had no AGIM. Medical records of the patients were checked and a structured direct interview was applied in order to collect clinical data, including digestive symptoms. In all cases, IFN-γ +874T>A, TGF-β1 +869T>C, TNF-α-308G>A and -238G>A, and IL-6 -174C>G polymorphisms were genotyped. Results: The mean age was significantly higher in the AGIM group, while the comorbidies were similar among patients with different localization of lesions or in patients without AGIM. There were no significant differences in digestive symptoms, nor in the consumption of non-steroidal anti-inflammatory drugs or proton pump inhibitor with the different extensions of AGIM. There was a significant association between oral anticoagulant consumption and localization of AGIM (P = 0.042), frequency being higher among patients with corpus-limited AGIM than those with no AGIM (P = 0.007, adjusted P = 0.041). TGF-β1 +869T>C was less frequent among patients with corpus-limited AGIM (n=7, 33.3%) and extended AGIM (n=5, 33.3%) than in antrum-limited AGIM (n=25, 67.6%). There were no other significant differences regarding variant and wild genotype frequencies of IFN-γ +874T>A (86.5%, 81.0%, 86.7%, p=0.814), TNF-α-308G>A (35.1%, 28.6%, 53.3%, p=0.48) and IL-6 -174C>G (70.3%. 61.9%, 73.3% p=0.656) among patients with antrum-limited, corpus-limited or extended AGIM. TGF-β1 +869T>C was associated with a decreased risk for corpus-affected AGIM (adjusted odds ratio: 0.42, 95% confidence interval: 0.19-0.93, P = 0.032). The dominant inheritance models no revealed significant association for IFN-γ +874T>A, TNF-α-308G>A and IL-6 -174C>G gene polymorphism and the risk of localization of AGIM. Conclusion: TGF-β1 +869T>C gene polymorphism is associated with a decreased risk for corporeal localization of premalignant lesions, while IFN-γ +874T>A, TNF-α-308G>A and IL-6 -174C>G are not associated with the risk for AGIM in immunohistochemically H. pylori negative patients.

Subcellular trafficking of tubular MDM2 implicates in acute kidney injury to chronic kidney disease transition during multiple low-dose cisplatin exposure

Acute kidney injury (AKI) is the leading cause of renal failure, and quite a few patients will advance to chronic kidney disease (CKD) in the long term. Here, we explore the roles and mechanisms of tubular epithelial cells (TECs) during repeated cisplatin (CP) induced AKI to CKD transition (AKI-CKD). Previously, we reported that murine double minute 2 (MDM2), an E3-ubiquitin ligase, is involved in tubulointerstitial fibrosis. However, whether tubular MDM2 is implicated in AKI-CKD is undefined. Currently, we confirmed that during AKI-CKD, MDM2 shifts from nucleus to cell membrane in TECs both in vivo and in vitro. Whereas regulating MDM2 distribution chemically or genetically has a prominent impact on tubular disorders. And then we investigated the mechanisms of the above findings. First, in the nucleus, repeated CP administration leads to MDM2 reduction with escalated p53 and cell cycle G2/M arrest. On the other hand, multiple CP treatment increases the level of membranous MDM2 with ensuing integrin β8 degradation and TGF-β1 activation. More interestingly, anchoring MDM2 on cell membranes can mimic the reduction of integrin β8 arousing by repeated CP exposure. Collectively, our findings provided the evidence that tubular MDM2 subcellular shuttling is involved in AKI-CKD through p53-G2/M arrest and integrin β8 mediated TGF-β1 activation.

TGF-β1 secreted by Tregs in lymph nodes promotes breast cancer malignancy via up-regulation of IL-17RB

Lymph node (LN) metastasis is commonly associated with systemic distant organ metastasis in human breast cancer and is an important prognostic predictor for survival of breast cancer patients. However, whether tumor‐draining LNs (TDLNs) play a significant role in modulating the malignancy of cancer cells for distant metastasis remains controversial. Using a syngeneic mouse mammary tumor model, we found that breast tumor cells derived from TDLN have higher malignancy and removal of TDLNs significantly reduced distant metastasis. Up‐regulation of oncogenic Il‐17rb in cancer cells derived from TDLNs contributes to their malignancy. TGF‐β1 secreted from regulatory T cells (Tregs) in the TDLNs mediated the up‐regulation of Il‐17rb through downstream Smad2/3/4 signaling. These phenotypes can be abolished by TGF‐β1 neutralization or depletion of Tregs. Consistently, clinical data showed that the up‐regulation of IL‐17RB in cancer cells from LN metastases correlated with the increased prevalence of Tregs as well as the aggressive growth of tumors in mouse xenograft assay. Together, these results indicate that Tregs in TDLNs play an important role in modulating the malignancy of breast cancer cells for distant metastasis. Blocking IL‐17RB expression could therefore be a potential approach to curb the process.

Histopathological and genotypic characterization of metastatic colorectal carcinoma with PD-L1 (CD274)-expression: Possible roles of tumour micro environmental factors for CD274 expression

Aberrant PD-L1 (CD274) expression has been described in different types of tumour and linked to tumour aggressiveness and a poor prognosis. In primary colorectal carcinomas (CRCs), CD274 expression was reported to be associated with mismatch repair (MMR)-deficiency, BRAF mutation, and "stem-like" immunophenotype defined by down-regulation of homeobox protein CDX2 and membranous expression of activated leukocyte cell adhesion molecule (ALCAM). However, the immunophenotype and genotype of CD274-positive metastatic CRC have not been extensively analysed. In this study, 189 CRC metastases were evaluated immunohistochemically for CD274, MMR proteins, CDX2, and ALCAM expression. Immunostaining for CD4, CD8, and FOXP3 was also performed to characterize tumour-associated immune cells. In addition, 34 arbitrarily selected lesions were genotyped using Sanger- and next-generation sequencing. Univariate analyses showed no clear association between CD274 expression and clinicopathological parameters including MMR-deficiency or "stem-like" immunophenotype after adjustment for multiple testing. Comparison of the clinicopathological profiles of CD274-positive primary and metastatic tumours revealed in the latter younger age of occurrence (60.9 ± 13.3 versus 72.6 ± 13.1 years, p = 0.001), cytoplasm-dominant CD274 expression (p < 0.001), infrequent MMR-deficiency (p < 0.001), and common KRAS mutations (54%, p < 0.001). In five cultured colon cancer cell lines, CD274 was expressed and modulated after exogenous exposure to IFNγ and TGF-β1. Thus, CD274 regulation mechanisms might include tumour micro environmental factors. Based on significantly different characteristics in CD274-positive metastatic and primary CRCs, evaluation of metastases should also be considered when planning immune checkpoint inhibitor therapy.

Evodiamine ameliorates liver fibrosis in rats via TGF-β1/Smad signaling pathway

Liver fibrosis is considered to be a result of chronic liver pathological changes, and hepatic stellate cells (HSCs) play an important role during this process. Evodiamine, an indole alkaloid derived from Evodia rutaecarpa, exhibits pharmacological activities. This study focused on the effects of evodiamine on carbon tetrachloride (CCl₄)-induced liver fibrosis in rats and HSCs in vitro via the TGF-β1/Smad signaling pathway. A liver fibrosis rat model was established by the intraperitoneal injection of CCl₄ (3 ml/kg, 30% in olive oil). Evodiamine (15 and 25 mg/kg) was administered orally for 8 weeks. HSCs were treated with different evodiamine concentrations. The results indicated that evodiamine could improve the histopathological abnormalities in liver tissues and decrease the level of aspartate aminotransferase (AST), alanine aminotransferase (ALT), hydroxyproline, and total bilirubin (TBIL). Concentrations of IL-6, tumor necrosis factor-α (TNF-α), collagen-I (COL-I), and collagen-III (COL-III) were reduced by evodiamine. Western blotting and real-time PCR showed that protein expression of transforming growth factor-β (TGF-β1), p-Smad 2/3 (phosphorylation of Smad 2/3), and smooth muscle alpha-actin (α-SMA) as well as mRNA expression of TGF-β1 and α-SMA in liver tissues were downregulated by evodiamine. The cell proliferation, production of hydroxyproline, and the protein expression of TGF-β1, p-Smad 2/3, and α-SMA in HSCs were dose-dependently reduced by evodiamine. Collectively, evodiamine had an antifibrosis effect in CCl₄-induced liver fibrosis, and reduced HSCs proliferation and collagen metabolism in vitro. The major mechanism was downregulation of relative expression of TGF-β1, p-Smad 2/3, and α-SMA.

Haploinsufficiency of the folliculin gene leads to impaired functions of lung fibroblasts in patients with Birt-Hogg-Dubé syndrome

Birt–Hogg–Dubé syndrome (BHDS) is an autosomal dominant inherited disorder caused by germline mutations in the FLCN gene, and characterized by skin fibrofolliculomas, multiple lung cysts, spontaneous pneumothorax, and renal neoplasms. Pulmonary manifestations frequently develop earlier than other organ involvements, prompting a diagnosis of BHDS. However, the mechanism of lung cyst formation and pathogenesis of pneumothorax have not yet been clarified. Fibroblasts were isolated from lung tissues obtained from patients with BHDS (n = 12) and lung cancer (n = 10) as controls. The functional abilities of these lung fibroblasts were evaluated by the tests for chemotaxis to fibronectin and three‐dimensional (3‐D) gel contraction. Fibroblasts from BHDS patients showed diminished chemotaxis as compared with fibroblasts from controls. Expression of fibronectin and TGF‐β1 was significantly reduced in BHDS fibroblasts when assessed by qPCR. Addition of TGF‐β1 in culture medium of BHDS lung fibroblasts significantly restored these cells' abilities of chemotaxis and gel contraction. Human fetal lung fibroblasts (HFL‐1) exhibited reduced chemotaxis and 3‐D gel contraction when FLCN expression was knocked down. To the contrary, a significant increase in chemotactic activity toward to fibronectin was demonstrated when wild‐type FLCN was overexpressed, whereas transduction of mutant FLCN showed no effect on chemotaxis. Our results suggest that FLCN is associated with chemotaxis in lung fibroblasts. Together with reduced TGF‐β1 expression by BHDS lung fibroblasts, a state of FLCN haploinsufficiency may cause lung fibroblast dysfunction, thereby impairing tissue repair. These may reveal one mechanism of lung cyst formation and pneumothorax in BHDS patients.

Pancreatic functions in high salt fed female rats

Salt consumption has been increased worldwide and the association of high salt diets with enhanced inflammation and target organ damage was reported. Little data were available about the effect of high salt diet on exocrine function of pancreas, while the relation between high salt intake and insulin sensitivity was controversial. This study was designed to investigate the effect of high salt diet on exocrine and endocrine pancreatic functions, and to elucidate the possible underlying mechanism(s). Twenty adult female Wistar rats were randomly divided into two groups; control group; fed standard rodent diet containing 0.3% NaCl, and high salt fed group; fed 8% NaCl for 8 weeks. On the day of sacrifice, rats were anesthized by i.p. pentobarbitone (40 μg/kg B.W.). Nasoanal length was measured and fasting blood glucose was determined from rat tail. Blood samples were obtained from abdominal aorta for determination of plasma sodium, potassium, amylase, lipase, aldosterone, insulin, transforming growth factor-β (TGF-β1), and interleukin 6 (IL6). Pancreata of both groups were histologically studied. Compared to control group, 8-week high salt fed group showed: significant elevation in body weight, body mass index, Lee index, plasma sodium, TGF-β1 and IL6, however, plasma aldosterone, amylase, lipase, and insulin levels were significantly decreased. A nonsignificant increase in plasma potassium and nonsignificant changes in fasting blood glucose and HOMA-IR were detected between groups. Pancreatic fibrosis was observed in test group. High salt diet for 8 weeks caused pancreatic fibrosis evidenced by decline of both exocrine and endocrine functions of pancreas in Wistar rats.

Zeb1 affects epithelial cell adhesion by diverting glycosphingolipid metabolism

This study proposes that the transcription factor Zeb1 modulates epithelial cell adhesion by diverting glycosphingolipid metabolism. Zeb1 promotes expression of a-series glycosphingolipids via regulating expression of GM3 synthase (St3gal5), which mechanistically involves Zeb1 binding to the St3gal5 promoter as well as suppressing microRNA-mediated repression of St3gal5. Functionally, the repression of St3gal5 suffices to elevate intercellular adhesion and expression of distinct junction-associated proteins, reminiscent of knockdown of Zeb1. Conversely, overexpressing St3gal5 sensitizes cells towards TGF-β1-induced disruption of cell-cell interaction and partially antagonizes elevation of intercellular adhesion imposed by Zeb1 knockdown. These results highlight a direct connection of glycosphingolipid metabolism and epithelial cell adhesion via Zeb1.

Vasohibin-1 deficiency enhances renal fibrosis and inflammation after unilateral ureteral obstruction

Tubulointerstitial injuries are known to predict the deterioration of renal function in chronic kidney disease (CKD). We recently reported the protective role of Vasohibin‐1(VASH‐1), a negative feedback regulator of angiogenesis, in diabetic nephropathy, but its impact on tubulointerstitial injuries remains to be elucidated. In the present study, we evaluated the role of endogenous VASH‐1 in regulating the tubulointerstitial alterations induced by unilateral ureteral obstruction (UUO), and assessed its role on fibrogenesis and the activation of Smad3 signaling in renal fibroblasts. UUO was induced in female Vasohibin‐1 heterozygous knockout mice (VASH‐1^+/−) or wild‐type (WT) (VASH‐1^+/+) littermates. Mice were sacrificed on Day 7 after left ureter ligation, and the kidney tissue was obtained. Interstitial fibrosis, the accumulation of type I and type III collagen and monocytes/macrophages infiltration in the obstructed kidneys (OBK) were significantly exacerbated in VASH‐1^+/− mice compared with WT mice (Day 7). The increases in the renal levels of TGF‐β1, pSmad3, NF‐κB pp65, CCL2 mRNA, and the number of interstitial fibroblast‐specific protein‐1 (FSP‐1)⁺ fibroblasts in the OBK were significantly aggravated in VASH‐1^+/− mice. In addition, treatment with VASH‐1 siRNA enhanced the TGF‐β1‐induced phosphorylation of Smad3, the transcriptional activation of the Smad3 pathway and the production of type I/type III collagen in fibroblasts, in vitro. Taken together, our findings demonstrate a protective role for endogenous VASH‐1 on tubulointerstitial alterations via its regulation of inflammation and fibrosis and also show the direct anti‐fibrotic effects of VASH‐1 on renal fibroblasts through its modulation of TGF‐β1 signaling.

In the present study, we evaluated the role of endogenous Vasohibn‐1 VASH‐1 in regulating tubulointerstitial alterations induced by unilateral ureteral obstruction (UUO), and assessed its regulatory role on fibrogenesis and the activation of TGF‐beta/Smad3 signaling in renal fibroblasts. This is the first study to demonstrate the potential protective role for endogenous VASH‐1 on tubulointerstitial alterations via regulating inflammation and fibrosis, partly mediated via its direct anti‐fibrotic effects on renal fibroblasts through modulating TGF‐β1 signaling.