Acid sphingomyelinase mediates ferroptosis induced by high glucose via autophagic degradation of GPX4 in type 2 diabetic osteoporosis.

BACKGROUND: Ferroptosis has been implicated in the pathological process of type 2 diabetic osteoporosis (T2DOP), although the specific underlying mechanisms remain largely unknown. This study aimed to clarify the role and possible mechanism of acid sphingomyelinase (ASM)-mediated osteoblast ferroptosis in T2DOP. METHODS: We treated hFob1.19 cells with normal glucose (NG) and different concentrations of high glucose (HG, 26.25 mM, 35 mM, or 43.75 mM) for 48 h. We then measured cell viability and osteogenic function, quantified ferroptosis and autophagy levels, and measured the levels of ASM and ceramide in the cells. To further investigate the specific mechanism, we examined these indicators by knocking down ASM expression, hydroxychloroquine (HCQ) treatment, or N-acetylcysteine (NAC) treatment. Moreover, a T2DOP rat model was induced and microcomputed tomography was used to observe the bone microstructure. We also evaluated the serum levels of iron metabolism-associated factors, ceramide and lipid peroxidation (LPO) and measured the expression of ASM, LC3 and GPX4 in bone tissues. RESULTS: HG inhibited the viability and osteogenic function of osteoblasts by inducing ferroptosis in a concentration-dependent manner. Furthermore, the expression of ASM and ceramide and autophagy levels were increased by HG treatment, and these factors were required for the HG-induced reactive oxygen species (ROS) generation and LPO. Similarly, inhibiting intracellular ROS also reduced HG-induced ASM activation and autophagy. ASM-mediated activation of autophagy was crucial for HG-induced degradation of GPX4, and inhibiting ASM improved osteogenic function by decreasing HG-induced autophagy, GPX4 degradation, LPO and subsequent ferroptosis. We also found that inhibiting ASM could alleviated ferroptosis and autophagy and improved osteogenic function in a T2DOP rat model. CONCLUSION: ASM-mediated autophagy activation induces osteoblast ferroptosis under HG conditions through the degradation of GPX4, providing a novel mechanistic insight into the treatment and prevention of T2DOP.

Combined Treatment of Bone Marrow Mesenchymal Stem Cells and Fasudil Promotes Neurovascular Remodeling and Neurological Function Recovery in Ischemic Stroke.

Stroke remains a highly deadly and disabling disease with limited treatment tragedies due to the limitations of available treatments; novel therapies for stroke are needed. In this article, the synergistic results of dual bone marrow mesenchymal stem cells (BMSC) and fasudil treatment in rat models of ischemic stroke still require further identification. Sprague-Dawley rats were used to construct the middle cerebral artery, occlusion models. BMSCs were incubated with fasudil, and MTT was performed to evaluate cell proliferation. The rats were treated with fasudil + BMSC, BMSC, fasudil, and saline. Blood samples were collected for complete blood count analysis and measurement of serum TNF-α levels. The neurological functions were evaluated. After the rats were sacrificed, immunohistochemical staining and TTC staining was performed. Fasudil promoted the proliferation of BMSCs and induced their differentiation into neuron-like cells. BMSCs increased the proportion of neutrophils; nevertheless, fasudil counteracted the neutrophil increase. The TUJ-1/MAP2/VIII factor expression in the fasudil + BMSC group was significantly higher than that in the other groups. The number of GFAP-positive cells decreased in the fasudil + BMSC and BMSC alone groups. The infarct volume in the fasudil + BMSC and BMSC alone groups was significantly lower than in the fasudil alone and control groups. Both BMSCs and fasudil exert neurorestorative effects in rat models of cerebral ischemia. Fasudil neutralizes the pro-inflammatory effects of BMSCs, while BMSCs and fasudil together had synergistic effects promoting neurovascular remodeling and neurological function recovery in stroke. A combination of BMSCs and fasudil provides a promising method for the treatment of ischemic stroke.

Preventive and therapeutic effects of sodium bicarbonate on melamine-induced bladder stones in mice.

The actual preventive and therapeutic effects of alkalinizing urine on melamine-induced bladder stones (cystolith) are not completely known. Using an ideal model, two experiments were conducted in Balb/c mice. The mice were fed a normal diet in controls and a melamine diet in the other groups. The first day was set as experiment-day 1. In "Experiment 1", either low-/mid-/high-dose sodium bicarbonate (SB) or sterile water was administered by intragastric perfusion (once daily) to the mice for 14 days. Relative to the model group, the mean pH of the urine in the SB groups was significantly elevated at 3 h after SB administration, with a significant decrease in cystolith incidence on experiment-day 14. In "Experiment 2", on experiment-day 12, the melamine diet was replaced by a normal diet in 4 groups with melamine withdrawal (MW). Meanwhile, either mid-/high-dose SB or sterile water was administered by intragastric perfusion (once) to the mice in the corresponding groups. On experiment-day 12, after an additional 8 h, the cystolith incidence was significantly reduced in the high-SB, MW + mid-SB and MW + high-SB groups than in the model group. In conclusion, low urinary pH is one of the main determinants of the formation of melamine-associated stones, urinary alkalinization can be achieved by a proper dose of oral SB, and SB acts to prevent and treat melamine-induced cystoliths in mice.

The recovery of bladder epithelial hyperplasia caused by a melamine diet-induced bladder calculus in mice.

Applying a model of bladder epithelial hyperplasia (BEH) caused by melamine-induced bladder calculus (BC), the recovery of BEH after melamine withdrawal was investigated. One experiment, comprising untreated, melamine and recovery groups, was conducted in Balb/c mice. Each group included 4 subgroups. Mice were fed normal-diet in untreated or a melamine-diet in other groups. The melamine-diet was then substituted with normal-diet in recovery group. Both of BC and BEH were observed after 14 and 56 days of melamine-diet. The BC is relatively uniform at the same melamine-diet durations. The BEH was diffuse with many mitotic figures, 4-7 rows of nuclei, and well-defined umbrella/intermediate cells. No marked differences in BEH degree were observed in the two different melamine-diet durations. On 4-42 days after melamine withdrawal, BC was not found, as the progressive regression with complete regression of BEH was observed, along with well-defined ageing/apoptotic cells in the superficial regions of BEH regression tissue. Conclusion, the melamine-induced BEH is relatively uniform, may be self-limiting in rows of nuclei, and can return to normal. Melamine withdrawal duration is critical for the BEH regression. Tissue of the BEH and its regression is ideal for exploring the renewal as well as growth biology of mammalian urothelium.

[Application of DNA methyltransferase inhibitors for myelodysplastic syndrome].

Epigenetic research plays an important role in the malignant tumor genotyping and tumor clinical treatment recently. Epigenetics is the study of changes in gene function that are mitotically and/or meiotically heritable and that do not entail a change in DNA sequence, including DNA methylation and histone modifications. DNA methylation is one of the most important epigenetic modifications often occurring on the cytosine of CpG islands located in gene promoter regions, which is thought to be closely correlated with tumorigenesis. The inducibility and reversibility of DNA methylation provide us an insight into tumor development and treatment. Aberrant DNA hypermethylation is associated with the progress of myelodysplastic syndrome (MDS). The DNA methyltransferase inhibitors (azacytidine and decitabine) have achieved suc-cess in treating high-and intermediate-risk MDS. This will bring new ideas to understand the cause and develop the treat-ment of MDS. This review mainly introduces the latest progress of the action mechanism of those two medicines, the clini-cal effect and new problems during the clinical application on MDS.

[Expression of CCAAT/enhancer binding protein beta in human gastric carcinoma and its clinical significance].

OBJECTIVE: To explore the expression of CCAAT/enhancer binding protein beta (CEBPB) in gastric carcinoma tissues and its association with clinicopathological features and prognosis. METHODS: CEBPB protein expression level was detected by immunohistochemistry method in resected gastric carcinomas and adjacent gastric mucosa tissues (n=81), and its association with clinicopathological features and prognosis was analyzed. RESULTS: The immunohistochemical staining of CEBPB was predominantly in the nucleus with some cytoplasmic staining. As a result, 16% (13/81) of the gastric carcinomas were stained positively, whereas there was hardly positive expression in adjacent gastric mucosa tissues. There was a significant association between the expression of CEBPB and distant metastasis on univariate analysis (P<0.05). The median survival time in patients with positive CEBPB expression was significantly lower than those with negative CEBPB expression (19.4 months vs. 45.2 months, P=0.024). Multivariable analysis showed that CEBPB was independently associated with prognosis (HR=2.544, 95%CI:1.154-5.610, P=0.021). CONCLUSION: Up-regulation of CEBPB suggests poor prognosis in patients with gastric cancer.

PTK7 as a novel marker for favorable gastric cancer patient survival.

BACKGROUND AND OBJECTIVES: Protein tyrosine kinase 7 (PTK7) plays important functions in several cancer types but its expression in gastric cancer remains unknown. This study was designed to investigate PTK7 expression in gastric cancer. METHODS: PTK7 expression was assessed by immunohistochemistry in 201 gastric cancer patients. The relationship between PTK7 expression and clinicopathological features and patients prognosis were statistically analyzed. RESULTS: PTK7 expression was detected in 56.72% (114 of 201) of gastric cancer patients. The immunostaining was predominantly localized in the cytoplasm. The statistical analyses showed that PTK7 expression was more frequently detected in patients with well-differentiated tumors (P = 0.001). Furthermore, PTK7 expression was significantly related to the favorable overall survival (OS; P = 0.012) and disease-free survival (DFS; P = 0.009). Multivariate Cox regression analyses revealed that PTK7 expression was an independent prognostic factor for both favorable OS (P = 0.028) and DFS (P = 0.012). CONCLUSION: Our findings demonstrate that PTK7 can serve as a novel prognostic biomarker for gastric cancer patients.

The natural outcome of melamine-induced bladder stones with bladder epithelial hyperplasia after the withdrawal of melamine in mice.

The natural outcome of melamine-induced bladder stones (cystoliths) with bladder epithelial hyperplasia (BEH) after melamine withdrawn is unclear. Using an ideal dual-model system, three experiments were conducted in BALB/c mice. Each experiment included a control, model 1 and model 2 groups. The mice were fed a regular diet in controls or a 9373 ppm melamine diet in models, and the first day was designated as dosing day 1. The melamine diet was then replaced by the regular diet in the model 2 groups, and the first day was designated as post-dosing day 1. On dosing days 12, 35 and 49, the incidence of cystoliths and diffusely active BEH was 8/8 in the mice of three model 1 groups. On post-dosing days 1, 4 and 8, in the mice of three model 2 groups, the incidence of cystoliths was 2/8, 0/8 and 1/8, respectively, and the progressive regression of BEH was observed. In conclusion, both the stones and BEH have the natural property of rapid development and rapid regression, and melamine withdrawn plays a key role in the stone dissolution-discharge necessary for BEH regression. BEH may be reversible after the discharge of the stones. The conventionally conservative therapy is thus reasonable.

The rapid establishment and implications of a melamine-induced standardized bladder stone model in mice.

The key to establishing a standardized melamine-induced animal bladder stone (cystolith) model is to determine the most appropriate daily dose of dietary melamine, which is unknown. Based on golden section theory that is a well-known preferred proportion (0.618), and the 50% lethal dose (LD50) of mouse oral melamine [4550 mg/kg body weight (bw)], we proposed that the daily dose may be close to the LD50's golden section (i.e., 0.618 × 4550 mg melamine/kg bw). The latter as an average daily dose corresponds to 9373 ppm melamine diet in mice. In repeated experiments, a 100% incidence of cystoliths was observed on modeling day 14 in Balb/c and C57BL/6 mice fed the diet but not in mice fed similar diets containing 9842 (i.e., 9373 × 105%) or 8904 (i.e., 9373 × 95%) ppm melamine; the stones were relatively uniform and the difference in stone incidences between sexes or ages was not found in each 9373 ppm melamine group. In conclusion, 9373 ppm melamine diet is at least near the optimal dose diet or ideal for the rapid and stable establishment of a standardized cystolith model in the mice, and dietary melamine dose neither sex nor age is critical for stone formation.