Endoscopic-ultrasound-guided biliary drainage with placement of electrocautery-enhanced lumen-apposing metal stent for palliation of malignant biliary obstruction: Updated meta-analysis.

BACKGROUND: Endoscopic ultrasound-guided biliary drainage using electrocautery-enhanced (ECE) delivery of lumen-apposing metal stent (LAMS) is gradually being recognized as a viable palliative technique for malignant biliary obstruction after endoscopic retrograde cholangiopancreatography (ERCP) failure. However, most of the studies that have assessed its efficacy and safety were small and heterogeneous. Prior meta-analyses of six or fewer studies that were published 2 years ago were therefore underpowered to yield convincing evidence. AIM: To update the efficacy and safety of ECE-LAMS for treatment of biliary obstruction after ERCP failure. METHODS: We searched PubMed, EMBASE, and Scopus databases from the inception of the ECE technique to May 13, 2022. Primary outcome measure was pooled technical success rate, and secondary outcomes were pooled rates of clinical success, reintervention, and adverse events. Meta-analysis was performed using a random-effects model following Freeman-Tukey double-arcsine transformation in R software (version 4.1.3). RESULTS: Fourteen eligible studies involving 620 participants were ultimately included. The pooled rate of technical success was 96.7%, and clinical success was 91.0%. Adverse events were reported in 17.5% of patients. Overall reintervention rate was 7.3%. Subgroup analyses showed results were generally consistent. CONCLUSION: ECE-LAMS has favorable success with acceptable adverse events in relieving biliary obstruction when ERCP is impossible. The consistency of results across most subgroups suggested that this is a generalizable approach.

[A case of neonatal liver failure]. / 新生儿肝衰竭1例.

The patient was a male infant, born full-term, admitted to the hospital at 28 days of age due to jaundice for 20 days and abdominal distension for 15 days. The patient developed symptoms of jaundice, hepatosplenomegaly, massive ascites, and progressively worsening liver function leading to liver failure, severe coagulation disorders, and thrombocytopenia one week after birth. Various treatments were administered, including anti-infection therapy, fluid restriction, use of diuretics, use of hepatoprotective and choleretic agents, intermittent paracentesis, blood exchange, and intravenous immunoglobulin, albumin, and plasma transfusions. However, the patient's condition did not improve, and on the 24th day of hospitalization, the family decided to discontinue treatment and provide palliative care. Sequencing of the patient's liver tissue and parental blood samples using whole-exome sequencing did not identify any pathogenic variants that could explain the liver failure. However, postmortem liver tissue pathology suggested congenital hepatic fibrosis (CHF). Given the rarity of CHF causing neonatal liver failure, further studies on the prognosis and pathogenic genes of CHF cases are needed in the future. This article provides a comprehensive description of the differential diagnosis of neonatal liver failure and introduces a multidisciplinary diagnostic and therapeutic approach to neonatal liver failure.

Whether Detection of Gene Mutations Could Identify Low- or High-Risk Papillary Thyroid Microcarcinoma? Data from 393 Cases Using the Next-Generation Sequencing.

Objective: The objective of this study is to explore the utilization of next-generation sequencing (NGS) technology in evaluating the likelihood of identifying individuals with papillary thyroid microcarcinoma (PTMC ≤10 mm) who are at high or low risk. Design: NGS was used to analyze 393 formalin-fixed, paraffin-embedded tissues of PTC tumors, all of which were smaller than 15 mm. Results: The study found that bilateralism, multifocality, intrathyroidal spread, and extrathyroidal extension were present in 84 (21.4%), 153 (38.9%), 16 (4.1%), and 54 (13.7%) cases, respectively. Metastasis of cervical lymph nodes was identified in 226 (57.5%) cases and 96 (24.4%) cases with CLNM >5. Out of the total number of cases studied, 8 cases (2.3%) showed signs of tumor recurrence, all of which were localized and regional. Genetic alterations were detected in 342 cases (87.0%), with 336 cases revealing single mutations and 6 cases manifesting compound mutations. 332 cases (84.5%) had BRAFV600E mutation, 2 cases had KRASQ61K mutation, 2 cases had NRASQ61R mutation, 8 cases had RET/PTC1 rearrangement, 3 cases had RET/PTC3 rearrangement, and 1 case had TERT promoter mutation. Additionally, six individuals harbored concurrent mutations in two genes. These mutations were of various types and combinations: BRAFV600E and NRASQ61R (n = 2), BRAFV600E and RET/PTC3 (n = 2), BRAFV600E and RET/PTC1 (n = 1), and BRAFV600E and TERT promoter (n = 1). The subsequent analysis did not uncover a significant distinction in the incidence of gene mutation or fusion between the cN0 and cN1 patient cohorts. The presence of BRAFV600E mutation and CLNM incidence rates were found to be positively correlated with larger tumor size in PTMC. Our data showed that gene mutations did not appear to have much to do with high-risk papillary thyroid microcarcinoma (PTMC). However, when we looked at tumor size, we found that if the tumor was at least 5 millimeters in size, there was a higher chance of it being at high risk for PTM (P < 0.001, odds ratio (OR) = 2.55, 95% confidence interval (CI): 1.57-4.14). Identification of BRAFV600E mutation was not demonstrated to be significantly correlated with advanced clinicopathological characteristics, although it was strongly associated with a bigger tumor diameter (OR = 4.92, 95% CI: 2.40-10.07, P < 0.001). Conclusion: In clinical practice, BRAFV600E mutation does not consistently serve as an effective biomarker to distinguish high-risk PTMC or predict tumor progression. The size of the tumor has a significant correlation with its aggressive characteristics. PTMC with a diameter of ≤5 mm should be distinguished and targeted as a unique subset for specialized treatment.

N-Trifluoromethylselenophthalimide, an Electrophilic Trifluoromethylselenolation Reagent and Its Application for the Synthesis of 4-Trifluoromethylselenolated Isoxazoles.

A new electrophilic trifluoromethylselenolation reagent, N-trifluoromethylselenophthalimide (Phth-SeCF3), was developed. A strategy for the synthesis of 4-trifluoromethylselenolated isoxazoles through electrophilic trifluoromethylselenolation cyclization has been established by using Phth-SeCF3 as an electrophilic reagent. Moreover, this protocol has the features of broad substrate scope, good functional group tolerance, and high yields.

Dapagliflozin can alleviate renal fibrosis in rats with streptozotocin­induced type 2 diabetes mellitus.

The aim of the present study was to explore the effects of Dapagliflozin on renal fibrosis in streptozotocin (STZ)-induced type 2 diabetes mellitus (T2DM) rats, and to determine the underlying mechanism of action. A total of 24 SPF male SD rats were randomly divided into 4 groups: A normal (Control) group, model group (STZ-induced T2DM rats), Dapagliflozin group (STZ-induced T2DM rats treated with 1 mg/kg Dapagliflozin), and a metformin group (STZ-induced T2DM rats treated with 200 mg/kg metformin), with 6 rats per a group. Peripheral blood and renal tissues were collected from these rats, and the renal indices of each group were examined. The fasting blood glucose (FBG), glycosylated hemoglobin (HbA1c), blood urea nitrogen (BUN), and serum creatinine (SCr) of rats were detected. After 24 h, the urine was collected and the urine protein levels were measured. Hematoxylin and eosin staining was used to detect histological changes in the rat kidney; Masson staining was used to observe the degree of fibrosis in rat renal tissues; and western blot was performed to determine the expression levels of α-smooth muscle actin (SMA), vimentin, E-cadherin, TGF-ß1, Smad7, and p-Smad3 in rat renal tissues. Dapagliflozin effectively inhibited the increase in FBG and HbA1c levels in diabetic mice, reduced renal tissue damage, reduced the renal index values, reduced collagen deposition in the glomerulus and interstitial area, and reduced the proliferation of glomerular mesangial cells. In addition, Dapagliflozin significantly lowered the levels of BUN, SCr, and 24-h urine protein, decreased the protein expression of α-SMA, vimentin, TGF-ß1, and p-Smad3, and increased the protein expression levels of E-cadherin and Smad7. Together, these results showed that Dapagliflozin alleviated renal fibrosis in STZ-induced T2DM rats, and its mechanism of action may be related to the inhibition of the TGF-ß1/Smad pathway.

Synthesis of Spiro[5.5]trienones- and Spiro[4.5]trienones-Fused Selenocyanates via Electrophilic Selenocyanogen Cyclization and Dearomative Spirocyclization.

A practical strategy for the synthesis of spiro[5.5]trienones-fused selenocyanates and spiro[4.5]trienones-fused selenocyanates through electrophilic selenocyanogen cyclization and dearomative spirocyclization is reported. This approach was conducted under mild conditions with broad substrate scope and good functional group tolerance. The utility of this procedure is exhibited in the late-stage functionalization of nature product and drug molecules.

Immunologic mechanism of fungal keratitis.

Fungal keratitis (FK) is a refractory disease that poses a serious threat to vision, with common risk factors like eye trauma, contact lens wearing, topical corticosteroids and antibiotic abuse. Nowadays, topical and systemic anti-fungal drugs and ocular surgeries are still the main therapeutic modalities. However, the pathogenesis of FK, especially the immunologic mechanism within it, has not yet been deeply clarified. A better understanding of the pathogenesis of FK is imperative for more effective therapies and prognosis. Meanwhile, the immune protection strategies are also urgently required to manage FK. This review highlights recent advances in the immunologic mechanism in the pathogenesis of FK, in hope of providing valuable reference information for more effective anti-fungal treatment.

Houttuynia cordata polysaccharide alleviated intestinal injury and modulated intestinal microbiota in H1N1 virus infected mice.

Houttuynia cordata polysaccharide (HCP) is extracted from Houttuynia cordata, a key traditional Chinese medicine. The study was to investigate the effects of HCP on intestinal barrier and microbiota in H1N1 virus infected mice. Mice were infected with H1N1 virus and orally administrated HCP at a dosage of 40 mg(kg-1(d-1. H1N1 infection caused pulmonary and intestinal injury and gut microbiota imbalance. HCP significantly suppressed the expression of hypoxia inducible factor-1α and decreased mucosubstances in goblet cells, but restored the level of zonula occludens-1 in intestine. HCP also reversed the composition change of intestinal microbiota caused by H1N1 infection, with significantly reduced relative abundances of Vibrio and Bacillus, the pathogenic bacterial genera. Furthermore, HCP rebalanced the gut microbiota and restored the intestinal homeostasis to some degree. The inhibition of inflammation was associated with the reduced level of Toll-like receptors and interleukin-1ß in intestine, as well as the increased production of interleukin-10. Oral administration of HCP alleviated lung injury and intestinal dysfunction caused by H1N1 infection. HCP may gain systemic treatment by local acting on intestine and microbiota. This study proved the high-value application of HCP.

Gene-based Therapeutic Tools in the Treatment of Cornea Disease.

BACKGROUND: As one of the main blinding ocular diseases, corneal blindness resulted from neovascularization that disrupts the angiogenic privilege of corneal avascularity. Following neovascularization, inflammatory cells are infiltrating into cornea to strengthen corneal injury. How to maintain corneal angiogenic privilege to treat corneal disease has been investigated for decades. METHODOLOGY: Local administration of viral and non-viral-mediated anti-angiogenic factors reduces angiogenic protein expression in situ with limited or free of off-target effects upon gene delivery. Recently, Mesenchymal Stem Cells (MSCs) have been studied to treat corneal diseases. Once MSCs are manipulated to express certain genes of interest, they could achieve superior therapeutic efficacy after transplantation. DISCUSSION: In the text, we first introduce the pathological development of corneal disease in the aspects of neovascularization and inflammation. We summarize how MSCs become an ideal candidate in cell therapy for treating injured cornea, focusing on cell biology, property and features. We provide an updated review of gene-based therapies in animals and preclinical studies in the aspects of controlling target gene expression, safety and efficacy. Gene transfer vectors are potent to induce candidate protein expression. Delivered by vectors, MSCs are equipped with certain characters by expressing a protein of interest, which facilitates better for MSC-mediated therapeutic intervention for the treatment of corneal disease. CONCLUSION: As the core of this review, we discuss how MSCs could be engineered to be vector system to achieve enhanced therapeutic efficiency after injection.

Conversion of phosphatidylinositol (PI) to PI4-phosphate (PI4P) and then to PI(4,5)P2 is essential for the cytosolic Ca2+ concentration under heat stress in Ganoderma lucidum.

How cells drive the phospholipid signal response to heat stress (HS) to maintain cellular homeostasis is a fundamental issue in biology, but the regulatory mechanism of this fundamental process is unclear. Previous quantitative analyses of lipids showed that phosphatidylinositol (PI) accumulates after HS in Ganoderma lucidum, implying the inositol phospholipid signal may be associated with HS signal transduction. Here, we found that the PI-4-kinase and PI-4-phosphate-5-kinase activities are activated and that their lipid products PI-4-phosphate and PI-4,5-bisphosphate are increased under HS. Further experimental results showed that the cytosolic Ca2+ ([Ca2+ ]c ) and ganoderic acid (GA) contents induced by HS were decreased when cells were pretreated with Li+ , an inhibitor of inositol monophosphatase, and this decrease could be rescued by PI and PI-4-phosphate. Furthermore, inhibition of PI-4-kinases resulted in a decrease in the Ca2+ and GA contents under HS that could be rescued by PI-4-phosphate but not PI. However, the decrease in the Ca2+ and GA contents by silencing of PI-4-phosphate-5-kinase could not be rescued by PI-4-phosphate. Taken together, our study reveals the essential role of the step converting PI to PI-4-phosphate and then to PI-4,5-bisphosphate in [Ca2+ ]c signalling and GA biosynthesis under HS.

Tiotropium plus formoterol versus tiotropium alone for stable moderate-to-severe chronic obstructive pulmonary disease: A meta-analysis.

PURPOSE: This meta-analysis was performed to compare the risks and benefits of combined treatment with tiotropium plus formoterol versus tiotropium alone for stable moderate-to-severe COPD. METHODS: A comprehensive search of MEDLINE, EMBASE, CINAHL, and the Cochrane Library was performed to identify randomized controlled trials (RCTs) that compared formoterol plus tiotropium to tiotropium alone in COPD patients with a duration of at least 4 weeks. The cut-off date for the search was July 1, 2015. The odds ratio (OR) or mean difference (MD) was used to pool the results with 95% confidence intervals (CI). RESULTS: Eight randomized controlled trials were eligible for this meta-analysis. A significant improvement was observed among patients treated with tiotropium plus formoterol compared with tiotropium alone in the following spirometric indices: mean change in trough FEV1 (P = .02), trough FVC (P = .007), peak FEV1 (P < .00001), and peak FVC (P < .00001). A similar result was noted for the transitional dyspnea index (TDI) (MD 1.46; 95% CI 1.07-1.85) and a clinically significant change in TDI between the tiotropium plus formoterol and tiotropium alone groups (P < .00001). Moreover, a trend toward fewer adverse events was seen in the combination treatment group compared with the tiotropium group (OR .88; 95% CI .70-1.11), although this difference was not statistically significant. CONCLUSIONS: Compared with tiotropium alone, tiotropium in combination with formoterol improved lung function and the symptoms of dyspnea in stable moderate-to-severe COPD patients. Moreover, the combined treatment group tended to have fewer adverse events compared with the tiotropium treatment alone group.

Phospholipase D and phosphatidic acid mediate heat stress induced secondary metabolism in Ganoderma lucidum.

Phospholipid-mediated signal transduction plays a key role in responses to environmental changes, but little is known about the role of phospholipid signalling in microorganisms. Heat stress (HS) is one of the most important environmental factors. Our previous study found that HS could induce the biosynthesis of the secondary metabolites, ganoderic acids (GA). Here, we performed a comprehensive mass spectrometry-based analysis to investigate HS-induced lipid remodelling in Ganoderma lucidum. In particular, we observed a significant accumulation of phosphatidic acid (PA) on HS. Further genetic tests in which pld-silencing strains were constructed demonstrated that the accumulation of PA is dependent on HS-activated phospholipase D (PLD) hydrolysing phosphatidylethanolamine. Furthermore, we determined the role of PLD and PA in HS-induced secondary metabolism in G. lucidum. Exogenous 1-butanol, which decreased PLD-mediated formation of PA, reverses the increased GA biosynthesis that was elicited by HS. The pld-silenced strains partly blocked HS-induced GA biosynthesis, and this block can be reversed by adding PA. Taken together, our results suggest that PLD and PA are involved in the regulation of HS-induced secondary metabolism in G. lucidum. Our findings provide key insights into how microorganisms respond to heat stress and then consequently accumulate secondary metabolites by phospholipid remodelling.

Polymyxin B as an inhibitor of lipopolysaccharides contamination of herb crude polysaccharides in mononuclear cells.

Lipopolysaccharides (LPS) contamination in herbal crude polysaccharides is inevitable. The present study was performed to explore the effect of polymyxin B on abolishing the influence of LPS contamination in mononuclear cells. LPS was pretreated with polymyxin B sulfate (PB) at different concentrations for 1, 5 or 24 h, and then used to stimulate RAW264.7 and mouse peritoneal macrophages (MPMs). The nitric oxide (NO) and tumor necrosis factor-α (TNF-α) in cell culture supernatant, as the indications of cell response, were assayed. Bupleurum chinensis polysaccharides (BCPs) with trace amount contamination of LPS was treated with PB. 30 µg·mL-1 of PB, treating LPS (10 and 1 000 ng·mL-1 in stimulating RAW264.7 and MPMs respectively) at 37 °C for 24 h, successfully abolished the stimulating effect of LPS on the cells. When the cells were stimulated with LPS, BCPs further promoted NO production. However, pretreated with PB, BCPs showed a suppression of NO production in MPMs and no change in RAW264.7. In the in vitro experiments, LPS contamination in polysaccharide might bring a great interference in assessing the activity of drug. Pretreatment with PB (30 µg·mL-1) at 37 °C for 24 h was sufficient to abolish the effects of LPS contamination (10 and 1 000 ng·mL-1).

Receptor for advanced glycation end as drug targets in diabetes-induced skin lesion.

The involvement of the receptor for advanced glycation end (RAGE) in different diseases has been reviewed in great detail, previously, but the effects of diabetic drugs on RAGE-induced skin lesion during long course diabetes remains poorly understood. In the present study, we have shown that RAGE was overexpressed in both diabetic rats and human keratinocytes (HaCaT cells). Cell cycle arrest and apoptosis as well as alternations of relative protein levels were also found in diabetic rats and HaCaT cells with overexpression of RAGE that were rectified by metformin (Met) treatment. Moreover, overexpression of RAGE was also found to induce secretions of TNF-α, IL-1ß, IL-6, ICAM-1 and COX-2 in HaCaT cells, and Met treatment corrected these inflammatory factor secretions. In addition, treatment with Met markedly reduced RAGE overexpression-induced p38 and NF-κB activation. Taken together, the findings of the present study have demonstrated, for the first time that Met protects HaCaT cells against diabetes-induced injuries and inflammatory responses through inhibiting activated RAGE.

Membrane fluidity is involved in the regulation of heat stress induced secondary metabolism in Ganoderma lucidum.

Ganoderma lucidum has become a potential model system for evaluating how environmental factors regulate the secondary metabolism of basidiomycetes. Heat stress (HS) is one of the most important environmental factors. It was previously reported that HS could induce the biosynthesis of ganoderic acids (GA). In this study, we found that HS increased GA biosynthesis and also significantly increased cell membrane fluidity. Furthermore, our results showed that addition of the membrane rigidifier dimethylsulfoxide (DMSO) could revert the increased GA biosynthesis elicited by HS. These results indicate that an increase in membrane fluidity is associated with HS-induced GA biosynthesis. Further evidence showed that the GA content was decreased in D9des-silenced strains and could be reverted to WT levels by addition of the membrane fluidizer benzyl alcohol (BA). In contrast, GA content was increased in D9des-overexpression strains and could be reverted to WT levels by the addition of DMSO. Furthermore, both membrane fluidity and GA biosynthesis induced by HS could be reverted by DMSO in WT and D9des-silenced strains. To the best of our knowledge, this is the first report demonstrating that membrane fluidity is involved in the regulation of heat stress induced secondary metabolism in filamentous fungi.

Identification of Reference Genes and Analysis of Heat Shock Protein Gene Expression in Lingzhi or Reishi Medicinal Mushroom, Ganoderma lucidum, after Exposure to Heat Stress.

Ganoderma lucidum has been considered an emerging model species for studying how environmental factors regulate the growth, development, and secondary metabolism of Basidiomycetes. Heat stress, which is one of the most important environmental abiotic stresses, seriously affects the growth, development, and yield of microorganisms. Understanding the response to heat stress has gradually become a hotspot in microorganism research. But suitable reference genes for expression analysis under heat stress have not been reported in G. lucidum. In this study, we systematically identified 11 candidate reference genes that were measured using reverse transcriptase quantitative polymerase chain reaction, and the gene expression stability was analyzed under heat stress conditions using geNorm and NormFinder. The results show that 5 reference genes-CYP and TIF, followed by UCE2, ACTIN, and UBQ1-are the most stable genes under our experimental conditions. Moreover, the relative expression levels of 3 heat stress response genes (hsp17.4, hsp70, and hsp90) were analyzed under heat stress conditions with different normalization strategies. The results show that use of a gene with unstable expression (SAND) as the reference gene leads to biased data and misinterpretations of the target gene expression level under heat stress.

PTEN Inhibits Cell Proliferation, Promotes Cell Apoptosis, and Induces Cell Cycle Arrest via Downregulating the PI3K/AKT/hTERT Pathway in Lung Adenocarcinoma A549 Cells.

PTEN plays an essential role in tumorigenesis and both its mutation and inactivation can influence proliferation, apoptosis, and cell cycle progression in tumor cells. However, the precise role of PTEN in lung cancer cells has not been well studied. To address this, we have generated lung adenocarcinoma A549 cells overexpressing wild-type or mutant PTEN as well as A549 cells expressing a siRNA directed toward endogenous PTEN. Overexpression of wild-type PTEN profoundly inhibited cell proliferation, promoted cell apoptosis, caused cell cycle arrest at G1, downregulated p-AKT, and decreased expression of the telomerase protein hTERT. In contrast, in cells expressing a PTEN directed siRNA, the opposite effects on cell proliferation, apoptosis, cell cycle arrest, p-AKT levels, and hTERT protein expression were observed. A549 cells transfected with a PTEN mutant lacking phosphatase activity (PTEN-C124A) or an empty vector (null) did not show any effect. Furthermore, using the PI3K/AKT pathway blocker LY294002, we confirmed that the PI3K/AKT pathway was involved in mediating these effects of PTEN. Taken together, we have demonstrated that PTEN downregulates the PI3K/AKT/hTERT pathway, thereby suppressing the growth of lung adenocarcinoma cells. Our study may provide evidence for a promising therapeutic target for the treatment of lung adenocarcinoma.

PTEN expression is a prognostic marker for patients with non-small cell lung cancer: a systematic review and meta-analysis of the literature.

Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is a known tumor suppressor in non-small cell lung cancer (NSCLC). By performing a systematic review and meta-analysis of the literature, we determined the prognostic value of decreased PTEN expression in patients with NSCLC. We comprehensively and systematically searched through multiple online databases up to May 22, 2016 for NSCLC studies reporting on PTEN expression and patient survival outcome. Several criteria, including the Newcastle-Ottawa Quality Assessment Scale (NOS), were used to discriminate between studies. In total, 23 eligible studies with a total of 2,505 NSCLC patients were included in our meta-analysis. Our results demonstrated that decreased expression of PTEN correlated with poor overall survival in NSCLC patients and was indicative of a poor prognosis for disease-free survival and progression-free survival in patients with NSCLC.

Exogenous spermine inhibits the proliferation of human pulmonary artery smooth muscle cells caused by chemically-induced hypoxia via the suppression of the ERK1/2- and PI3K/AKT-associated pathways.

Pulmonary vascular remodeling is a significant pathological feature of hypoxia-induced pulmonary hypertension (HPH), while pulmonary artery smooth muscle cell (PASMC) proliferation plays a leading role in pulmonary vascular remodeling. Spermine (Sp), a polyamine, plays a critical role in periodic cell proliferation and apoptosis. The present study was conducted to observe the association between hypoxia-induced PASMC proliferation and polyamine metabolism, and to explore the effects of exogenous Sp on PASMC poliferation and the related mechanisms. In the present study, PASMCs were cultured with cobalt chloride (CoCl2) to establish a hypoxia model, and Sp at various final concentrations (0.1, 1, 10 and 100 µM) was added to the medium of PASMCs 40 min prior to the induction of hypoxia. Cell proliferation was measured by 3-(4,5-dimethylthiazol­2­yl)­2,5­diphenyltetrazolium bromide (MTT) assay, cell counting kit-8 assay and 5-bromo­2'­deoxyuridine (BrdU) incorporation assay. Cell cycle progression was determined by flow cytometry, and the protein expression levels of spermidine/spermine N1-acetyltransferase (SSAT; the key enzyme in the terminal degradation of polyamine), ornithine decarboxylase (ODC; the key enzyme of polyamine biosynthesis), cyclin D1 and p27 were measured by western blot analysis. The results revealed that the proliferation of the PASMCs cultured with CoCl2 at 50 µM for 24 h markedly increased. The expression of ODC was decreased and the expression of SSAT was increased in the cells under hypoxic conditions. Exogenous Sp at concentrations of 1 and 10 µM significantly inhibited hypoxia-induced PASMC proliferation, leading to cell cycle arrest at the G1/G0 phase. In addition, Sp decreased cyclin D1 expression, increased p27 expression, and suppressed the phosphorylation of extracellular signal­regulated kinase 1/2 (ERK1/2), phosphatidylinositol 3-kinase (PI3K) and protein kinase B (AKT); however, the above-metioned parameters were not markedly affected by Sp at concentrations of 0.1 or 100 µM. These results suggest that hypoxia disrupts polyamine metabolism, and Sp at concentrations of 1 and 10 µM inhibits the increase in human PASMC proliferation caused by chemically-induced hypoxia via the suppression of the ERK1/2- and PI3K/AKT-associated pathways. This study thus offer new insight into the prevention and treatment of HPH.