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Biomedical subjects

Bo Shen

Publications and source records attributed to Bo Shen.

At least 19 recordsLinked to original sources
PubMed2026

CeOx-Induced Spatial and Electronic Modulation for General Direct Oxo Coupling in Transition Metal Hydroxides.

Electrochemical water splitting has emerged as a sustainable paradigm for hydrogen generation, where sluggish kinetics of the oxygen evolution reaction (OER) catalyzed by transition metal-based materials remain the critical bottleneck. Herein, we present a strategy that anchors CeOx nanoparticles (∼2 nm) onto two-dimensional Ni(OH)2 nanosheets, enabling dual modulation of spatial configuration and electronic states to accelerate O-O coupling. Spatially, interfacial lattice distortion between CeOx and Ni(OH)2 optimizes Ni-Ni dual-metal sites with reduced interatomic spacing. Electronically, dynamic modulation through reversible Ce3+/Ce4+ redox cycling positions Ce as an electronic regulation hub, stabilizing Ni species at the catalytically favorable +3 oxidation state through Ce─O─Ni interactions. This synergistic effect shifts the pathway from adsorbate evolution mechanism (AEM) to oxide pathway mechanism (OPM). The prepared CeOx@Ni(OH)2 achieves an overpotential of 152 mV at 10 mA cm-2 and operates continuously over 2000 h with limited performance decay. When integrated into an alkaline anion exchange membrane water electrolyzer (AEMWE), it requires 1.91 V to attain 1 A cm-2 and maintains stable operation for 450 h. This OPM activation strategy shows potential applicability across CeOx-loaded transition metal hydroxides, including Ni(OH)2, Co(OH)2, NiCo, and NiFe layered double hydroxides, offering a promising approach for alkaline OER enhancement.

alkaline water oxidation↗
PubMed2025

Beta-catenin/sirtuin 1/farnesoid X receptor pathway promotion of portal vein ligation and parenchymal transection-induced rapid liver regeneration.

BACKGROUND: By accelerating the regeneration of the future liver remnant, portal vein ligation and parenchymal transection allows for more extensive hepatectomy. Given that the mechanism remains poorly understood, the aim of this study was to investigate the mechanism of portal vein ligation and parenchymal transection-induced liver regeneration. METHODS: A portal vein ligation and parenchymal transection-induced liver regeneration mouse model was established, followed by RNA microarray analysis to identify candidate molecules. Genomic deletion and chemical manipulation of target molecules were used to explore their functions in portal vein ligation and parenchymal transection-induced liver regeneration. Validation was conducted using a diseased liver model and human samples. RESULTS: Portal vein ligation and parenchymal transection-induced liver regeneration was significantly accelerated compared with that in sham-operated mice (P < .05). An RNA microarray revealed that Sirtuin 1 is a crucial molecule in the proliferation of the future liver remnant. Regardless of whether Sirtuin 1 is inhibited chemically or through genetic deletion, portal vein ligation and parenchymal transection-induced liver regeneration is distinctly attenuated. Further investigation revealed that Sirtuin 1 promoted portal vein ligation and parenchymal transection-induced liver regeneration via the farnesoid X receptor. In addition, beta-catenin also was found to participate in the process of future liver remnant proliferation. Chemical inhibition of beta-catenin markedly impaired but activation of WNT/beta-catenin mildly enhanced portal vein ligation and parenchymal transection-induced liver regeneration (P < .05). Deletion of Sirtuin 1 blocked the facilitating effect of beta-catenin on portal vein ligation and parenchymal transection-induced liver regeneration. These findings were validated in diseased liver models and patient samples, confirming the correlation between the beta-catenin/Sirtuin 1/farnesoid X receptor pathway and portal vein ligation and parenchymal transection-induced liver regeneration. CONCLUSION: Activation of the beta-catenin/Sirtuin 1/farnesoid X receptor pathway offers critical mechanistic insights into accelerating portal vein ligation and parenchymal transection-induced liver regeneration. Modulation of beta-catenin/Sirtuin 1/farnesoid X receptor may therefore improve clinical outcomes in patients receiving staged hepatectomy.

Liver Regeneration↗
PubMed2025

Decoding nitrogen uptake efficiency in maize and sorghum: insights from comparative gene regulatory networks.

Nitrogen (N) is an essential macronutrient for plant growth and yield, yet optimizing nitrogen use efficiency remains a challenge in agriculture. To better understand the regulatory basis of plant responses to N availability, we constructed a maize-specific nitrogen uptake efficiency gene regulatory network (mNUEGRN) comprising 1625 protein-DNA interactions (PDI) between 70 promoters and 301 transcription factors using enhanced yeast one-hybrid assays. We also projected a sorghum NUE GRN (spNUEGRN) based on maize orthologs and analyzed N-responsive subnetworks in both species using transcriptome profiling under N stress of early deprivation and recovery. Cross-species comparison with an existing Arabidopsis GRN revealed about 18% conserved interaction, corresponding to 11% of the mNUEGRN, particularly within the nitrate assimilation pathways. Notably, bZIP18 and bZIP30 emerged as central regulators in mNUEGRN, forming highly connected feed-forward loops (FFLs). From our time series data, we identified 19&#x2009;236 and 23&#x2009;864 differentially expressed genes in maize and sorghum, respectively. Gini correlation analysis uncovered 764 and 638 FFLs in mNUEGRN and spNUEGRN, respectively, of which 22 FFLs in maize and 35 in sorghum were identified in both leaf and root for each species. These FFLs may represent candidate regulatory motifs that contribute to modulating transcriptional responses under fluctuating N conditions, but their potential roles require further investigation. Together, our findings reveal evolutionarily conserved and species-specific regulatory strategies that mediate early N responsiveness, offering a foundation for engineering crops with improved NUE.

Sorghum↗
PubMed2007

Kinin infusion prevents renal inflammation, apoptosis, and fibrosis via inhibition of oxidative stress and mitogen-activated protein kinase activity.

The progression of renal disease displays several characteristics, including proteinuria, apoptosis, inflammation, and fibrosis. In this study, we investigated the effect of long-term infusion of kinin in protection against salt-induced renal damage in Dahl salt-sensitive rats. Dahl salt-sensitive rats were fed a high-salt diet for 2 weeks and were then infused with bradykinin (500 ng/h) via subcutaneously implanted minipumps for 3 weeks. Kinin infusion attenuated salt-induced impaired renal function as evidenced by reduced proteinuria, serum creatinine, and blood urea nitrogen levels without apparent effect on blood pressure. Morphological analysis indicated that kinin administration reduced salt-induced glomerular sclerosis, tubular dilatation, luminal protein cast formation, and interlobular arterial thickness. Kinin also significantly lowered collagen I, III, and IV deposition and their mRNA levels. Moreover, kinin reduced interstitial monocyte/macrophage accumulation, as well as tubular cell apoptosis and caspase-3 activity. Protection of renal injury by kinin was associated with increased renal NO levels and reduced nicotinamide adenine dinucleotide/nicotinamide adenine dinucleotide phosphate oxidase activities and superoxide generation. Suppression of oxidative stress by kinin was accompanied by reduced transforming growth factor-beta1 protein and mRNA levels, as well as decreased phosphorylation of mitogen-activated protein kinases. This is the first study to demonstrate that kinin infusion can directly protect against salt-induced renal injury without blood pressure reduction by inhibiting apoptosis, inflammation, and fibrosis via suppression of oxidative stress, transforming growth factor-beta1 expression, and mitogen-activated protein kinase activation.

Animals↗
PubMed2007

Extraction of paeonol from Jisheng Shenqi Wan using supercritical fluid extraction.

Supercritical carbon dioxide with or without methanol and 95% ethanol modifiers was used to extract paeonol from the pills of Jisheng Shenqi Wan and high-performance liquid chromatography (HPLC) was used to analyze the extract. The effect of temperature and pressure on the yield of paeonol was tested. The results show that the recovery of paeonol was improved by adding a polar modifier, such as methanol and 95% ethanol in supercritical fluid. The yield obtained after 120 min extraction with 95% ethanol modified-supercritical carbon dioxide was the highest (1.51, w/w at 60 degrees C and 400 bar), while that obtained with supercritical carbon dioxide only at 40 degrees C was the lowest from 0.67 to 0.83 over a range of 200-600 bar.

Acetophenones↗
PubMed2007

Risk factors for anemia in patients with ileal pouch-anal anastomosis.

PURPOSE: Anemia is frequently observed in patients with ileal pouch-anal anastomosis. The identification of the underlying causes can be challenging. This study was designed to define the prevalence and to identify etiologic factors for anemia in this patient population. METHODS: A prospectively maintained database and medical records of patients who had restorative proctocolectomy between 1998 and 2005 were reviewed. All patients with laboratory evaluation at least six months after the surgery were studied. The last reported hemoglobin served as the index value. All patients with anemia (hemoglobin < 13.5 g/dl for males, <12 g/dl for females) were identified. A second group of randomly selected, ileal-pouch patients with normal hemoglobin served as control. Demographic and clinical variables were evaluated. RESULTS: A total of 389 patients (214 males) had documented hemoglobin values. Sixty-seven patients (17 percent; 40 males) had anemia. The prevalence of anemia was 19 and 15 percent in males and females, respectively. The prevalence was 17 percent among patients with underlying ulcerative colitis vs. 26 percent in patients with familial adenomatous polyposis (P = 0.27). The mean hemoglobin in the anemia group was 11.4 (median, 11.7) g/dl. One patient (2 percent) had severe (<7 g/dl), 11 (16 percent) had moderate (7-9.9 g/dl), and 55 (82 percent) had mild (> or =10 g/dl) anemia. One patient (2 percent) had macrocytic, 16 (24 percent) had microcytic, and 49 (74 percent) had normocytic anemia. Sixteen patients (24 percent) had unidentified causes for anemia. Multivariable analysis showed that the presence of malignancy or desmoid tumor and the J-pouch configuration were the only independent risk factors associated with anemia. CONCLUSIONS: Anemia is common in ileal-pouch patients. Malignancy or desmoid tumor and J-pouch configuration are independent risk factors for anemia. One-fourth of the patients with anemia have unclear etiology.

Anemia↗
PubMed2006

Tissue kallikrein infusion prevents cardiomyocyte apoptosis, inflammation and ventricular remodeling after myocardial infarction.

We investigated the effect of tissue kallikrein infusion on cardiac protection at acute and sub-acute phases after myocardial infarction (MI). Immediately after MI, rats were infused with purified tissue kallikrein, with or without icatibant (a kinin B2 receptor antagonist). Intramyocardial injection of kallikrein reduced myocardial infarct size and inhibited cardiomyocyte apoptosis at 1 day after MI associated with increased nitric oxide levels, Akt and glycogen synthase kinase-3beta phosphorylation and decreased caspase-3 activation. Kallikrein infusion for 7 days improved cardiac function, normalized left ventricular wall thickness and decreased monocyte/macrophage infiltration in the infarct heart. Kallikrein treatment reduced NADH oxidase expression and activity, superoxide formation and malondialdehyde levels, and reduced MAPK and Ikappa-Balpha phosphorylation, NF-kappaB activation and MCP-1 and VCAM-1 expression. Kallikrein's effects were all blocked by icatibant. These results indicate that kallikrein through kinin B2 receptor activation prevents apoptosis, inflammation and ventricular remodeling by increased nitric oxide formation and suppression of oxidative stress-mediated signaling pathways.

Animals↗
PubMed2006

Clostridium difficile-associated pouchitis.

Pouchitis is the most common long-term sequela of ileal pouch-anal anastomosis (IPAA) following total proctocolectomy. No single pathogen is identified as being solely responsible for the pathogenesis of the disease. Here we describe a case of Clostridium difficile-associated pouchitis that was successfully treated with ciprofloxacin and tinidazole. Diagnosis and management of a patient with medically refractory pouchitis associated with Clostridium difficile infection is described. A 63-year-old male with underlying ulcerative colitis and IPAA presented with increased stool frequency and seepage for 2 months, which partially responded to oral metronidazole. While on the antibiotic therapy, pouch endoscopy was performed and showed severe pouchitis. Assays for Clostridium difficile toxins in stool specimens were positive. He was treated with a 4-week course of ciprofloxacin 500 mg BID and tinidazole 500 mg TID. His symptoms resolved within several days from the initiation of therapy. A repeat pouch endoscopy at week 5 showed a complete resolution of mucosal inflammation of the pouch, while tests for Clostridium difficile toxins became negative. Clostridium difficile-associated pouchitis is rare. However, Clostridium difficile infection should be excluded in patients with chronic refractory pouchitis.

Anti-Infective Agents↗
PubMed2006

Tissue kallikrein protects against pressure overload-induced cardiac hypertrophy through kinin B2 receptor and glycogen synthase kinase-3beta activation.

OBJECTIVE: We assessed the role of glycogen synthase kinase-3beta (GSK-3beta) and kinin B2 receptor in mediating tissue kallikrein's protective effects against cardiac hypertrophy. METHODS: We investigated the effect and mechanisms of tissue kallikrein using hypertrophic animal models of rats as well as mice deficient in kinin B1 or B2 receptor after aortic constriction (AC). RESULTS: Intramyocardial delivery of adenovirus containing the human tissue kallikrein gene resulted in expression of recombinant kallikrein in rat myocardium. Kallikrein gene delivery improved cardiac function and reduced heart weight/body weight ratio and cardiomyocyte size without affecting mean arterial pressure 28 days after AC. Icatibant and adenovirus carrying a catalytically inactive GSK-3beta mutant (Ad.GSK-3beta-KM) abolished kallikrein's effects. Kallikrein treatment increased cardiac nitric oxide (NO) levels and reduced NAD(P)H oxidase activity and superoxide production. Furthermore, kallikrein reduced the phosphorylation of apoptosis signal-regulating kinase1, mitogen-activated protein kinases (MAPKs), Akt, GSK-3beta, and cAMP-response element binding (CREB) protein, and decreased nuclear factor-kappaB (NF-kappaB) activation in the myocardium. Ad.GSK-3beta-KM abrogated kallikrein's actions on GSK-3beta and CREB phosphorylation and NF-kappaB activation, whereas icatibant blocked all kallikrein's effects. The protective role of kinin B2 receptor in cardiac hypertrophy was further confirmed in kinin receptor knockout mice as heart weight/body weight ratio and cardiomyocyte size increased significantly in kinin B2 receptor knockout mice after AC compared to wild type and B1 receptor knockout mice. CONCLUSIONS: These findings indicate that tissue kallikrein, through kinin B2 receptor and GSK-3beta signaling, protects against pressure overload-induced cardiomyocyte hypertrophy by increased NO formation and oxidative stress-induced Akt-GSK-3beta-mediated signaling events, MAPK and NF-kappaB activation.

Adenoviridae↗
PubMed2006

Paneth cell antimicrobial peptides: topographical distribution and quantification in human gastrointestinal tissues.

Antimicrobial peptides and proteins are key effectors of innate immunity, expressed both by circulating phagocytic cells and by epithelial cells of mucosal tissues. In the human small intestine, Paneth cells are secretory epithelial cells that express the antimicrobials human alpha-defensin-5 (HD5), HD6, lysozyme and secretory phospholipase A(2) (sPLA(2)), and recent studies have implicated reduced HD5 and HD6 expression levels in the pathogenesis of ileal Crohn's disease. However, expression levels of these molecules have not been determined routinely by techniques that readily permit quantitative comparisons of their distribution between tissues and samples. Using quantitative real-time PCR with external standards and Northern blot analysis, we compared expression levels of mRNA encoding these four Paneth cell antimicrobial peptides, as well as circulating human neutrophil defensins in several different gastrointestinal tissues and the bone marrow. HD5 and HD6 were the most abundant antimicrobials expressed in the small intestine. The concentration of HD5 mRNA is approximately 5 x 10(5) copies per 10ng RNA in the jejunum and ileum; HD6 mRNA levels were about six times lower than those of HD5. With the exception of low levels in the pancreas (10(3) copies/10 ng RNA), the expression of HD5 and HD6 in tissues other than small intestine was at or below detectable limits. The expression of sPLA2 and lysozyme mRNA was observed in the small intestine (approximately, 3 x 10(3) and 9 x 10(3) copies/10 ng RNA, respectively), but also in several other tissues. Lysozyme expression was high in the duodenum (10(5) copies/10 ng RNA), and the protein localized to both Brunner's glands in the lamina propria and Paneth cells. By comparison, the hematopoietic alpha-defensins HNP1-3 mRNA were detected at 6 x 10(5) copies per 10 ng RNA in the bone marrow. These quantitative RT-PCR data from healthy tissues represents the first quantitative topographical assessment of antimicrobial expression in the gastrointestinal tract and provides a means to directly compare expression levels between healthy tissues and disease specimens for multiple antimicrobial peptides.

Anti-Infective Agents↗
PubMed2006

Postischemic brain injury is exacerbated in mice lacking the kinin B2 receptor.

Kallikrein cleaves low molecular weight kininogen to generate vasoactive kinins, which bind to the kinin B2 receptor, triggering a host of biological effects. Kallikrein gene delivery has been shown previously to reduce ischemia/reperfusion-induced cerebral infarction. In this study, we tested the hypothesis that the kinin B2 receptor plays a protective role in ischemic brain injury using kinin B2 receptor gene knockout (B2R-KO) mice subjected to middle cerebral artery occlusion (MCAO). The mortality rate and neurological deficit scores of B2R-KO mice (n=48) after MCAO were significantly increased compared with wild-type (WT) mice (n=40) when examined over a 14-day period. In addition, the infarct volume in B2R-KO mice was significantly larger than in WT mice at days 1 and 3 after MCAO. Similarly, apoptotic cells, detected by TUNEL labeling counterstained with propidium iodide, and caspase-3 activity in the ischemic brain increased significantly in B2R-KO mice at days 1 and 3 after MCAO. Furthermore, the accumulation of neutrophils in the ischemic brain of B2R-KO mice after MCAO increased when compared with WT mice and was associated with elevated tumor necrosis factor alpha expression. These alterations in B2R-KO mice correlated with decreased NO levels, Akt, and glycogen synthase kinase-3beta phosphorylation and increased nicotinamide-adenine dinucleotide oxidase activity. These results indicate that the kinin B2 receptor promotes survival and protects against brain injury by suppression of apoptosis and inflammation induced by ischemic stroke.

Animals↗
PubMed2006

The homeobox gene GLABRA2 affects seed oil content in Arabidopsis.

Despite a good understanding of genes involved in oil biosynthesis in seed, the mechanism(s) that controls oil accumulation is still not known. To identify genes that control oil accumulation in seed, we have developed a simple screening method to isolate Arabidopsis seed oil mutants. The method includes an initial screen for seed density followed by a seed oil screen using an automated Nuclear Magnetic Resonance (NMR). Using this method, we isolated ten low oil mutants and one high oil mutant. The high oil mutant, p777, accumulated 8% more oil in seed than did wild type, but it showed no differences in seed size, plant growth or development. The high-oil phenotype is caused by the disruption of the GLABRA2 gene, a previously identified gene that encodes a homeobox protein required for normal trichome and root hair development. Knockout of GLABRA2 did not affect LEAFY COTYLEDON 1 and PICKLE expression in developing embryo. The result indicates that in addition to its known function in trichome and root hair development, GLABRA2 is involved in the control of seed oil accumulation.

Adhesives↗
PubMed2006

Diagnosis and treatment of ileal pouch diseases in patients with underlying ulcerative colitis.

Ileal pouch-anal anastomosis (IPAA) after total proctocolectomy is the surgical treatment of choice for ulcerative colitis (UC) patients with medically refractory disease or dysplasia. IPAA significantly improves quality of life in UC patients who require surgery. However, certain inflammatory and noninflammatory diseases can develop after the surgery, including pouchitis, Crohn's disease (CD) of the pouch, cuffitis, and irritable pouch syndrome. The cause and pathogenesis of these disease conditions of IPAA are largely unknown. Accurate diagnosis and classification are important for appropriate management.

Journal Article↗
PubMed2006

Risk factors for diseases of ileal pouch-anal anastomosis after restorative proctocolectomy for ulcerative colitis.

BACKGROUND & AIMS: Although pouchitis is considered the most common adverse sequela of ileal pouch-anal anastomosis (IPAA), inflammatory and noninflammatory conditions other than pouchitis are increasingly being recognized. The risk factors for these non-pouchitis conditions, including Crohn's disease (CD) of the pouch, cuffitis, and irritable pouch syndrome (IPS), have not been studied. The aim of this study was to assess risk factors for inflammatory and noninflammatory diseases of IPAA in a tertiary care setting. METHODS: The study consisted of 240 consecutive patients who were classified as having healthy pouches (N = 49), pouchitis (N = 61), CD of the pouch (N = 39), cuffitis (N = 41), or IPS (N =50). Demographic and clinical features were assessed to determine risk factors for each of these conditions by using logistic regression analysis. RESULTS: Risk factors remaining in the final logistic regression models were for pouchitis: IPAA indication for dysplasia (odds ratio [OR], 3.89; 95% confidence interval [CI], 1.69-8.98), never having smoked (OR, 5.09; 95% CI, 1.01-25.69), no use of anti-anxiety agents (OR, 5.19; 95% CI, 1.45-18.59), or use of NSAIDs (OR, 3.24; 95% CI, 1.71-6.13); for CD of the pouch: a long duration of IPAA (OR, 1.20; 95% CI, 1.12-1.30) and current smoking (OR, 4.77; 95% CI, 1.39-16.25); for cuffitis: arthralgias (OR, 4.13; 95% CI, 1.91-8.94) and younger age (OR, 1.16; 95% CI, 1.01-1.33); and for IPS: use of antidepressants (OR, 4.17, 95% CI, 1.95-8.92) or anti-anxiety agents (OR, 3.21; 95% CI, 1.34-7.47). CONCLUSIONS: The majority of risk factors for the 4 inflammatory and noninflammatory conditions of IPAA are different, suggesting that each of these diseases has a different etiology and pathogenesis. The identification and modification of these risk factors might help patients and clinicians to make a preoperative decision for IPAA, reduce IPAA-related morbidity, and improve response to treatment.

Adult↗