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Biomedical subjects

Peng Jiang

Publications and source records attributed to Peng Jiang.

At least 19 recordsLinked to original sources

Conditional eIF2A Deletion Suggests Extra-Adipose Mechanisms Underlying Metabolic Syndrome in Total-Body eIF2A Knockout Mice.

Dynamic regulation of protein synthesis is essential for metabolic homeostasis, with translation initiation playing a key role in this process. Emerging evidence strongly indicates that in addition to canonical eukaryotic initiation factors (e.g., eIF2, eIF4E) non-canonical factors, such as eukaryotic initiation factor 2A can modulate metabolic homeostasis. eIF2A is a highly conserved eukaryotic protein originally proposed to function analogously to bacterial IF2, promoting initiator Met-tRNAi recruitment to the 40S ribosomal subunit, though its precise mechanism remains debated. To investigate its organismal role, we have previously generated the total-body eIF2A knockout mouse, which revealed eIF2A functions in lipid homeostasis, glucose tolerance, insulin sensitivity, and susceptibility to metabolic syndrome. To further determine whether adipose tissue drives these phenotypes, we presently generated adipose-specific eIF2A knockout mice. Despite dysregulation of some key adipokines, including for example, adiponectin, these mice did not develop metabolic syndrome, even under high-fat diet conditions, indicating that adipose tissue specific deficiency of eIF2A is insufficient to reproduce the metabolic defects observed in total-body knockout. However, we found that eIF2A deficiency in the liver of the total body eIF2A-KO mice can independently drive metabolic syndrome components via translational control of Lpin1 (a phosphatidate phosphatase and a transcriptional coactivator) that controls hepatic lipid storage and metabolism. eIF2A deficiency in the liver leads to disruption of fatty acid oxidation and the production of ketone bodies, not observed in adipose-specific eIF2A knockout mice. Our findings suggest that systemic metabolic effects observed in the total body eIF2A-KO mice may arise from coordinated functions across multiple organs.

adipose tissue↗

SIVA: diagonal integration of spatial multi-omics data via spatially informed variational autoencoders and anchor guidance.

MOTIVATION: Understanding cellular states and regulatory programs requires integrative analysis of multiple omics layers. Although recent spatial sequencing technologies allow molecular profiling of cells within their tissue context, paired spatial multi-omics assays are still limited by technical complexity and cost. This creates a pressing need for diagonal integration methods that enable joint analysis of unpaired spatial omics datasets. RESULTS: We propose SIVA, a deep generative framework based on Spatially-Informed Variational Autoencoders with Anchor Guidance, for diagonal integration of spatial multi-modal data. SIVA employs modality-specific variational autoencoders (VAEs) with a hybrid latent embedding that integrates Gaussian process and standard Gaussian priors, enabling joint modeling of spatially structured variation and dominant underlying data distributions across modalities. To facilitate cross-modal alignment in the absence of one-to-one cell correspondence, SIVA adopts a dual integration strategy combining global distribution alignment via Maximum Mean Discrepancy and local correspondence guidance using mutual nearest neighbor anchors. Extensive experiments across multiple cross-slice integration scenarios demonstrate that SIVA achieves robust and accurate integration of unpaired spatial omics datasets, consistently outperforming existing methods. AVAILABILITY AND IMPLEMENTATION: The source codes are available at https://github.com/PelenJiang/SIVA.

Autoencoder↗

Effects of hepatotrophic factors on the liver after portacaval shunt in rats with portal hypertension.

BACKGROUND: Portacaval shunt (PCS) prevent hepatotrophic factors from flowing into the liver, but they enter directly the systemic circulation and worsen liver injury. This study was designed to investigate the effects of hepatotrophic factors through the portal vein on the liver in rats with portal hypertension after portacaval shunt. METHODS: Intrahepatic portal hypertension (IHPH) was induced by intragastric administration of carbon tetrachloride, and end-to-side PCS was performed. Eight normal rats served as controls, and eight rats with IHPH served as IHPH model (IHPH group). Another 32 rats with IHPH-PCS were randomly subdivided into 4 groups: normal saline (NS) given to 8 rats, hepatocyte growth factor (HGF) 8, insulin (INS) 8, hepatocyte growth factor and insulin (HGF + INS) 8. Hepatotrophic factors were infused into the portal vein through an intravenous catheter. Portal venous pressure (PVP) was measured. The levels of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were tested biochemically and those of hyaluronic acid (HA) and laminin (LN) were measured by radioimmunoassay. Hepatic fibrosis was assessed histologically and the expression of collagens type I and III were detected immunohistochemically. Ultrastructural change of hepatocytes and the number of mitochondria were observed under an electron microscope. The data were compared between groups and subgroups by Student-Newman-Keuls procedure with SPSS10.0. RESULTS: PVP was significantly higher in the IHPH rats than in the control rats (P < 0.05). The levels of serum ALT, AST, HA, and LN, hepatic fibrosis score, the amount of collagen deposition, collagens type I and III increased more significantly in the IHPH group than in the control rats (P < 0.05). The number of mitochondria decreased more significantly in the IHPH rats than in the control rats (P < 0.05). The levels of serum ALT, AST, HA and LN as well as hepatic fibrosis score, the amount of collagen deposition, and the amount of collagens type I and III in the HGF and HGF + INS rats were significantly lower than those in the NS rats (P < 0.05). The damage to hepatocyte ultrastructure was markedly alleviated and the number of mitochondria was increased more significantly in the HGF and HGF + INS rats than in the NS rats under an electron microscope. CONCLUSIONS: Perfusion of exogenous hepatotrophic factors through the portal vein can alleviate liver injury, minimize the damage to the ultrastructure of hepatocyte, protect liver function, and lessen hepatic fibrosis in rats with portal hypertension after PCS.

Alanine Transaminase↗

Rotational polymorphism in 2-naphthalenethiol SAMs on Au(111).

We evidence by STM that 2-naphthalenethiol self-assembled monolayers formed at the n-tetradecane/Au(111) interface coexist as two structural phases which both possess molecules into two different orientations (standing and lying). Such a rotational polymorphism is observed and understood at the molecular level for the first time.

Crystallization↗

The Bad guy cooperates with good cop p53: Bad is transcriptionally up-regulated by p53 and forms a Bad/p53 complex at the mitochondria to induce apoptosis.

Although the regulation of several Bcl-2 family molecules, including Puma, Noxa, Bax, and Bid, by p53 has been studied intensively, the interplay between Bad (Bcl-2 antagonist of cell death) and p53 has not yet been reported thus far. Here, we report that p53 activates Bad transcription and expression through binding to a short conserved sequence located approximately 6.6 kb upstream of the translation start point. We also demonstrate that Bad physically interacts with cytoplasmic p53, thereby preventing p53 from entering the nucleus and resulting in reduced transcription of Bad. Moreover, Bad is able to direct p53 to the mitochondria and forms a p53/Bad complex at the mitochondria. Two lines of evidences support this hypothesis: first, when mitochondria purified from p53-deficient H1299 cells are incubated with p53 and either wild-type (wt) Bad or mutant Bad (this mutant binds p53 yet is unable to migrate to mitochondria), p53 can be detected only in mitochondria incubated with wt Bad and not in those incubated with mutant Bad; second, knockdown of Bad expression reduces mitochondrial localization of p53. The mitochondrial p53/Bad complex promotes apoptosis via activation and oligomerization of Bak. Elimination of Bad expression by RNA interference notably attenuates apoptosis induced by etoposide. Hence, our collective data provide the first evidence that Bad plays dual roles in both p53 transcription-dependent and -independent pathways.

Apoptosis↗

[Endovascular treatment of posterior cerebral artery aneurysm: analysis of 21 patients].

OBJECTIVE: To investigate the effect of endovascular treatment on posterior cerebral artery (PCA) aneurysm. METHODS: The clinical data of 21 patients with PCA aneurysm, 12 males and 9 females, aged 3 - 60, totally 22 aneurysms, 3 located in the P1 segment, 16 (in 15 patients) on the P2 segment, and 3 being serpentine aneurysms and involving P2-3 segment, were analyzed. One patients gave up treatment, 6 patients, with 7 aneurysms, underwent aneurysm sac occlusion, and 14 patients underwent parent vessel occlusion. RESULTS: Complete aneurysm sac occlusion was achieved in 5 patients with 6 aneurysms, and incomplete occlusion was achieved in 1 patient who died of bleeding of aneurysm the next day after the operation. All 14 patients undergoing parent vessel occlusion survived without aneurysm detected by angiography, among which 3 presented hemianesthesia of the contralateral side and 2 recovered completely. CONCLUSION: Endovascular treatment is safe and effective for PCA aneurysm.

Adolescent↗

Large-scale fabrication of periodic nanostructured materials by using hexagonal non-close-packed colloidal crystals as templates.

This letter reports a versatile nonlithographic technique for mass fabricating three types of technologically important materials-polymer microwell arrays, 2D-ordered magnetic nanodots, and semiconductor nanopillar arrays, each with high crystalline qualities and wafer-scale sizes. Spin-coated hexagonal non-close-packed silica colloidal crystals embedded in a polymer matrix are used as starting templates to create 2D polymeric microwell arrays. These through-hole arrays can then be used as second-generation templates to make periodic magnetic nanodots and semiconductor nanopillars. This self-assembly approach is compatible with standard semiconductor microfabrication, and complex micropatterns can be created for potential device applications. The wafer-scale technique may find important applications in biomicroanalysis, high-density magnetic recording media, and microphotonics.

Journal Article↗

Novel link between E2F1 and Smac/DIABLO: proapoptotic Smac/DIABLO is transcriptionally upregulated by E2F1.

Deregulated expression of E2F1 not only promotes S-phase entry but also induces apoptosis. Although it has been well documented that E2F1 is able to induce p53-dependent apoptosis via raising ARF activity, the mechanism by which E2F induces p53-independent apoptosis remains unclear. Here we report that E2F1 can directly bind to and activate the promoter of Smac/DIABLO, a mitochondrial proapoptotic gene, through the E2F1-binding sites BS2 (-542 approximately -535 bp) and BS3 (-200 approximately -193 bp). BS2 and BS3 appear to be utilized in combination rather than singly by E2F1 in activation of Smac/DIABLO. Activation of BS2 and BS3 are E2F1-specific, since neither E2F2 nor E2F3 is able to activate BS2 or BS3. Using the H1299 ER-E2F1 cell line where E2F1 activity can be conditionally induced, E2F1 has been shown to upregulate the Smac/DIABLO expression at both mRNA and protein levels upon 4-hydroxytamoxifen treatment, resulting in an enhanced mitochondria-mediated apoptosis. Reversely, reducing the Smac/DIABLO expression by RNA interference significantly diminishes apoptosis induced by E2F1. These results may suggest a novel mechanism by which E2F1 promotes p53-independent apoptosis through directly regulating its downstream mitochondrial apoptosis-inducing factors, such as Smac/DIABLO.

Apoptosis↗

[Transvenous embolization in treatment of refractory carotid-cavernous sinus fistula].

OBJECTIVE: To investigate the effects of transvenous embolization in treatment of refractory carotid-cavernous sinus fistula (CCF). METHODS: Twenty-five patients of refractory CCF with 28 foci underwent transvenous embolization, femoral vein-inferior petrosal sinus approach was used in 12 of which, and femoral vein-facial vein-superior ophthalmic vein approach was used in 12 of which. The embolizing materials included controllable coils (GDC, EDC), free coil, and silk. Three to twenty-four months after the treatment angiography was conducted on 10 patients and telephone follow-up was conducted on the other 15 patients. RESULTS: Immediate complete angiographic obliteration of the fistula was achieved in 20 patients. Residual shunting was left in 5 patients, 2 with pterygoid drainage and 3 with inferior petrosal sinus drainage. Headache and vomiting were the common symptoms after embolization. The angiography during follow-up showed that there were residual shunting in 4 patients, residual inferior petrosal drainage in 1 patient, and residual pterygoid drainage in 1 patient, and that no reoccurrence was found in the 6 patients with complete angiographic obliteration. The patients undergoing telephone follow-up reported that they had not any symptom. CONCLUSION: Safe and effective, transvenous embolization can be the first choice after the failure in treatment of the carotid-cavernous sinus fistula.

Adolescent↗

[Endovascular stent implantation in treatment of intracranial wide-necked aneurysms].

OBJECTIVE: To evaluate the effectiveness and feasibility of treatment of intracranial wide-necked aneurysms with a new technique of Neuroform self-expanding stent combined with detachable coil. METHODS: A retrospective analysis of thirty patients with intracranial wide-necked aneurysms, 14 males and 16 females, aged 48 (18-68), wide-necked aneurysms, underwent occlusion of aneurysms using Neuroform self-expanding stent combined with detachable coil. RESULTS: 21 of the 30 aneurysms were completely occluded (70%) and 9 of the 30 aneurysms were incompletely occluded (30%) after initial coils embolization. Thromboembolic events were found in one case and migration of stent in two cases. Clinical follow-up performed in 29 patients showed that only one patient had permanent mild hemi-paralysis. Twenty-one patients were followed up for 6-12 months, 7 of which needed second treatment and 4 of which showed complete occlusion. CONCLUSION: A flexible device, Neuroform self-expanding stent can be safely maneuvered through tortuous intracranial vessels, enabling the endovascular treatment of complex wide-necked aneurysms. The new technique of Neuroform stent combined with detachable coil increases the early outcome of intracranial wide-necked aneurysm.

Adolescent↗

[Changes of serum and cerebrospinal fluid insulin-like growth factor-II levels in neonates with hypoxic-ischemic encephalopathy].

OBJECTIVE: Many studies have demonstrated that low levels of insulin-like growth factor-I (IGF-I) may be associated with the hypoxic-ischemic brain damage (HIBD) and that IGF-I has a neuroprotective effect. The role of IGF-II, a structurally and functionally homologous polypeptide with IGF-I, is unclear in HIBD. This study was designed to observe the changes of serum and cerebrospinal fluid (CSF) IGF-II levels in neonates with hypoxic-ischemic encephalopathy (HIE) and to investigate its effects on HIE. METHODS: Serum and CSF IGF-II levels in 41 neonates with HIE were measured by radioimmunoassay in the acute phase (postnatal age 12-24 hrs) and the convalescence phase (postnatal age 10-12 days). The 41 HIE neonates included 10 cases of mild, 12 moderate, and 19 severe HIE. Serum samples of 10 normal neonates were used as controls. RESULTS: In the acute phase, serum IGF-II levels in the Mild HIE group (203.28 +/- 40.09 ng/mL) and the Moderate HIE group (192.33 +/- 39.66 ng/mL) were not significantly reduced, but were obviously reduced in the Severe HIE group (116.72 +/- 39.50 ng/mL) compared with normal controls (229.38 +/- 43.39 ng/mL) (P<0.01). During the convalescence phase, serum IGF-II levels in the Mild HIE group (285.53 +/- 49.44 ng/mL) and in the Moderate HIE group (278.69 +/- 51.34 ng/mL) increased significantly (P < 0.01); CSF IGF-II levels increased in the Mild HIE group from 27.23 +/- 7.82 ng/mL (acute phase) to 81.58 +/- 9.77 ng/mL (convalescence phase) (P < 0.01) and also increased in the Moderate HIE group from 23.43 +/- 7.79 ng/mL (acute phase) to 78.48 +/- 10.44 ng/mL (convalescence phase) (P < 0.01). The patients from the severe HIE group whose neurological symptoms or signs were improved in the convalescence showed higher serum and CSF IGF-II levels than in the acute phase (254.08 +/- 48.50 ng/mL vs 122.21 +/- 46.26 ng/mL; 69.42 +/- 10.20 ng/mL vs 15.05 +/- 7.03 ng/mL; P < 0.01). A positive correlation was found between the serum and CSF IGF-II levels in the HIE group (r=0.69, P < 0.01). CONCLUSIONS: IGF-II levels in serum and CSF are associated with the pathogenesis and the prognosis of neonatal HIE.

Female↗

[Influence and mechanism of peroxisome proliferation activated receptor-alpha expression induced by WY14643 in rat lung with acute lung injury].

OBJECTIVE: To investigate the effect of WY14643 [peroxisome proliferation activated receptor-alpha (PPAR-alpha) activator, 4-cholro-6-(2.3-xylidino)-2-pyrimidinylthio acetic acid] on PPAR-alpha expression in lung of acute lung injury (ALI) induced by lipopolysaccharide (LPS) and its mechanism. METHODS: One hundred and four male Wistar rats were randomly divided into four groups: control group, ALI group, WY14643 1 mg group and WY14643 3 mg group. Wistar rats were given LPS (5 mg/kg) before intratracheal challenge with WY14643 (1 mg/kg and 3 mg/kg). Rats of all groups were sacrificed at 1, 2, 4, 8 hours after LPS challenge. The levels of PPAR-alpha mRNA in lung were measured by semi quantitative reverse transcription-polymerase chain reaction, the levels of PPAR-alpha protein in rats lung homogenate were measured by Western blot. RESULTS: The levels of PPAR-alpha mRNA at 2,4 and 8 hours in WY14643 1 mg group and WY14643 3 mg group were significantly higher than that in ALI group (P<0.05 or P<0.01). The levels of PPAR-alpha mRNA at all time in ALI group was significantly lower than that in control group (P<0.01). Meanwhile,the levels of PPAR-alpha protein at all time in WY14643 1 mg group and WY14643 3 mg group were significantly higher than that in ALI group (P<0.01). The level of PPAR-alpha mRNA at 4 hours and 8 hours in WY14643 1 mg group and at 2,4 and 8 hours in WY14643 3 mg group were significantly higher than those in control group too (P<0.05 or P<0.01). CONCLUSION: The expressions of PPAR-alpha mRNA and protein are all significantly low in the lung of rats with acute lung injury. WY14643 may upregulate the level of PPAR-alpha in the lung tissue in rats with acute lung injury.

Acute Lung Injury↗

[Studies on preparation of sustained-release Shuxiong formulation, a traditional Chinese medicine compound recipe, using time-controlled release techniques].

OBJECTIVE: To prepare a sustained-release formulation of traditional Chinese medicine compound recipe by adopting time-controlled release techniques. METHOD: Shuxiong tablets were chosen as model drug. The prescription and technique of core tablets were formulated with selecting disintegrating time and swelling volume of core tablets in water as index. The time-controlled release tablets were prepared by adopting press-coated techniques, using PEG6000, HCO and EVA as coating materials. The influences of compositions, preparation process and dissolution conditions in vitro on the lag time (T(lag)) of drug release were investigated. RESULT: The composition of core tablets was as follow: 30% of drug, 50% MCC and 20% CMS-Na. The T(lag) of time-controlled release tablets was altered remarkably by PEG6000 content of the outer layer, the amount of outer layer and hardness of tablet. The viscosity of dissolution media and basket rotation had less influence on the T(lag) but more on rate of drug release. CONCLUSION: The core tablets pressed with the optimized composition had preferable swelling and disintegrating properties. The shuxiong sustained-release formulations which contained core tablet and two kinds of time-controlled release tablets with 3 h and 6 h of T(lag) could release drug successively at 0 h, 3 h and 6 h in vitro. The technique made it possible that various components with extremely different physicochemical properties in these preparations could release synchronously.

Carthamus tinctorius↗

Wafer-scale periodic nanohole arrays templated from two-dimensional nonclose-packed colloidal crystals.

This communication reports a simple yet versatile nonlithographic approach for fabricating wafer-scale periodic nanohole arrays from a large variety of functional materials, including metals, semiconductors, and dielectrics. Spin-coated two-dimensional (2D) nonclose-packed colloidal crystals are used as first-generation shadow masks during physical vapor deposition to produce isolated nanohole arrays. These regular nanoholes can then be used as second-generation etching masks to create submicrometer void arrays in the substrates underneath. Complex patterns with micrometer-scale resolution can be made by standard microfabrication techniques for potential device applications. These 2D-ordered nanohole arrays may find important technological applications ranging from subwavelength optics to interferometric biosensors.

Biosensing Techniques↗

PII signal transduction proteins: sensors of alpha-ketoglutarate that regulate nitrogen metabolism.

PII proteins are small homotrimeric signal transduction proteins that regulate the activities of metabolic enzymes and permeases, and control the activities of signal transduction enzymes. The protein family shows high conservation, with examples in eukaryota (plants and eukaryotic algae), archaea, and bacteria. This distribution indicates that PII is one of the most ancient signalling proteins known.

Bacterial Physiological Phenomena↗

Transforming kelp into a marine bioreactor.

The past decade has seen the genetic engineering of various types of seaweed. To date, genetic transformation studies have been carried out in several seaweeds, including the red seaweeds Porphyra, Gracilaria, Grateloupia, Kappaphycus and Ceramium and the green seaweed Ulva. A genetic transformation model system has been established in the most commonly cultivated seaweed, the brown seaweed Laminaria japonica (kelp), based on the transfer of technology used in land plant transformation and also by modulating the seaweed life cycle. This model showed the potential for application of transgenic kelp to the production of valuable products and an indoor cultivation system for transgenic kelp was proposed, taking into account necessary factors for bio-safety. In this review, the establishment at use of the kelp transformation model is introduced, highlighting the potential for transforming kelp into a marine bioreactor.

Bioreactors↗

New and one pot chemoselective synthesis of nucleoside 5'-H-phosphonate diesters.

Arbuzov reaction of phenyl phosphorodichloridite with two equiv of alcohol, or mixture of one equiv of alcohol and one equiv of tert-butyl alcohol led to the corresponding aryl H-phosphonate diesters. Following displacement of the H-phosphonate diesters with unprotected nucleosides chemoselectively produced nucleoside 5-H-phosphonate diesters in good yields, respectively.

Biochemistry↗