Extracorporeal photopheresis reduces inflammation and joint damage in a rheumatoid arthritis murine model

BACKGROUND

Rheumatoid arthritis (RA) is an autoimmune disease characterized by inflammatory reactions and tissue damage in the joints. Long-term drug use in clinical practice is often accompanied by adverse reactions. Extracorporeal photopheresis (ECP) is an immunomodulatory therapy with few side effects, offering a potential and safe therapeutic alternative for RA through the induction of immune tolerance. This study aimed to investigate the therapeutic effects of ECP on RA using a collagen-induced arthritis (CIA) murine model, as well as to explore its immunomodulatory effects in vivo. Additionally, particular attention was given to the significant role of monocytes during the ECP process.

METHODS

A murine model of rheumatoid arthritis was established by administering two injections of bovine type II collagen to DBA/1J mice. ECP, ECP-MD (mononuclear cells were depleted during the ECP), MTX, and PBS treatment were applied to the CIA mice. During the treatment process, clinical scores and body weight changes of CIA mice were closely monitored. After six treatment sessions, micro-CT images of the hind paws from live mice were captured. Ankle joints and paws of the mice were collected and processed for histological evaluation. Spleen samples were collected to measure the Th17/Treg cells ratio, and serum samples were collected to assess cytokine and anti-type II collagen IgG levels. Monocytes and dendritic cells populations before and after ECP in vitro were detected by flow cytometry.

RESULT

ECP therapy significantly attenuated the progression of CIA, alleviated the severity of clinical symptoms in CIA mice and effectively suppressed synovial hyperplasia, inflammation, and cartilage damage. There was an expansion in the percentage of CD3 + CD4 + CD25 + FoxP3 + Tregs and a decrease in CD3 + CD4 + IL17A + Th17 cells in vivo. Furthermore, ECP reduced the serum levels of pro-inflammatory cytokines IL-6 (53.47 ± 7.074 pg/mL vs 5.142 ± 1.779 pg/mL, P < 0.05) and IL-17A (3.077 ± 0.401 pg/mL vs 0.238 ± 0.082 pg/mlL, P < 0.0001) compared with PBS. Interestingly, the depletion of monocytes during the ECP process did not lead to any improvement in clinical symptoms or histological scores in CIA mice. Moreover, the imbalance in the Th17/Treg cells ratio became even more pronounced, accompanied by an augmented secretion of pro-inflammatory cytokines IL-6 and IL-17A. In vitro, compared with cells without ECP treatment, the proportion of CD11b + cells were significantly reduced (P < 0.01), the proportion of CD11c + cells were significantly elevated (P < 0.001) 24 h after ECP treatment. Additionally, the expression of MHC II (P < 0.0001), CD80 (P < 0.01), and CD86 (P < 0.001) was downregulated in CD11c + cells 24 h after ECP treatment.

CONCLUSION

Our study demonstrates that ECP exhibits a therapeutic effect comparable to conventional therapy in CIA mice, and the protective mechanisms of ECP against RA involve Th17/Treg cells ratio, which result in decreased IL-6 and IL-17A. Notably, monocytes derived from CIA mice are an indispensable part to the efficacy of ECP treatment, and the proportion of monocytes decreased and the proportion of tolerogenic dendritic cells increased after ECP treatment in vitro.

Long-Term Results of Induction Chemotherapy for Esophageal Squamous Cell Carcinoma Receiving Concurrent Chemoradiotherapy

PURPOSE/OBJECTIVE(S)

This study aimed to investigate the long-term clinical outcomes and toxicities of induction chemotherapy (IC) followed by concurrent chemoradiotherapy (CCRT) versus CCRT alone in patients with esophageal squamous cell carcinoma (ESCC).

MATERIALS/METHODS

Between 2008 and 2022, 271 ESCC patients who received definitive CCRT (IC followed by CCRT, n = 72; CCRT alone, n = 199) were enrolled. Radiotherapy technique included intensity modulated radiation therapy (IMRT) or volumetric modulated arc therapy (VMAT). Through a propensity score matched (PSM) method, 71 patients receiving IC and CCRT were matched 1:1 to patients who received CCRT alone, according to age, gender, performance status, tumor length, and pre-treatment TN stage. The Kaplan-Meier method and Cox proportional hazards model were applied to analyze survival and prognosis.

RESULTS

The IC + CCRT group had no improvement in 5-year overall survival (OS) rate (39.0% vs 29.3%, p = 0.360), recurrence-free survival (RFS) rate (39.0% vs 26.9%, p = 0.142), and distant metastasis-free survival (DMFS) rate (33.6% vs 27.2%, p = 0.515) compared with the CCRT group. The overall clinical response rate was 45.1% after IC in the IC + CCRT group. The IC responders (CR + PR + SD) group showed more favorable 5-year OS (41.7% vs. 14.3% vs. 29.3%, p < 0.001), RFS (41.7% vs. 14.3% vs. 26.9%, p < 0.001) and DMFS (37.3% vs. 0% vs. 27.2%, p < 0.001) compared with the IC non-responders (PD) group and the CCRT group. Besides, the 5-year OS rate (65.6% vs. 17.6% vs. 29.3%, p < 0.001), RFS rate (65.6% vs. 17.6% vs. 26.9%, p < 0.001), and DMFS rate (62.5% vs. 10.3% vs. 27.2%, p < 0.001) of the IC good responders (CR + PR) were significantly higher than that of the IC poor responders (SD + PD) and CCRT group. Multivariate analysis revealed that total radiotherapy time (≥ 49 days) and AJCC stage (Ⅲ/Ⅳ) were independent predictive factors of OS, RFS and DMFS. Besides, age was an independent predictive factor of DMFS. No significant difference was observed in the rates of grades 3-4 toxicities between both groups.

CONCLUSION

Our results showed the addition of IC to CCRT was not superior to CCRT in unselected ESCC patients, while IC responders could benefit from this regime without increase in toxicities.

Re-Irradiation for Locally Primary Recurrence in Esophageal Squamous Cell Carcinoma Treated with IMRT/VMAT

PURPOSE/OBJECTIVE(S)

Locally primary recurrence of esophageal squamous cell carcinoma (ESCC) after definitive treatment has the potential for increasing overall survival with re-irradiation (Re-RT), especially with advanced technique. This study aimed to evaluate the efficacy and toxicities of Re-RT using intensity-modulated radiotherapy (IMRT)/volumetric modulated arc therapy (VMAT) for local primary-recurrence of ESCC.

MATERIALS/METHODS

A total of 130 ESCC patients with local primary-recurrence from Xijing hospital between 2008 and 2021 were enrolled and 30 patients underwent IMRT/VMAT based salvage Re-RT. Cox regression analysis was used to analyze the prognostic factors for overall survival (OS) and after recurrence survival (ARS). The toxicities of 30 patients receiving Re-RT were also assessed.

RESULTS

The median OS and ARS of the 130 recurrent patients were 21 months (1-164 months) and 6 months (1-142 months). The 1-, 2-, and 3-year OS rates were 81.5%, 39.2%, and 23.8%, respectively. Besides, the 1-, 2-, and 3-year ARS rates were 30.0%, 10%, and 6.2%. Multivariate analysis showed that Re-RT ± chemotherapy (p = 0.043) and chemotherapy alone (p < 0.001) and esophageal stents (p = 0.004) were independent prognostic factors for OS. The median OS of 30 patients treated with Re-RT were significantly better than that of 29 patients treated with chemotherapy (34.5 months vs. 22 months, p = 0.030). Among 30 ESCC patients treated with Re-RT, the median OS and ARS were 34.5 months (range 12-163 months) and 6 months (range 1-132 months), respectively. The recurrence-free interval (RFI) (> 12 months) and initial radiation dose (> 60 Gy) were significantly associated with improved OS. Radiation esophagitis (Grade 1-2) occurred in 16 patients and myelosuppression (Grade1-2) occurred in 10 patients. Grade 3 toxicities (radiation esophagitis and myelosuppression) were only 13.3%. There were no grade 4 toxicities.

CONCLUSION

Our results demonstrated that IMRT/VMAT-based Re-RT was an effective therapeutic option for ESCC patients with local primary-recurrence compared with chemotherapy alone or without any treatment. Re-RT had improved OS but unfavorable ARS.

A novel NET-related gene signature for predicting DLBCL prognosis

BACKGROUND

Diffuse large B-cell lymphoma (DLBCL) is an aggressive malignancy. Neutrophil extracellular traps (NETs) are pathogen-trapping structures in the tumor microenvironment that affect DLBCL progression. However, the predictive function of NET-related genes (NRGs) in DLBCL has received little attention. This study aimed to investigate the interaction between NRGs and the prognosis of DLBCL as well as their possible association with the immunological microenvironment.

METHODS

The gene expression and clinical data of patients with DLBCL were downloaded from the Gene Expression Omnibus database. We identified 148 NRGs through the manual collection of literature. GSE10846 (n = 400, GPL570) was used as the training dataset and divided into training and testing sets in a 7:3 ratio. Univariate Cox regression analysis was used to identify overall survival (OS)-related NETs, and the least absolute shrinkage and selection operator was used to evaluate the predictive efficacy of the NRGs. Kaplan-Meier plots were used to visualize survival functions. Receiver operating characteristic (ROC) curves were used to assess the prognostic predictive ability of NRG-based features. A nomogram containing the clinical information and prognostic scores of the patients was constructed using multivariate logistic regression and Cox proportional risk regression models.

RESULTS

We identified 36 NRGs that significantly affected patient overall survival (OS). Eight NRGs (PARVB, LYZ, PPARGC1A, HIF1A, SPP1, CDH1, S100A9, and CXCL2) were found to have excellent predictive potential for patient survival. For the 1-, 3-, and 5-year survival rates, the obtained areas under the receiver operating characteristic curve values were 0.8, 0.82, and 0.79, respectively. In the training set, patients in the high NRG risk group presented a poorer prognosis (p < 0.0001), which was validated using two external datasets (GSE11318 and GSE34171). The calibration curves of the nomogram showed that it had excellent predictive ability. Moreover, in vitro quantitative real-time PCR (qPCR) results showed that the mRNA expression levels of CXCL2, LYZ, and PARVB were significantly higher in the DLBCL group.

CONCLUSIONS

We developed a genetic risk model based on NRGs to predict the prognosis of patients with DLBCL, which may assist in the selection of treatment drugs for these patients.

High expression of ACE2 in the human lung leads to the release of IL6 by suppressing cellular immunity: IL6 plays a key role in COVID-19

OBJECTIVE

The pathogenesis of coronavirus disease 2019 (COVID-19) remains clear, and no effective treatment exists. SARS-CoV-2 is the virus that causes COVID-19 and uses ACE2 as a cell receptor to invade human cells. Therefore, ACE2 is a key factor to analyze the SARS-CoV-2 infection mechanism.

MATERIALS AND METHODS

We included 9,783 sequencing results of different organs, analyzed the effects of different ACE2 expression patterns in organs and immune regulation.

RESULTS

We found that ACE2 expression was significantly increased in the lungs and digestive tract. The cellular immunity of individuals with elevated ACE2 expression is activated, whereas humoral immunity is dampened, leading to the release of many inflammatory factors dominated by IL6. Furthermore, by studying the sequencing results of SARS-CoV-2-infected and uninfected cells, IL6 was found to be an indicator of a significant increase in the number of infected cells. However, although patients with high expression of ACE2 will release many inflammatory factors dominated by IL6, cellular immunity in the colorectum is significantly activated. This effect may explain why individuals with SARS-CoV-2 infection have severe lung symptoms and digestion issues, which are important causes of milder symptoms.

CONCLUSIONS

This finding indicates that ACE2 and IL6 inhibitors have important value in COVID-19.

The role of Br in the selective synthesis of thin-walled carbon-nanotubes with micrometre-length Fe3C-filling, Fe3C tip-filled carbon nanotubes or empty carbon nanotubes by pyrolysis of ferrocene and (6-bromohexyl)ferrocene mixtures

We report an advanced chemical vapour deposition method which allows the synthesis-selection of thin walled carbon nanotubes filled with Fe₃C, Fe₃C tip-filled nanotubes or of empty nanotubes by addition of (6-bromohexyl)ferrocene to ferrocene.

Serum uric acid is associated with arterial stiffness in men with newly diagnosed type 2 diabetes mellitus

BACKGROUND

Increased serum uric acid levels and vascular atherosclerosis are very common in diabetes. However, few studies focused on the relationship between serum uric acid and aortic or peripheral arterial stiffness in newly diagnosed diabetic patients. This study investigated the association between serum uric acid levels and carotid-femoral pulse wave velocity (cfPWV) or carotid-radial (cr) PWV in male patients with newly diagnosed type 2 diabetes mellitus (T2DM).

METHODS

106 male patients with newly diagnosed T2DM were recruited. cfPWV and crPWV as well as anthropometric parameters, blood pressure, serum uric acid, blood glucose, fasting insulin, C-reactive protein and blood lipids were measured.

RESULTS

The subjects were divided into low uric acid (UA) subgroup and high UA subgroup according to uric acid median. cfPWV and crPWV were significantly higher in high UA subgroup. Serum uric acid significantly correlated with cfPWV (r = 0.533, P < 0.001), crPWV (r = 0.334, P = 0.001), waist circumference (r = 0.350, P < 0.001), waist-to-hip ratio (r = 0.254, P = 0.009), fasting insulin (r = 0.432, P < 0.001), HOMA-IR (r = 0.173, P = 0.042), fasting blood glucose (r = -0.271, P = 0.005), haemoglobin A1c (r = -0.202, P = 0.038), and HDL-cholesterol (r = -0.267, P = 0.006) after correction for age. Stepwise multiple regressions showed that the independent determinants of cfPWV were serum uric acid, age, C-reactive protein, HDL-cholesterol, and smoking status. And the independent determinants of crPWV were serum uric acid, age, diastolic blood pressure, and HDL-cholesterol.

CONCLUSIONS

Serum uric acid is significantly associated with increased aortic and peripheral arterial stiffness in men with T2DM at the early stage.

Relationship between autoantibody to the angiotensin II-1 receptor and cardiovascular manifestations of Graves' disease

OBJECTIVE

To investigate the role of autoantibody against angiotensin II-1 receptor (AT1-AA) in patients with cardiovascular manifestations of Graves' disease (GD).

METHODS

The epitope of the second extracellular loop of AT1 receptor (165-191) was synthesized and used as antigens to screen the autoantibody by enzyme linked immunosorbent assay (ELISA). The patients with GD were divided into the patients with cardiovascular manifestations associated to GD (Group A, n=58) and the patients with GD not complicated by heart disease (Group B, n=60). 40 healthy subjects were included in the study (Group C, n=40). Echocardiography was performed and the differences of echocardiography parameters were compared between AT1-AA positive and negative groups in group A. Factors related to left heart enlargement were analyzed by multiple logistic regression.

RESULTS

(1) The frequency of AT1-AA in Group A (52.2%, 32/58) were significantly higher than those in Group B (16.7%, 10/60) and Group C (12.5%, 5/40) (all p<0.001). (2) There were no differences in the level of TGAb, TPOAb and TRAb between AT1-AA positive and negative groups in patients with GD (all p>0.05). (3) In patients with cardiovascular manifestations of GD, the ratios between left atrial and ventricular enlargement (LAE and LVE) were significantly higher in the AT1-AA positive group than in the AT1-AA negative group (68.8% vs. 26.9%, 62.5% vs. 23.1%, all p<0.01); the frequency of atrial fibrillation differed significantly between these 2 groups (53.1% vs. 19.2%, p<0.01). (4) Regression analysis demonstrated that the positive AT1-AA and course of GD were significantly correlated to the presence of LAE and LVE.

CONCLUSIONS

AT1-AA plays an important role in the pathogenesis of cardiovascular manifestations associated to GD. Especially, AT1-AA is involved in left cardiac dilatation of GD complicated by heart disease, which represents a cardio-vascular risk factor for GD patients.

Data Anonymization that Leads to the Most Accurate Estimates of Statistical Characteristics: Fuzzy-Motivated Approach

To preserve privacy, the original data points (with exact values) are replaced by boxes containing each (inaccessible) data point. This privacy-motivated uncertainty leads to uncertainty in the statistical characteristics computed based on this data. In a previous paper, we described how to minimize this uncertainty under the assumption that we use the same standard statistical estimates for the desired characteristics. In this paper, we show that we can further decrease the resulting uncertainty if we allow fuzzy-motivated weighted estimates, and we explain how to optimally select the corresponding weights.

Current-induced polarization and the spin Hall effect at room temperature

Electrically induced electron spin polarization is imaged in n-type ZnSe epilayers using Kerr rotation spectroscopy. Despite no evidence for an electrically induced internal magnetic field, current-induced in-plane spin polarization is observed with characteristic spin lifetimes that decrease with doping density. The spin Hall effect is also observed, indicated by an electrically induced out-of-plane spin polarization with opposite sign for spins accumulating on opposite edges of the sample. The spin Hall conductivity is estimated as 3+/-1.5 Omega(-1) m(-1)/|e| at 20 K, which is consistent with the extrinsic mechanism. Both the current-induced spin polarization and the spin Hall effect are observed at temperatures from 10 to 295 K.

Tunable anomalous Hall effect in a nonferromagnetic system

We measure the low-field Hall resistivity of a magnetically doped two-dimensional electron gas as a function of temperature and electrically gated carrier density. Comparing these results with the carrier density extracted from Shubnikov-de Haas oscillations reveals an excess Hall resistivity that increases with decreasing temperature. This excess Hall resistivity qualitatively tracks the paramagnetic polarization of the sample, in analogy to the ferromagnetic anomalous Hall effect. The data are consistent with skew scattering of carriers by disorder near the crossover to localization.

Myocardial homing and neovascularization by human bone marrow angioblasts is regulated by IL-8/Gro CXC chemokines

In the adult, new blood vessel formation can occur either through angiogenesis from pre-existing mature endothelium or vasculogenesis mediated by bone marrow-derived endothelial precursors. We recently isolated endothelial progenitor cells, or angioblasts, in human adult bone marrow which have selective migratory properties for ischemic tissues, including myocardium, to where they home and induce vasculogenesis. Here we show that myocardial production of the IL-8/Gro-alpha CXC chemokine family is significantly increased after acute ischemia, and that this provides a chemoattractant gradient for bone marrow-derived endothelial progenitors, or angioblasts. This chemokine-mediated homing of bone marrow angioblasts to the ischemic heart regulates their ability to induce myocardial neovascularization, protection against cardiomyocyte apoptosis, and functional cardiac recovery. Together, our results indicate that CXC chemokines play a central role in regulating vasculogenesis in the adult, and suggest that manipulation of interactions between chemokines and their receptors on autologous human bone marrow-derived angioblasts could augment neovascularization of ischemic myocardial tissue.

Myocardial neovascularization by bone marrow angioblasts results in cardiomyocyte regeneration

The primary cardiac response to ischemic insult is cardiomyocyte hypertrophy, which initiates a genetic program culminating in apoptotic myocyte loss, progressive collagen replacement, and heart failure, a process termed cardiac remodeling. Although a few cardiomyocytes at the peri-infarct region can proliferate and regenerate after injury, no approaches are known to effectively induce endogenous cardiomyocytes to enter the cell cycle. We recently isolated, in human adult bone marrow, endothelial progenitor cells, or angioblasts, that migrate to ischemic myocardium, where they induce neovascularization and prevent myocardial remodeling. Here we show that increasing the number of angioblasts trafficking to the infarct zone results in dose-dependent neovascularization with development of progressively larger-sized capillaries. This results in sustained improvement in cardiac function by mechanisms involving protection against apoptosis and, strikingly, induction of proliferation/regeneration of endogenous cardiomyocytes. Our results suggest that agents that increase myocardial homing of bone marrow angioblasts could effectively induce endogenous cardiomyocytes to enter the cell cycle and improve functional cardiac recovery.

Advanced glycation end products (AGEs)-induced expression of TGF-beta 1 is suppressed by a protease in the tubule cell line LLC-PK1

BACKGROUND

Advanced glycation end products (AGEs) are assumed to play a key role in diabetic nephropathy (DN). Since little is known about their action in tubule cells, we investigated in LLC-PK1 cells: (i) whether AGE-bovine serum albumin (AGE-BSA) affects cell proliferation and expression of transforming growth factor-beta (TGF-beta 1); and (ii) whether the AGE-induced effects can be modulated by trypsin due to interference with its binding proteins at the cell surface.

METHODS

Arrested cells were exposed to vehicle (control), AGE-BSA (19--76 microM) and BSA (38 microM) in the presence or absence of trypsin (0.625--5.0 microg/ml) (2.5 microg/ml) for 24 h. We evaluated cell proliferation by cell count and by [(3)H]thymidine incorporation, TGF-beta 1 expression by reverse transcription-polymerase chain reaction (RT-PCR), and TGF-beta 1 protein by ELISA. In addition, cell accumulation of AGEs was studied by immunohistochemical staining of the AGE imidazolone.

RESULTS

AGE-BSA inhibited [(3)H]thymidine incorporation, lowered cell number and increased cell protein content as well as TGF-beta 1 mRNA and protein as compared with control and BSA. Immunohistochemical staining revealed a marked intracellular accumulation of the AGE imidazolone. Co-incubation of AGE-BSA with trypsin ameliorated the impaired thymidine incorporation, the decreased cell count and the enhanced cell protein content. TGF-beta 1 overexpression was normalized, while TGF-beta 1 protein declined insignificantly. Intracellular imidazolone accumulation was strikingly suppressed.

CONCLUSIONS

In the tubule cell line LLC-PK1, AGE-BSA exerts an antiproliferative effect, most probably due to TGF-beta 1 overproduction. The co-administration of trypsin abrogated this alteration, very likely as a result of an interaction with AGE-binding protein(s), which is supported by the decreased intracellular AGE accumulation. These findings may be the starting point for the development of specific proteolytic enzymes to interfere with the interaction between AGEs and their receptors/binding proteins.

Advanced glycation end products impair protein turnover in LLC-PK1: amelioration by trypsin

BACKGROUND

Advanced glycation end products (AGEs) are assumed to play a key role in the pathogenesis of diabetic nephropathy (DN) and other diabetic complications. While AGEs have been shown to exert marked effects on mesangial and endothelial cells as well as on monocytes/macrophages, little is known about their effects on tubule cells. Therefore, we addressed the questions of (1) whether AGE-bovine serum albumin (AGE-BSA) impairs the protein metabolism in the tubule cells, and if so, (2) whether the AGE-induced effects are mediated via a protease sensitive mechanism.

METHODS

Arrested LLC-PK1 cells were exposed to a medium containing the vehicle (control, serum free), AGE-BSA (38 micromol/L), or BSA (38 micromol/L) in the presence or absence of trypsin (2.5 microg/mL) for 24 hours. We evaluated cell number, cell size, and cell protein content, as well as protein synthesis and protein degradation.

RESULTS

After an incubation period of 24 hours, AGE-BSA decreased the cell number to 84.5 +/- 5.5% of control and 82.5 +/- 5.6% of BSA-treated cells (P < 0.05). [3H]-thymidine incorporation declined to 66% of control (P < 0.05), while BSA was without any effect. The same AGE-BSA dose reduced protein degradation (P < 0.05) and stimulated total protein synthesis slightly, as determined by L-[14C]Phe incorporation into acidic-insoluble proteins. These effects resulted in a rise in cell protein content (AGE-BSA vs. control, 21.9 +/- 6.7%; AGE-BSA vs. BSA, 11.1 +/- 6.0%, P < 0.05) and cell volume (AGE-BSA vs. control 9.4 +/- 3.2%, AGE-BSA vs. BSA 18.4 +/- 3.7%, P < 0.05). Coincubation with AGE-BSA and trypsin was associated with an amelioration of all investigated parameters concerning cell number, cell proliferation, raised cell protein content, decreased protein degradation, and enhanced protein synthesis.

CONCLUSION

These data indicate that AGE-BSA impairs cell proliferation and protein turnover in LLC-PK1 cells with a consequent rise in cell protein. Since these alterations were abrogated by coincubation with trypsin, an interference of this serine protease with the AGE-binding proteins on cell surfaces is assumed.

[The relationship of Apo E2 and renal insufficiency lipid levels in NIDDM]

OBJECTIVE

To study the relationship of ApoE2 and renal insufficiency, lipid levels in NIDDM patients.

METHODS

PCR/ASO probe technique was used to determine ApoE genotypes. 46 NIDDM patients with renal insufficiency and 84 NIDDM patients without renal insufficiency as well as 50 healthy individuals were selected. Of the patients with renal insufficiency, 10 belonged to ApoE2 and 38 to ApoE3/3. In addition, 57 NIDDM patients with normalbuminuria (6 with ApoE2, 51 with ApoE3/3) were selected from the 84 NIDDM patients without renal insufficiency.

RESULTS

Allele frequency was significantly higher in diabetic patients with renal insufficiency than in diabetic patients without renal insufficiency and in healthy individuals (P < 0.05). Tc, TG levels were significantly higher in ApoE2 group with renal insufficiency than in E3/3 group with renal insufficiency, ApoE3/3 and ApoE2 groups with normoal buminuria. HDL-c level was significantly lower in ApoE2 group with renal insufficiency than in other 3 groups.

CONCLUSION

ApoE2 is associated with renal insufficiency in NIDDM patients and that ApoE2 may be a factor that aggravates lipid abnormalities in NIDDM patients with renal insufficiency.

Advanced glycated albumin impairs protein degradation in the kidney proximal tubules cell line LLC-PK1

Advanced glycation end-products (AGEs) are assumed to play a major role in the genesis of diabetic nephropathy and other diabetic complications. We studied the potential effect of AGEs on protein turnover and lysosomal proteinase activities in LLC-PK1 cells, a pig kidney proximal tubules cell line. Advanced glycated bovine serum albumin (AGE-BSA) was used as a model of AGEs and its action was compared to that of nonglycated BSA. AGE-BSA but not BSA (50 micromol/l) induced a significant increase in cell volume (BSA: 4870.6 +/- 74.8 fl, AGE-BSA: 5718.0 +/- 20.7 fl, p<0.01). Protein degradation rate was decreased by 13.8% after 48 hrs. incubation with AGE-BSA (p<0.01) while protein synthesis increased by 19,1%, (p<0.01). After incubation with AGE-BSA but not BSA activities of lysosomal cathepsins (B, L+B and H) decreased in a time- and dose-dependent fashion. This decline was neither caused by a shift in lysosomal pH outside the optimal range for cathepsins, nor by a direct inhibitory effect of AGEs modified proteins or peptides but most probably by inhibition of cathepsin B expression as measured by RT-PCR. It is supposed that impaired protease activities participated in decreased protein breakdown and cell enlargement. For the first time our data provide the evidence that AGEs induce hypertrophy of LLC-PK1 cells due to decreased protein breakdown resulting from reduced lysosomal proteinase activities with a concomitant stimulation of protein synthesis.

Synthesis and triplex forming properties of an acyclic N7-glycosylated guanine nucleoside

A chiral acyclic nucleoside, one in which the ribose carbohydrate has been replaced with a glycerol-based linker, is prepared by glycosylating guanine at the N7-nitrogen. The stereochemically pure derivative is converted to a DMT-protected phosphoramidite for incorporation into DNA sequences. Sequence containing the acyclic N7-dG nucleoside are capable of forming DNA triplexes in which it is likely that the N1-H and N2-amino groups of the N7-dG are involved in recognition of the guanine base in G-C base pairs.

Importance of specific adenosine N3-nitrogens for efficient cleavage by a hammerhead ribozyme

Five modified hammerhead ribozyme/substrate complexes have been prepared in which individual adenosine N3-nitrogens have been excised and replaced with carbon. The modified complexes were chemically synthesized with the substitution of a single 3-deazzaadenosine (c3A) base analogue for residues A6, A9, A13, A14, or A15.1. Steady-state kinetic analyses indicate that the cleavage efficiencies, as measured by kcat/K(M), for the c3A6, c3A9, and c3A14 complexes were only marginally reduced (< or = 5-fold) relative to the native complex. By comparison, the cleavage efficiencies for the c3A13 and c315.1 complexes were reduced by 9-fold and 55-fold, respectively. these reductions in cleavage efficiency are primarily a result of lower kcat values. Profiles of pH and cleavage rate suggest that the chemical cleavage step is the rate-limiting reaction for these complexes. These results suggest that the N3-nitrogen of the A13 residue and particularly the A15.1 residue in the hammerhead ribozyme/substrate complex are critical for transition state stabilization and efficient cleavage activity. We have additionally compared the locations of these critical functional groups, as well as those identified from other studies, with recent crystallographic analyses. In some cases, the critical functional groups are clustered around proposed metal binding sites and may reflect functional groups critical for binding the metal cofactor. In other cases, clusters of functional groups may form a network of hydrogen bonds necessary for transition state stabilization.

Use of a pyrimidine nucleoside that functions as a bidentate hydrogen bond donor for the recognition of isolated or contiguous G-C base pairs by oligonucleotide-directed triplex formation

Synthesis of the nucleoside building block of the 6-keto derivative of 2'-deoxy-5-methylcytidine (m5oxC) as an analog of an N3-protonated cytosine derivative is described. A series of 15mer oligonucleotides containing either four or six m5oxC residues has been prepared by chemical synthesis. Complexation of the 15 residue oligonucleotides with target 25mer duplexes results in DNA triplexes containing T-A-T and m5oxC-G-C base triplets. When the m5oxC-G-C base triplets are present in sequence positions that alternate with TAT base triplets, DNA triplexes are formed with Tm values that are pH independent in the range 6.4-8.5. A 25mer DNA duplex containing a series of five contiguous G-C base pairs cannot be effectively targeted with either m5C or M5oxC in the third strand. In the former case charge-charge repulsion effects likely lead to destabilization of the complex, while in the latter case ineffective base stacking may be to blame. However, if the m5C and M5oxC residues are present in the third strand in alternate sequence positions, then DNA triplexes can be formed with contiguous G-C targets even at pH 8.0.