Synthesis of glycyrrhizin analogues as HMGB1 inhibitors and their activity against sepsis in acute kidney injury.

Glycyrrhizin (GL) is one of the antagonists of highly conserved nuclear protein (HMGB1). The researches have shown that the glycosyl of GL is an important pharmacophore for GL binding to HMGB1, and it is the determinant factor for mechanism of action. To get the HMGB1 inhibitors with higher activity and good pharmacokinetic properties, two classes of GL analogues containing C-N glycoside bond were synthesized, and their anti-inflammatory, anti-oxidative stress and anti-septic kidney injury were evaluated. The results are as follows. First, in the anti-inflammatory assay, all the compounds inhibited NO release in some degree; among them, compound 6 displayed the strongest NO inhibitory effect with IC50 value of 15.9 µM, and compound 15 with IC50 of 20.2 µM. The two compounds not only decreased IL-1ß and TNF-α levels in RAW264.7 cells and HK-2 cells, but also downregulated the levels of NLRP3, P-NF-κB p65 and HMGB1 in activated HK-2 cells in a dose-dependent manner. Second, in the renal protection assay with H2O2-stimulated HK-2 cell line, they reduced MDA level and increased SOD in HK-2 cells; additionally, they also inhibited the HK-2 cell apoptosis and downregulated the Caspase-1 p20 level. Third, in the in vivo activity tests of the septic mouse, they also showed good activities just like in vitro, decreasing the IL-1ß, TNF-α, MDA, blood creatinine (Scr) and urea nitrogen (BUN) in serum, and increasing SOD levels in a dose-dependent manner. The immunoblotting results showed the two compounds downregulated the levels of HMGB1, P-NF-κB p65, NLRP3 and Caspase-1 p20 protein. All in all, the two compounds improved the renal injury of septic mice, and alleviated the tube wall structure damage and renal tubular dilation in kidney, which further proved by H&E staining. This suggests the two compounds have septic acute kidney injury activity, and they will be potential therapeutic drugs for septic acute kidney injury.

Design and synthesis of salidroside analogs and their bioactivity against septic myocardial injury.

Cardiac tissue suffers much from sepsis, and the incidence of myocardial injury is high in septic patients. The treatment of sepsis myocardial injury (SMI) has been the focus of clinical medicine. Salidroside shows myocardial cell protection, anti-oxidation and anti- inflammation effects, and it is thought as one of the potential compounds to treat sepsis myocardial injury. However, its anti-inflammatory activity is lower and its pharmacokinetic properties are not ideal, which is far from clinical application. Here, a series of salidroside analogs were synthesized, and their bioactivities were evaluated from several aspects, including their anti-oxidant and anti-inflammatory activities in vitro and anti-sepsis myocardial injury activities in vivo. Of all the compounds which synthesized, compounds 2 and 3 exhibited stronger anti-inflammatory activities than the others; after treating LPS-stimulated RAW264.7 or H9c2 cells with each of them, the levels of IL-1ß, IL-6 and TNF-α were down-regulated in a dose-dependent manner. In the anti-oxidative stress injury test, compounds 2 and 3 not only markedly increased the survival rate of cells, and but also improved the cellular oxidative stress-related indicators MDA, SOD and cell damage marker LDH in a dose-dependent manner. In the LPS-induced septic rat myocardial injury models (in vivo), the two compounds also showed good bioactivities. They also reduced the expression of IL-1ß, IL-6 and TNF-α, and blocked cell damage by suppressing overhauled oxidation in septic rats. In addition, the myocardial injury was significantly improved and the inflammatory infiltration was reduced after treatment with the two compounds. In conclusion, the salidroside analogs (2 and 3) showed promising therapeutical effect on septic myocardial injury in LPS-model rats, and they could be good candidates for clinical trials against inflammation and septic myocardial injury.

Design and synthesis of bile acid derivatives and their activity against colon cancer.

Bile acids (BAs) containing both hydrophilic hydroxyl and carboxyl groups and hydrophobic methyl and steroid nuclei can promote the absorption of fat and other substances in the intestine, and they are synthesized by cholesterol in the liver and then returned to the liver through enteric liver circulation. Because there are many BA receptors on the cell membrane of colon tissues, BAs can improve the specific delivery and transport of medicines to colon tissues. Moreover, BAs have a certain anticancer and inflammation activity by themselves. Based on this theory, a series of BA derivatives against colon cancer including cholic acid (CA), chenodeoxycholic acid (CDCA), ursodeoxycholic acid (UDCA) and lithocholic acid (LCA) were designed and synthesized, and their antitumor activity was evaluated. For in vitro anti-tumor tests, all the compounds displayed cell proliferative inhibition to nine human malignant tumor cell lines to some degree, and in particular they showed stronger inhibition to the colon cancer cells than the other cell lines. Among them, four compounds (4, 5, 6, and 7) showed stronger activity than the other compounds as well as the positive control 5-FU against HCT116 cells, and their IC50 was between 21.32 µmol L-1 and 28.90 µmol L-1; cell clone formation and migration tests showed that they not only effectively inhibited the formation of HCT116 cell colonies, but also inhibited the HCT116 cell migration and invasion; moreover, they induced apoptosis, arrested the mitotic process at the G2/M phase of the cell cycle, reduced the mitochondrial membrane potential, increased the intracellular ROS levels, and reduced the expression of Bcl-2 and p-STAT3 in HCT 116 cells. In addition, they also displayed intermediate anti-inflammatory activity by inhibiting inflammatory mediators NO and downregulating TNF-α expression, which also is one of the causes of colon cancer. This suggests that they deserve to be further investigated as candidates for colon cancer treatment drugs.

Tight adherent feature on optical coherence tomography predict postoperative visual outcome in epiretinal membrane eyes.

BACKGROUND: To identify the predictive parameter among preoperative measurements that best predicts postoperative visual outcome in the epiretinal membrane (ERM). METHODS: Thirty-three consecutive patients with idiopathic unilateral ERM patients between 2015 and 2018 were enrolled. Nineteen healthy normal eyes were selected as an independent age-matched group. Based on preoperative optical coherence tomography (OCT), we further divided the patients with ERM into two groups: type 1, loosely attached ERM, and type 2, tight adherent ERM. We documented the vision and thickness of various retinal layers: nerve fiber layer, ganglion cell layer, inner plexiform layer (GCL + IPL), inner nuclear layer (INL), outer retinal layer (ORL), and retinal pigment epithelium/Bruch complex layer before and after the surgery. The association between postoperative visual acuity and these variables was analyzed using multiple linear regression analysis. RESULTS: All retinal layers of ERM eyes were thicker than the normal eyes (P < 0.05). Among ERMs, we identified 11 eyes with type 1 adhesions and 22 eyes with type 2 adhesions. The preoperative GCL + IPL layers were significantly thicker in type 2 patients than in type 1 patients (93.67 ± 33.03 um vs 167.71 ± 13.77 um; P = 0.023). Greater GCL + IPL thickness was correlated with a worse postoperative visual acuity and multiple linear regression analysis showed that GCL + IPL thickness was an independent predictor of postoperative visual acuity (VA) (beta value = 0.689; P = 0.012). A greater thickness of GCL + IPL layers of type 2 patients had worse postoperative best-corrected visual acuity (BCVA) (P = 0.028). Ectopic inner foveal layers with disappearance of fovea pit were persistently presented in OCT profiles of both groups. CONCLUSION: Idiopathic ERM demonstrated significantly thicker inner retinal layers (GCL + IPL and INL). However, the ORL thickness was similar between the normal eyes and ERM eyes. The preoperative GCL + IPL layers were significantly thicker in patients with type 2 ERM than that in patients with type 1 ERM. The increase in GCL + IPL thickness was significantly correlated with worse postoperative visual outcomes.

Real-life experience of ranibizumab for diabetic macular edema in Taiwan.

PURPOSE: To evaluate the visual and anatomical outcomes of intravitreal ranibizumab for diabetic macular edema (DME) in the healthcare system of Taiwan. METHODS: A total of 39 eyes from 39 patients were retrospectively enrolled in the study. All eyes that fulfilled the key criteria, including a baseline vision between 20 and 70 ETDRS letters and a minimum central macular thickness (CMT) of 300 µm, had at least 3 monthly loading injections of ranibizumab in a year. Macular laser or posterior subtenon injections of triamcinolone acetonide (PSTA) could be performed as supplementary treatments following loading injections. Primary outcomes include best-corrected visual acuity and CMT. RESULTS: Patients' vision improved from 46.5 ± 15.3 letters at baseline to 51.4 ± 16.6 letters at 12 months (p = 0.031). Mean CMT at baseline was 406 ± 105 µm, which decreased to 329 ± 108 µm (p = 0.002). At 12 months, 44.4% of eyes with total injection number < 5 and 42.9% with injection number ≥ 5 achieved a gain in vision that was 10 letters or more. A total of 5 injections or more did not lead to a better visual gain in comparison with only 3-4 injections (p = 0.71), and both had similar number of supplementary treatments (p = 0.43). Monthly reinjections of ranibizumab resulted in a lower likelihood of visual loss of 10 or 15 letters (p = 0.019 and 0.015, respectively, adjusted for age, baseline vision, severity of diabetic retinopathy and the presence of previous treatments); however, supplementary macular lasers, PSTA or ranibizumab without monthly reinjections did not (all p > 0.05). The average number of injections was 4.3 ± 1.0. CONCLUSION: Treatment for DME with at least three monthly ranibizumab loading injections, with or without other supplementary treatments, is effective at 12 months thereafter. Two monthly reinjections of ranibizumab, while not significantly increasing vision, may have a role in preventing visual loss.

Impact of metabolic control on macular thickness in diabetic macular oedema.

PURPOSE: To investigate the impact of metabolic control on macular thickness measured using optical coherence tomography in patients with diabetic retinopathy with or without macular oedema. METHODS: A total of 124 patients with diabetic retinopathy ( n = 70 without macular oedema and n = 54 with macular oedema) were enrolled. Optical coherence tomography parameters measured included central macular thickness and total macular volume. Metabolic factors with correlation to optical coherence tomography parameters were fasting plasma glucose, glycosylated haemoglobin, triglyceride, low-density lipoprotein and estimated glomerular filtration rate. Multiple linear regression models were used to evaluate associations between optical coherence tomography parameters and metabolic factors. RESULTS: Higher glycosylated haemoglobin values were correlated with increased central macular thickness in patients without macular oedema ( R = 0.289, p = 0.015), whereas glycosylated haemoglobin values were inversely associated with central macular thickness in patients with macular oedema ( R = -0.374, p = 0.005). Both were found to be statistically significant after adjusting for age, sex and diabetic retinopathy severity in addition to other metabolic factors ( p = 0.009 and p = 0.002, respectively). CONCLUSION: Strict metabolic control may not be associated with better macular thickness in diabetic patients with co-existing macular oedema.

Biodegradable balloon-expandable self-locking polycaprolactone stents as buckling explants for the treatment of retinal detachment: an in vitro and in vivo study.

The purpose of this report was to develop biodegradable balloon-expandable self-locking poly(ε-caprolactone) (PCL) stents for the treatment of retinal detachment. To create the biodegradable stents, polycaprolactone components were first fabricated by a laboratory-scale microinjection molding machine. The components were then assembled into mesh-like stents of 6 and 8 mm in diameter. A special geometry of the components was designed to self-lock the assembled stents after being expanded by balloons. Characterization of the biodegradable PCL stents was carried out. PCL stents exhibited comparable mechanical properties with that of silicone sponge. Neither significant amount of collapse pressure reduction nor weight loss of the stents was observed after being submerged in phosphate buffered saline for 30 days. In addition, the stents were also implanted in the episcleral space of 10 New Zealand white rabbits. The stents were placed in radial direction and left unsutured after balloon expansion. The stents achieved an efficient buckling effect in echographic and fundus photographic examinations. The ocular pressure was significantly elevated after stent implantation and gradually normalized after the second week. The computed tomography studies verified the hypothesis of minimal migration of the PCL stents. The in vivo result suggests that balloon-expandable biodegradable stents can potentially serve as an ideal indenting biomaterial in retinal detachment surgery.

The application of tissue engineering in reversing mitomycin C-induced ischemic conjunctiva.

The purpose of this study is to evaluate the angiogenic potential of collagen-glycosaminoglycan (CG) matrices in mitomycin C-induced ischemic conjunctival defect, in New Zealand white rabbits. After creating a conjunctival defect at the center of ischemic conjunctiva, a CG matrix was implanted into subconjunctival space to evaluate the conjunctival reepithelialization and angiogenesis during the wound healing process. In the grafted group, the vessel count of the healed conjunctiva was substantially elevated by two fold within the initial 4 weeks and the increased vascular content originated mostly from the fornix site. The rate of conjunctival reepithelialization was not retarded in the grafted group, and the final thickness of healed conjunctiva was similar in both grafted and ungrafted groups. The histological studies revealed that the collagen matrix did not elicit pronounced inflammatory reaction and the regenerated conjunctiva showed loosely arranged collagen deposition without significant scar formation. The α SMA staining positive myofibroblasts were identified in the acute inflammatory stage and were absent, 8 weeks after implantation in both groups. The results indicated that the porous collagen scaffold was able to enhance vascularization and physiological recovery of ischemic conjunctival defect, implying a potential alternative therapy for the ischemic leaking bleb after glaucoma filtrating surgery in ophthalmic practices.

Transcleral posterior chamber paracentesis for angle closure glaucoma secondary to posterior chamber gas entrapment after intravitreal c3f8 injection in a phakic eye.

PURPOSE: The purpose of this study was to describe a new technique for treating a case of angle closure glaucoma secondary to posterior chamber (PC) gas entrapment after intravitreal C3F8 injection. METHODS: Retrospective case report. RESULTS: A 26-year-old woman received intravitreal injection of 0.4 mL of C3F8 after segmental scleral buckling for retinal detachment of her phakic eye. Prone positioning was not maintained postoperatively, and severe eye pain developed within hours of surgery. Intraocular pressure increased to 50 mmHg, and PC was found to be filled with gas accompanying with 360° iridocorneal apposition and angle closure. Transcleral PC paracentesis was performed to evacuate the gas. Anterior chamber angle was reopened inferiorly, and intraocular pressure dropped to 13 mmHg immediately and remained normal. No evidence of lens or iris damage was noted. Postoperatively, the vision improved to 20/25 without major sequelae. CONCLUSION: Posterior chamber gas entrapment with anterior chamber collapse is a rare complication of intravitreal gas injection in phakic eyes. Transcleral PC paracentesis is a safe way to treat angle closure glaucoma secondary to PC gas entrapment.

Isomeric trimethylene and ethylene pendant-armed cross-bridged tetraazamacrocycles and in vitro/in vivo comparisions of their copper(II) complexes.

Ethylene cross-bridged tetraamine macrocycles are useful chelators in coordination, catalytic, medicinal, and radiopharmaceutical chemistry. Springborg and co-workers developed trimethylene cross-bridged analogues, although their pendant-armed derivatives received little attention. We report here the synthesis of a bis-carboxymethyl pendant-armed cyclen with a trimethylene cross-bridge (C3B-DO2A) and its isomeric ethylene-cross-bridged homocyclen ligand (CB-TR2A) as well as their copper(II) complexes. The in vitro and in vivo properties of these complexes are compared with respect to their potential application as (64)Cu-radiopharmaceuticals in positron emission tomography (PET imaging). The inertness of Cu-C3B-DO2A to decomplexation is remarkable, exceeding that of Cu-CB-TE2A. Electrochemical reduction of Cu-CB-TR2A is quasi-reversible, whereas that of Cu-C3B-DO2A is irreversible. The reaction conditions for preparing (64)Cu-C3B-DO2A (microwaving at high temperature) are relatively harsh compared to (64)Cu-CB-TR2A (basic ethanol). The in vivo behavior of the (64)Cu complexes was evaluated in normal rats. Rapid and continual clearance of (64)Cu-CB-TR2A through the blood, liver, and kidneys suggests relatively good in vivo stability, albeit inferior to (64)Cu-CB-TE2A. Although (64)Cu-C3B-DO2A clears continually, the initial uptake is high and only about half is excreted within 22 h, suggesting poor stability and transchelation of (64)Cu to proteins in the blood and/or liver. These data suggest that in vitro inertness of a chelator complex may not always be a good indicator of in vivo stability.

Experimental absorbable stent permits airway remodeling.

OBJECTIVE: Despite metallic and silicone stents being effective in treating various airway lesions, many concerns still remain. A bioresorbable stent that scaffolds the airway lumen and dissolves after the remodeling process is completed has advantages over metallic and silicone stents. We designed and fabricated a new mesh-type bioresorbable stent with a backbone of polycaprolactone (PCL), and evaluated its safety and biocompatibility in a rabbit trachea model. METHODS: The PCL stent was fabricated by a laboratory-made microinjection molding machine. In vitro mechanical strength of the PCL stents was tested and compared to that of commercial silicone stents. The bioresorbable stents were surgically implanted into the cervical trachea of New Zealand white rabbits (n=6). Animals received bronchoscopic examination at 1, 2, 4, 8, and 12 weeks after surgery. Histological examination was completed to evaluate the biocompatibility of the stents. RESULTS: No animals died during the period of study. Distal stent migration was noted in 1 rabbit. In-stent secretion accumulation was found in 2 rabbits. Histological examination showed intact ciliated epithelium and marked leukocyte infiltration in the submucosa of the stented area at 10 and 28 weeks. Stent degradation was minimal, and the mechanical strength was well preserved at the end of 33 weeks. CONCLUSIONS: These preliminary findings showed good safety and biocompatibility of the new PCL stent when used in the airway remodeling. PCL could be a promising bioresorbable material for stent design if prolonged degradation time is required.

Preparation and biological evaluation of copper-64-labeled tyr3-octreotate using a cross-bridged macrocyclic chelator.

PURPOSE: Somatostatin receptors (SSTr) are expressed on many neuroendocrine tumors, and several radiotracers have been developed for imaging these types of tumors. For this reason, peptide analogues of somatostatin have been well characterized. Copper-64 (t(1/2) = 12.7 hours), a positron emitter suitable for positron emission tomography (PET) imaging, was shown recently to have improved in vivo clearance properties when chelated by the cross-bridged tetraazamacrocycle 4,11-bis(carboxymethyl)-1,4,8,11-tetraazabicyclo(6.6.2)hexadecane (CB-TE2A) compared with 1,4,8,11-tetraazacyclotetradecane-1,4,8,11-tetraacetic acid (TETA). EXPERIMENTAL DESIGN: CB-TE2A and TETA were conjugated to the somatostatin analogue tyrosine-3-octreotate (Y3-TATE) for evaluation of CB-TE2A as a bifunctional chelator of 64Cu. The in vitro affinity of each compound for SSTr was determined using a homologous competitive binding assay. In vivo characteristics of both radiolabeled compounds were examined in biodistribution and microPET studies of AR42J tumor-bearing rats. RESULTS: Cu-CB-TE2A-Y3-TATE (Kd = 1.7 nmol/L) and Cu-TETA-Y3-TATE (Kd = 0.7 nmol/L) showed similar affinities for AR42J derived SSTr. In biodistribution studies, nonspecific uptake in blood and liver was lower for 64Cu-CB-TE2A-Y3-TATE. Differences increased with time such that, at 4 hours, blood uptake was 4.3-fold higher and liver uptake was 2.4-fold higher for 64Cu-TETA-Y3-TATE than for 64Cu-CB-TE2A-Y3-TATE. In addition, 4.4-times greater tumor uptake was detected with 64Cu-CB-TE2A-Y3-TATE than with 64Cu-TETA-Y3-TATE at 4 hours postinjection. MicroPET imaging yielded similar results. CONCLUSIONS: CB-TE2A appears to be a superior in vivo bifunctional chelator of 64Cu for use in molecular imaging by PET or targeted radiotherapy due to both improved nontarget organ clearance and higher target organ uptake of 64Cu-CB-TE2A-Y3-TATE compared with 64Cu-TETA-Y3-TATE.