Evaluation of trabecular meshwork-specific promoters in vitro and in vivo using scAAV2 vectors expressing C3 transferase

AIM:To evaluate the potential of two trabecular meshwork(TM)-specific promoters,Chitinase 3-like 1(Ch3L1)and matrix gla protein(MGP),for improving specificity and safety in glaucoma gene therapy based on self-complementary AAV2(scAAV2)vector technologies.METHODS:An scAAV2 vector with C3 transferase(C3)as the reporter gene(scAAV2-C3)was selected.The scAAV2-C3 vectors were driven by Ch3L1(scAAV2-Ch3L1-C3),MGP(scAAV2-MGP-C3),enhanced MGP(scAAV2-eMGP-C3)and cytomegalovirus(scAAV2-CMV-C3),respectively.The cultured primary human TM cells were treated with each vector at different multiplicities of infections.Changes in cell morphology were observed by phase contrast microscopy.Actin stress fibers and Rho GTPases/Rho-associated protein kinase pathway-related molecules were assessed by immunofluorescence staining,real-time quantitative polymerase chain reaction and Western blot.Each vector was injected intracamerally into the one eye of each rat at low and high doses respectively.In vivo green fluorescence was visualized by a Micron III Retinal Imaging Microscope.Intraocular pressure(IOP)was monitored using a rebound tonometer.Ocular responses were evaluated by slit-lamp microscopy.Ocular histopathology analysis was examined by hematoxylin and eosin staining.RESULTS:In TM cell culture studies,the vectormediated C3 expression induced morphologic changes,disruption of actin cytoskeleton and reduction of fibronectin expression in TM cells by inhibiting the Rho GTPases/Rhoassociated protein kinase signaling pathway.At the same dose,these changes were significant in TM cells treated with scAAV2-CMV-C3 or scAAV2-Ch3L1-C3,but not in cells treated with scAAV2-eMGP-C3 or scAAV2-MGP-C3.At lowinjected dose,the IOP was significantly decreased in the scAAV2-Ch3L1-C3-injected eyes but not in scAAV2-MGPC3-injected and scAAV2-eMGP-C3-injected eyes.At highinjected dose,significant IOP reduction was observed in the scAAV2-eMGP-C3-injected eyes but not in scAAV2-MGP-C3-injected eyes.Similar to scAAV2-CMV-C3,scAAV2-Ch3L1-C3 vector showed efficient transduction both in the TM and corneal endothelium.In anterior segment tissues of scAAV2-eMGP-C3-injected eyes,no obvious morphological changes were found except for the TM.Inflammation was absent.CONCLUSION:In scAAV2-transduced TM cells,the promoter-driven efficiency of Ch3L1 is close to that of cytomegalovirus,but obviously higher than that of MGP.In the anterior chamber of rat eye,the transgene expression pattern of scAAV2 vector is presumably affected by MGP promoter,but not by Ch3L1 promoter.These findings would provide a useful reference for improvement of specificity and safety in glaucoma gene therapy using scAAV2 vector.

Comparison between recombinant human parathyroid hormone(1-34) and elcatonin in treatment of primary osteoporosis

Objective:To evaluate the efficacy and safety of rhPTH(1-34) vs.elcatonin.Methods:Sixty palients with primary OP were randomly divided into two groups according to the ratio of 3:1.rhPTH(1-34) group(PTH group) was treated with subcutaneous injection of rhPTH(1-34) 20 μg daily for 18 months,and the elcalonin group(CT group) was treated with intramuscular injection of elcatonin 20 U weekly for 12 months.Bone mineral density(BMD) of the lumbar spine 2-4(L_(2-4))and femoral neck,serum calcium and phosphorus,urinary calcium,serum hone specific alkaline phosphatase(BSAP).and urinary c-terminal telopeptides of type Ⅰ collagen/creatinine(uCTX-Ⅰ /Cn were tested at baseline,and 6.12.and 18 months after treatment.Results:In PTH group.HMD of L_(2-4),at 6,12.and 18 months,BDM of Femoral neck at 18 month,BSAP at 6 and 12 months and uCTX- Ⅰ /Cr at 6.12 and 18 months were all significantly raised.In CT group.HMD of L_(2-4) at12 month and that of femoral neck at 12 and 18 months were significantly elevated,while HSAP was significantly decreased at 12 and 18 months,and no significant difference on CTX- Ⅰ /Cr was observed.When BMD growth and growth rate between two groups were compared.PTH group had better improvement in L_(2-4) BMD and growth rate than CT group at 6.12.and 18 months.BMD growth and growth rale of femoral neck al 12 month and its growth at 18 month in CT group were higher than in PTH group,hut there was no significant difference between two groups regarding the growth rates at 18 month.Besides,there were no significant differences regarding the rales ol adverse reactions between two groups.Conclusions:rhPTH(1—34),is safe and effective in the treatment of primary OP.It is superior to elcatonin in improving vertebral HMD at onset time,growth rate and growth range,but inferior to elcatonin at HMD of femoral neck.

Deletion of phosphatidylserine flippase β-subunit Tmem30a in satellite cells leads to delayed skeletal muscle regeneration

Phosphatidylserine(PS)is distributed asymmetrically in the plasma membrane of eukaryotic cells.Phosphatidylserine flippase(P4-ATPase)transports PS from the outer leaflet of the lipid bilayer to the inner leaflet of the membrane to maintain PS asymmetry.TheβsubunitTMEM30 Ais indispensable for transport and proper function of P4-ATPase.Previous studies have shown that the ATP11 A and TMEM30 A complex is the molecular switch for myotube formation.However,the role of Tmem30 a in skeletal muscle regeneration remains elusive.In the current study,Tmem30 a was highly expressed in the tibialis anterior(TA)muscles of dystrophin-null(mdx)mice and BaCl2-induced muscle injury model mice.We generated a satellite cell(SC)-specific Tmem30 a conditional knockout(cKO)mouse model to investigate the role of Tmem30 a in skeletal muscle regeneration.The regenerative ability of cKO mice was evaluated by analyzing the number and diameter of regenerated SCs after the TA muscles were injured by BaCl2-injection.Compared to the control mice,the cKO mice showed decreased Pax7+and MYH3+SCs,indicating diminished SC proliferation,and decreased expression of muscular regulatory factors(MYOD and MYOG),suggesting impaired myoblast proliferation in skeletal muscle regeneration.Taken together,these results demonstrate the essential role of Tmem30 a in skeletal muscle regeneration.

Overexpression of Twist1 in vascular endothelial cells promotes pathological retinal angiogenesis in mice

Retinal angiogenesis is a critical process for normal retinal function.However,uncontrolled angiogenesis can lead to pathological neovascularization(NV),which is closely related to most irreversible blindness-causing retinal diseases.Understanding the molecular basis behind pathological NV is important for the treatment of related diseases.Twist-related protein 1(TWIST1)is a well-known transcription factor and principal inducer of epithelial-mesenchymal transition(EMT)in many human cancers.Our previous study showed that Twist1 expression is elevated in pathological retinal NV.To date,however,the role of TWIST1 in retinal pathological angiogenesis remains to be elucidated.To study the role of TWIST1 in pathological retinal NV and identify specific molecular targets for antagonizing pathological NV,we generated an inducible vascular endothelial cell(EC)-specific Twist1 transgenic mouse model(Tg-Twist1iEC+).Whole-mount retinas from Tg-Twist1iEC+mice showed retarded vascular progression and increased vascular density in the front end of the growing retinal vasculature,as well as aneurysm-like pathological retinal NV.Furthermore,overexpression of Twist1 in the ECs promoted cell proliferation but disturbed cell polarity,thus leading to uncontrolled retinal angiogenesis.TWIST1 promoted pathological NV by activating the Wnt/β-catenin signaling pathway and inducing the expression of NV formation-related genes,thereby acting as a‘valve’in the regulation of pathological angiogenesis.This study identified the critical role of TWIST1 in retinal pathological NV,thus providing a potential therapeutic target for pathological NV.