Emerging structures and dynamic mechanisms ofγ-secretase for Alzheimer’s disease

γ-Secretase,called“the proteasome of the membrane,”is a membrane-embedded protease complex that cleaves 150+peptide substrates with central roles in biology and medicine,including amyloid precursor protein and the Notch family of cell-surface receptors.Mutations inγ-secretase and amyloid precursor protein lead to early-onset familial Alzheimer’s disease.γ-Secretase has thus served as a critical drug target for treating familial Alzheimer’s disease and the more common late-onset Alzheimer’s disease as well.However,critical gaps remain in understanding the mechanisms of processive proteolysis of substrates,the effects of familial Alzheimer’s disease mutations,and allosteric modulation of substrate cleavage byγ-secretase.In this review,we focus on recent studies of structural dynamic mechanisms ofγ-secretase.Different mechanisms,including the“Fit-Stay-Trim,”“Sliding-Unwinding,”and“Tilting-Unwinding,”have been proposed for substrate proteolysis of amyloid precursor protein byγ-secretase based on all-atom molecular dynamics simulations.While an incorrect registry of the Notch1 substrate was identified in the cryo-electron microscopy structure of Notch1-boundγ-secretase,molecular dynamics simulations on a resolved model of Notch1-boundγ-secretase that was reconstructed using the amyloid precursor protein-boundγ-secretase as a template successfully capturedγ-secretase activation for proper cleavages of both wildtype and mutant Notch,being consistent with biochemical experimental findings.The approach could be potentially applied to decipher the processing mechanisms of various substrates byγ-secretase.In addition,controversy over the effects of familial Alzheimer’s disease mutations,particularly the issue of whether they stabilize or destabilizeγ-secretase-substrate complexes,is discussed.Finally,an outlook is provided for future studies ofγ-secretase,including pathways of substrate binding and product release,effects of modulators on familial Alzheimer’s disease mutations of theγ-secretase-substrate complexes.Comprehensive understanding of the functional mechanisms ofγ-secretase will greatly facilitate the rational design of effective drug molecules for treating familial Alzheimer’s disease and perhaps Alzheimer’s disease in general.

Progress of research in the application of ultrasound technology for the treatment of Alzheimer’s disease

Alzheimer’s disease is a common neurodegenerative disorder defined by decreased reasoning abilities,memory loss,and cognitive deterioration.The presence of the blood-brain barrier presents a major obstacle to the development of effective drug therapies for Alzheimer’s disease.The use of ultrasound as a novel physical modulation approach has garnered widespread attention in recent years.As a safe and feasible therapeutic and drug-delivery method,ultrasound has shown promise in improving cognitive deficits.This article provides a summary of the application of ultrasound technology for treating Alzheimer’s disease over the past 5 years,including standalone ultrasound treatment,ultrasound combined with microbubbles or drug therapy,and magnetic resonance imaging-guided focused ultrasound therapy.Emphasis is placed on the benefits of introducing these treatment methods and their potential mechanisms.We found that several ultrasound methods can open the blood-brain barrier and effectively alleviate amyloid-βplaque deposition.We believe that ultrasound is an effective therapy for Alzheimer’s disease,and this review provides a theoretical basis for future ultrasound treatment methods.

Prevention and Treatment of KSHV-associated Diseases with Antiviral Drugs

Kaposi’s sarcoma-associated herpesvirus (KSHV) was first identified as the etiologic agent of Kaposi’s sarcoma (KS) in 1994. KSHV infection is necessary,but not sufficient for the development of Kaposi sarcoma (KS),primary effusion lymphoma (PEL),and multicentric Castleman disease (MCD). Advances in the prevention and treatment of KSHV-associated Diseases have been achieved,even though current treatment options are ineffective,or toxic to many affected persons. The identification of new targets for potential future therapies and the randomized trial to evaluate the efficacy of new antivirals are required.

Resistance to Anti-Thyroid Drugs in Graves’ Disease: Clinical-Biological Characteristics and Alternative Therapy in Tropical Area

Background: Resistance to anti-thyroid drugs (ATDs) is a rare entity recently described. We report two African observations in the treatment of Graves’ disease. Case 1: A 19-year-old Senegalese woman presented on admission with thyrotoxicosis syndrome associated with diffuse goitre and Grave’s orbitopathy. TSH levels were low (0.005 mIU/ml;N = 0.27 - 4.20) and fT4 elevated (60 pmol/L;N = 12 - 22]. Combination therapy with propranolol (40 mg/day) and carbimazole (starting dose of 45 mg/day and increased to 60 mg/day) was initiated. In view of the persistence of symptoms despite good therapeutic compliance, carbimazole was replaced by methimazole with an initial starting dose of 40 mg/day, followed by 60 mg/day. Despite the change in therapy, clinical symptoms of thyrotoxicosis persisted, and fT4 levels remained elevated. The patient was diagnosed with resistance to ATDs in Graves’ disease. Total thyroidectomy following 10 days of preoperative preparation with 1% Lugol’s solution was performed successfully. Case 2: A 22-year-old woman was referred for continued management of Graves’ disease with elevated thyroid-stimulating hormone receptor antibody (TRAb) levels (34 UI/mL;N < 1.75). Treatment included propranolol (80 mg/day) and carbimazole at an unusual dose of 80 mg/day. Combined therapy was clinically and biologically ineffective, with an fT4 level of 100 pmol/L [N: 12 - 22]. Upon admission, methimazole (40 mg/day) followed by propylthiouracil (800 mg/day) replaced carbimazole. Despite good patient compliance, the patient’s symptoms remained unaltered and fT4 levels elevated. A total robot thyroidectomy using the right axillary approach was performed successfully after 10 days of preoperative preparation, including prednisone (40 mg/day) combined with 1% Lugol’s solution. Conclusion: Resistance to ATDs complicates the management of Graves’ disease. Total thyroidectomy following preoperative preparation with Lugol’s solution and/or corticosteroids was shown to be successful.

Effects of proton pump inhibitors on inflammatory bowel disease:An updated review

Inflammatory bowel disease(IBD)is believed to be caused by various factors,including abnormalities in disease susceptibility genes,environmental factors,immune factors,and intestinal bacteria.Proton pump inhibitors(PPIs)are the primary drugs used to treat acid-related diseases.They are also commonly prescribed to patients with IBD.Recent studies have suggested a potential association between the use of certain medications,such as PPIs,and the occurrence and progression of IBD.In this review,we summarize the potential impact of PPIs on IBD and analyze the underlying mechanisms.Our findings may provide insights for conducting further investigations into the effects of PPIs on IBD and serve as an important reminder for physicians to exercise caution when prescribing PPIs to patients with IBD.

Early proactive monitoring of DNA-thioguanine in patients with Crohn’s disease predicts thiopurine-induced late leucopenia in NUDT15/TPMT normal metabolizers

BACKGROUND Thiopurine-induced leucopenia significantly hinders the wide application of thiopurines.Dose optimization guided by nudix hydrolase 15(NUDT15)has significantly reduced the early leucopenia rate,but there are no definitive biomarkers for late risk leucopenia prediction.AIM To determine the predictive value of early monitoring of DNA-thioguanine(DNATG)or 6-thioguanine nucleotides(6TGN)for late leucopenia under a NUDT15-guided thiopurine dosing strategy in patients with Crohn’s disease(CD).METHODS Blood samples were collected within two months after thiopurine initiation for detection of metabolite concentrations.Late leucopenia was defined as a leukocyte count<3.5×10^(9)/L over two months.RESULTS Of 148 patients studied,late leucopenia was observed in 15.6%(17/109)of NUDT15/thiopurine methyltransferase(TPMT)normal and 64.1%(25/39)of intermediate metabolizers.In patients suffering late leucopenia,early DNATG levels were significantly higher than in those who did not develop late leucopenia(P=4.9×10^(-13)).The DNATG threshold of 319.43 fmol/μg DNA could predict late leucopenia in the entire sample with an area under the curve(AUC)of 0.855(sensitivity 83%,specificity 81%),and in NUDT15/TPMT normal metabolizers,the predictive performance of a threshold of 315.72 fmol/μg DNA was much more remarkable with an AUC of 0.902(sensitivity 88%,specificity 85%).6TGN had a relatively poor correlation with late leucopenia whether in the entire sample(P=0.021)or NUDT15/TPMT normal or intermediate metabolizers(P=0.018,P=0.55,respectively).CONCLUSION Proactive therapeutic drug monitoring of DNATG could be an effective strategy to prevent late leucopenia in both NUDT15/TPMT normal and intermediate metabolizers with CD,especially the former.

Liposome based drug delivery as a potential treatment option for Alzheimer’s disease

Alzheimer’s disease is a neurodegenerative condition leading to atrophy of the brain and robbing nearly 5.8 million individuals in the United States age 65 and older of their cognitive functions.Alzheimer’s disease is associated with dementia and a progressive decline in memory,thinking,and social skills,eventually leading to a point that the individual can no longer perform daily activities independently.Currently available drugs on the market temporarily alleviate the symptoms,however,they are not successful in slowing down the progression of Alzheimer’s disease.Treatment and cures have been constricted due to the difficulty of drug delivery to the blood-brain barrier.Several studies have led to identification of vesicles to transport the necessary drugs through the blood-brain barrier that would typically not achieve the targeted area through systemic delivered medications.Recently,liposomes have emerged as a viable drug delivery agent to transport drugs that are not able to cross the blood-brain barrier.Liposomes are being used as a component of nanoparticle drug delivery;due to their biocompatible nature;and possessing the capability to carry both lipophilic and hydrophilic therapeutic agents across the blood brain barrier into the brain cells.Studies indicate the importance of liposomal based drug delivery in treatment of neurodegenerative disorders.The idea is to encapsulate the drugs inside the properly engineered liposome to generate a response of treatment.Liposomes are engineered to target specific diseased moieties and also several surface modifications of liposomes are under research to create a clinical path to the management of Alzheimer’s disease.This review deals with Alzheimer’s disease and emphasize on challenges associated with drug delivery to the brain,and how liposomal drug delivery can play an important role as a drug delivery method for the treatment of Alzheimer’s disease.This review also sheds some light on variation of liposomes.Additionally,it emphasizes on the liposomal formulations which are currently researched or used for treatment of Alzheimer’s disease and also discusses the future prospect of liposomal based drug delivery in Alzheimer’s disease.

Advances in Drug Therapy for Alzheimer’s Disease

Alzheimer’s disease(AD)is a chronic neurodegenerative disease that mainly causes dementia.It is a serious threat to the health of the global elderly population.Considerable money and effort has been invested in the development of drug therapy for AD worldwide.Many drug therapies are currently under development or in clinical trials,based on two known mechanisms of AD,namely,Aβtoxicity and the abnormal Tau hyperphosphorylation.Numerous drugs are also being developed for other AD associated mechanisms such as neuroinflammation,neurotransmitter imbalance,oxidative damage and mitochondrial dysfunction,neuron loss and degeneration.Even so,the number of drugs that can successfully improve symptoms or delay the progression of the disease remains very limited.However,multi-drug combinations may provide a new avenue for drug therapy for AD.In addition,early diagnosis of AD and timely initiation of treatment may allow drugs that act on the early pathological processes of AD to help improve the symptoms and prevent the progression of the condition.

Novel drug delivery systems for inflammatory bowel disease

Inflammatory bowel disease(IBD)is a chronic illness characterized by relapsing inflammation of the intestines.The disorder is stratified according to the severity and is marked by its two main phenotypical representations:Ulcerative colitis and Crohn’s disease.Pathogenesis of the disease is ambiguous and is expected to have interactivity between genetic disposition,environmental factors such as bacterial agents,and dysregulated immune response.Treatment for IBD aims to reduce symptom extent and severity and halt disease progression.The mainstay drugs have been 5-aminosalicylates(5-ASAs),corticosteroids,and immunosuppressive agents.Parenteral,oral and rectal routes are the conventional methods of drug delivery,and among all,oral administration is most widely adopted.However,problems of systematic drug reactions and low specificity in delivering drugs to the inflamed sites have emerged with these regular routes of delivery.Novel drug delivery systems have been introduced to overcome several therapeutic obstacles and for localized drug delivery to target tissues.Enteric-coated microneedle pills,various nano-drug delivery techniques,prodrug systems,lipid-based vesicular systems,hybrid drug delivery systems,and biologic drug delivery systems constitute some of these novel methods.Microneedles are painless,they dislodge their content at the affected site,and their release can be prolonged.Recombinant bacteria such as genetically engineered Lactococcus Lactis and eukaryotic cells,including GM immune cells and red blood cells as nanoparticle carriers,can be plausible delivery methods when evaluating biologic systems.Nano-particle drug delivery systems consisting of various techniques are also employed as nanoparticles can penetrate through inflamed regions and adhere to the thick mucus of the diseased site.Prodrug systems such as 5-ASAs formulations or their derivatives are effective in reducing colonic damage.Liposomes can be modified with both hydrophilic and lipophilic particles and act as lipid-based vesicular systems,while hybrid drug delivery systems containing an internal nanoparticle section for loading drugs are potential routes too.Leukosomes are also considered as possible carrier systems,and results from mouse models have revealed that they control anti-and pro-inflammatory molecules.

Therapeutic drug monitoring in inflammatory bowel disease:At the right time in the right place

Therapeutic drug monitoring(TDM)was one of most sought-after objective tools to determine therapeutic efficiency of different biologics and its role in the management of patients with inflammatory bowel disease(IBD)was regarded with great anticipation.But implementation of the TDM in clinical practice was challenged by several factors including uncertainty of the optimal cut-off values,assay variable sensitivity in detecting drug levels and antibodies and,most importantly,individual pharmacokinetics.While reactive TDM was embraced in clinical practice as a useful tool in assessing lack of response to therapy,the utility of proactive TDM in managing IBD therapy is still challenged by the lack of consistency between evidence.Described here,there are four groups of IBD patients for whom proactive TDM has the potential to greatly impact their therapeutic outcomes:Patients with perianal Crohn’s disease,patients with severe ulcerative colitis,pregnant women with IBD and children.As the future of IBD management moves towards personalizing treatment,TDM will be an important decision node in a machine learning based algorithm predicting the best strategy to maximize treatment results while minimizing the loss of response to therapy.

Challenges and trends in apomorphine drug delivery systems for the treatment of Parkinson's disease

Parkinson's disease(PD) is a chronic debilitating disease affecting approximately 1% of the population over the age of 60. The severity of PD is correlated to the degree of dopaminergic neuronal loss. Apomorphine has a similar chemical structure as the neurotransmitter dopamine and has been used for the treatment of advanced PD patients. In PD patients,apomorphine is normally administered subcutaneously with frequent injections because of the compound's extensive hepatic first-pass metabolism. There is, hence, a large unmet need for alternative administrative routes for apomorphine to improve patient compliance.The present review focuses on the research and development of alternative delivery of apomorphine, aiming to highlight the potential of non-invasive apomorphine therapy in PD,such as sublingual delivery and transdermal delivery.

Repositioning of clinically approved drug Bazi Bushen capsule for treatment of Alzheimer′s disease using network pharma⁃cology approach and in vitro experimental validation

OBJECTIVE To explore the new indications and key mechanism of Bazi Bushen capsule(BZBS)by network pharmacology and in vitro experiment.METHODS The potential tar⁃get profiles of the components of BZBS were pre⁃dicted.Subsequently,new indications for BZBS were predicted by disease ontology(DO)enrich⁃ment analysis and initially validated by GO and KEGG pathway enrichment analysis.Further⁃more,the therapeutic target of BZBS acting on AD signaling pathway were identified by intersec⁃tion analysis.Two Alzheimer′s disease(AD)cell models,BV-2 and SH-SY5Y,were used to pre⁃liminarily verify the anti-AD efficacy and mecha⁃nism of BZBS in vitro.RESULTS In total,1499 non-repeated ingredients were obtained from 16 herbs in BZBS formula,and 1320 BZBS targets with high confidence were predicted.Disease enrichment results strongly suggested that BZBS formula has the potential to be used in the treat⁃ment of AD.In vitro experiments showed that BZ⁃BS could significantly reduce the release of TNF-αand IL-6 and the expression of COX-2 and PSEN1 in Aβ25-35-induced BV-2 cells.BZBS reduced the apoptosis rate of Aβ25-35 induced SH-SY5Y cells,significantly increased mitochon⁃drial membrane potential,reduced the expres⁃sion of Caspase3 active fragment and PSEN1,and increased the expression of IDE.CONCLU⁃SIONS BZBS formula has a potential use in the treatment of AD,which is achieved through regu⁃lation of ERK1/2,NF-κB signaling pathways,and GSK-3β/β-catenin signaling pathway.Further⁃more,the network pharmacology technology is a feasible drug repurposing strategy to reposition new clinical use of approved TCM and explore the mechanism of action.The study lays a foun⁃dation for the subsequent in-depth study of BZBS in the treatment of AD and provides a basis for its application in the clinical treatment of AD.

Nose-to-brain drug delivery approach：a key to easily accessing the brain for the treatment of Alzheimer＇s disease

Alzheimer＇s disease（AD）：AD,a neurodegenerative disorder and a significant cause of dementia throughout the world mostly affects the older adults but sometimes also seen in young age（early state AD）（Agrawal et al.,2017）.

Updates in therapeutic drug monitoring in inflammatory bowel disease

Biologics and immunomodulators(IMM)are generally considered the most effective therapies for the treatment of ulcerative colitis and Crohn’s disease.However,despite the efficacy of these therapies,many patients either have a primary lack of response or a secondary loss of response to these medications.Therapeutic drug monitoring(TDM)is a systematic approach to managing such patients.In this review,we summarize the latest data on TDM,including reactive and proactive TDM,in patients with inflammatory bowel disease on biologics and/or IMM.

Real world studies are essential for drug therapy in Parkinson's disease

Prospective real-world data from large patient samples, which re- port on the long-term effectiveness of the employed different drug therapies, are rare in Parkinson＇s disease （PD）. The non interven- tional ＂Transdermal Rotigotine User Surveillance Study＂ （TRUST） trial represents such a real-world study. It investigated long-term treatment with different dopamine substituting treatment regimens in 2195 PD patients （Mfiller et al., 2018）. Participation in TRUST meant that the treating neurologists were only asked to document and modify the dopaminergic drug regimen without any prior PD patient selection criteria. Thus this unique trial design reflects the real world of patient maintenance.

Is it time to rethink the Alzheimer's disease drug development strategy by targeting its silent phase?

Alzheimer＇s disease （AD） is the most frequent cause of dementia in the western world. In clinical terms, AD is characterized by progres- sive cognitive decline that usually begins with memory impairment. As the disease progresses, AD inevitably affects all intellectual functions including executive functions, leading to complete dependence for basic activities of daily life and premature death.

S4B-2 Bushen-Yizhi Formula Inhibits the NLRP3/NFκB Mediated Neuroinflammation and Improves the Motor Dysfunction in a Mouse Model of Parkinson’s Disease

Objective:Parkinson’s disease(PD)is the second largest neurodegenerative disease following Alzheimer’s disease(AD),which associated with aging.There are many similarities in pathology and pathogenesis,even in the TCM theory understanding,so we can learn from each other in the process of drug discovery.The clinical results showed that Bushen-Yizhi formula(BSYZ)could effectively improve the neurological function score of senile dementia patients and had a better anti-dementia effect.Further pharmacological studies showed that BSYZ had neuroprotective effects,such as anti-inflammatory,anti-oxidation,anti-apoptosis and neurotrophic effects.In this study,the therapeutic effect of BSYZ on PD was evaluated in vivo and in vivo,and its molecular mechanism was discussed in order to expand the scope of application of BSYZ and to provide strategies for drug discovery of related neurodegenerative diseases.Methods:C57 BL/6 mice were injected intraperitoneally with MPTP to construct a PD mouse model.BSYZ(1.46,2.92,5.84 mg·kg-1)was administered for two weeks,and the positive control group was given a NSAID,piroxicam(12.5 mg·kg-1).After 1 week of pretreatment,MPTP was used to construct a PD mouse model.The mice were subjected to Rotation test on days 1,3 and 5,6th day.and the movement coordination and exercise ability of the drug on PD mice were observed on theThe number of TH-positive cells,Iba1 and CD68-labeled microglial cells in SNpc region were observed by immunofluorescence to observe the proliferation and activation of microglial cells and GFAP-labeled astrocytes.Western blotting was used to detect the nuclear transfer of NLRP3,Caspase-1,ASC,pro-IL-1β,IL-1βand NF-κB in the midbrain.Results:1.BSYZ could significantly improve the expression of MPTP model mice in the experiment of fatigue and Y-maze,increase the number of neurons in SNpc region and the positive expression of TH protein.2.BSYZ significantly inhibited the number of Iba1/CD68-positive microglial cells in MPTP-model mice and decreased the number of GFAP-positive astrocytes.3.BSYZ significantly inhibited the expression of NLRP3-associated protein in BV2 microglial cells induced by LPS+ATP and inhibited the nuclear transfer of NF-κB.Conclusion:BSYZ can effectively relieve the motor dysfunction of PD model mice,improve the damage of dopaminergic neurons,inhibit the proliferation and activation of microglial cells and astrocytes,and have good anti-MPTPinduced neuroinflammation and neuroinflammation mediated by nuclear transfer of NF-κB.The results show that BSYZ has a good prospect of anti-Parkinson’s disease and provides valuable drug discovery strategies for the related neurodegenerative diseases.

Management of perianal fistulas in Crohn's disease:An upto-date review

Perianal disease is one of the most disabling manifestations of Crohn's disease.A multidisciplinary approach of gastroenterologist,colorectal surgeon and radiologist is necessary for its management.A correct diagnosis,based on endoscopy,magnetic resonance imaging,endoanal ultrasound and examination under anesthesia,is crucial for perianal fistula treatment.Available medical and surgical therapies are discussedin this review,including new local treatment modalities that are under investigation.

New treatments for inflammatory bowel disease

ＩＮＴＲＯＤＵＣＴＩＯＮＡｌｔｈｏｕｇｈｉｎｆｌａｍｍａｔｏｒｙｂｏｗｅｌｄｉｓｅａｓｅ（ＩＢＤ）ｉｓａｐｐａｒｅｎｔｌｙｓｔｉｌｒｅｌａｔｉｖｅｌｙｒａｒｅｉｎｔｈｅＥａｓｔ，ｅｖｉｄｅｎｃｅｆｒｏｍＨｏｎｇＫｏｎｇｓｕｇｇｅｓｔｓｔｈａｔｏｖｅｒ...

Emerging treatments for complex perianal fistula in Crohn's disease

Complex perianal fistulas have a negative impact on the quality of life of sufferers and should be treated.Correct diagnosis,characterization and classification of the fistulas are essential to optimize treatment.Nevertheless, in the case of patients whose fistulas are associated with Crohn's disease,complete closure is particularly difficult to achieve.Systemic medical treatments(antibiotics, thiopurines and other immunomodulatory agents,and, more recently,anti-tumor necrosis factor-αagents such as infliximab)have been tried with varying degrees of success.Combined medical(including infliximab)and less aggressive surgical therapy(drainage and seton placement)offer the best outcomes in complex Crohn's fistulas while more aggressive surgical procedures such as fistulotomy or fistulectomy may increase the risk of incontinence.This review will focus on emerging novel treatments for perianal disease in Crohn's patients. These include locally applied infliximab or tacrolimus, fistula plugs,instillation of fibrin glue and the use of adult expanded adipose-derived stem cell injection.More welldesigned controlled studies are required to confirm the effectiveness of these emerging treatments.