The Protective A673T Mutation of Amyloid Precursor Protein (APP) in Alzheimer's Disease

Alzheimer's disease is a progressive neurodegenerative disorder characterized by extracellular amyloid beta peptides and neurofibrillary tangles consisted of intracellular hyperphosphorylated Tau in the hippocampus and cerebral cortex. Most of the mutations in key genes that code for amyloid precursor protein can lead to significant accumulation of these peptides in the brain and cause Alzheimer's disease. Moreover, some point mutations in amyloid precursor protein can cause familial Alzheimer's disease, such as Swedish mutation (KM670/671NL) and A673V mutation. However, recent studies have found that the A673T mutation in amyloid precursor protein gene can protect against Alzheimer's disease, even if it is located next to the Swedish mutation (KM670/671NL) and at the same site as A673V mutation, which are pathogenic. It makes us curious about the protective A673T mutation. Here, we summarize the most recent insights of A673T mutation, focus on their roles in protective mechanisms against Alzheimer's disease, and discuss their involvement in future treatment.

Nanocarriers-loaded with natural actives as newer therapeutic interventions for treatment of hepatocellular carcinoma

Introduction: Cancer has always been a menace for the society. Hepatocellular carcinoma (HCC) is one of the most lethal and 3rdlargest causes of deaths around the world.Area covered: The emergence of natural actives is considered as the greatest boon for fighting cancer. The natural actives take precedence over the traditional chemotherapeutic drugs in terms of their multi-target, multi-level and coordinated effects in the treatment of HCC. Literature reports have indicated the tremendous potential of bioactive natural products in inhibiting the HCC via molecular drug targeting, augmented bioavailability, and the ability for both passive or active targeting and stimulus-responsive drug release characteristics. This review provides a newer treatment approaches involved in the mechanism of action of different natural actives used for the HCC treatment via different molecular pathways. Besides, the promising advantage of natural bioactive-loaded nanocarriers in HCC treatment has also been also presented in this review. Expert opinion: The remarkable outcomes have been observed with therapeutic efficacy of the nanocarriers of natural actives in the treatment of HCC.Furthermore, it requires a thorough assessment of the safety and efficacy evaluation of the nanocarriers for the delivery of targeted natural active ingredients in HCC.].

A Review of Gene Therapy Delivery Systems for Intervertebral Disc Degeneration

Background: :

Intervertebral Disc (IVD) degeneration is a major public health concern, and gene therapy seems a promising approach to delay or even reverse IVD degeneration. However, the delivery system used to transfer exogenous genes into intervertebral disc cells remains a challenge.

Methods::

The MEDLINE, Web of Science, and Scopus databases were searched for English-language articles related to gene therapy for IVD degeneration articles from 1999 to May 2019. The keywords included “gene therapy” AND “intervertebral disc”. The history of the development of different delivery systems was analysed, and the latest developments in viral and non-viral vectors for IVD degeneration treatment were reviewed.

Results: :

Gene therapy delivery systems for IVD degeneration are divided into two broad categories: viral and non-viral vectors. The most commonly used viral vectors are adenovirus, adeno-associated virus (AAV), and lentivirus. Enthusiasm for the use of adenovirus vectors has gradually declined and has been replaced by a preference for lentivirus and AAV vectors. New technologies, such as RNAi and CRISPR, have further enhanced the advantage of viral vectors. Liposomes are the classic non-viral vector, and their successors, polyplex micelles and exosomes, have more potential for use in gene therapy for IVD degeneration.

Conclusion::

Lentivirus and AAV are the conventional viral vectors used in gene therapy for IVD degeneration, and the new technologies RNAi and CRISPR have further enhanced their advantages. Nonviral vectors, such as polyplex micelles and exosomes, are promising gene therapy vectors for IVD degeneration.

Recent Advances in Therapeutic Genome Editing in China

Editing of the genome to correct disease-causing mutations is a promising approach for the treatment of human diseases. Recent advances in the development of programmable nuclease-based genome editing tools have substantially improved the ability to make precise changes in the human genome. Genome editing technologies are already being used to correct genetic mutations in affected tissues and cells to treat diseases that are refractory to traditional gene therapies. Chinese scientists have made remarkable breakthroughs in the field of therapeutic genome editing, particularly with the first clinical trial involving the clustered regularly interspaced short palindromic repeats-caspase 9 system that began in China. Herein, current progress toward developing programmable nuclease-based gene therapies is introduced, as well as future prospects and challenges in China.

Spinal cord astrocytomas: progresses in experimental and clinical investigations for developing recovery neurobiology-based novel therapies

Spinal cord astrocytomas (SCAs) have discernibly unique signatures in regards to epidemiology, clinical oncological features, genetic markers, pathophysiology, and research and therapeutic challenges. Overall, there are presently very limited clinical management options for high grade SCAs despite progresses made in validating key molecular markers and standardizing tumor classification. The endeavors were aimed to improve diagnosis, therapy design and prognosis assessment, as well as to define more effective oncolytic targets. Efficacious treatment for high grade SCAs still remains an unmet medical demand. This review is therefore focused on research state updates that have been made upon analyzing clinical characteristics, diagnostic classification, genetic and molecular features, tumor initiation cell biology, and current management options for SCAs. Particular emphasis was given to basic and translational research endeavors targeting SCAs, including establishment of experimental models, exploration of unique profiles of SCA stem cell-like tumor survival cells, characterization of special requirements for effective therapeutic delivery into the spinal cord, and development of donor stem cell-based gene-directed enzyme prodrug therapy. We concluded that precise understanding of molecular oncology, tumor survival mechanisms (e.g., drug resistance, metastasis, and cancer stem cells/tumor survival cells), and principles of Recovery Neurobiology can help to create clinically meaningful experimental models of SCAs. Establishment of such systems will expedite the discovery of efficacious therapies that not only kill tumor cells but simultaneously preserve and improve residual neural function.

Responsive Nanocarriers as an Emerging Platform for Cascaded Delivery of Nucleic Acids to Cancer

Cascades of systemic and intracellular obstacles, including low stability in blood, little tumor accumulation, weak tumor penetration, poor cellular uptake, inefficient endosomal escape and deficient disassembly in the cytoplasm, must be overcome in order to deliver nucleic acid drugs for cancer therapy. Nanocarriers that are sensitive to a variety of physiological stimuli, such as pH, redox status, and cell enzymes, are substantially changing the landscape of nucleic acid drug delivery by helping to overcome cascaded systemic and intracellular barriers. This review discusses nucleic acid-based therapeutics, systemic and intracellular barriers to efficient nucleic acid delivery, and nanocarriers responsive to extracellular and intracellular biological stimuli to overcome individual barriers. In particular, responsive nanocarriers for the cascaded delivery of nucleic acids in vivo are highlighted. Developing novel cascaded nanocarriers that transform their physicochemical properties in response to various stimuli in a timely and spatially controlled manner for nucleic acid drug delivery holds great potential for translating the promise of nucleic acid drugs and achieving clinically successful cancer therapy.

Extracellular vesicles: Pharmacological modulators of the peripheral and central signals governing obesity

Obesity and its metabolic resultant dysfunctions such as insulin resistance, hyperglycemia, dyslipidemia and hypertension, grouped as the "metabolic syndrome", are chronic inflammatory disorders that represent one of the most severe epidemic health problems. The imbalance between energy intake and expenditure, leading to an excess of body fat and an increase of cardiovascular and diabetes risks, is regulated by the interaction between central nervous system (CNS) and peripheral signals in order to regulate behavior and finally, the metabolism of peripheral organs. At present, pharmacological treatment of obesity comprises actions in both CNS and peripheral organs. In the last decades, the extracellular vesicles have emerged as participants in many pathophysiological regulation processes. Whether used as biomarkers, targets or even tools, extracellular vesicles provided some promising effects in the treatment of a large variety of diseases. Extracellular vesicles are released by cells from the plasma membrane (microvesicles) or from multivesicular bodies (exosomes) and contain lipids, proteins and nucleic acids, such as DNA, protein coding, and non-coding RNAs. Owing to their composition, extracellular vesicles can (i) activate receptors at the target cell and then, the subsequent intracellular pathway associated to the specific receptor; (ii) transfer molecules to the target cells and thereby change their phenotype and (iii) be used as shuttle of drugs and, thus, to carry specific molecules towards specific cells. Herein, we review the impact of extracellular vesicles in modulating the central and peripheral signals governing obesity.

Identification of genetic defect of an epilepsy: strategies for therapeutic advances

Advances in molecular genetics and molecular biology are transforming the biology of human disease. Cures for diseases previously refractory to all treatments have become the reality for some disorders and the legitimate promise for others. In the case of the epilepsies, identification of mutant genes underlying familial epilepsies may lead to a new pharmacology, through the development of in vitro expression systems permitting rapid search for novel drugs, creation of highly specific animal models based on expression of the precise mutation, and correction of disease phenotype by introducing novel and highly specific genetic information into the person with epilepsy.

A brief history of gene therapy

The concepts of gene therapy arose initially during the 1960s and early 1970s whilst the development of genetically marked cells lines and the clarification of mechanisms of cell transformation by the papaovaviruses polyoma and SV40 was in progress. With the arrival of recombinant DNA techniques, cloned genes became available and were used to demonstrate that foreign genes could indeed correct genetic defects and disease phenotypes in mammalian cells in vitro. Efficient retroviral vectors and other gene transfer methods have permitted convincing demonstrations of efficient phenotype correction in vitro and in vivo, now making gene therapy a broadly accepted approach to therapy and justifying clinically applied studies with human patients.

Concepts and strategies for human gene therapy

Methods of modern molecular genetics have been developed that allow stable transfer and expression of foreign DNA sequences in human and other mammalian somatic cells. It is therefore no surprise that the methods have been applied in attempts to complement genetic defects and correct disease phenotypes. Two decades of research have now led to the first clinically applicable attempts to introduce genetically modified cells into human beings to cure diseases caused at least partially by genetic defects. We discuss here some of the strategies being followed for both in vitro and in vivo application of therapeutic gene transfer and summarize some of the technical and conceptual difficulties associated with somatic-cell gene therapy.

Unsuccessful trial of gene replacement in arginase deficiency

The Shope virus following cutaneous inoculation produces skin papillomas in rabbits and induces a virus-coded arginase in the squameous epithelium of these papillomas. The only discernible effect of the virus inoculated intravenously in rabbits and other animals was a decrease of the serum arginine concentration. Intravenous injection in 3 hyperargininemic patients, however, did not influence the underlying metabolic disease.