Proliferative and protective effects of SurR9-C84A on differentiated neural cells

Utility of nanomedicine targeting scar-forming myofibroblasts to attenuate corneal scarring and haze

Corneal scarring refers to the loss of normal corneal tissue, replaced by fibrotic tissue (during wound repair) thereby affecting corneal transparency and vision quality. The corneal wound healing process involves a complex series of physiological events resulting in the transformation of transparent keratocytes into opaque myofibroblasts; the prominent cause of irregular extracellular matrix synthesis leading to the development of corneal opacity/hazy vision. Globally, corneal scarring/haze is one of the most prevalent causes of blindness. Ocular trauma (physical and chemical) and microbial infections induce corneal tissue damage. Although great progress has been made in the clinical management of ocular diseases, the global rates of corneal blindness remain high, nonetheless. The topical conventional modalities treating corneal wounds/injuries have inherent limitations/side effects such as low bioavailability of a therapeutic agent, upregulation of the intraocular pressure and the toxicity/allergy of the drug. These limitations/side effects rather than treating the wound, often negatively affect the healing process, especially, when applied frequently for longer periods. Recently, there has been an increasing evidence provided by the preclinical studies that nanotechnology-based drug-delivery systems can improve drug bioavailability, through controlled drug release and targeted delivery. After reviewing the epidemiology, risk factors of corneal scarring/haze and the conventional ocular medicines, we review here the different nanodrug-delivery systems and potential drug candidates including nanoherbal formulations investigated for their efficacy to heal the damaged cornea. Finally, we discuss the challenges of using these nanomedicinal platforms.

Effect of the autism-associated lncRNA Shank2-AS on architecture and growth of neurons

The pathogenic mechanism of autism is complex, and current research has shown that long noncoding RNAs (lncRNAs) may play important roles in this process. The antisense lncRNA of SH3 and multiple ankyrin repeat domains 2 (Shank2-AS) is upregulated in patients with autism spectrum disorder (ASD), whereas the expression of its sense strand gene Shank2 is downregulated. In neuronal cells, Shank2-AS and Shank2 can form a double-stranded RNA and inhibit Shank2 expression. Overexpression of Shank2-AS decreases neurite numbers and lengths, thereby inhibiting the proliferation of neuronal cells and promoting their apoptosis. Overexpression of Shank2 inhibits the abovementioned effects of Shank2-AS, and transfection of a vector containing the 10th intron of Shank2 (Shank2-AS is reverse-transcribed from this region) also blocks the function of Shank2-AS. Shank2 small interfering RNA plays a role similar to Shank2-AS. Therefore, Shank2-AS is abnormally expressed in patients with ASD and may affect the structure and growth of neurons by regulating Shank2 expression, thereby facilitating the development of ASD.

Recent advances in nanomedicine and survivin targeting in brain cancers

Brain cancer is a highly lethal disease, especially devastating toward both the elderly and children. This cancer has no therapeutics available to combat it, predominately due to the blood-brain barrier (BBB) preventing treatments from maintaining therapeutic levels within the brain. Recently, nanoparticle technology has entered the forefront of cancer therapy due to its ability to deliver therapeutic effects while potentially passing physiological barriers. Key nanoparticles for brain cancer treatment include glutathione targeted PEGylated liposomes, gold nanoparticles, superparamagnetic iron oxide nanoparticles and nanoparticle-albumin bound drugs, with these being discussed throughout this review. Recently, the survivin protein has gained attention as it is over-expressed in a majority of tumors. This review will briefly discuss the properties of survivin, while focusing on how both nanoparticles and survivin-targeting treatments hold potential as brain cancer therapies. This review may provide useful insight into new brain cancer treatment options, particularly survivin inhibition and nanomedicine.

Topical Ophthalmic Formulation of Trichostatin A and SurR9-C84A for Quick Recovery Post-alkali Burn of Corneal Haze

Alkali burn injury is a true ocular emergency of the conjunctiva and cornea that requires immediate precision. Lack of an immediate therapy can lead to a substantial damage in the ocular surface and anterior segment further causing visual impairment and disfigurement. We explored the regenerative capability of dominant negative survivin protein (SurR9-C84A) and histone deacetylase inhibitor trichostatin-A (TSA) in vivo, in a rat alkali burn model. A topical insult in rat eyes with NaOH led to degradation of the conjunctival and corneal epithelium. The integrity of the conjunctival and corneal tissue was increased by TSA and SurR9-C84A by improving the clathrin and claudin expressions. Wound healing was initiated by an increase in TGF-beta-1 and, increased endogenous survivin which inhibited apoptosis post-TSA and SurR9-C84A treatments. Protein expressions of fibronectin and alpha-integrin 5 were found to increase promoting corneal integrity. The cytokine analysis confirmed increased expressions of IL-1beta, IL-6, IL-12, IL-13, IFN-gamma, TNF-alpha, GMCSF, Rantes, and MMP-2 in injured cornea, which were found to be significantly downregulated by the combined treatment of SurR9-C84A and TSA. The ocular and systemic pharmacokinetic (PK) parameters were measured post-topical ocular administration of TSA and SurR9-C84A. The SurR9-C84A and TSA sustained relatively longer in the cornea, conjunctiva, and aqueous humor than in the tear fluid and plasma. Our results confirmed that a combination of TSA with SurR9-C8A worked in synergy and showed a promising healing and anti-inflammatory effect in a very short time against alkali burn. Therefore, a combination of TSA and SurR9-C84A can fulfill the need for an immediate response to wound healing in alkali burnt cornea. We also synthesized ultra-small chitosan nanoparticles (USC-NPs) targeted with alpha-SMA antibodies that can be used for delivery of TSA and SurR9-C84A specifically to the ocular burn site.

SurR9C84A protects and recovers human cardiomyocytes from hypoxia induced apoptosis

Survivin, as an anti-apoptotic protein and a cell cycle regulator, is recently gaining importance for its regenerative potential in salvaging injured hypoxic cells of vital organs such as heart. Different strategies are being employed to upregulate survivin expression in dying hypoxic cardiomyocytes. We investigated the cardioprotective potential of a cell permeable survivin mutant protein SurR9C84A, for the management of hypoxia mediated cardiomyocyte apoptosis, in a novel and clinically relevant model employing primary human cardiomyocytes (HCM). The aim of this research work was to study the efficacy and mechanism of SurR9C84A facilitated cardioprotection and regeneration in hypoxic HCM. To mimic hypoxic microenvironment in vitro, well characterized HCM were treated with 100µm (48h) cobalt chloride to induce hypoxia. Hypoxia induced (HI) HCM were further treated with SurR9C84A (1µg/mL) in order to analyse its cardioprotective efficacy. Confocal microscopy showed rapid internalization of SurR9C84A and scanning electron microscopy revealed the reinstatement of cytoskeleton projections in HI HCM. SurR9C84A treatment increased cell viability, reduced cell death via, apoptosis (Annexin-V assay), and downregulated free cardiac troponin T and MMP-9 expression. SurR9C84A also upregulated the expression of proliferation markers (PCNA and Ki-67) and downregulated mitochondrial depolarization and ROS levels thereby, impeding cell death. Human Apoptosis Array further revealed that SurR9C84A downregulated expression of pro-apoptotic markers and augmented expression of HSPs and HTRA2/Omi. SurR9C84A treatment led to enhanced levels of survivin, VEGF, PI3K and pAkt. SurR9C84A proved non-toxic to normoxic HCM, as validated through unaltered cell proliferation and other marker levels. Its pre-treatment exhibited lesser susceptibility to hypoxia/damage. SurR9C84A holds a promising clinical potential for human cardiomyocyte survival and proliferation following hypoxic injury.

A Study of Gene Expression of Survivin, its Antiapoptotic Variants, and Targeting Survivin In Vitro for Therapy in Retinoblastoma

Apoptosis is a natural process regulated by apoptotic and antiapoptotic molecules. We investigated mRNA expression of survivin and its splice variants, along with B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X (Bax), in a cohort of 20 retinoblastoma (RB) tumors by real-time polymerase chain reaction. We hypothesized a correlation between the Bcl-2/Bax and survivin splice variants and also that expression of these would be associated with clinicopathologic features of tumors. The Bcl-2 expression was significantly higher (P<0.001) in RB, and Bcl-2/Bax ratio was remarkably higher in poorly differentiated tumors. A statistically significant higher expression of Survivin-WT (wild type) compared with its variant Survivin-2β (P<0.05) was observed. Bcl-2 did not exhibit positive correlation with any of the survivin variants except Survivin-2β, whereas Bax exhibited significant (P<0.05) correlation with the variants. Thus, it could be suggested that a superior player out of a likely interaction between the variants and Bcl-2/Bax uses its activity for the progression of RB. Silencing of Survivin-WT in the Y79 cell line was studied by siRNA technology and cell-permeable dominant negative survivin (SurR9-C84A). siRNA showed higher proapoptotic effects and increased caspase 3/7 activity in Y79 cells. Effective internalization of SurR9-C84A in Y79 cells induced cytotoxic effects. Thus, the current study confirms survivin as a promising target for therapy.

Ophthalmic Combination of SurR9-C84A and Trichostatin-A Targeting Molecular Pathogenesis of Alkali Burn

Background: Alkali burn is a frequently occurring ocular injury that resembles ocular inflammation caused by eye allergies, infection, and refractive surgeries.

Methods: We investigated the synergistic regenerative potential of dominant negative survivin mutant (SurR9-C84A) and histone deacetylase (HDAC) inhibitor trichostatin-A (TSA) against alkali burn and corneal haze using human keratocytes and rabbit alkali burn model (Female New Zealand white rabbits).

Results: Combination of SurR9-C84A and TSA suppressed levels of transforming growth factor (TGF)-β, alpha smooth-muscle actin (α-SMA), fibronectin and HDAC1, leading to apoptosis in myofibroblast cells and, showed the potential to clear the corneal haze. An insult with 0.5 N NaOH for 1 min led to neutrophils infiltration and formation of large vacuoles in the stroma. Treatments with TSA and SurR9-C84A for 40 min led to improvement in the conjunctival and corneal tissue integrity, marked by an increase in clathrin, and claudin expressions. An increase in TGF-β and endogenous survivin confirmed wound healing and cell proliferation in rabbit cornea. The blood analysis revealed a substantial decrease in the RBC, WBC, platelets, or the hemoglobin content post alkali burn. The cytokine array analysis revealed that NaOH induced expressions of IL-1α and MMP-9, which were found to be significantly downregulated (1.8 and 11.5 fold respectively) by the combinatorial treatment of SurR9-C84A and TSA.

Conclusion: Our results confirmed that combination of SurR9-C84A with TSA worked in synergy to heal ocular injury and inflammations due to alkali burn and led to the regeneration of ocular tissue by increasing clathrin, claudin, survivin, and TGF-β and reversal of alkali burn by suppressing IL-1α and MMP-9 without inducing haze.

Cissus quadrangularis inhibits IL-1β induced inflammatory responses on chondrocytes and alleviates bone deterioration in osteotomized rats via p38 MAPK signaling

INTRODUCTION

Inflammatory mediators are key players in the pathogenesis of osteoarthritis (OA) and bone destruction. Conventional drugs suppress symptomatic activity and have no therapeutic influence on disease. Cissus quadrangularis and Withania somnifera are widely used for the treatment of bone fractures and wounds; however, the cellular and molecular mechanisms regulated by these herbals are still unclear.

METHODS

We established an in vitro OA culture model by exposing human chondrocytes to proinflammatory cytokine and interleukin (IL)-1β for 36 hours prior to treatment with the herbals: C. quadrangularis, W. somnifera, and the combination of the two herbals. Cell viability, toxicity, and gene expression of OA modifying agents were examined. In addition, expression of survivin, which is crucial for cell growth, was analyzed. In vivo work on osteotomized rats studied the bone and cartilage regenerative effects of C. quadrangularis, W. somnifera, and the combination therapy.

RESULTS

Exposure of chondrocytes to IL-1β induced significant toxicity and cell death. However, herbal treatment alleviated IL-1β induced cell toxicity and upregulated cell growth and proliferation. C. quadrangularis inhibited gene expression of cytokines and matrix metalloproteinases, known to aggravate cartilage and bone destruction, and augmented expression of survivin by inhibiting p38 MAPK. Interestingly, osteotomized rats treated with C. quadrangularis drastically enhanced alkaline phosphatase and cartilage tissue formation as compared to untreated, W. somnifera only, or the combination of both herbals.

CONCLUSION

Our findings demonstrate for the first time the signaling mechanisms regulated by C. quadrangularis and W. somnifera in OA and osteogenesis. We suggest that the chondroprotective effects and regenerative ability of these herbals are via the upregulation of survivin that exerts inhibitory effects on the p38 MAPK signaling pathway. These findings thus validate C. quadrangularis as a potential therapeutic for rheumatic disorders.

Competitive inhibition of survivin using a cell-permeable recombinant protein induces cancer-specific apoptosis in colon cancer model

Endogenous survivin expression has been related with cancer survival, drug resistance, and metastasis. Therapies targeting survivin have been shown to significantly inhibit tumor growth and recurrence. We found out that a cell-permeable dominant negative survivin (SurR9-C84A, referred to as SR9) competitively inhibited endogenous survivin and blocked the cell cycle at the G1/S phase. Nanoencapsulation in mucoadhesive chitosan nanoparticles (CHNP) substantially increased the bioavailability and serum stability of SR9. The mechanism of nanoparticle uptake was studied extensively in vitro and in ex vivo models. Our results confirmed that CHNP-SR9 protected primary cells from autophagy and successfully induced tumor-specific apoptosis via both extrinsic and intrinsic apoptotic pathways. CHNP-SR9 significantly reduced the tumor spheroid size (three-dimensional model) by nearly 7-fold. Effects of SR9 and CHNP-SR9 were studied on 35 key molecules involved in the apoptotic pathway. Highly significant (4.26-fold, P≤0.005) reduction in tumor volume was observed using an in vivo mouse xenograft colon cancer model. It was also observed that net apoptotic (6.25-fold, P≤0.005) and necrotic indexes (3.5-fold, P≤0.05) were comparatively higher in CHNP-SR9 when compared to void CHNP and CHNP-SR9 internalized more in cancer stem cells (4.5-fold, P≤0.005). We concluded that nanoformulation of SR9 did not reduce its therapeutic potential; however, nanoformulation provided SR9 with enhanced stability and better bioavailability. Our study presents a highly tumor-specific protein-based cancer therapy that has several advantages over the normally used chemotherapeutics.

Nanoformulated cell-penetrating survivin mutant and its dual actions

In this study, we investigated the differential actions of a dominant-negative survivin mutant (SurR9-C84A) against cancerous SK-N-SH neuroblastoma cell lines and differentiated SK-N-SH neurons. In both the cases, the mutant protein displayed dual actions, where its effects were cytotoxic toward cancerous cells and proliferative toward the differentiated neurons. This can be explained by the fact that tumorous (undifferentiated SK-N-SH) cells have a high endogenous survivin pool and upon treatment with mutant SuR9-C84A causes forceful survivin expression. These events significantly lowered the microtubule dynamics and stability, eventually leading to apoptosis. In the case of differentiated SK-N-SH neurons that express negligible levels of wild-type survivin, the mutant indistinguishably behaved in a wild-type fashion. It also favored cell-cycle progression, forming the chromosome-passenger complex, and stabilized the microtubule-organizing center. Therefore, mutant SurR9-C84A represents a novel therapeutic with its dual actions (cytotoxic toward tumor cells and protective and proliferative toward neuronal cells), and hence finds potential applications against a variety of neurological disorders. In this study, we also developed a novel poly(lactic-co-glycolic acid) nanoparticulate formulation to surmount the hurdles associated with the delivery of SurR9-C84A, thus enhancing its effective therapeutic outcome.

Nanotechnology based platforms for survivin targeted drug discovery

INTRODUCTION

Development of an effective, safe and targeted drug delivery system to fight cancer and other diseases is a prime focus in the area of drug discovery. The emerging field of nanotechnology has revolutionised the way cancer therapy and diagnosis is achieved primarily due to the recent advances in material engineering and drug availability. Further, the recognition of the crucial role played by anti-apoptotic proteins such as survivin, has initiated the development of therapeutics that can target this protein as an attempt to develop alternative cancer therapies. However, a key challenge faced in drug development is the efficient delivery of survivin-targeted molecules to specific areas in the body.

AREAS COVERED

This review primarily focuses on the different strategies employing nanotechnology for targeting survivin expressed in human cancers. Different nanomaterials incorporating nucleic molecules or drugs targeted at survivin are discussed and the results obtained from studies are highlighted.

EXPERT OPINION

There are extensive studies reporting different treatment regimens for cancer, however, they still result in systemic toxicity, reduced bioavailability and ineffective delivery. Novel approaches involve the use of biocompatible nanomaterials together with gene or drug molecules to target proteins such as survivin, which is overexpressed in cancerous cells. These nanoformulations allow the benefits of protecting easily degradable molecules, allow controlled release, and enhance targeted delivery and effectiveness. Hence, nanotherapy utilizing survivin targeting can be considered to play a key role in the development of personalized nanomedicine for cancer.

Cell-penetrating properties of the transactivator of transcription and polyarginine (R9) peptides, their conjugative effect on nanoparticles and the prospect of conjugation with arsenic trioxide

Cell-penetrating peptides (CPPs) are short chains of amino acids with the distinct ability to cross cell plasma membranes. They are usually between seven and 30 residues in length. The mechanism of action is still a highly debated subject among researchers; it seems that a commonality between all CPPs is the presence of positively charged residues within the amino acid chain. Polyarginine and the transactivator of transcription peptide are two widely used CPPs. One distinct application of these CPPs is the ability to further enhance the therapeutic properties of a range of different agents. One group of agents of particular importance are nanoparticles (NPs). Most NPs have no mechanism for cellular uptake. Hence, by conjugating CPPs to NPs, the amount of NPs taken up by cells can be increased, and therefore, the therapeutic benefits can be maximized. Some examples of this will be explored further in this review. In addition to CPPs, the concept of conjugation with the anticancer drug arsenic trioxide is reviewed and the prospect of transactivator of transcription-conjugated arsenic trioxide albumin microspheres is also discussed. Recent locked nucleic acid technology to stabilize nucleotides (RNA or DNA) aptamer complexes able to target cancer cells more specifically and selectively to kill tumour cells and spare normal body cells. NPs tagged with modified locked nucleic acid-aptamers have the potential to kill cancer cells more specifically and effectively while sparing normal cells.

Neurological disorders and therapeutics targeted to surmount the blood-brain barrier

We are now in an aging population, so neurological disorders, particularly the neurodegenerative diseases, are becoming more prevalent in society. As per the epidemiological studies, Europe alone suffers 35% of the burden, indicating an alarming rate of disease progression. Further, treatment for these disorders is a challenging area due to the presence of the tightly regulated blood-brain barrier and its unique ability to protect the brain from xenobiotics. Conventional therapeutics, although effective, remain critically below levels of optimum therapeutic efficacy. Hence, methods to overcome the blood-brain barrier are currently a focus of research. Nanotechnological applications are gaining paramount importance in addressing this question, and yielding some promising results. This review addresses the pathophysiology of the more common neurological disorders and novel drug candidates, along with targeted nanoparticle applications for brain delivery.

Nanoparticles in the treatment and diagnosis of neurological disorders: untamed dragon with fire power to heal

The incidence of neurological diseases of unknown etiology is increasing, including well-studied diseases such as Alzhiemer's, Parkinson's, and multiple sclerosis. The blood-brain barrier provides protection for the brain but also hinders the treatment and diagnosis of these neurological diseases, because the drugs must cross the blood-brain barrier to reach the lesions. Thus, attention has turned to developing novel and effective delivery systems that are capable of carrying drug and that provide good bioavailability in the brain. Nanoneurotechnology, particularly application of nanoparticles in drug delivery, has provided promising answers to some of these issues in recent years. Here we review the recent advances in the understanding of several common forms of neurological diseases and particularly the applications of nanoparticles to treat and diagnose them. In addition, we discuss the integration of bioinformatics and modern genomic approaches in the development of nanoparticles.

FROM THE CLINICAL EDITOR

In this review paper, applications of nanotechnology-based diagnostic methods and therapeutic modalities are discussed addressing a variety of neurological disorders, with special attention to blood-brain barrier delivery methods. These novel nanomedicine approaches are expected to revolutionize several aspects of clinical neurology.

Targeting survivin in cancer: the cell-signalling perspective

Survivin, a prominent anticancer target, is ubiquitously expressed in a plethora of cancers and the evolving complexity in functional regulation of survivin is yet to be deciphered. However, pertaining to the recent studies, therapeutic modulation of survivin is critically regulated by interaction with prominent cell-signalling pathways [HIF-1α, HSP90, PI3K/AKT, mTOR, ERK, tumour suppressor genes (p53, PTEN), oncogenes (Bcl-2, Ras)] and a wide range of growth factors (EGFR, VEGF, among others). In our article we discuss, in detail, an overview of the recent developments in the pharmacological modulation of survivin via cell-signalling paradigms and antisurvivin therapeutics, along with an outlook on therapeutic management of survivin in drug-resistant cancers.

Targeting survivin in cancer: patent review

IMPORTANCE OF THE FIELD

Survivin is a prominent anti-apoptotic molecule expressed widely in the majority of cancers. Overexpression of survivin leads to uncontrolled cancer cell growth and drug resistance. Efficient downregulation of survivin expression and its functions can sensitise the tumour cells to various therapeutic interventions such as chemotherapeutic agents leading to cell apoptosis.

AREAS COVERED IN THIS REVIEW

The article thoroughly analyses up-to-date information on the knowledge generated from the survivin patents. Various key areas of research in terms of understanding survivin biology and its targeting are discussed in detail.

WHAT THE READER WILL GAIN

The article clearly gives an insight on the recent developments undertaken to understand the roles of survivin in cancer and in validating various treatment paradigms that suppress survivin expression in cancer cells.

TAKE HOME MESSAGE

Most recent developments are helpful for effectively downregulating survivin expression by using various therapeutic platforms such as chemotherapeutic drugs, immunotechnology, antisense, dominant negative survivin mutant, RNA interference and peptide-based methods. However, selective and specific targeting of survivin in cancer cells still poses a major challenge. Nanotechnology-based platforms are currently under development to enable site-specific targeting of survivin in tumour cells.

Survivin mutant protects differentiated dopaminergic SK-N-SH cells against oxidative stress

Oxidative stress is due to an imbalance of antioxidant/pro-oxidant homeostasis and is associated with the progression of several neurological diseases, including Parkinson's and Alzheimer's disease and amyotrophic lateral sclerosis. Furthermore, oxidative stress is responsible for the neuronal loss and dysfunction associated with disease pathogenesis. Survivin is a member of the inhibitors of the apoptosis (IAP) family of proteins, but its neuroprotective effects have not been studied. Here, we demonstrate that SurR9-C84A, a survivin mutant, has neuroprotective effects against H₂O₂-induced neurotoxicity. Our results show that H₂O₂ toxicity is associated with an increase in cell death, mitochondrial membrane depolarisation, and the expression of cyclin D1 and caspases 9 and 3. In addition, pre-treatment with SurR9-C84A reduces cell death by decreasing both the level of mitochondrial depolarisation and the expression of cyclin D1 and caspases 9 and 3. We further show that SurR9-C84A increases the antioxidant activity of GSH-peroxidase and catalase, and effectively counteracts oxidant activity following exposure to H₂O₂. These results suggest for the first time that SurR9-C84A is a promising treatment to protect neuronal cells against H₂O₂-induced neurotoxicity.

Novel survivin mutant protects differentiated SK-N-SH human neuroblastoma cells from activated T-cell neurotoxicity

Currently, there are no known treatments for protection of axonal loss associated with neuroinflammatory diseases such as multiple sclerosis (MS). Survivin is a member of the inhibitors of the apoptosis (IAP) family of proteins that its neuroprotective effects have not been studied. We demonstrate here that SurR9-C84A, a survivin mutant, exhibits a neuroprotective role against the cytotoxic effects of activated T-cell infiltrates, such as granzyme B (GrB). The activated T-cell supernatants induce toxicity on differentiated SK-N-SH cells, which is associated with the loss of Ca(2+) homeostasis, the increased population of dead cells, mitochondrial membrane depolarisation, and the accelerated expression of cyclinD1, caspase3 and Fas, as observed for most apoptotic cells. Alternatively, the pre-treatment with SurR9-C84A reduces the population of dead cells by balancing the cytosolic Ca(2+) homeostasis, decreasing the level of mitochondrial depolarisation, and also reducing the expression of cyclinD1 and caspase3. Our findings suggest that SurR9-C84A has a neuroprotective effect against the cytotoxins existing in activated T-cell supernatants including GrB.