Current approaches for the regeneration and reconstruction of ocular surface in dry eye.

Significant research revealed the preocular tear film composition and regulations that remain vital for maintaining Ocular surface functional integrity. Inflammation triggered by many factors is the hallmark of Ocular surface disorders or dry eyes syndrome (DES). The tear deficiencies may lead to ocular surface desiccation, corneal ulceration and/or perforation, higher rates of infectious disease, and the risk of severe visual impairment and blindness. Clinical management remains largely supportive, palliative, and frequent, lifelong use of different lubricating agents. However, few advancements such as punctal plugs, non-steroidal anti-inflammatory drugs, and salivary gland autografts are of limited use. Cell-based therapies, tissue engineering, and regenerative medicine, have recently evolved as long-term cures for many diseases, including ophthalmic diseases. The present article focuses on the different regenerative medicine and reconstruction/bioengineered lacrimal gland formation strategies reported so far, along with their limiting factors and feasibility as an effective cure in future.

Preclinical evaluation and molecular docking of 1,3-benzodioxole propargyl ether derivatives as novel inhibitor for combating the histone deacetylase enzyme in cancer.

Even after huge strides in medicine, cancer continues to be a formidable disease, which is slated to become the leading cause of death worldwide. The present study investigates the 1,3-benzodioxole and its propargyl ether derivatives as a novel histone deacetylase enzyme inhibitor in order to cure cancer, as aberrant expression of histone deacetylases (HDACs) is associated with carcinogenesis. Bioinformatics approaches were employed to carry out preclinical and pharmacological evaluations of designed benzodioxole derivatives. Furthermore, their interaction with HDAC-1 enzyme was studied through computational methods for their specific inhibitory effects and evaluated for their LD50 (oral rat acute toxicity) value. In addition to this work, three-dimensional (3D) structure of HDAC-1 enzyme was extracted and evaluated using various parameters including Ramachandran plot and molecular docking stimulation. In our study, we found that compound 7 and compound 9 have higher binding score than approved drugs (SAHA, TSA and VPA). Importantly, these compounds were found to possess good pharmacological and pharmacokinetic properties and can be considered as potent novel compound to combat the HDAC-1 enzyme to cure cancer. Compounds were also analyzed and validated with parameters like absorption, metabolism, excretion, toxicity and synthetic accessibility during the preclinical evaluation. This study paves way to search for novel and potent small chemical compounds for inhibiting HDAC-1 enzyme and in particular to combat the cancer progression by interrupting the cell cycle.

Exploring the interplay between autoimmunity and cancer to find the target therapeutic hotspots.

Autoimmunity arises when highly active immune responses are developed against the tissues or substances of one's own body. It is one of the most prevalent disorders among the old-age population with prospects increasing with age. The major cause of autoimmunity and associated diseases is the dysregulation of host immune surveillance. Impaired repairment of immune system and apoptosis regulation can be seen as major landmarks in autoimmune disorders such as the mutation of p53 gene which results in rheumatoid arthritis, bowel disease which consequently lead to tissue destruction, inflammation and dysfunctioning of body organs. Cytokines mediated apoptosis and proliferation of cells plays a regulatory role in cell cycle and further in cancer development. Anti-TNF therapy, Treg therapy and stem cell therapy have been used for autoimmune diseases, however, with the increase in the use of immunomodulatory therapies and their development for autoimmune diseases and cancer, the understanding of human immune system tends to become an increasing requirement. Hence, the findings associated with the relationship between autoimmune diseases and cancer may prove to be beneficial for the improvement in the health of suffering patients. Here in, we are eliciting the underlying mechanisms which result in autoimmune disorders causing the onset of cancer, exploration of interactome to find the pathways which are mutual to both, and recognition of hotspots which might play important role in autoimmunity mediated therapeutics with different therapies such as anti-TNF therapy, Treg therapy and stem cell therapy.

A Novel Peptide Thrombopoietin Mimetic Designing and Optimization Using Computational Approach.

Thrombopoietin receptor (TPOR) is a cytokine receptor protein present on the cell surface. The activation of TPOR by thrombopoietin (TPO) (a glycoprotein hormone) triggers an intracellular cascade of megakaryocytopoiesis for the formation of platelets. Recent studies on ex vivo megakaryocytopoiesis have evolved the possibilities of therapeutics uses. These findings have paved the way for the development of various TPO alternatives (recombinant TPO, peptide, and non-peptide TPO mimetics), which are useful in regenerative medicine. However, these alternatives possess various limitations such as induction of autoimmune effects, high production cost, low specificity, and hence activity. In the present study, a novel peptidic TPO mimetic was designed through computational studies by studying the binding sites of TPO and TMP to TPOR and analogs of known mimetics. Screening of combinatorial library was done through molecular docking using ClusPro. These studies indicated mimetic-9 as a significant molecule since it was found to have better binding score of -938.8 kcal/mol with seven hydrogen bonds and a high number of hydrophobic interactions, than known mimetic TMP with docking score of -798.4 kcal/mol and TMP dimer with docking score of -811.9 kcal/mol for TPOR. Mimetic9-TPOR complex was further assessed by the molecular dynamics simulation, and their complex was found to be stable with an RMSD value of 0.091 Å. While studying the parameters, mimetic-9 was found to have overall good physiochemical properties with positive grand average hydropathy (GRAVY) score and high instability index score and was found to be localized in the extracellular region. The designed mimetic-9 might prove to be a useful lead molecule for mimicking the role of TPO for in vitro platelet production with higher efficiency.

Stage-Specific Regulation of Erythropoiesis and Its Implications in Ex-Vivo RBCs Generation.

Ex vivo erythropoiesis methods are being developed for more than a decade now, and all the distinct types of stem cells (such as CD34+ HSCs, ESCs, IPSCs, and extensively proliferating erythropoietic progenitor cells) are defined to bear the potential for large scale RBC production shortly. The various regulating factors at different levels of RBCs production are being explored. Since most of the ex-vivo erythropoiesis protocols mimic the dogma followed by hematopoietic stem cells in vivo to give rise to mature RBCs which essentially deals with the intermediate stages of erythropoiesis such as burst forming unit-erythroid (BFU-E) and committed erythroid colony forming unit-erythroid (CFU-E). In vivo generation of erythroid progenitors (BFU-E/CFU-E) is essentially controlled by several factors including glucocorticoids, inflammation, and stress. Furthermore, regular production of functionally mature /transfusable units of RBCs is possible only through the coordinated regulation of terminal proliferation and differentiation of erythroid progenitors by external signals, such as erythropoietin, SCF, IL-3 and interaction to extracellular matrix protein(s) in a 3D culture system. We discuss these complex intracellular networks of coordinated factors and try to understand their molecular mechanism through gene regulation by transcription factors, and miRNAs that might be helpful in developing the optimal RBCs production protocols for commercial production.

Mechanism of Induction: Induced Pluripotent Stem Cells (iPSCs).

Induced Pluripotent Stem Cells (iPSCs) are self renewable and can differentiate to different types of adult cells, which has shown great promises in the field of regenerative medicine. iPSCs are reprogrammed from human somatic cells through ectopic expression of various transcription factors viz. Oct4, Sox2, Klf4, and c-Myc (OSKM). This novel technology enables derivation of patient specific cells, which possess a potential cure for many diseases. During the last decade, significant progresses have been achieved in enhancing the reprogramming efficiency, safety of iPSCs derivation, development of different delivery techniques by various research groups. Nevertheless, it is important to resolve and define the mechanism underlying the pluripotent stem cells. Major bottleneck which arises during iPSCs generation is the availability of source material (cells/tissues), difficulty to deliver transcription factors with no aberrant genetic modifications and limited reprogramming efficiency. Reprogramming may be achieved by employing different cocktails with number of different transcription factors, application of miRNA and some small molecules such as (Valproic acid, CHiR99021, Sodium butyrate, Vitamin C, Parnate etc). Similarly, various starting source materials have been demonstrated for iPSC based therapies including fibroblasts, cord blood, peripheral blood, keritinocytes, urine, etc., with their specific uses and limitations. Moreover, with the advent of many new reprogramming techniques, various direct delivery methods have been introduced such as using synthetic mRNA expressing pluripotent gene network has been shown to be an appropriate technique to deliver transcription factors and a dozen of small molecules which can replace transcription factors or enhance reprogramming efficiency. This article addresses the iPSCs technology mechanisms, progresses and current perspectives in the field.

Stem cell therapy: a novel & futuristic treatment modality for disaster injuries.

Stem cell therapy hold the potential to meet the demand for transplant cells/tissues needed for treating damages resulting from both natural and man-made disasters. Pluripotency makes embryonic stem cells and induced pluripotent stem cells ideal for use, but their teratogenic character is a major hindrance. Therapeutic benefits of bone marrow transplantation are well known but characterizing the potentialities of haematopoietic and mesenchymal cells is essential. Haematopoietic stem cells (HSCs) have been used for treating both haematopoietic and non-haematopoietic disorders. Ease of isolation, in vitro expansion, and hypoimmunogenecity have brought mesenchymal stem cells (MSCs) into limelight. Though differentiation of MSCs into tissue-specific cells has been reported, differentiation-independent mechanisms seem to play a more significant role in tissue repair which need to be addressed further. The safety and feasibility of MSCs have been demonstrated in clinical trials, and their use in combination with HSC for radiation injury treatment seems to have extended benefit. Therefore, using stem cells for treatment of disaster injuries along with the conventional medical practice would likely accelerate the repair process and improve the quality of life of the victim.

Mesenchymal stem cell-based therapy: a new paradigm in regenerative medicine.

Mesenchymal stem cells (MSCs), adherent fibroblastoid cells, present in bone marrow and many other tissues can be easily isolated and expanded in vitro. They are capable of differentiating into different cell types such as osteoblasts, chondrocytes, adipocytes, cardiomyocytes, hepatocytes, endothelial cells and neuronal cells. Such immense plasticity coupled with their ability to modulate the activity of immune cells makes them attractive for stem cell-based therapy aimed at treating previously incurable disorders. Preclinical studies have reported successful use of MSCs for delivering therapeutic proteins and repairing defects in a variety of disease models. These studies highlighted the in vivo potential of MSCs and their ability to home to injury sites and modify the microenvironment by secreting paracrine factors to augment tissue repair. Their therapeutic applicability has been widened by genetic modification to enhance differentiation and tissue targeting, and use in tissue engineering. Clinical trials for diseases such as osteogenesis imperfecta, graft-versus-host disease and myocardial infarction have shown some promise, demonstrating the safe use of both allogeneic and autologous cells. However, lack of knowledge of MSC behaviour and responses in vitro and in vivo force the need for basic and animal studies before heading to the clinic. Contrasting reports on immunomodulatory functions and tumorigenicity along with issues such as mode of cell delivery, lack of specific marker, low survival and engraftment require urgent attention to harness the potential of MSC-based therapy in the near future.

Mesenchymal stem cells: molecular targets for tissue engineering.

Mesenchymal stem cells (MSCs) represent an adherent, fibroblast-like population present not only in the bone marrow, but in a number of tissues, including blood, adipose tissue, muscle, and dermis. Their extensive proliferation and transdifferentiation potential makes them best suited for tissue engineering applications. Identification of growth factors and signaling pathways involved in self-renewal and differentiation is important for designing strategies to overcome replicative senescence and attain directed differentiation. Wnt, bone morphogenetic protein (BMP), and Notch pathways have been implicated to play key roles in self-renewal and differentiation of hematopoietic, intestinal, and epidermal stem cells. They are also involved in regulating MSC differentiation. However, MSC self-renewal has not received much attention, with Nucleostemin being the only recently identified proliferation molecule. Although immortalization using viral oncogenes and telomerase has been achieved, transformation in long-term cultures is a potential risk. Understanding of the mechanisms governing osteogenic differentiation of MSCs is expanding with the recent identification of two major transcription factors, Osterix and Runx2. Enhanced expansion as well as osteogenic differentiation of MSCs can be attained using a combinatorial approach involving co-expression of proliferation and differentiation genes. However, a thorough understanding of the molecular mechanism is necessary for enhancing the self-renewal ability and osteogenic potential in vitro.

Stem cell c-KIT and HOXB4 genes: critical roles and mechanisms in self-renewal, proliferation, and differentiation.

Hematopoietic stem cells (HSCs) possess a distinct ability to perpetuate through self-renewal and to generate progeny that differentiate into mature cells of myeloid and lymphoid lineages. A better understanding of the molecular mechanisms by which HSCs replicate and differentiate from the perspective of developing new approaches for HSC transplantation is necessary for further advances. The interaction of the receptor tyrosine kinase--c-KIT--with its ligand stem cell factor plays a key role in HSC survival, mitogenesis, proliferation, differentiation, adhesion, homing, migration, and functional activation. Evidence that activating site-directed point mutations in the c-KIT gene contributes to its ligand-independent constitutive activation, which induces enhanced proliferation of HSCs, is accumulating. Similarly, and equally important, self-renewal is a process by which HSCs generate daughter cells via division. Self-renewal is necessary for retaining the HSC pool. Therefore, elucidating the molecular machinery that governs self-renewal is of key importance. The transcription factor, HOXB4 is a key molecule that has been reported to induce the in vitro expansion of HSCs via self-renewal. However, critical downstream effector molecules of HOXB4 remain to be determined. This concisely reviewed information on c-KIT and HOXB4 helps us to update our understanding of their function and mechanism of action in self-renewal, proliferation, and differentiation of HSCs, particularly modulation by c-KIT mutant interactions, and HOXB4 overexpression showing certain therapeutic implications.

Structural conservation of residues in BH1 and BH2 domains of Bcl-2 family proteins.

The sequence of Bcl-2 homology domains, BH1 and BH2, is known to be conserved among anti- and pro-apoptotic members of Bcl-2 family proteins. But structural conservation of these domains with respect to functionally active residues playing role in heterodimerization-mediated regulation of apoptosis has never been elucidated. Here, we have suggested the formation of an active site by structurally conserved residues in BH1 (glycine, arginine) and BH2 (tryptophan) domains of Bcl-2 family members, which also accounts for the functional effect of known mutations in BH1 (G145A, G145E) and BH2 (W188A) domains of Bcl-2.