An impactful prospective study on pulmonary tuberculosis in geriatric populations besides its clinical outcomes and implications in the Indian subcontinent.

OBJECTIVE: Geriatric populations are most at risk for the tuberculosis pandemic, and as people age, the rate of infection rises steadily and drastically. Geriatric individuals frequently experience diagnostic challenges with a wide range of comorbidities, but employing all available standard and novel methods to diagnose any infection is crucial. The prophylactic and therapeutic management for the geriatric population presents a significant difficulty and challenge in assessing an appropriate and effective therapeutic outcome due to prolonged drug therapy and adverse drug reactions. The present study aims to determine the prevalence of tuberculosis in the geriatric population in the Indian subcontinent, its risk factors, clinical outcomes, and adherence to the medication. PATIENTS AND METHODS: A prospective observational investigation was conducted in a tertiary care Hospital in Erode, Tamil Nadu, India, from April 2021 to September 2022. A total of 1,014 patients were screened, and 176 participants were selected. The participants were then subjected to medication adherence evaluation, and clinical data was collected.  The statistical analysis was performed using SPSS version 20.0. RESULTS: Among 176 participants, 135 (76.70%) were old (65-74 age), 37 (21.02%) were very old (75-84 age) TB patients, and 4 (2.27%) patients were extremely old TB patients (>85). Medication adherence was improved from baseline to the end of the study (p≤0.000). 110 patients completed the treatment (62.5%). 41 patients were cured in between treatments (23.29%), 13 patients died during the treatment (7.38%), 9 patients lost their follow-up (5.11%), 3 patients failed to respond to the treatment (1.70%). CONCLUSIONS: The effectiveness of therapy critically depends on the patient's medication adherence to anti-TB therapy. In addition to having a higher likelihood of therapy failure, elderly patients did not appropriately respond to the treatment and completely recovered from the infection even after effective pharmacotherapy.

Ciproxifan attenuates the memory impairment induced by lipopolysaccharide through modulation of cholinergic transmission in the mouse brain.

OBJECTIVE: We investigated the protective effect of ciproxifan on lipopolysaccharide (LPS)-induced memory impairment by altering the cholinergic system in a mouse model. MATERIALS AND METHODS: Groups of mice were given ciproxifan (1 or 3 mg/kg, p.o.) for 30 days. Neurotoxicity was induced with four doses of LPS (250 µg/kg, i.p.) from day-22 to day-25 of drug treatment in three groups. Then, mice were subjected to behavioral assessments using tests [elevated plus maze (EPM), novel object recognition (NOR), and Y-maze]. Also, brain tissues were collected for estimation of cholinergic transmission [acetylcholine (ACh) and acetylcholinesterase (AChE) levels]. RESULTS: Ciproxifan could rescue the memory impairment caused by LPS by shortening the transfer latency in the EPM test, increasing the time spent to explore a novel object and increasing the Discrimination Index in the NOR test and increasing the number of entries to the novel arm and duration of time spent in the novel arm in the Y-maze test. Ciproxifan increased the levels of ACh by decreasing AChE activity in LPS-treated mice. CONCLUSIONS: Ciproxifan treatment can improve memory impairment in mice by increasing ACh levels and decreasing AChE levels.

Benzylpiperazine: "A messy drug".

Designer drugs are synthetic structural analogues/congeners of controlled substances with slightly modified chemical structures intended to mimic the pharmacological effects of known drugs of abuse so as to evade drug classification. Benzylpiperazine (BZP), a piperazine derivative, elevates synaptic dopamine and serotonin levels producing stimulatory and hallucinogenic effects, respectively, similar to the well-known drug of abuse, methylenedioxymethamphetamine (MDMA). Furthermore, BZP augments the release of norepinephrine by inhibiting presynaptic autoreceptors, therefore, BZP is a "messy drug" due to its multifaceted regulation of synaptic monoamine neurotransmitters. Initially, pharmaceutical companies used BZP as a therapeutic drug for the treatment of various disease states, but due to its contraindications and abuse potential it was withdrawn from the market. BZP imparts predominately sympathomimetic effects accompanied by serious cardiovascular implications. Addictive properties of BZP include behavioral sensitization, cross sensitization, conditioned place preference and repeated self-administration. Additional testing of piperazine derived drugs is needed due to a scarcity of toxicological data and widely abuse worldwide.

Impaired ILK Function Is Associated with Deficits in Hippocampal Based Memory and Synaptic Plasticity in a FASD Rat Model.

Fetal Alcohol Spectrum Disorder (FASD) is an umbrella term that encompasses a wide range of anatomical and behavioral problems in children who are exposed to alcohol during the prenatal period. There is no effective treatment for FASD, because of lack of complete characterization of the cellular and molecular mechanisms underlying this condition. Alcohol has been previously characterized to affect integrins and growth factor signaling receptors. Integrin Linked Kinase (ILK) is an effector of integrin and growth-factor signaling which regulates various signaling processes. In FASD, a downstream effector of ILK, Glycogen Synthase Kinase 3ß (GSK3ß) remains highly active (reduced Ser9 phosphorylation). GSK3ß has been known to modulate glutamate receptor trafficking and channel properties. Therefore, we hypothesize that the cognitive deficits accompanying FASD are associated with impairments in the ILK signaling pathway. Pregnant Sprague Dawley rats consumed a "moderate" amount of alcohol throughout gestation, or a calorie-equivalent sucrose solution. Contextual fear conditioning was used to evaluate memory performance in 32-33-day-old pups. Synaptic plasticity was assessed in the Schaffer Collateral pathway, and hippocampal protein lysates were used to evaluate ILK signaling. Alcohol exposed pups showed impaired contextual fear conditioning, as compared to control pups. This reduced memory performance was consistent with decrease in LTP as compared to controls. Hippocampal ILK activity and GSK3ß Ser21/9 phosphorylation were significantly lower in alcohol-exposed pups than controls. Increased synaptic expression of GluR2 AMPA receptors was observed with immunoprecipitation of post-synaptic density protein 95 (PSD95). Furthermore, immunoprecipitation of ILK revealed a decreased interaction with GluR2. The ILK pathway appears to play a significant role in memory and synaptic plasticity impairments in FASD rats. These impairments appear to be mediated by reduced GSK3ß regulation and increased synaptic stabilization of the calcium-impermeable GluR2 AMPA receptors.

Immunophenotypic comparison of heterogenous non-sorted versus sorted mononuclear cells from human umbilical cord blood: a novel cell enrichment approach.

Human umbilical cord blood (hUCB) has been the preferred source of stem cells for the treatment of haematological malignancies and genetic disorders. This is primarily due to its non-invasiveness, high accessibility with relative ease of isolation. Still failures do prevail due to its heterogeneity and lesser frequency of MSC identified in UCB. This study, thus, employs a cell enrichment technology to improve its therapeutic efficacy. This was achieved by immunophenotypic comparison of stem cells isolated from the heterogenous non-sorted mononuclear cells (MNCs), linage depleted (Lin+ and Lin-) fractions obtained from magnetic activated cell sorter (MACS) and sorted MNCs obtained by fluorescent activated cell sorter (FACS). The markers under consideration were CD29, CD44, CD34, CD45, CD133, CD90 and CD117. FACS sorted MNCs were rich in naive stem cell population, whereas non-sorted MNCs and lineage depleted fractions were found to be rich in progenitors. Thus, we suggest that a combination therapy of both sorted population might serve as an alternative valuable tool in treating haematologic/genetic disorders. However, further research on cell enrichment technology might give a clue for improved cell based therapy in regenerative medicine.

Polycaprolactone scaffold engineered for sustained release of resveratrol: therapeutic enhancement in bone tissue engineering.

Biomaterials-based three-dimensional scaffolds are being extensively investigated in bone tissue engineering. A potential scaffold should be osteoconductive, osteoinductive, and osteogenic for enhanced bone formation. In this study, a three-dimensional porous polycapro-lactone (PCL) scaffold was engineered for prolonged release of resveratrol. Resveratrol-loaded albumin nanoparticles (RNP) were synthesized and entrapped into a PCL scaffold to form PCL-RNP by a solvent casting and leaching method. An X-ray diffraction study of RNP and PCL-RNP showed that resveratrol underwent amorphization, which is highly desired in drug delivery. Furthermore, Fourier transform infrared spectroscopy indicates that resveratrol was not chemically modified during the entrapment process. Release of resveratrol from PCL-RNP was sustained, with a cumulative release of 64% at the end of day 12. The scaffold was evaluated for its bone-forming potential in vitro using human bone marrow-derived mesenchymal stem cells for 16 days. Alkaline phosphatase activity assayed on days 8 and 12 showed a significant increase in activity (1.6-fold and 1.4-fold, respectively) induced by PCL-RNP compared with the PCL scaffold (the positive control). Moreover, von Kossa staining for calcium deposits on day 16 showed increased mineralization in PCL-RNP. These results suggest PCL-RNP significantly improves mineralization due to its controlled and prolonged release of resveratrol, thereby increasing the therapeutic potential in bone tissue engineering.

Lineage depletion of stromal vascular fractions isolated from human adipose tissue: a novel approach towards cell enrichment technology.

The therapeutic rationale for tissue repair and regeneration using stem cells is at its infancy and needs advancement in understanding the role of individual component's innate capability. As stem cells of adipose tissue reside in a more heterogeneous population of stromal vascular fractions, cell separation or sorting becomes an eminent step towards revealing their unique properties. This study elucidates the comparative efficacy of lineage depleted adipose derived stromal vascular fraction (SVF) and their innate ability using magnetic activated cell sorter (MACS). To this end, isolated SVF from human adipose tissue was lineage depleted according to the manufacturer's instructions using specific antibody cocktail through MACS. The enriched lineage negative (lin-) and lineage positive (lin+) cell fractions were cultured, phenotypically characterized for the panel of cell surface markers using flowcytometry and subjected to osteoblastic and adipogenic differentiation. The expression profile obtained for lin- cells was CD34-/CD45-/HLADR-/CD49d-/CD140b-/CD31-/CD90+/CD105+/CD73+/CD54+/CD166+/CD117- when compared to Lin+ cells expressing CD34+/CD45+/HLADR-/CD49d-/CD140b+/CD31-/CD90+/CD105+/CD73+/CD54+/CD166+/CD117+ (CD-cluster of differentiation). These results, thus, advances our understanding on the inherent property of the individual cell population. Furthermore, both the fractions exhibited mesodermal lineage differentiation capacity. To conclude, this research pursuit rationalized the regenerative therapeutic applicability of both lin- and lin+ cultures of human adipose tissue for disorders of mesodermal, haematological and vascular origin.

Comparison of feto-maternal organ derived stem cells in facets of immunophenotype, proliferation and differentiation.

Scientific explorations on feto-maternal organ stem cells revealed its possible applicability in treatment of various diseases. However, establishment of an ideal placental tissue stem cell source in regenerative application is inconclusive and arduous. Hence, this study aims to resolve this tribulation by comparison of mesenchymal stem cells (MSC) from fetal placenta - amniotic membrane (AM-MSC), chorionic plate (CP-MSC) tissue and the maternal placenta-Decidua (D-MSC), thereby facilitating the researchers to determine their pertinent source. The cells were expanded and scrutinized for expression profiling, proliferation and differentiation ability. Remarkable expressions of certain markers in addition to its prospective mesodermal differentiation confirmed their mesenchyme origin. Despite the specified alikeness among these sources, reliable and non-invasive procurement of AM-MSC coupled with its higher growth potency makes it the most constructive stem cell source. However, exhibited similarities demands further investigations on extensive expandability and cytogenetic stability of these sources prior to its therapeutic applicability.

Prospective biomarkers of stem cells of human endometrium and fallopian tube compared with bone marrow.

The applicability of stem cells from the human endometrium and fallopian tube for regeneration is a fascinating area of research because of the role of these cells in dynamic tissue remodelling and their cyclical regenerative property during the menstrual cycle and pregnancy. Nevertheless, studies on the identity of biomarkers of these stem cells are limited and need to be extended. The present study has aimed at exploring the tissue-specific biomarkers of stem cells derived from the human endometrium and fallopian tube compared with those from bone marrow. Cells were isolated from human endometrium and fallopian tubes and characterized for biomarkers, including CD34, CD133, CD117, CD90, CD105, CD73, nestin, CD29, CD44, CD31, CD54, CD166, CD106, CD49d, CD45, ABCG2, SSEA4, OCT4, SOX2, CD140b and CD146, by flowcytometry. Both endometrium and fallopian tube sources exhibited positivity over a wide range of markers, as did bone marrow. In particular, they exhibited pluripotency, perivascular and mesenchymal stem cell markers and cell adhesion molecules, thereby suggesting their relevance in tissue repair and regeneration. Overall, the results of this study provide evidence for the presence of stem cells in the human endometrium and fallopian tube, which could thus represent additional stem cell sources for regenerative medicine.

Human omentum fat-derived mesenchymal stem cells transdifferentiates into pancreatic islet-like cluster.

Current protocols of islet cell transplantation for the treatment of diabetes mellitus have been hampered by islet availability and allograft rejection. Although bone marrow and subcutaneous adipose tissue stem cells feature their tissue repair efficacy, applicability of stem cells from various sources is being researched to develop a promising therapy for diabetes mellitus. Although omentum fat has emerged as an innovative source of stem cells, the dearth of researches confirming its transdifferentiation potential limits its applicability as a regenerative tool in diabetic therapy. Thus, this work is a maiden attempt to explore the colossal potency of omentum fat-derived stem cells on its lucrative differentiation ability. The plasticity of omentum fat stem cells was substantiated by transdifferentiation into pancreatic islet-like clusters, which was confirmed by dithizone staining and immunocytochemistry for insulin. It was also confirmed by the expression of pancreatic endocrine markers nestin and pancreatic duodenal homeobox 1 (Pdx 1) using Fluorescence-activated cell sorting (FACS), neurogenic 3, islet-1 transcription factor, paired box gene 4, Pdx 1 and insulin using quantitative real-time polymerase chain reaction and through insulin secretion assay. This study revealed the in vitro differentiation potency of omentum fat stem cells into pancreatic islet-like clusters. However, further research pursuits exploring its in vivo endocrine efficacy would make omentum fat stem cells a superior source for ß-cell replacement therapy.

Exploring the stem cell and non-stem cell constituents of human breast milk.

The immense potency of nutritional components of human breast milk and importance of breastfeeding is known worldwide. Recent researches had identified stem cells as integral component of human breast milk. Nevertheless, there is little proof of evidence on the stem cell constituents of breast milk. It is imperative to explore the cellular constituents of human breast milk, including of stem cells, to open new avenue in child's development and regeneration. Thus, we aimed at identifying the cellular constituents of human breast milk by phenotypic characterisation of diverse cell surface markers of hematopoietic stem cells (CD 34, CD 133, CD 117), mesenchymal stem cells (CD 90, CD 105, CD 73), myoepithelial cells (CD 29, CD 44), Immune cells (CD 209, CD 86, CD 83, CD 14, CD 13, HLADR, CD 45), as well as cell adhesion molecules (CD 31, CD 54, CD 166, CD 106, CD 49d), and other markers (ABCG2, CD140b) using flowcytometry. We found a lower expression of CD 34 (13.07 ± 2.0 %), CD 90 (7.79 ± 0.8 %) and CD 73 (2.19 ± 0.41 %), indicating scanty hematopoietic and mesenchymal stem cell population in human breast milk. On contrary, myoepithelial progenitors, cell adhesion molecules, immune cells and growth factors were identified as the major constituents of breast milk. Overall, this study illuminates the benefits of breast feeding as breast milk encompasses heterogeneous cellular components that benefits child's growth, immunity and development. However, further research on these constituents of human breast milk will widen their applicability in treatment of neonatal disorders.

Plasticity and banking potential of cultured adipose tissue derived mesenchymal stem cells.

The present day research on stem cells is yet not filled to the gunwales. The correlation of stem cell technology with tissue repair still has a long way to go. Since Embryonic stem cells are a kind of thorn inside when it comes to therapeutics, there emerged few potent contemporary sources of stem cells. Though bone marrow proves to be the pioneer among these, they lose themselves to adipose tissue in various aspects. The major shortcoming of bone marrow lies in lieu of its loss in potency with age. Adipose tissue puts up a tough competition among leading edge stem cell sources like cord blood and cord matrix. Adipose tissue wins over its counterparts in that it possesses astounding proliferation potency in vitro and holds a prominent stand in showcasing in vivo tissue repair efficacy. In spite of its precedence, the whole enchilada of adipose derived stem cells is still in its salad days. In our work we aim at excogitating the Mesenchymal stem cell population present in cultured adipose derived stem cells, in a wide perspective. Furthermore, the coalition of cell adhesion molecules with the proliferation potency of MSC and analysis of growth curve of ADSC was also paid accolade. The presence of robust MSC with immense differentiation and transdifferentiation potency was endorsed by lucrative differentiation of P3 cells into mesodermal and neuronal lineages. Additionally, mesenchymal stem cells exhibiting coherent expression of surface markers at P3 in all samples can be cryopreserved for therapeutic applications.

A comprehensive study on optimization of proliferation and differentiation potency of bone marrow derived mesenchymal stem cells under prolonged culture condition.

Bone marrow derived stem cells (BMSC) have paved way to clinical approaches for its utilization in a variety of diseases due to its ease of isolation combined with its multilineage differentiation capacity. However, the applicability of BMSC is not successful due to the lesser number of nucleated cells obtained from large samples. Hence, culture expansion of BMSC is a prerequisite, as high numbers of stem cells are needed to meet the standards of clinical advancement. There are attempts on optimizing culture condition for large scale production of BMSC. It was believed that, prolonged culture of BMSC is difficult since they tend to lose their characteristics and differentiation potential. Hence, our study aims to determine whether BMSCs could retain its proliferative and differentiation capacity in prolonged in vitro culture by a comparative study on extensive culturing of BMSC with the following four media, DMEM LG (DMEM-Low Glucose), DMEM KO (DMEM-Knock Out), Alpha MEM (Alpha Minimal Essential Medium), DMEM F 12. We found that two samples among the three cultured tend to lose their property in long term culturing. Besides, we also found that DMEM LG and Alpha MEM were the optimal media for in vitro culturing of BMSC. Overall, it was concluded that BMSC can be cultured until passage 15 without losing its characteristics. However, its potency beyond passage 15 has to be further elucidated for utilization of the ex vivo expanded BMSC for subsequent cellular therapies.

Effect of high glucose on extensive culturing of mesenchymal stem cells derived from subcutaneous fat, omentum fat and bone marrow.

Frontline research progresses the applicability of bone marrow and adipose tissue in regenerative medicine, but fails to account for the functional improvement of the diseased. The justification for the failure in terms of stem cell survival, proliferation and regeneration is unclear. However, hyperglycemia rising during pathological conditions might be one such stumbling block. The prevailing literature accounts for both detrimental and beneficial effect of high glucose on mesenchymal stem cells (MSCs) leading to perplexity. Thus, this study focuses on the effect of high glucose on mesenchymal stem cells derived from subcutaneous fat, omentum fat and bone marrow in extensive cultures. We provide evidence for the retention of MSC characteristics of all sources with regards to surface marker profiling, proliferation, differentiation and karyotyping when cultured extensively under DMEM-HG containing glucose concentration of 25 mmol.l(-1) . Thus, it can be concluded that hyperglycemia in vivo (11 mmol.l(-1) ) might not be a barrier for the ineffective functional improvement of transplanted stem cells. Furthermore, we elucidated subcutaneous and omentum fat as better sources of MSCs when compared with bone marrow, thereby making these sources optimal for therapies during hyperglycemic conditions. However, further research is needed to clear the path for efficient stem cell transplantation.

Unravelling the retention of proliferation and differentiation potency in extensive culture of human subcutaneous fat-derived mesenchymal stem cells in different media.

OBJECTIVES: This study has intended to investigate longevity of subcutaneous fat-derived mesenchymal stem cells (SF-MSCs) under extensive culturing. It has also focused on optimization of culture media for them over prolonged periods in vitro. MATERIALS AND METHODS: We evaluated SF-MSCs with reference to phenotypic characterization, proliferative ability, karyotype stability and differentiation potency with early (P3) and late passage (P20) conditions, using four different media, DMEM-LG, ALPHA-MEM, DMEM-F12 and DMEM-KO. RESULTS: This study unravels retention of SF-MSC characteristics in facets of phenotypic expression profile (CD 90, CD 105, CD 73, CD 34, CD 29, CD 54, CD 49d, CD 117, HLA-DR, CD 166, CD 31, CD 44), proliferative characteristics, karyotyping and differentiation potency prolonged culturing to P25 in all media. Population doubling time (PDT) in Alpha MEM, DMEM LG, DMEM F 12, DMEM KO were identified to be (1.81, 1.84, 1.9, 2.08 days) at early passage and (2.93, 2.94, 3.12, 3.06 days) at late passage. As a corollary, Alpha MEM and DMEM LG serve as appropriate basal media for SF-MSC when proliferative potency is considered. CONCLUSIONS: In research, it is imperative that SF-MSC uphold their expansion potency in the aforesaid attributes in all media over extensive culturing, thereby transforming their colossal in vitro potency, with the aim of curing a wide horizon of diseases.

Surface antigenic profiling of stem cells from human omentum fat in comparison with subcutaneous fat and bone marrow.

Omentum fat derived stem cells have emerged as an alternative and accessible therapeutic tool in recent years in contrast to the existing persuasive sources of stem cells, bone marrow and subcutaneous adipose tissue. However, there has been a scanty citation on human omentum fat derived stem cells. Furthermore, identification of specific cell surface markers among aforesaid sources is still controversial. In lieu of this existing perplexity, the current research work aims at signifying omentum fat as a ground-breaking source of stem cells by surface antigenic profiling of stem cell population. In this study, we examined and compared the profiling of cell surface antigenic expressions of hematopoietic stem cells, mesenchymal stem cells, cell adhesion molecules and other unique markers such as ABCG2, ALDH and CD 117 in whole cell population of human omentum fat, subcutaneous fat and bone marrow. The phenotypic characterization through flowcytometry revealed the positive expressions of CD 34, CD 45, CD 133, HLADR, CD 90, CD 105, CD 73, CD 29, CD 13, CD 44, CD 54, CD 31, ALDH and CD 117 in all sources. The similarities between the phenotypic expressions of omentum fat derived stem cells to that of subcutaneous fat and bone marrow substantiates that identification of ultimate source for curative therapeutics is arduous to assess. Nevertheless, these results support the potential therapeutic application of omentum fat derived stem cells.

Mechanism-based protein design: attempted "nucleation-condensation" approach to a possible minimal helix-bundle protein.

In an intended mechanism-based de novo approach, a 22-mer peptide was so designed as to make it both a stereochemically nucleatable and hydrophobically condensable minimal globular protein. Framework-like nucleation of a triple-helix bundle was targeted by employing as folding nucleators composite beta-turns that could both nucleate helices and place them in close juxtaposition for possible interhelical interaction. To promote the targeted triple-helix bundle to condense as a globular protein, an amphipathic sequence pattern was adopted for possible hydrophobic interhelical interaction. A predominantly helicogenic 22-mer amphipathic peptide was thus designed, punctuating it with composite type II'-III and type II-Asx type beta-turns as the helix nucleators cum chain reversal elements. The peptide made by solid-phase synthesis was shown by NMR and CD to be a nascent and distorted triple-helix bundle in a trifluoroethanol (TFE)-water mixture, but more or less a random coil in water. A fold nucleation effect is evident in the TFE-water mixture, but apparently the hydrophobic effect cannot sustain the peptide conformational order in water. A lack of synergy between folding nucleation and hydrophobic condensation of the peptide is possible. Indeed, a mismatch between the sequential H,P pattern of the peptide and its nascent-type globular fold in a TFE-water mixture is evident based on a simulated annealing study guided by NMR.

Structural characterization of peptide fragments from hCD81-LEL.

The solution conformation of two peptides [1: PSGSNIISNLFKED; 2: GSSTLTALTTSVLKNNL] from human CD81 (hCD81) large extra-cellular loop (LEL) with known importance in the hepatitis C virus glycoprotein E2 (HCV-E2) binding interaction was characterized using circular dichroism spectroscopy. In addition, the solution structure of peptide 1 that contains a phenylalanine residue (F186 in hCD81) known to be critical in the binding interaction with HCV-E2 was determined using 1D and 2D 1H NMR spectroscopy. Both peptides are unstructured in water but begin forming significant helical conformation following the addition of 20% or more trifluoroethanol (v/v), a result consistent with their alpha-helical conformation found in the native protein. The CD data recorded as a function of pH and NaCl concentration are consistent with stabilization of the helical structure from electrostatic forces for both peptides. Peptide 1 is able to block the binding interaction of recombinant HCV-E2 (rHCV-E2) to hCD81 expressed on Molt-4 T cells at high concentrations (3.5 mM), a low affinity that we attributed to the random coil structure in water.

Solution conformation of a rationally designed nonapeptide.

Partial 'turn-helix' type modules comprised of LD and DL chiral beta-turns serving as potential helix nucleators have been connected with a view to designing a nascent 'helix-turn-helix' type structure. Conformation of the resultant peptide Boc-(D)Glu-Ala-Aib-Lys-Val-Pro-(D)Asp-Leu-Leu-NHMe has been described in both DMSO and water.

SCH 51344-induced reversal of RAS-transformation is accompanied by the specific inhibition of the RAS and RAC-dependent cell morphology pathway.

RAS interacts with multiple targets in the cell and controls at least two signaling pathways, one regulating extracellular signal-regulated kinase (ERK) activation and the other controlling membrane ruffling formation. These two pathways appear to act synergistically to cause transformation. SCH 51344 is a pyrazolo-quinoline derivative identified based on its ability to derepress transformation sensitive alpha-actin promoter in RAS-transformed cells. Previous studies have shown that SCH 51344 is a potent inhibitor of RAS-transformation. However, SCH 51344 had very little effect on the activities of proteins in the ERK pathway, suggesting that it inhibits RAS-transformation by a novel mechanism. In this study, we show that SCH 51344 specifically blocks membrane ruffling induced by activated forms of H-RAS, K-RAS, N-RAS and RAC. Treatment of fibroblast cells with this compound had very little effect on RAS-mediated activation of ERK and JUN kinase activities. SCH 51344 was effective in inhibiting the anchorage-independent growth of Rat-2 fibroblast cells transformed by the three forms of oncogenic RAS and RAC V12. These results indicate that SCH 51344 inhibits a critical component of the membrane ruffling pathway downstream from RAC and suggest that targeting this pathway may be an effective approach to inhibit transformation by RAS and other oncogenes.