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1.
bioRxiv ; 2024 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-39282366

RESUMO

The size of a cell is important for its function and physiology. Interestingly, size variation can be easily observed in clonally derived embryonic and hematopoietic stem cells. Here, we investigated the regulation of stem cell growth and its association with cell fate. We observed heterogeneous sizes of neuroblasts or neural stem cells (NSCs) in the Drosophila ventral nerve cord (VNC). Specifically, thoracic NSCs were larger than those in the abdominal region of the VNC. Our research uncovered a significant role of the Hox gene abdominal A (abdA) in the regulation of abdominal NSC growth. Developmental expression of AbdA retards their growth and delays mitotic entry compared to thoracic NSCs. The targeted loss of abdA enhanced their growth and caused an earlier entry into mitosis with a faster cycling rate. Furthermore, ectopic expression of abdA reduced the size of thoracic NSCs and delayed their entry into mitosis. We suggest that abdA plays an instructive role in regulating NSC size and exit from quiescence. This study demonstrates for the first time the involvement of abdA in NSC fate determination by regulating their growth, entry into mitosis and proliferation rate, and thus their potential to make appropriate number of progeny for CNS patterning.

2.
Indian J Otolaryngol Head Neck Surg ; 76(4): 3146-3153, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39130278

RESUMO

Patients with Voice problems are frequently encountered in clinics. There is no tool available in Punjabi language for evaluation of impact of voice disorder on patient's life. The aim of this study was to adapt Voice Handicap Index in Punjabi language and to obtain validity, reliability and consistency of the developed tool. The study also aims to compare the scores of VHI-Punjabi between patients with voice problems and asymptomatic age-matched controls. The study follows qualitative research design with purposive sampling. The study was conducted at the Audiology and SLP unit of ENT, Guru Gobind Singh Medical College and Hospital, Faridkot, Punjab. A total of 200 subjects in the age group of 20-50 years were included, 100 each in study and control group. Combination of reverse translation, committee, and bilingual models were used for development of VHI-Punjabi. The construct validity was very good (r = 0.91). A statistically significant difference (p < 0.001) was obtained between the study group and control group in all the subtest scores and on the total scores of VHI-Punjabi. Statistical significant correlation is found in two administrations of VHI-Punjabi after a gap of 2 weeks in both study group and control group (p < 0.001). To find the internal consistency of VHI-Punjabi, Chronbach alpha was calculated, which came to be 0.97. The internal consistency was high. The results of the present study indicate that VHI-Punjabi is a valid and reliable tool that can be used for evaluation of patients with different types of voice problems.

3.
Br Dent J ; 236(9): 683-687, 2024 05.
Artigo em Inglês | MEDLINE | ID: mdl-38730156

RESUMO

The continuation of bone-modifying agents (BMAs) in patients with established medication-related osteonecrosis of the jaw (MRONJ) is a common concern among dentists and oncologists. There is little evidence supporting or refuting the continued use of BMAs or drug holidays and their impact on established MRONJ. This paper evaluates the outcome of continued BMAs use on the patient's MRONJ status. A retrospective review of 29 oncology patients undergoing active cancer care for either metastatic disease or multiple myeloma was conducted. Data on demographics, oncological status, BMA history and MRONJ status were collected. In total, 90% of patients were judged to have healed or stable MRONJ while continuing BMAs. Most patients (69%) continued the same BMA regime (three- or four-weekly) that they were on before developing MRONJ. The average number of BMAs doses received after an MRONJ diagnosis was 12 (range 1-48). Three patients (10.3%) were found to have MRONJ progression, with two patients developing new sites of necrosis. This real-world dataset suggests that the majority of MRONJ cases remain stable and will not worsen with the continuation of BMAs.


Assuntos
Osteonecrose da Arcada Osseodentária Associada a Difosfonatos , Conservadores da Densidade Óssea , Humanos , Osteonecrose da Arcada Osseodentária Associada a Difosfonatos/etiologia , Estudos Retrospectivos , Masculino , Feminino , Pessoa de Meia-Idade , Conservadores da Densidade Óssea/efeitos adversos , Conservadores da Densidade Óssea/uso terapêutico , Idoso , Idoso de 80 Anos ou mais , Adulto , Mieloma Múltiplo/tratamento farmacológico , Neoplasias/tratamento farmacológico
4.
Genetics ; 226(1)2024 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-37751321

RESUMO

Cortex glia in Drosophila central nervous system form a niche around neural cells for necessary signals to establish cross talk with their surroundings. These cells grow and expand their thin processes around neural cell bodies. Although essential for the development and function of the nervous system, how these cells make extensive and intricate connected networks remains largely unknown. In this study, we show that Cut, a homeodomain transcription factor, directly regulates the fate of the cortex glia, impacting neural stem cell (NSC) homeostasis. Focusing on the thoracic ventral nerve cord, we found that Cut is required for the normal growth and development of cortex glia and timely increase in DNA content through endocycle to later divide via acytokinetic mitosis. Knockdown of Cut in cortex glia significantly reduces the growth of cellular processes, the network around NSCs, and their progeny's cell bodies. Conversely, overexpression of Cut induces overall growth of the main processes at the expense of side ones. Whereas the Cut knockdown slows down the timely increase of DNA, the Cut overexpression results in a significant increase in nuclear size and volume and a 3-fold increase in DNA content of cortex glia. Further, we note that constitutively high Cut also interfered with nuclei separation during acytokinetic mitosis. Since the cortex glia form syncytial networks around neural cells, the finding identifies Cut as a novel regulator of glial growth and variant cell cycles to support a functional nervous system.


Assuntos
Proteínas de Drosophila , Fatores de Transcrição , Animais , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteínas de Drosophila/metabolismo , Neuroglia/metabolismo , Proteínas de Ligação a DNA/genética , Drosophila/genética , Morfogênese , DNA/metabolismo
5.
Indian J Otolaryngol Head Neck Surg ; 74(Suppl 2): 1979-1988, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36452639

RESUMO

Voice disorders are thought to be one of the major occupational hazards of school teaching. There is a need to study the prevalence of vocal fatigue in school teachers as it is unknown in Indian population and its awareness is at a very basic level. We aim to investigate percentage of school teachers reporting vocal fatigue and to find if there is any relationship between vocal fatigue and acoustic voice parameters. A total of 100 subjects (50-males and 50-females) in the age range of 25-35 years participated in the study. Voice Sample was obtained from the subject using a digital tape recorder and was analyzed in Visi pitch and Dr.Speech softwares. The sample was taken twice in a day, that is, before teaching and after teaching. The mean values obtained on all the questions of the vocal fatigue questionnaire show a significant increase in mean values on all the questions at post teaching ratings. Results revealed a statistically significant difference in pre and post teaching values of F0 and shimmer in males. In females, statistical significant difference was obtained in Noise to Harmonic Ratio in /u/ production. No significant correlation between acoustic parameters and overall vocal fatigue was found except for Noise to Harmonic ratio in females for /u/.

6.
Prim Dent J ; 11(3): 98-103, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36073049

RESUMO

Dental practitioners are well versed in informing patients of the risks and benefits associated with dental extractions. The purpose of this service evaluation was to determine whether patients understood and recalled information relevant to their planned oral surgery procedure, prior to second stage consent.A questionnaire was distributed to patients who were attending for their elective treatment appointment. This explored their ability to recall the planned intervention, the modality of treatment (local anaesthetic, intravenous sedation, or general anaesthetic), understanding of alternative treatment options and the risks associated with the procedure. Completed responses were received from 29 of the distributed questionnaires (response rate=58%). The majority of patients were not aware of the following risks with their procedure: pain, bleeding, bruising, swelling, infection, damage to adjacent structures.Despite a well-documented consent form and comprehensive discussion, we identified that patients may not comprehend or recollect the risks associated with their dental extraction. As dental professionals we have a duty to seek ways to facilitate patient understanding and maximise their autonomy.


Assuntos
Odontólogos , Papel Profissional , Anestesia Geral/efeitos adversos , Humanos , Consentimento Livre e Esclarecido , Extração Dentária
7.
ACS Chem Biol ; 17(7): 1756-1768, 2022 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-35767698

RESUMO

ERAP1 and ERAP2 are endoplasmic reticulum zinc-binding aminopeptidases that play crucial roles in processing peptides for loading onto class I major histocompatibility complex proteins. These enzymes are therapeutic targets in cancer and autoimmune disorders. The discovery of inhibitors specific to ERAP1 or ERAP2 has been challenging due to the similarity in their active site residues and domain architectures. Here, we identify 4-methoxy-3-{[2-piperidin-1-yl-4-(trifluoromethyl) phenyl] sulfamoyl} benzoic acid (compound 61) as a novel inhibitor of ERAP2 and determine the crystal structure of ERAP2 bound to compound 61. Compound 61 binds near the catalytic center of ERAP2, at a distinct site from previously known peptidomimetic inhibitors, and inhibits by an uncompetitive mechanism. Surprisingly, for ERAP1, compound 61 was found to activate model substrate hydrolysis, similarly to the previously characterized 5-trifluoromethyl regioisomer of compound 61, known as compound 3. We characterized the specificity determinants of ERAP1 and ERAP2 that control the binding of compounds 3 and 61. At the active site of ERAP1, Lys380 in the S1' pocket is a key determinant for the binding of both compounds 3 and 61. At the allosteric site, ERAP1 binds either compound, leading to the activation of model substrate hydrolysis. Although ERAP2 substrate hydrolysis is not activated by either compound, the mutation of His904 to alanine reveals a cryptic allosteric site that allows for the activation by compound 3. Thus, we have identified selectivity determinants in the active and allosteric sites of ERAP2 that govern the binding of two similar compounds, which potentially could be exploited to develop more potent and specific inhibitors.


Assuntos
Aminopeptidases , Ácido Benzoico , Aminopeptidases/química , Retículo Endoplasmático/metabolismo , Antígenos de Histocompatibilidade Menor/metabolismo , Peptídeos/química
8.
Nat Commun ; 12(1): 5302, 2021 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-34489420

RESUMO

The endoplasmic-reticulum aminopeptidase ERAP1 processes antigenic peptides for loading on MHC-I proteins and recognition by CD8 T cells as they survey the body for infection and malignancy. Crystal structures have revealed ERAP1 in either open or closed conformations, but whether these occur in solution and are involved in catalysis is not clear. Here, we assess ERAP1 conformational states in solution in the presence of substrates, allosteric activators, and inhibitors by small-angle X-ray scattering. We also characterize changes in protein conformation by X-ray crystallography, and we localize alternate C-terminal binding sites by chemical crosslinking. Structural and enzymatic data suggest that the structural reconfigurations of ERAP1 active site are physically linked to domain closure and are promoted by binding of long peptide substrates. These results clarify steps required for ERAP1 catalysis, demonstrate the importance of conformational dynamics within the catalytic cycle, and provide a mechanism for the observed allosteric regulation and Lys/Arg528 polymorphism disease association.


Assuntos
Aminopeptidases/química , Antígenos de Histocompatibilidade Menor/química , Simulação de Dinâmica Molecular , Polimorfismo Genético , Sítio Alostérico , Aminopeptidases/genética , Aminopeptidases/metabolismo , Apresentação de Antígeno/genética , Linfócitos T CD8-Positivos/citologia , Linfócitos T CD8-Positivos/imunologia , Domínio Catalítico , Clonagem Molecular , Cristalografia por Raios X , Retículo Endoplasmático/genética , Retículo Endoplasmático/imunologia , Expressão Gênica , Humanos , Antígenos de Histocompatibilidade Menor/genética , Antígenos de Histocompatibilidade Menor/metabolismo , Ligação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Soluções
9.
Indian J Otolaryngol Head Neck Surg ; 71(Suppl 2): 1241-1247, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31750159

RESUMO

Very few published studies have reported auditory speech perception in Hindi children with pre-lingual hearing loss. The study is aimed at comparing the speech perception skills of Hindi speaking children with pre-lingual severe to profound hearing loss using hearing aids and cochlear implants. Forty-three 6 to 8-year old children were included as participants, of which 22 were bilateral behind-the-ear hearing aid (HA) users and 21 were unilateral cochlear implant (CI) users. Speech perception was assessed through a forced-choice, picture-pointing task using recorded stimuli presented at 70 dB HL in the sound field. The skills assessed include: (a) pattern perception, (b) bisyllabic word identification, (c) monosyllabic word identification, (d) sentence identification and (e) minimal pair identification. Children using CI consistently performed significantly better than those with HA on all tasks. For the skills assessed, best performance was seen in pattern perception and poorest performance was seen in monosyllabic word identification. One participant from the CI group obtained ceiling scores for pattern perception and bisyllabic word identification. There was no statistically significant difference in the performance of 6 to 7 and 7 to 8-year-old children for any of the tasks. Children fitted with CI have better access to the cues important for perception of speech and hence perform consistently better than those using hearing aids. Recorded speech perception test can be used with children using cochlear implants and hearing aids.

10.
Indian J Otolaryngol Head Neck Surg ; 71(Suppl 2): 1442-1448, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31750193

RESUMO

To compare sentence recognition scores in quiet and noise in 8 to 15-years old children using bimodal hearing in CI only condition and bimodal condition (BM) (CI + HA). Twenty prelingually deafened participants (8-15 years) using cochlear implant in one ear and hearing aid in the other ear were recruited. The sentence recognition was assessed in CI Quiet, CI + 15 dB SNR, CI + 8 dB SNR, BM Quiet, BM + 15 dB SNR and BM + 8 dB SNR. The highest sentence recognition scores were obtained in the quiet condition, followed by the + 15 dB SNR and then by the + 8 dB SNR condition in both CI only and BM conditions. The sentence recognition scores obtained in BM condition were significantly better than CI only condition. Variables like unaided PTA and aided PTA correlated significantly with the sentence recognition scores in BM conditions. This study was done on Indian population where till date no published data is available. It recommends that all the school going children using unilateral cochlear implants should be recommended to use a hearing aid in the contra lateral ear. This practice will help them to receive all the binaural benefits, better listening in noise, localization, spatial release from masking and pitch perception in comparison to unilateral CI use. Moreover, it will help to keep the auditory nerve viable for future implantation which is an important implication for children who have limited benefit from the contra lateral hearing aid.

11.
Curr Comput Aided Drug Des ; 15(5): 421-432, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30848208

RESUMO

BACKGROUND: Rho-kinase is an essential downstream target of GTP-binding protein RhoA, and plays a crucial role in the calcium-sensitization pathway. Rho-kinase pathway is critically involved in phosphorylation state of myosin light chain, leading to increased contraction of smooth muscles. Inhibition of this pathway has turned out to be a promising target for several indications such as cardiovascular diseases, glaucoma and inflammatory diseases. METHODS: The present work focuses on a division-based 2D quantitative structure-activity relationship (QSAR) analysis along with a docking study to predict structural features that may be essential for the enhancement of selectivity and potency of the target compounds. Furthermore, a set of indoles and azaindoles were also projected based on the regression equation as novel developments. Molecular docking was applied for exploring the binding sites of the newly predicted set of compounds with the receptor. RESULTS: Results of the docked conformations suggested that introduction of non-bulky and substituted groups in the hinge region of ROCK-II ATP binding pocket would improve the activity by decreasing the bulkiness or length of the compounds. CONCLUSION: ADME studies were performed to ascertain the novelty and drug-like properties of the designed molecules, respectively.


Assuntos
Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Quinases Associadas a rho/antagonistas & inibidores , Trifosfato de Adenosina/metabolismo , Doenças Cardiovasculares/tratamento farmacológico , Desenho de Fármacos , Humanos , Indóis/química , Indóis/farmacologia , Simulação de Acoplamento Molecular , Relação Quantitativa Estrutura-Atividade , Quinases Associadas a rho/química , Quinases Associadas a rho/metabolismo
12.
Biochim Biophys Acta Proteins Proteom ; 1867(3): 163-174, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30543875

RESUMO

Acyl carrier proteins (ACPs) play crucial roles in the biosynthesis of fatty acids, non-ribosomal polypeptides and polyketides. The three-dimensional NMR structure of Leishmania major holo-LmACP, belonging to the type II pathway, has been reported previously, but the structure of its apo-form and its conformational differences with the holo-form remain to be explored. Here we report the crystal structures of apo-LmACP (wild-type and S37A mutant) at 2.0 Šresolution and compare their key features with the structures of holo-LmACP (wild-type) and other type II ACPs from Escherichia coli and Plasmodium falciparum. The crystal structure of apo-LmACP, which is homologous to other type II ACPs, displays some key structural rearrangements as compared to its holo-structure. Contrary to holo-form, which exists predominantly as a monomer, the apo-form exists as a mixture of monomeric and dimeric population in solution. In contrast to the closed structure of apo-LmACP, holo-LmACP structure was observed in an open conformation as a result of reorganization of specific helices and loops. We propose that the structural changes exhibited by LmACP occur due to the attachment of the phosphopantetheine arm and may be a prerequisite for the initiation of fatty acid synthesis. The movement of helix 3 may also play a role in the dissociation of holo-LmACP from its cognate enzymes of the FAS II pathway.


Assuntos
Proteína de Transporte de Acila/química , Proteínas de Protozoários/química , Cristalização , Leishmania major , Modelos Moleculares , Conformação Proteica
13.
Sci Rep ; 7(1): 1284, 2017 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-28455498

RESUMO

Src homology domain containing leukocyte protein of 65 kDa (SLP65), the growth factor receptor binding protein 2 (Grb2), and the guanine nucleotide exchange factor for the Rho family GTPases (Vav), self associate in unstimulated B cells as components of the preformed B cell receptor transducer module, in an SH3-dependent manner. The complex enables the B cell to promptly respond to BCR aggregation, resulting in signal amplification. It also facilitates Vav translocation to the membrane rafts, for activation. Here we uncover the molecular mechanism by which the complex may be formed in the B cell. The C-terminal SH3 domain (SH3C) of Grb2 bivalently interacts with the atypical non-PxxP proline rich region of SLP65, and the N-terminal SH3 domain (SH3N) of Vav, both the interactions crucial for the proper functioning of the B cell. Most surprisingly, the two ligands bind the same ligand binding site on the surface of Grb2 SH3C. Addition of SLP65 peptide to the Grb2-Vav complex abrogates the interaction completely, displacing Vav. However, the addition of Vav SH3N to the SLP65-Grb2 binary complex, results in a trimeric complex. Extrapolating these results to the in vivo conditions, Grb2 should bind the SLP65 transducer module first, and then Vav should associate.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/química , Proteína Adaptadora GRB2/química , Proteínas Proto-Oncogênicas c-vav/química , Domínios de Homologia de src , Animais , Ligantes , Camundongos , Domínios Proteicos Ricos em Prolina , Ligação Proteica , Sistemas de Translocação de Proteínas/química
14.
Biochemistry ; 55(49): 6832-6847, 2016 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-27951646

RESUMO

Since its discovery, neuroglobin (Ngb), a neuron-specific oxygen binding hemoglobin, distinct from the classical myoglobin and blood hemoglobin, has attracted attention as an endogenous neuroprotectant. Recent reports suggest that Ngb protects neurons from brain stroke, ischemic stress-induced degeneration, and other brain disorders. Proteins with a specific role in neuroprotection are often associated with neurodegeneration, as well, depending on the cellular environment or specific cellular triggers that tilt the balance one way or the other. This investigation explored the potential role of Ngb in amyloid fibril-related neuronal disorder. Ngb was capable of amyloid formation in vitro at neutral pH and ambient temperature, in both apo and holo forms, albeit at a slower rate in the holo form, unlike other hemoglobins that exhibit such behavior exclusively in the apo states. Elevated temperature enhanced the rate of fibril formation significantly. The B-helix, which is known to play a major role in Ngb ligand binding kinetics, was found to be amyloidogenic with the Phe28B10 amino acid side chain as the key inducer of fibrillation. The Ngb amyloid fibril was also significantly cytotoxic to neuroblastoma cell lines, compared to those obtained from reference hemoglobins. The Ngb fibril probably promoted toxicity by inducing channel formation in the cell membrane, as investigated here using synthetic lipid bilayer membranes and the propidium iodide uptake assay. These findings imply that Ngb plays a role in neurodegenerative disorders in vivo, for which there seems to be indirect evidence by association. Ngb thus presents a novel prospect for understanding amyloid-related brain disorders beyond the limited set of proteins currently investigated for such diseases.


Assuntos
Amiloide/química , Encéfalo/metabolismo , Globinas/química , Hemoglobinas/química , Proteínas do Tecido Nervoso/química , Fenilalanina/química , Linhagem Celular Tumoral , Dicroísmo Circular , Globinas/genética , Humanos , Concentração de Íons de Hidrogênio , Microscopia Eletrônica de Transmissão , Mutagênese Sítio-Dirigida , Proteínas do Tecido Nervoso/genética , Neuroglobina , Temperatura
15.
Indian J Otolaryngol Head Neck Surg ; 68(4): 417-423, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27833865

RESUMO

The study was conducted to evaluate the audiological and electrophysiological findings in patients with Vitiligo and to compare the findings with otologically and audiologically normal controls. Study group included 50 subjects (25 Males, 25 Females) with Vitiligo (Mean age-27.4 years) and control group contained 40 age-matched normal hearing subjects. Pure tone audiometry (PTA) with extended high frequency audiometry, Otoacoustic emissions (OAEs), Tympanometry, Auditory brainstem responses (ABR) and Middle latency responses (MLR) were conducted in all subjects. Comparison of the study group with the control group showed statistically significant differences (p < 0.05) on PTA, in Transient otoacoustic emissions (TOAEs) at 1, 2, 3, 4 kHz and in distortion product otoacoustic emissions (DPOAEs) at 357, 499, 704, 1003 Hz. On ABR, statistically significant differences were observed between the groups in wave I (p < 0.01) in both ears, wave V (p < 0.05) in left ear and on interpeak latency of I-III (p < 0.01, p < 0.05), III-V (p < 0.01 in left ear) and I-V (p < 0.01, p < 0.05) in left and right ears respectively. When patients with localized vitiligo were compared with generalized vitiligo, the SNR of TOAEs was highly significant in both ears at 2 KHz (p < 0.05), 3 kHz (p < 0.01) and 4 kHz (p < 0.05). PTA average of 2 KHz, 4 and 8 kHz (PTA2) showed a significant difference (p < 0.01) when localized vitiligo was compared to generalized vitiligo. Results support possible auditory and electrophysiological changes in Vitiligo patients along with decreased cochlear function.

16.
Semin Cell Dev Biol ; 39: 12-9, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25668151

RESUMO

Programmed cell death eliminates unneeded and dangerous cells in a timely and effective manner during development. In this review, we examine the role cell death plays during development in worms, flies and mammals. We discuss signaling pathways that regulate developmental cell death, and describe how they communicate with the core cell death pathways. In most organisms, the majority of developmental cell death is seen in the nervous system. Therefore we focus on what is known about the regulation of developmental cell death in this tissue. Understanding how the cell death is regulated during development may provide insight into how this process can be manipulated in the treatment of disease.


Assuntos
Morte Celular , Drosophila/citologia , Drosophila/crescimento & desenvolvimento , Morfogênese , Transdução de Sinais , Animais , Apoptose , Humanos , Neoplasias/patologia , Doenças Neurodegenerativas/patologia
17.
Artigo em Inglês | MEDLINE | ID: mdl-25138131

RESUMO

Medicines developed from traditional systems are well known for their various important pharmaceutical uses. Cancer has been known since ancient times and has been mentioned in the ancient Ayurvedic books. Thus natural based products play a significant role in cancer chemotherapeutics. Further, approximately 70% of anticancer compounds are based on natural products or have been derived from their structural scaffolds. Hence, there is a growing interest for developing medicines from these natural resources. Amongst the methods of treating cancer, therapies targeting cancer stem cell are found to control metastatic tumor which is a newly identified factor associated with relapse. This patent review aims to highlight the use of natural products to treat cancer by targeting the cancer stem cells. The review will also provide insights into the reported mechanisms by which the natural products act in order to suppress or kill cancer stem cells. The analysis has been done using various criteria such as the patenting trend over the years, comparison of active assignee and a comparison of the technical aspects as disclosed in the different patent documents. The analysis further highlights different bioactives, the scaffolds of which could thus be a promising candidate in the development of anti-cancer drugs by targeting the cancer stem cells. The technical aspects covered in this review include: Bioactives and formulations comprising the extracts or bioactives, their mode of action and the type of assay considered to study the efficacy of the natural products. Further the mapping has helped us to identify potential therapeutic areas to evaluate herbs/bioactives and their uses for developing new formulations.


Assuntos
Produtos Biológicos/uso terapêutico , Descoberta de Drogas/métodos , Células-Tronco Neoplásicas/efeitos dos fármacos , Patentes como Assunto , Produtos Biológicos/farmacologia , Humanos , Neoplasias/tratamento farmacológico
18.
Cell Stress Chaperones ; 13(4): 509-26, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18506601

RESUMO

Apart from their roles as chaperones, heat shock proteins are involved in other vital activities including apoptosis with mammalian Hsp60 being ascribed proapoptotic as well as antiapoptotic roles. Using conditional RNAi or overexpression of Hsp60D, a member of the Hsp60 family in Drosophila melanogaster, we show that the downregulation of this protein blocks caspase-dependent induced apoptosis. GMR-Gal4-driven RNAi for Hsp60D in developing eyes dominantly suppressed cell death caused by expression of Reaper, Hid, or Grim (RHG), the key activators of canonical cell death pathway. Likewise, Hsp60D-RNAi rescued cell death induced by GMR-Gal4-directed expression of full-length and activated DRONC. Overexpression of Hsp60D enhanced cell death induced either by directed expression of RHG or DRONC. However, the downregulation of Hsp60D failed to suppress apoptosis caused by unguarded caspases in DIAP1-RNAi flies. Furthermore, in DIAP1-RNAi background, Hsp60D-RNAi also failed to inhibit apoptosis induced by RHG expression. The Hsp60 and DIAP1 show diffuse and distinct granular overlapping distributions in the photoreceptor cells with the bulk of both proteins being outside the mitochondria. Depletion of either of these proteins disrupts the granular distribution of the other. We suggest that in the absence of Hsp60D, DIAP1 is unable to dissociate from effecter and executioner caspases, which thus remain inactive.


Assuntos
Apoptose , Caspases/metabolismo , Chaperonina 60/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/citologia , Drosophila melanogaster/enzimologia , Animais , Animais Geneticamente Modificados , Chaperonina 60/genética , Grânulos Citoplasmáticos/metabolismo , Regulação para Baixo , Proteínas de Drosophila/genética , Drosophila melanogaster/embriologia , Desenvolvimento Embrionário , Receptores ErbB/metabolismo , Olho/citologia , Olho/enzimologia , Galactosidases/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Homozigoto , Proteínas Inibidoras de Apoptose/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Larva/metabolismo , Mitocôndrias/metabolismo , Mutação/genética , Fenótipo , Células Fotorreceptoras de Invertebrados/citologia , Células Fotorreceptoras de Invertebrados/metabolismo , Interferência de RNA , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores de Peptídeos de Invertebrados/metabolismo
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