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1.
ACS Infect Dis ; 10(5): 1431-1457, 2024 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-38682683

RESUMO

Mucormycosis, a rare but deadly fungal infection, was an epidemic during the COVID-19 pandemic. The rise in cases (COVID-19-associated mucormycosis, CAM) is attributed to excessive steroid and antibiotic use, poor hospital hygiene, and crowded settings. Major contributing factors include diabetes and weakened immune systems. The main manifesting forms of CAM─cutaneous, pulmonary, and the deadliest, rhinocerebral─and disseminated infections elevated mortality rates to 85%. Recent focus lies on small-molecule inhibitors due to their advantages over standard treatments like surgery and liposomal amphotericin B (which carry several long-term adverse effects), offering potential central nervous system penetration, diverse targets, and simpler dosing owing to their small size, rendering the ability to traverse the blood-brain barrier via passive diffusion facilitated by the phospholipid membrane. Adaptation and versatility in mucormycosis are facilitated by a multitude of virulence factors, enabling the pathogen to dynamically respond to various environmental stressors. A comprehensive understanding of these virulence mechanisms is imperative for devising effective therapeutic interventions against this highly opportunistic pathogen that thrives in immunocompromised individuals through its angio-invasive nature. Hence, this Review delineates the principal virulence factors of mucormycosis, the mechanisms it employs to persist in challenging host environments, and the current progress in developing small-molecule inhibitors against them.


Assuntos
Antifúngicos , Inteligência Artificial , COVID-19 , Mucormicose , Fatores de Virulência , Mucormicose/tratamento farmacológico , Humanos , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Fatores de Virulência/antagonistas & inibidores , Fatores de Virulência/metabolismo , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/patogenicidade
2.
ACS Chem Neurosci ; 15(6): 1254-1264, 2024 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-38436259

RESUMO

The reactivation of ubiquitously present Epstein-Barr virus (EBV) is known to be involved with numerous diseases, including neurological ailments. A recent in vitro study from our group unveiled the association of EBV and its 12-amino acid peptide glycoprotein M146-157 (gM146-157) with neurodegenerative diseases, viz., Alzheimer's disease (AD) and multiple sclerosis. In this study, we have further validated this association at the in vivo level. The exposure of EBV/gM146-157 to mice causes a decline in the cognitive ability with a concomitant increase in anxiety-like symptoms through behavioral assays. Disorganization of hippocampal neurons, cell shrinkage, pyknosis, and apoptotic appendages were observed in the brains of infected mice. Inflammatory cytokines such as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were found to be elevated in infected mouse brain tissue samples, whereas TNF-α exhibited a decline in the serum of these mice. Further, the altered levels of nuclear factor-kappa B (NF-kB) and neurotensin receptor 2 affirmed neuroinflammation in infected mouse brain samples. Similarly, the risk factor of AD, apolipoprotein E4 (ApoE4), was also found to be elevated at the protein level in EBV/gM146-157 challenged mice. Furthermore, we also observed an increased level of myelin basic protein in the brain cortex. Altogether, our results suggested an integral connection of EBV and its gM146-157 peptide to the neuropathologies.


Assuntos
Infecções por Vírus Epstein-Barr , Herpesvirus Humano 4 , Animais , Camundongos , Herpesvirus Humano 4/metabolismo , Infecções por Vírus Epstein-Barr/patologia , Fator de Necrose Tumoral alfa/metabolismo , Citocinas , Glicoproteínas
3.
BMC Complement Med Ther ; 23(1): 362, 2023 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-37833682

RESUMO

BACKGROUND: Sterile fecal filtrate (SFF) is being considered a safer alternative to fecal microbiota transplantation (FMT) therapy; however, its bioactive potency is very little understood. The present study thus assessed the age-dependent immunostimulatory and immunomodulatory attributes of murine SFF in vitro. METHODS: SFF from young (Y-SFF) and old (O-SFF) Swiss albino mice were prepared. Immunostimulatory and immunomodulatory effects of SFF were evaluated in resting and lipopolysaccharide (LPS) stimulated macrophage cells by measuring intracellular reactive oxygen species (ROS), nitric oxide (NO) production, inflammatory cytokines profile, as well as gene expression of oxidative and inflammatory transcription factors. SFF were also evaluated for native antioxidant capacity by measuring DPPH and ABTS free radical scavenging activity. Bioactive components present in SFF were also determined by GC/MS analysis. RESULTS: Both Y-SFF and O-SFF induced potent immunostimulatory effects characterized by changes in cell morphology, a significant increase in NO production, ROS levels, and an increased ratio of pro-inflammatory (IL-6, TNF-α, IL-1ß) to anti-inflammatory (IL-10) secretory proteins although no significant aggravation in the transcription of NF-κB and Nrf-2 could be observed. Application of LPS to cells significantly augmented a pro-oxidative and pro-inflammatory response which was much higher in comparison to Y-SFF or O-SFF application alone and mediated by strong suppression of Nrf-2 gene expression. Pre-treatment of macrophages with both Y-SFF and O-SFF robustly attenuated cellular hyperresponsiveness to LPS characterized by significantly decreased levels of NO, ROS, and inflammatory cytokines while a concomitant increase in anti-inflammatory protein (IL-10) was observed. Further, both Y-SFF and O-SFF strongly resisted LPS-induced downregulation of Nrf-2 expression although O-SFF appeared to protect cells slightly better from the overall LPS threat. Neat SFF samples exhibited moderate antioxidant capacity and GC/MS analysis of SFF revealed diverse volatile organic compounds characterized by alkanes, organosulphur compounds, furans, amides, amino acids, and antimicrobial elements. CONCLUSION: Our results indicate that SFF is a potent stimulant of macrophages and confers strong anti-inflammatory effects regardless of donor age thereby suggesting its therapeutic efficacy in lieu of FMT therapy.


Assuntos
Antioxidantes , Interleucina-10 , Animais , Camundongos , Antioxidantes/química , Transdução de Sinais , Espécies Reativas de Oxigênio/metabolismo , Lipopolissacarídeos/farmacologia , Macrófagos , Anti-Inflamatórios/farmacologia , Citocinas/metabolismo , Óxido Nítrico/metabolismo
4.
Probiotics Antimicrob Proteins ; 15(1): 44-62, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36357656

RESUMO

The growing consumer awareness towards healthy and safe food has reformed food processing strategies. Nowadays, food processors are aiming at natural, effective, safe, and low-cost substitutes for enhancing the shelf life of food products. Milk, besides being a rich source of nutrition for infants and adults, serves as a readily available source of precious functional peptides. Due to the existence of high genetic variability in milk proteins, there is a great possibility to get bioactive peptides with varied properties. Among other bioactive agents, milk-originated antimicrobial peptides (AMPs) are gaining interest as attractive and safe additive conferring extended shelf life to minimally processed foods. These peptides display broad-spectrum antagonistic activity against bacteria, fungi, viruses, and protozoans. Microbial proteolytic activity, extracellular peptidases, food-grade enzymes, and recombinant DNA technology application are among few strategies to tailor specific peptides from milk and enhance their production. These bioprotective agents have a promising future in addressing the global concern of food safety along with the possibility to be incorporated into the food matrix without compromising overall consumer acceptance. Additionally, in conformity to the current consumer demands, these AMPs also possess functional properties needed for value addition. This review attempts to present the basic properties, synthesis approaches, action mechanism, current status, and prospects of antimicrobial peptide application in food, dairy, and pharma industry along with their role in ensuring the safety and health of consumers.


Assuntos
Peptídeos Antimicrobianos , Proteínas do Leite , Leite , Animais , Humanos , Peptídeos Antimicrobianos/análise , Peptídeos Antimicrobianos/uso terapêutico , Bactérias , Leite/química , Proteínas do Leite/análise , Proteínas do Leite/uso terapêutico , Peptídeos/farmacologia , Peptídeos/química
5.
J Chem Inf Model ; 62(7): 1744-1759, 2022 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-35333517

RESUMO

Acinetobacter baumannii is a multidrug-resistant, opportunistic, nosocomial pathogen for which a new line of treatments is desperately needed. We have targeted the enzyme of the first step of the histidine biosynthesis pathway, viz., ATP-phosphoribosyltransferase (ATP-PRT). The three-dimensional structure of ATP-PRT was predicted on the template of the known three-dimensional structure of ATP-PRT from Psychrobacter arcticus (PaATPPRT) using a homology modeling approach. High-throughput virtual screening (HTVS) of the antibacterial library of Life Chemicals Inc., Ontario, Canada was carried out followed by molecular dynamics simulations of the top hit compounds. In silico results were then biochemically validated using surface plasmon resonance spectroscopy. We found that two compounds, namely, F0843-0019 and F0608-0626, were binding with micromolar affinities to the ATP-phosphoribosyltransferase from Acinetobacter baumannii (AbATPPRT). Both of these compounds were binding in the same way as AMP in PaATPPRT, and the important residues of the active site, viz., Val4, Ser72, Thr76, Tyr77, Glu95, Lys134, Val136, and Tyr156, were also interacting via hydrogen bonds. The calculated binding energies of these compounds were -10.5 kcal/mol and -11.1 kcal/mol, respectively. These two compounds can be used as the potential lead molecules for designing antibacterial compounds in the future, and this information will help in drug discovery programs against Acinetobacter worldwide.


Assuntos
Acinetobacter baumannii , Acinetobacter baumannii/metabolismo , Trifosfato de Adenosina/metabolismo , Antibacterianos/química , Histidina , Simulação de Acoplamento Molecular
6.
J Biol Chem ; 297(6): 101353, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34717958

RESUMO

Within the superfamily of small GTPases, Ras appears to be the master regulator of such processes as cell cycle progression, cell division, and apoptosis. Several oncogenic Ras mutations at amino acid positions 12, 13, and 61 have been identified that lose their ability to hydrolyze GTP, giving rise to constitutive signaling and eventually development of cancer. While disruption of the Ras/effector interface is an attractive strategy for drug design to prevent this constitutive activity, inhibition of this interaction using small molecules is impractical due to the absence of a cavity to which such molecules could bind. However, proteins and especially natural Ras effectors that bind to the Ras/effector interface with high affinity could disrupt Ras/effector interactions and abolish procancer pathways initiated by Ras oncogene. Using a combination of computational design and in vitro evolution, we engineered high-affinity Ras-binding proteins starting from a natural Ras effector, RASSF5 (NORE1A), which is encoded by a tumor suppressor gene. Unlike previously reported Ras oncogene inhibitors, the proteins we designed not only inhibit Ras-regulated procancer pathways, but also stimulate anticancer pathways initiated by RASSF5. We show that upon introduction into A549 lung carcinoma cells, the engineered RASSF5 mutants decreased cell viability and mobility to a significantly greater extent than WT RASSF5. In addition, these mutant proteins induce cellular senescence by increasing acetylation and decreasing phosphorylation of p53. In conclusion, engineered RASSF5 variants provide an attractive therapeutic strategy able to oppose cancer development by means of inhibiting of procancer pathways and stimulating anticancer processes.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Adenocarcinoma de Pulmão/genética , Proteínas Reguladoras de Apoptose/genética , Neoplasias Pulmonares/genética , Células A549 , Proteínas Adaptadoras de Transdução de Sinal/química , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Adenocarcinoma de Pulmão/metabolismo , Adenocarcinoma de Pulmão/patologia , Proteínas Reguladoras de Apoptose/química , Proteínas Reguladoras de Apoptose/metabolismo , Genes Supressores de Tumor , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Modelos Moleculares , Mutação , Ligação Proteica , Domínios Proteicos , Proteínas ras/genética , Proteínas ras/metabolismo
7.
Int J Biol Macromol ; 187: 988-998, 2021 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-34324905

RESUMO

Mucormycosis is a deadly infection which is caused by fungi of the order Mucorales including species belonging to the genus Rhizopus, Mucor, Mycocladus, Rhizomucor, Cunninghamella, and Apophysomyces. Despite antifungal therapy and surgical procedures, the mortality rate of this disease is about 90-100% which is exceptionally high. The hypersensitivity of patients with raised available serum iron indicates that the Mucorales are able to use host iron as a critical factor of virulence. This is because iron happens to be a crucial element playing its role in the growth of cells and development. In this review, we have described Lactoferrin (Lf) as a potential iron-chelator. Lf is a naturally occurring glycoprotein which is expressed in most of the biological fluids. Moreover, Lf possesses exclusive anti-inflammatory effects along with several anti-fungal effects that could prove to be helpful to the pathological physiology of inexorable mucormycosis cases. This literature summarises the biological insights into the Lf being considered as a potential fungistatic agent and an immune regulator. The review also proposes that unique potential of Lf as an iron-chelator can be exploited as the adjunct treatment for mucormycosis infection.


Assuntos
Antifúngicos/uso terapêutico , Quelantes de Ferro/uso terapêutico , Ferro/metabolismo , Lactoferrina/uso terapêutico , Mucorales/efeitos dos fármacos , Mucormicose/tratamento farmacológico , Animais , Antifúngicos/efeitos adversos , Interações Hospedeiro-Patógeno , Humanos , Quelantes de Ferro/efeitos adversos , Lactoferrina/efeitos adversos , Mucorales/metabolismo , Mucorales/patogenicidade , Mucormicose/diagnóstico , Mucormicose/metabolismo , Mucormicose/microbiologia , Valor Preditivo dos Testes , Fatores de Risco
8.
Bioact Mater ; 6(8): 2231-2249, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33553812

RESUMO

Diabetic peripheral neuropathy (DPN) is a long-term complication associated with nerve dysfunction and uncontrolled hyperglycemia. In spite of new drug discoveries, development of effective therapy is much needed to cure DPN. Here, we have developed a combinatorial approach to provide biochemical and electrical cues, considered to be important for nerve regeneration. Exosomes derived from bone marrow mesenchymal stromal cells (BMSCs) were fused with polypyrrole nanoparticles (PpyNps) containing liposomes to deliver both the cues in a single delivery vehicle. We developed DPN rat model and injected intramuscularly the fused exosomal system to understand its long-term therapeutic effect. We found that the fused system along with electrical stimulation normalized the nerve conduction velocity (57.60 ± 0.45 m/s) and compound muscle action potential (16.96 ± 0.73 mV) similar to healthy control (58.53 ± 1.10 m/s; 18.19 ± 1.45 mV). Gastrocnemius muscle morphology, muscle mass, and integrity were recovered after treatment. Interestingly, we also observed paracrine effect of delivered exosomes in controlling hyperglycemia and loss in body weight and also showed attenuation of damage to the tissues such as the pancreas, kidney, and liver. This work provides a promising effective treatment and also contribute cutting edge therapeutic approach for the treatment of DPN.

9.
Front Cell Infect Microbiol ; 10: 561366, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33102253

RESUMO

Platelets are anucleated blood cells derived from bone marrow megakaryocytes and play a crucial role in hemostasis and thrombosis. Platelets contain specialized storage organelles, called alpha-granules, contents of which are rich in cytokines such as C-X-C Motif Chemokine Ligand (CXCL) 1/4/7, (C-C motif) ligand (CCL) 5/3, CXCL8 (also called as interleukin 8, IL-8), and transforming growth factor ß (TGF-ß). Activation of platelets lead to degranulation and release of contents into the plasma. Platelet activation is a common event in many viral infections including human immunodeficiency virus (HIV), H1N1 influenza, Hepatitis C virus (HCV), Ebola virus (EBV), and Dengue virus (DENV). The cytokines CXCL8, CCL5 (also known as Regulated on Activation, Normal T Expressed and Secreted, RANTES), tumor necrosis factor α (TNF-α), CXCL1/5 and CCL3 released, promote development of a pro-inflammatory state along with the recruitment of other immune cells to the site of infection. Platelets also interact with Monocytes and Neutrophils and facilitate their activation to release different cytokines which further enhances inflammation. Upon activation, platelets also secrete factors such as CXCL4 (also known as platelet factor, PF4), CCL5 and fibrinopeptides which are critical regulators of replication and propagation of several viruses in the host. Studies suggest that CXCL4 can both inhibit as well as enhance HIV1 infection. Data from our lab show that CXCL4 inhibits interferon (IFN) pathway and promotes DENV replication in monocytes in vitro and in patients significantly. Inhibition of CXCL4 mediated signaling results in increased IFN production and suppressed DENV and JEV replication in monocytes. In this review, we discuss the role of platelets in viral disease progression with a focus on dengue infection.


Assuntos
Vírus da Dengue , Dengue , Vírus da Influenza A Subtipo H1N1 , Plaquetas , Citocinas , Humanos
10.
Sci Signal ; 13(653)2020 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-33051258

RESUMO

Small guanosine triphosphatases (GTPases) of the RAS superfamily signal by directly binding to multiple downstream effector proteins. Effectors are defined by a folded RAS-association (RA) domain that binds exclusively to GTP-loaded (activated) RAS, but the binding specificities of most RA domains toward more than 160 RAS superfamily GTPases have not been characterized. Ten RA domain family (RASSF) proteins comprise the largest group of related effectors and are proposed to couple RAS to the proapoptotic Hippo pathway. Here, we showed that RASSF1-6 formed complexes with the Hippo kinase ortholog MST1, whereas RASSF7-10 formed oligomers with the p53-regulating effectors ASPP1 and ASPP2. Moreover, only RASSF5 bound directly to activated HRAS and KRAS, and RASSFs did not augment apoptotic induction downstream of RAS oncoproteins. Structural modeling revealed that expansion of the RASSF effector family in vertebrates included amino acid substitutions to key residues that direct GTPase-binding specificity. We demonstrated that the tumor suppressor RASSF1A formed complexes with the RAS-related GTPases GEM, REM1, REM2, and the enigmatic RASL12. Furthermore, interactions between RASSFs and RAS GTPases blocked YAP1 nuclear localization. Thus, these simple scaffolds link the activation of diverse RAS family small G proteins to Hippo or p53 regulation.


Assuntos
Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Proteínas de Transporte Vesicular/metabolismo , Proteínas ras/metabolismo , Sequência de Aminoácidos , Apoptose/genética , Cálcio/metabolismo , Linhagem Celular Tumoral , Células HEK293 , Células HeLa , Via de Sinalização Hippo , Humanos , Microscopia Confocal , Microtúbulos/metabolismo , Ligação Proteica , Domínios Proteicos , Proteínas Serina-Treonina Quinases/genética , Homologia de Sequência de Aminoácidos , Transdução de Sinais/genética , Proteínas Supressoras de Tumor/química , Proteínas Supressoras de Tumor/genética , Proteínas de Transporte Vesicular/química , Proteínas de Transporte Vesicular/genética , Proteínas ras/genética
11.
Appl Microbiol Biotechnol ; 104(18): 7801-7814, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32761464

RESUMO

The methylotrophic yeast Komagataella phaffii is among the most popular hosts for recombinant protein synthesis. Most recombinant proteins have been expressed in the wild-type Mut+ host strain from the methanol-inducible alcohol oxidase (AOX) promoter PAOX1. Since methanol metabolism has undesirable consequences, two additional host strains, Muts (Δaox1) and Mut- (Δaox1Δaox2), were introduced which consume less methanol and reportedly also express recombinant protein better than Mut+. Both results follow from a simple model based on two widespread assumptions, namely methanol is transported by diffusion and the sole inducer of PAOX1. To test this model, we studied 14C-methanol uptake in the Mut- strain and ß-galactosidase expression in all three strains. We confirmed that methanol is transported by diffusion, but in contrast to the literature, Mut+ expressed ß-galactosidase 5- and 10-fold faster than Muts and Mut-. These results imply that methanol is not the sole inducer of PAOX1-metabolites downstream of methanol also induce PAOX1. We find that formate or/and formaldehyde are probably true inducers since both induce PAOX1 expression in Mut- which cannot synthesize intracellular methanol from formate or formaldehyde. Formate offers a promising substitute for methanol since it does not appear to suffer from the deficiencies that afflict methanol. KEY POINTS: • This is the first study to systematically compare all three Mut phenotypes as host strains. • Mut+ strain expresses 5- and 10-fold faster than Muts and Mut- strains. • Methanol is transported by diffusion in Komagataella phaffii. • Formate and formaldehyde are true and strong inducers of PAOX1 expression.


Assuntos
Metanol , Pichia , Formaldeído , Formiatos , Pichia/genética , Proteínas Recombinantes/genética , Saccharomycetales
12.
Biomaterials ; 249: 120020, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32305816

RESUMO

Lack of oxygen, reduced vascularization, elevated oxidative stress, and infection are critical clinical hallmarks of non-healing chronic diabetic wounds. Therefore, delivering oxygen, inducing angiogenesis, and management of oxidative stress and infection may provide newer and improved therapeutic avenues for better clinical outcomes in diabetic wound healing. Here, we report the development and evaluation of an exosome laden oxygen releasing antioxidant wound dressing OxOBand to promote wound closure and skin regeneration in diabetic wounds. OxOBand is composed of antioxidant polyurethane (PUAO), as highly porous cryogels with sustained oxygen releasing properties and supplemented with adipose-derived stem cells (ADSCs) exosomes. Exosomes engulfed by the cells enhanced the migration of human keratinocytes and fibroblasts and increased the survival of human neuroblastoma cells under hyperglycemic conditions. OxOBand facilitated faster wound closure, enhanced collagen deposition, faster re-epithelialization, increased neo-vascularization, and decreased oxidative stress within two weeks as compared to untreated diabetic control wounds. The dressing promoted the development of mature epithelial structures with hair follicles and epidermal morphology similar to that of healthy skin. In clinically challenging infected diabetic wounds, these dressings prevented infection and ulceration, improved wound healing with increased collagen deposition, and re-epithelialization. Altogether, OxOBand is a remarkably newer treatment strategy for enhanced diabetic wound healing and may lead to novel therapeutic interventions for the treatment of diabetic ulcers.


Assuntos
Diabetes Mellitus , Exossomos , Antibacterianos , Antioxidantes , Bandagens , Criogéis , Humanos , Oxigênio , Cicatrização
13.
J Obstet Gynaecol Res ; 46(5): 791-794, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32043297

RESUMO

Broad ligament is the common extrauterine site for fibroid. We present a case of huge broad ligament fibroid with cystic degeneration. Patient presented with abdominal swelling and mild pain abdomen. On abdominal examination, a large tense cystic mass of 34 weeks gravid uterus size arising from pelvis was noted. Cervix was pulled up and all fornices were full with mass on pelvic examination. Ultrasound suggested adnexal mass as ovaries were not seen. Contrast-enhanced computed tomography abdomen too reported adnexal mass likely of ovarian origin. On laparotomy, 6 L of straw color fluid drained from the mass which was seen arising from left broad ligament, bilateral ovaries were separate from the mass and appeared healthy. Enucleation of mass was done to ease the hysterectomy and careful evaluation of ureteric course was done throughout the surgery to avoid its injury. Total hysterectomy with bilateral salpingo-opherectomy and pelvic lymphadenectomy was performed. This case is being reported for its rare incidence, diagnostic dilemma and surgical challenge.


Assuntos
Ligamento Largo/patologia , Leiomioma/patologia , Neoplasias Pélvicas/patologia , Adulto , Ligamento Largo/cirurgia , Diagnóstico Diferencial , Feminino , Humanos , Histerectomia/métodos , Leiomioma/diagnóstico , Leiomioma/cirurgia , Neoplasias Ovarianas/diagnóstico , Neoplasias Pélvicas/diagnóstico , Neoplasias Pélvicas/cirurgia , Salpingo-Ooforectomia/métodos , Tomografia Computadorizada por Raios X , Ultrassonografia
14.
Appl Opt ; 58(27): 7280-7284, 2019 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-31674371

RESUMO

Analytical expressions of electric field radiation pattern, coupling sensitivity, and scattering parameters of vertical grating couplers have been derived in this paper. Excellent agreement has been found between these expressions, finite element method (FEM) simulations, and experimental results. The results give an insight on how to design vertical grating couplers and reduce the number of iterations while designing and efficiently aligning the fiber over the chip without carrying out time-consuming electromagnetic simulations for the couplers.

15.
J Biol Chem ; 294(21): 8336-8347, 2019 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-30979723

RESUMO

Primary hyperparathyroidism (PHPT) is a common endocrinopathy characterized by hypercalcemia and elevated levels of parathyroid hormone. The primary cause of PHPT is a benign overgrowth of parathyroid tissue causing excessive secretion of parathyroid hormone. However, the molecular etiology of PHPT is incompletely defined. Here, we demonstrate that semaphorin3d (Sema3d), a secreted glycoprotein, is expressed in the developing parathyroid gland in mice. We also observed that genetic deletion of Sema3d leads to parathyroid hyperplasia, causing PHPT. In vivo and in vitro experiments using histology, immunohistochemistry, biochemical, RT-qPCR, and immunoblotting assays revealed that Sema3d inhibits parathyroid cell proliferation by decreasing the epidermal growth factor receptor (EGFR)/Erb-B2 receptor tyrosine kinase (ERBB) signaling pathway. We further demonstrate that EGFR signaling is elevated in Sema3d-/- parathyroid glands and that pharmacological inhibition of EGFR signaling can partially rescue the parathyroid hyperplasia phenotype. We propose that because Sema3d is a secreted protein, it may be possible to use recombinant Sema3d or derived peptides to inhibit parathyroid cell proliferation causing hyperplasia and hyperparathyroidism. Collectively, these findings identify Sema3d as a negative regulator of parathyroid growth.


Assuntos
Proliferação de Células , Hiperparatireoidismo Primário/epidemiologia , Glândulas Paratireoides/embriologia , Semaforinas/deficiência , Transdução de Sinais , Animais , Receptores ErbB/genética , Receptores ErbB/metabolismo , Hiperparatireoidismo Primário/genética , Hiperparatireoidismo Primário/patologia , Camundongos , Camundongos Knockout , Glândulas Paratireoides/patologia , Semaforinas/metabolismo
16.
Curr Top Med Chem ; 19(5): 337-355, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30806318

RESUMO

Tuberculosis (TB) still continues to be a major killer disease worldwide. Unlike other bacteria Mycobacterium tuberculosis (Mtb) has the ability to become dormant within the host and to develop resistance. Hence efforts are being made to overcome these problems by searching for new antitubercular agents which may be useful in the treatment of multidrug-(MDR) and extensively drugresistant (XDR) M. tuberculosis and shortening the treatment time. The recent introduction of bedaquiline to treat MDR-TB and XDR-TB may improve the status of TB treatment. The target enzymes in anti-TB drug discovery programs play a key role, hence efforts have been made to review the work on molecules including antiTB drugs acting on different enzyme targets including ATP synthase, the target for bedaquiline. Literature searches have been carried out to find the different chemical molecules including drugs and their molecular targets responsible for their antitubercular activities in recent years. This review provides an overview of the chemical structures with their antitubercular activities and enzyme targets like InhA, ATP synthase, Lip Y, transmembrane transport protein large (MmpL3), and decaprenylphospho-ß-D-ribofuranose 2-oxidase, (DprE1). The major focus has been on the new target ATP synthase. Such an attempt may be useful in designing new chemical entities (NCEs) for specific and multi-drug targeting against Mtb.


Assuntos
Antituberculosos/farmacologia , Inibidores Enzimáticos/farmacologia , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/enzimologia , Adenosina Trifosfatases/antagonistas & inibidores , Adenosina Trifosfatases/metabolismo , Antituberculosos/química , Sistemas de Liberação de Medicamentos , Inibidores Enzimáticos/química , Testes de Sensibilidade Microbiana , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia
17.
ACS Biomater Sci Eng ; 5(6): 3007-3021, 2019 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-33405655

RESUMO

With the advances in tissue engineering and regenerative medicine, various approaches have been developed for peripheral nerve tissue repair and regeneration. In the current study, we have synthesized a cryogel matrix from chitosan and gelatin incorporated with polypyrrole for neural tissue regeneration. The three-dimensional (3-D) cryogel matrix was fabricated to mimic the in vivo microenvironment and analyzed for stem cell differentiation. Isolated bone marrow stem cells (BMSCs) cultured on a 3-D cryogel matrix differentiated into neural lineage on the basis of scaffold properties, in a co-culture system and by treatment with the spent media of Neuro 2a cells. To validate the cell-cell contact and BMSCs differentiation, scanning electron micrography and fluorescent imaging were done, which revealed the differentiation of the BMSCs. Immunostaining and gene expression analysis showed the BMSCs differentiation in all of the three cases studied. However, BMSCs in the co-culture system showed increased neurotransmitter levels of dopamine (34%) and acetylcholine (16%) with a respective concentration of 2.04 ± 0.03 ng/mL and 15.06 ± 0.19 pg/mL. Based on these properties, an in vivo study explored the potential of the synthesized cryogel in regeneration of a 1.5 cm nerve gap in the sciatic nerve of rats for a period of 12 weeks. The biocompatibility analysis showed that the scaffold did not induce any adverse immune response. Moreover, the walking track analysis and electrophysiological and immunostaining analyses revealed enhanced sciatic nerve regeneration in comparison to the negative control group. This study reveals the regenerative potential of the cryogel matrix for peripheral nerve regeneration.

18.
Biomacromolecules ; 20(2): 662-673, 2019 02 11.
Artigo em Inglês | MEDLINE | ID: mdl-30354073

RESUMO

Recent trends in peripheral nerve regeneration are directed toward the development of nerve guidance channels to assist the regeneration of the nerves across critical size defects. Advanced nerve guidance channels (aNGCs) should possess multifunctional properties to direct the axonal regeneration from proximal to distal end, allow the concentration of growth factors secreted by the injured nerve end, and attenuate the ingrowth of scar tissue at the site of injury. The design of the nerve guidance channel (NGC) is critical for providing the necessary topographical, chemotactic, as well as haptotactic cues for efficient nerve regeneration. In this study, we have designed and fabricated clinically relevant aNGCs comprising an antioxidant polyurethane (PUAO) conduit filled with aligned chitosan-gelatin (CG) cryogel filler for peripheral nerve regeneration. The effects of temperature, polymer concentration, and cross-linker concentration on the physicochemical properties of the CG cryogel filler were studied. The synthesized scaffolds were evaluated by scanning electron microscopy (SEM) and compression testing to obtain the matrix best suited to form the aNGC. The nanofibrous PUAO conduit was fabricated by electrospinning with a wall thickness of 114.16 ± 26.91 µm, which was filled with CG (1.2/6.4%)-aligned cryogel matrix to obtain the aNGCs. The aNGCs with 2.01 ± 0.04 mm internal diameter, 15 mm length, and internal CG filler with a pore diameter of 29.60 ± 9.83 µm were fabricated. The aNGCs were evaluated by SEM and in vitro neuronal culture for biocompatibility and cellular alignment. In vitro dorsal root ganglion cultures showed the aligned growth and cellular migration along the aligned pores of aNGCs. With this study, we conclude that this clinically relevant aligned porous aNGC will have a promising effect in repair and regeneration of peripheral nerve injuries.


Assuntos
Quitosana/análogos & derivados , Criogéis/química , Gelatina/química , Regeneração Nervosa , Poliuretanos/química , Engenharia Tecidual/métodos , Animais , Linhagem Celular Tumoral , Células Cultivadas , Camundongos , Nanocompostos/química , Ratos , Alicerces Teciduais/química
19.
Protein Pept Lett ; 25(12): 1090-1100, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30457042

RESUMO

Peptides are recognized as highly specific and efficacious molecules, thus have found increasing use in developing therapeutics in recent years. It has also been realized that pathophyisology of diseases are very complex and targeting multiple pathways often result in better outcome. The therapeutic potential of a single entity multifunctional peptides that act on two or more distinct receptors with the complementary mechanism of action to gain additive or synergistic benefit compared to monotherapy has been exploited in various disease areas. Herein, we reviewed the therapeutic potential of multifunctional peptides with examples from the field of metabolic, cardiovascular and neuropathic pain disease.


Assuntos
Peptídeos/síntese química , Peptídeos/uso terapêutico , Animais , Doenças Cardiovasculares/tratamento farmacológico , Desenho de Fármacos , Avaliação Pré-Clínica de Medicamentos , Reposicionamento de Medicamentos , Humanos , Síndrome Metabólica/tratamento farmacológico , Neuralgia/tratamento farmacológico , Peptídeos/química
20.
J Med Chem ; 61(8): 3738-3744, 2018 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-29578343

RESUMO

ß-Defensin 3 (BD3) was identified as a ligand for the melanocortin receptors (MCRs) in 2007, although the pharmacology activity of BD3 has not been clearly elucidated. Herein, it is demonstrated that human BD3 and mouse BD3 are full micromolar agonists at the MCRs. Furthermore, mouse ß-defensin 1 (BD1) and human BD1 are also MCR micromolar agonists. This work identifies BD1 as an endogenous MCR ligand and clarifies the controversial role of BD3 as a micromolar agonist.


Assuntos
Receptores de Melanocortina/agonistas , beta-Defensinas/farmacologia , Sequência de Aminoácidos , Animais , AMP Cíclico/metabolismo , Humanos , Ligantes , Masculino , Camundongos Endogâmicos C57BL , Receptores de Melanocortina/metabolismo , beta-Defensinas/metabolismo
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