Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 164
Filtrar
1.
Cells ; 13(11)2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38891089

RESUMO

Inflammatory bowel disease (IBD) is a chronic gut disorder that also elevates the risk of colorectal cancer (CRC). The global incidence and severity of IBD are rising, yet existing therapies often lead to severe side effects. Curcumin offers potent anti-inflammatory and chemotherapeutic properties. However, its clinical translation is hindered by rapid metabolism, as well as poor water solubility and stability, which limits its bioavailability. To address these challenges, we developed OC-S, a water-soluble and colon-targeted curcumin formulation that protects against colitis in mice. The current study advances OC-S as a dietary supplement by establishing its stability and compatibility with various commercial dietary products. Further, OC-S exhibited specific binding to inflamed colon tissue, potentially aiding in targeted drug retention at the inflammation site in colitis with diarrhea symptoms. We further investigated its efficacy in vivo and in vitro using a murine model of colitis and tumoroids from APCmin mice. OC-S significantly reduced colitis severity and pro-inflammatory cytokine expression compared with curcumin, even at very low doses (5 mg/kg/day). It also demonstrated higher anti-proliferative activity in CRC cells and colon cancer tumoroids vs. curcumin. Overall, this study demonstrated that OC-S effectively targets and retains water-soluble curcumin at the inflamed colon sites, while showing promise in addressing both colitis and colorectal cancer, which potentially paves the way for OC-S to advance into clinical development as a dietary product for both IBD and CRC.


Assuntos
Colite , Neoplasias Colorretais , Curcumina , Animais , Curcumina/farmacologia , Curcumina/uso terapêutico , Neoplasias Colorretais/patologia , Neoplasias Colorretais/tratamento farmacológico , Colite/tratamento farmacológico , Colite/patologia , Colite/induzido quimicamente , Camundongos , Humanos , Camundongos Endogâmicos C57BL , Modelos Animais de Doenças , Proliferação de Células/efeitos dos fármacos , Suplementos Nutricionais , Masculino , Substâncias Protetoras/farmacologia
2.
Exp Hematol ; : 104247, 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38848877

RESUMO

Hematopoietic stem cells (HSCs) adapt to organismal blood production needs by balancing self-renewal and differentiation, adjusting to physiological demands and external stimuli. Although sex differences have been implicated in differential hematopoietic function in males versus females, the mediators responsible for these effects require further study. Here, we characterized hematopoiesis at a steady state and during regeneration following hematopoietic stem cell transplantation (HST). RNA sequencing of lineage(-) bone marrow cells from C57/Bl6 mice revealed a broad transcriptional similarity between the sexes. However, we identified distinct sex differences in key biological pathways, with female cells showing reduced expression of signatures involved in inflammation and enrichment of genes related to glycolysis, hypoxia, and cell cycle regulation, suggesting a more quiescent and less inflammatory profile compared with male cells. To determine the functional impacts of the observed transcriptomic differences, we performed sex-matched and mismatched transplantation studies of lineage(-) donor cells. During short-term 56-day HST recovery, we found a male donor cell proliferative advantage, coinciding with elevated serum TNF-α, and a male recipient engraftment advantage, coinciding with increased serum CXCL12. Together, we show that sex-specific cell responses, marked by differing expression of pathways regulating metabolism, hypoxia, and inflammation, shape normal and regenerative hematopoiesis, with implications for the clinical understanding of hematopoietic function.

3.
Artigo em Inglês | MEDLINE | ID: mdl-38771154

RESUMO

Microtubule-associated serine-threonine kinase-like (MASTL) has recently been identified as a oncogenic kinase given its overexpression in numerous cancers. Our group has shown that MASTL expression is upregulated in mouse models of sporadic CRC and colitis associated cancer (CAC). CAC is one of the most severe complications of chronic IBD, but a limited understanding of the mechanisms governing the switch from normal healing to neoplasia in IBD underscores the need for increased research in this area. However, MASTL expression in IBD patients and its molecular regulation in IBD and CAC have not been studied. This study reveals that MASTL is upregulated by the cytokine interleukin (IL)-22, which promotes proliferation and has important functions in colitis recovery; however, IL-22 can also promote tumorigenesis when chronically elevated. Upon reviewing the publicly available data, we found significantly elevated MASTL and IL-22 levels in the biopsies from late-stage ulcerative colitis patients compared to controls, and that MASTL upregulation was associated with high IL-22 expression. Our subsequent in vitro studies found that IL-22 increases MASTL expression in intestinal epithelial cell lines, facilitating IL-22- mediated cell proliferation and downstream survival signaling. Inhibition of AKT activation abrogated IL-22-induced MASTL upregulation. We further found an increased association of carbonic anhydrase IX (CAIX) with MASTL in IL-22-treated cells, which stabilized MASTL expression. Inhibition of CAIX prevented IL-22-induced MASTL expression and cell survival. Overall, we show that IL-22/AKT signaling increases MASTL expression to promote cell survival and proliferation. Further, CAIX stabilizes MASTL by associating with it in response to IL-22 stimulation.

4.
Nat Chem Biol ; 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38528120

RESUMO

Exportin-1 (XPO1/CRM1) plays a central role in the nuclear-to-cytoplasmic transport of hundreds of proteins and contributes to other cellular processes, such as centrosome duplication. Small molecules targeting XPO1 induce cytotoxicity, and selinexor was approved by the Food and Drug Administration in 2019 as a cancer chemotherapy for relapsed multiple myeloma. Here, we describe a cell-type-dependent chromatin-binding function for XPO1 that is essential for the chromatin occupancy of NFAT transcription factors and thus the appropriate activation of T cells. Additionally, we establish a class of XPO1-targeting small molecules capable of disrupting the chromatin binding of XPO1 without perturbing nuclear export or inducing cytotoxicity. This work defines a broad transcription regulatory role for XPO1 that is essential for T cell activation as well as a new class of XPO1 modulators to enable therapeutic targeting of XPO1 beyond oncology including in T cell-driven autoimmune disorders.

5.
Br J Cancer ; 130(6): 1046-1058, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38278978

RESUMO

BACKGROUND: The repurposing of FDA-approved drugs for anti-cancer therapies is appealing due to their established safety profiles and pharmacokinetic properties and can be quickly moved into clinical trials. Cancer progression and resistance to conventional chemotherapy remain the key hurdles in improving the clinical management of colon cancer patients and associated mortality. METHODS: High-throughput screening (HTS) was performed using an annotated library of 1,600 FDA-approved drugs to identify drugs with strong anti-CRC properties. The candidate drug exhibiting most promising inhibitory effects in in-vitro studies was tested for its efficacy using in-vivo models of CRC progression and chemoresistance and patient derived organoids (PTDOs). RESULTS: Albendazole, an anti-helminth drug, demonstrated the strongest inhibitory effects on the tumorigenic potentials of CRC cells, xenograft tumor growth and organoids from mice. Also, albendazole sensitized the chemoresistant CRC cells to 5-fluorouracil (5-FU) and oxaliplatin suggesting potential to treat chemoresistant CRC. Mechanistically, Albendazole treatment modulated the expression of RNF20, to promote apoptosis in CRC cells by delaying the G2/M phase and suppressing anti-apoptotic-Bcl2 family transcription. CONCLUSIONS: Albendazole, an FDA approved drug, carries strong therapeutic potential to treat colon cancers which are aggressive and potentially resistant to conventional chemotherapeutic agents. Our findings also lay the groundwork for further clinical testing.


Assuntos
Neoplasias do Colo , Neoplasias Colorretais , Humanos , Animais , Camundongos , Albendazol/farmacologia , Albendazol/uso terapêutico , Neoplasias Colorretais/patologia , Ubiquitina/farmacologia , Ubiquitina/uso terapêutico , Resistencia a Medicamentos Antineoplásicos , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/genética , Fluoruracila/uso terapêutico , Apoptose , Linhagem Celular Tumoral , Proliferação de Células , Ubiquitina-Proteína Ligases
6.
Cancer Lett ; 579: 216479, 2023 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-37924938

RESUMO

Therapy resistance is the primary problem in treating late-stage colorectal cancer (CRC). Claudins are frequently dysregulated in cancer, and several are being investigated as novel therapeutic targets and biomarkers. We have previously demonstrated that Claudin-1 (CLDN1) expression in CRC promotes epithelial-mesenchymal transition, metastasis, and resistance to anoikis. Here, we hypothesize that CLDN1 promotes cancer stemness and chemoresistance in CRC. We found that high CLDN1 expression in CRC is associated with cancer stemness and chemoresistance signaling pathways in patient datasets, and it promotes chemoresistance both in vitro and in vivo. Using functional stemness assays, proteomics, biophysical binding assays, and patient-derived organoids, we found that CLDN1 promotes properties of cancer stemness including CD44 expression, tumor-initiating potential, and chemoresistance through a direct interaction with ephrin type-A receptor 2 (EPHA2) tyrosine kinase. This interaction is dependent on the CLDN1 PDZ-binding motif, increases EPHA2 protein expression by inhibiting its degradation, and enhances downstream AKT signaling and CD44 expression to promote stemness and chemoresistance. These results suggest CLDN1 is a viable target for pharmacological intervention and/or biomarker development.


Assuntos
Neoplasias Colorretais , Humanos , Linhagem Celular Tumoral , Claudina-1/genética , Claudina-1/metabolismo , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Resistencia a Medicamentos Antineoplásicos , Regulação Neoplásica da Expressão Gênica , Transdução de Sinais
7.
Gut Microbes ; 15(2): 2282789, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38010872

RESUMO

Dysregulation of both the gut barrier and microbiota (dysbiosis) promotes susceptibility to and severity of Inflammatory Bowel Diseases (IBD). Leaky gut and dysbiosis often coexist; however, potential interdependence and molecular regulation are not well understood. Robust expression of claudin-3 (CLDN3) characterizes the gut epithelium, and studies have demonstrated a positive association between CLDN3 expression and gut barrier maturity and integrity, including in response to probiotics. However, the exact status and causal role of CLDN3 in IBD and regulation of gut dysbiosis remain unknown. Analysis of mouse and human IBD cohorts helped examine CLDN3 expression in IBD. The causal role was determined by modeling CLDN3 loss of expression during experimental colitis. 16S sequencing and in silico analysis helped examine gut microbiota diversity between Cldn3KO and WT mice and potential host metabolic responses. Fecal microbiota transplant (FMT) studies were performed to assess the role of gut dysbiosis in the increased susceptibility of Cldn3KO mice to colitis. A significant decrease in CLDN3 expression characterized IBD and CLDN3 loss of expression promoted colitis. 16S sequencing analysis suggested gut microbiota changes in Cldn3KO mice that were capable of modulating fatty acid metabolism and oxidative stress response. FMT from naïve Cldn3KO mice promoted colitis susceptibility in recipient germ-free mice (GFM) compared with GFM-receiving microbiota from WT mice. Our data demonstrate a critical role of CLDN3 in maintaining normal gut microbiota and inflammatory responses, which can be harnessed to develop novel therapeutic opportunities for patients with IBD.


Assuntos
Claudina-3 , Colite , Microbioma Gastrointestinal , Doenças Inflamatórias Intestinais , Humanos , Claudina-3/genética , Colite/genética , Colite/complicações , Disbiose/complicações , Transplante de Microbiota Fecal , Doenças Inflamatórias Intestinais/complicações , Animais , Camundongos
8.
Biol Psychiatry Glob Open Sci ; 3(4): 824-836, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37881577

RESUMO

Background: Posttraumatic stress disorder (PTSD) is a mental health condition triggered by exposure to traumatic events in an individual's life. Patients with PTSD are also at a higher risk for comorbidities. However, it is not well understood how PTSD affects human health and/or promotes the risk for comorbidities. Nevertheless, patients with PTSD harbor a proinflammatory milieu and dysbiotic gut microbiota. Gut barrier integrity helps to maintain normal gut homeostasis and its dysregulation promotes gut dysbiosis and inflammation. Methods: We used a mouse model of repeated social defeat stress (RSDS), a preclinical model of PTSD. Behavioral studies, metagenomics analysis of the microbiome, gut permeability assay (on mouse colon, using an Ussing chamber), immunoblotting, and immunohistochemical analyses were performed. Polarized intestinal epithelial cells and 3-dimensional crypt cultures were used for mechanistic analysis. Results: The RSDS mice harbor a heightened proinflammatory gut environment and microbiota dysbiosis. The RSDS mice further showed significant dysregulation of gut barrier functions, including transepithelial electrical resistance, mucin homeostasis, and antimicrobial responses. RSDS mice also showed a specific increase in intestinal expression of claudin-2, a tight junction protein, and epinephrine, a stress-induced neurotransmitter. Treating intestinal epithelial cells or 3-dimensional cultured crypts with norepinephrine or intestinal luminal contents (fecal contents) upregulated claudin-2 expression and inhibited transepithelial electrical resistance. Conclusions: Traumatic stress induces dysregulation of gut barrier functions, which may underlie the observed gut microbiota changes and proinflammatory gut milieu, all of which may have an interdependent effect on the health and increased risk of comorbidities in patients with PTSD.

9.
J Clin Invest ; 133(23)2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37815870

RESUMO

Patients with inflammatory bowel disease (IBD) are susceptible to colitis-associated cancer (CAC). Chronic inflammation promotes the risk for CAC. In contrast, mucosal healing predicts improved prognosis in IBD and reduced risk of CAC. However, the molecular integration among colitis, mucosal healing, and CAC remains poorly understood. Claudin-2 (CLDN2) expression is upregulated in IBD; however, its role in CAC is not known. The current study was undertaken to examine the role for CLDN2 in CAC. The AOM/DSS-induced CAC model was used with WT and CLDN2-modified mice. High-throughput expression analyses, murine models of colitis/recovery, chronic colitis, ex vivo crypt culture, and pharmacological manipulations were employed in order to increase our mechanistic understanding. The Cldn2KO mice showed significant inhibition of CAC despite severe colitis compared with WT littermates. Cldn2 loss also resulted in impaired recovery from colitis and increased injury when mice were subjected to intestinal injury by other methods. Mechanistic studies demonstrated a possibly novel role of CLDN2 in promotion of mucosal healing downstream of EGFR signaling and by regulation of Survivin expression. An upregulated CLDN2 expression protected from CAC and associated positively with crypt regeneration and Survivin expression in patients with IBD. We demonstrate a potentially novel role of CLDN2 in promotion of mucosal healing in patients with IBD and thus regulation of vulnerability to colitis severity and CAC, which can be exploited for improved clinical management.


Assuntos
Neoplasias Associadas a Colite , Colite , Doenças Inflamatórias Intestinais , Animais , Humanos , Camundongos , Claudina-2/genética , Claudina-2/metabolismo , Colite/induzido quimicamente , Colite/complicações , Colite/genética , Neoplasias Associadas a Colite/complicações , Neoplasias Associadas a Colite/metabolismo , Sulfato de Dextrana/toxicidade , Modelos Animais de Doenças , Doenças Inflamatórias Intestinais/complicações , Doenças Inflamatórias Intestinais/genética , Doenças Inflamatórias Intestinais/metabolismo , Mucosa Intestinal/metabolismo , Camundongos Endogâmicos C57BL , Survivina/metabolismo
10.
Cells ; 12(14)2023 07 18.
Artigo em Inglês | MEDLINE | ID: mdl-37508547

RESUMO

BACKGROUND: Despite significant progress in clinical management, colorectal cancer (CRC) remains the third most common cause of cancer-related deaths. A positive association between PYCR2 (pyrroline-5-carboxylate reductase-2), a terminal enzyme of proline metabolism, and CRC aggressiveness was recently reported. However, how PYCR2 promotes colon carcinogenesis remains ill understood. METHODS: A comprehensive analysis was performed using publicly available cancer databases and CRC patient cohorts. Proteomics and biochemical evaluations were performed along with genetic manipulations and in vivo tumor growth assays to gain a mechanistic understanding. RESULTS: PYCR2 expression was significantly upregulated in CRC and associated with poor patient survival, specifically among PYCR isoforms (PYCR1, 2, and 3). The genetic inhibition of PYCR2 inhibited the tumorigenic abilities of CRC cells and in vivo tumor growth. Coinciding with these observations was a significant decrease in cellular proline content. PYCR2 overexpression promoted the tumorigenic abilities of CRC cells. Proteomics (LC-MS/MS) analysis further demonstrated that PYCR2 loss of expression in CRC cells inhibits survival and cell cycle pathways. A subsequent biochemical analysis supported the causal role of PYCR2 in regulating CRC cell survival and the cell cycle, potentially by regulating the expression of MASTL, a cell-cycle-regulating protein upregulated in CRC. Further studies revealed that PYCR2 regulates Wnt/ß-catenin-signaling in manners dependent on the expression of MASTL and the cancer stem cell niche. CONCLUSIONS: PYCR2 promotes MASTL/Wnt/ß-catenin signaling that, in turn, promotes cancer stem cell populations and, thus, colon carcinogenesis. Taken together, our data highlight the significance of PYCR2 as a novel therapeutic target for effectively treating aggressive colon cancer.


Assuntos
Neoplasias do Colo , Proteínas Serina-Treonina Quinases , Humanos , Proteínas Serina-Treonina Quinases/metabolismo , beta Catenina/metabolismo , Cromatografia Líquida , Espectrometria de Massas em Tandem , Carcinogênese , Via de Sinalização Wnt/genética , Microtúbulos/metabolismo , Prolina , Oxirredutases/metabolismo , Serina , Proteínas Associadas aos Microtúbulos/metabolismo
11.
Commun Biol ; 6(1): 740, 2023 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-37460613

RESUMO

Impaired autophagy promotes Inflammatory Bowel Disease (IBD). Claudin-2 is upregulated in IBD however its role in the pathobiology remains uncertain due to its complex regulation, including by autophagy. Irrespective, claudin-2 expression protects mice from DSS colitis. This study was undertaken to examine if an interplay between autophagy and claudin-2 protects from colitis and associated epithelial injury. Crypt culture and intestinal epithelial cells (IECs) are subjected to stress, including starvation or DSS, the chemical that induces colitis in-vivo. Autophagy flux, cell survival, co-immunoprecipitation, proximity ligation assay, and gene mutational studies are performed. These studies reveal that under colitis/stress conditions, claudin-2 undergoes polyubiquitination and P62/SQSTM1-assisted degradation through autophagy. Inhibiting autophagy-mediated claudin-2 degradation promotes cell death and thus suggest that claudin-2 degradation promotes autophagy flux to promote cell survival. Overall, these data inform for the previously undescribed role for claudin-2 in facilitating IECs survival under stress conditions, which can be harnessed for therapeutic advantages.


Assuntos
Colite , Doenças Inflamatórias Intestinais , Camundongos , Animais , Claudina-2/metabolismo , Proteína Sequestossoma-1/genética , Proteína Sequestossoma-1/metabolismo , Mucosa Intestinal/metabolismo , Colite/metabolismo , Autofagia/fisiologia , Doenças Inflamatórias Intestinais/metabolismo
12.
Cancer Discov ; 13(9): 2090-2105, 2023 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-37378557

RESUMO

Sex differences in glioblastoma (GBM) incidence and outcome are well recognized, and emerging evidence suggests that these extend to genetic/epigenetic and cellular differences, including immune responses. However, the mechanisms driving immunologic sex differences are not fully understood. Here, we demonstrate that T cells play a critical role in driving GBM sex differences. Male mice exhibited accelerated tumor growth, with decreased frequency and increased exhaustion of CD8+ T cells in the tumor. Furthermore, a higher frequency of progenitor exhausted T cells was found in males, with improved responsiveness to anti-PD-1 treatment. Moreover, increased T-cell exhaustion was observed in male GBM patients. Bone marrow chimera and adoptive transfer models indicated that T cell-mediated tumor control was predominantly regulated in a cell-intrinsic manner, partially mediated by the X chromosome inactivation escape gene Kdm6a. These findings demonstrate that sex-biased predetermined behavior of T cells is critical for inducing sex differences in GBM progression and immunotherapy response. SIGNIFICANCE: Immunotherapies in patients with GBM have been unsuccessful due to a variety of factors, including the highly immunosuppressive tumor microenvironment in GBM. This study demonstrates that sex-biased T-cell behaviors are predominantly intrinsically regulated, further suggesting sex-specific approaches can be leveraged to potentially improve the therapeutic efficacy of immunotherapy in GBM. See related commentary by Alspach, p. 1966. This article is featured in Selected Articles from This Issue, p. 1949.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Masculino , Feminino , Camundongos , Animais , Glioblastoma/genética , Exaustão das Células T , Linfócitos T CD8-Positivos , Imunoterapia , Imunidade , Neoplasias Encefálicas/patologia , Microambiente Tumoral
13.
J Assoc Physicians India ; 71(5): 11-12, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37355825

RESUMO

Dermatophytosis is a very common public health problem with high prevalence. Dermatophytes are a highly specialized set of filamentous fungi, which are adapted to keratinized tissues of humans and animals. Dermatophytosis is the most common fungal infection worldwide, affecting approximately 20-25% of the world's population. The etiological agents of dermatophytosis, called dermatophytes, change with geography and socioeconomic status. Trichophyton rubrum (T. rubrum) is the prime species for skin and nail infections followed by T. mentagrophytes/ T. interdigital complex. There is a shift from T. rubrum to T. mentagrophytes in India for superficial fungal infections. In order to deal with fungal infections, treatment strategies involve the use of systemic antifungals and/or topical antifungal agents. Naftifine is a synthetic allylamine antifungal first reported in 1974 and in 1985 became the first commercially available allylamine. The highly lipophilic nature of allylamine allows efficient penetration and reasonably high concentrations in the stratum corneum (SC) and hair follicles. Naftifine is fungicidal as well as fungistatic. The higher efficacy rates of allylamines over imidazoles for the treatment of fungal infections, even for months after cessation of treatment, is thought to be due to their fungicidal effect, as well as to potentially greater keratin binding and slower release from the SC. The effectiveness of naftifine is also demonstrated against various bacteria belonging to both gram-negative and gram-positive classes. The antiinflammatory property of naftifine has been reported in various preclinical studies where it has been shown to target the prostaglandin pathway. Naftifine 1 and 2% gel and cream is approved by The United States Food and Drug Administration (USFDA), recently naftifine has been approved in India by the Indian regulatory authority Drug Controller General of India (DCGI) for the treatment of dermatophytosis. Naftifine 2% also appears to be a promising treatment, requiring fewer applications than the 1% formulation. Naftifine appears to be effective in a single dose and has a shorter treatment duration than azoles. Naftifine demonstrated its efficacy and safety in various clinical studies of tinea infections. Naftifine offers a very useful and promising option for treating dermatophytosis.


Assuntos
Alilamina , Dermatomicoses , Tinha , Humanos , Alilamina/uso terapêutico , Alilamina/metabolismo , Pele , Dermatomicoses/tratamento farmacológico , Antifúngicos/uso terapêutico , Tinha/tratamento farmacológico , Tinha/metabolismo
14.
Sci Rep ; 13(1): 6824, 2023 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-37100848

RESUMO

PdTe is a superconductor with Tc ~ 4.25 K. Recently, evidence for bulk-nodal and surface-nodeless gap features has been reported in PdTe. Here, we investigate the physical properties of PdTe in both the normal and superconducting states via specific heat and magnetic torque measurements and first-principles calculations. Below Tc, the electronic specific heat initially decreases in T3 behavior (1.5 K < T < Tc) then exponentially decays. Using the two-band model, the superconducting specific heat can be well described with two energy gaps: one is 0.372 meV and another 1.93 meV. The calculated bulk band structure consists of two electron bands (α and ß) and two hole bands (γ and η) at the Fermi level. Experimental detection of the de Haas-van Alphen (dHvA) oscillations allows us to identify four frequencies (Fα = 65 T, Fß = 658 T, Fγ = 1154 T, and Fη = 1867 T for H // a), consistent with theoretical predictions. Nontrivial α and ß bands are further identified via both calculations and the angle dependence of the dHvA oscillations. Our results suggest that PdTe is a candidate for unconventional superconductivity.

15.
World J Gastroenterol ; 29(7): 1157-1172, 2023 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-36926666

RESUMO

Mucosal healing (MH) is vital in maintaining homeostasis within the gut and protecting against injury and infections. Multiple factors and signaling pathways contribute in a dynamic and coordinated manner to maintain intestinal homeostasis and mucosal regeneration/repair. However, when intestinal homeostasis becomes chronically disturbed and an inflammatory immune response is constitutively active due to impairment of the intestinal epithelial barrier autoimmune disease results, particularly inflammatory bowel disease (IBD). Many proteins and signaling pathways become dysregulated or impaired during these pathological conditions, with the mechanisms of regulation just beginning to be understood. Consequently, there remains a relative lack of broadly effective therapeutics that can restore MH due to the complexity of both the disease and healing processes, so tissue damage in the gastrointestinal tract of patients, even those in clinical remission, persists. With increased understanding of the molecular mechanisms of IBD and MH, tissue damage from autoimmune disease may in the future be ameliorated by developing therapeutics that enhance the body's own healing response. In this review, we introduce the concept of mucosal healing and its relevance in IBD as well as discuss the mechanisms of IBD and potential strategies for altering these processes and inducing MH.


Assuntos
Doenças Inflamatórias Intestinais , Mucosa Intestinal , Humanos , Mucosa Intestinal/patologia , Transdução de Sinais
16.
Biomed Pharmacother ; 159: 114255, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36696800

RESUMO

Colorectal cancer (CRC) is a leading cause of the cancer-related deaths worldwide. Thus, developing novel and targeted therapies for inhibiting CRC progression and metastasis is urgent. Several studies, including ours, have reported a causal role for an upregulated claudin-1 expression in promoting CRC metastasis through the activation of the Src and ß-catenin-signaling. In murine models of colon tumorigenesis, claudin-1 overexpression promotes oncogenic properties such as transformation and invasiveness. Conversely, the downregulation of claudin-1 inhibits colon tumorigenesis. Despite being a desirable target for cancer treatment, there are currently no known claudin-1 inhibitors with antitumor efficacy. Using a rigorous analytical design and implementing in- vitro and in-vivo testing and a brief medicinal chemistry campaign, we identified a claudin-1-specific inhibitor and named it I-6. Despite its high potency, I-6 was rapidly cleared in human liver microsomes. We, therefore, synthesized I-6 analogs and discovered a novel small molecule, PDS-0330. We determined that PDS0330 inhibits claudin-1-dependent CRC progression without exhibiting toxicity in in-vitro and in-vivo models of CRC and that it binds directly and specifically to claudin-1 with micromolar affinity. Further analyses revealed that PDS-0330 exhibits antitumor and chemosensitizer activities with favorable pharmacokinetic properties by inhibiting the association with metastatic oncogene Src. Overall, our data propose that PDS-0330 interferes with claudin-1/Src association to inhibit CRC progression and metastasis. Our findings are of direct clinical relevance and may open new therapeutic opportunities in colon cancer treatment and/or management by targeting claudin-1.


Assuntos
Neoplasias do Colo , Neoplasias Colorretais , Camundongos , Humanos , Animais , Claudina-1/metabolismo , Neoplasias do Colo/patologia , Transformação Celular Neoplásica/genética , Carcinogênese/metabolismo , Neoplasias Colorretais/patologia , Regulação Neoplásica da Expressão Gênica , Linhagem Celular Tumoral
17.
Tissue Barriers ; 11(2): 2077069, 2023 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-35603609

RESUMO

The intestinal barrier orchestrates selective permeability to nutrients and metabolites while excluding noxious stimuli. Recent scientific advances establishing a causal role for the gut microbiota in human health outcomes have generated a resurgent interest toward intestinal permeability. Considering the well-established role of the gut barrier in protection against foreign antigens, there is mounting evidence for a causal link between gut permeability and the microbiome in regulating human health. However, an understanding of the dynamic host-microbiota interactions that govern intestinal barrier functions remains poorly defined. Furthermore, the system-level mechanisms by which microbiome-targeted therapies, such as probiotics and prebiotics, simultaneously promote intestinal barrier function and host health remain an area of active investigation. This review summarizes the recent advances in understanding the dynamics of intestinal permeability in human health and its integration with gut microbiota. We further summarize mechanisms by which probiotics/prebiotics influence the gut microbiota and intestinal barrier functions.


Assuntos
Microbiota , Probióticos , Humanos , Prebióticos , Dieta , Probióticos/uso terapêutico , Permeabilidade
18.
Dis Model Mech ; 16(5)2023 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-36426663

RESUMO

The intestinal microbiome is essential to human health and homeostasis, and is implicated in the pathophysiology of disease, including congenital heart disease and cardiac surgery. Improving the microbiome and reducing inflammatory metabolites may reduce systemic inflammation following cardiac surgery with cardiopulmonary bypass (CPB) to expedite recovery post-operatively. Limited research exists in this area and identifying animal models that can replicate changes in the human intestinal microbiome after CPB is necessary. We used a piglet model of CPB with two groups, CPB (n=5) and a control group with mechanical ventilation (n=7), to evaluate changes to the microbiome, intestinal barrier dysfunction and intestinal metabolites with inflammation after CPB. We identified significant changes to the microbiome, barrier dysfunction, intestinal short-chain fatty acids and eicosanoids, and elevated cytokines in the CPB/deep hypothermic circulatory arrest group compared to the control group at just 4 h after intervention. This piglet model of CPB replicates known human changes to intestinal flora and metabolite profiles, and can be used to evaluate gut interventions aimed at reducing downstream inflammation after cardiac surgery with CPB.


Assuntos
Ponte Cardiopulmonar , Cardiopatias Congênitas , Animais , Humanos , Suínos , Ponte Cardiopulmonar/efeitos adversos , Disbiose , Citocinas , Modelos Animais
19.
Pharm Res ; 40(1): 107-122, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36271204

RESUMO

Nucleic acid (NA) therapy has gained importance over the past decade due to its high degree of selectivity and minimal toxic effects over conventional drugs. Currently, intravenous (IV) or intramuscular (IM) formulations constitute majority of the marketed formulations containing nucleic acids. However, oral administration is traditionally preferred due to ease of administration as well as higher patient compliance. To leverage the benefits of oral delivery for NA therapy, the NA of interest must be delivered to the target site avoiding all degrading and inhibiting factors during its transition through the gastrointestinal tract. The oral route presents myriad of challenges to NA delivery, making formulation development challenging. Researchers in the last few decades have formulated various delivery systems to overcome such challenges and several reviews summarize and discuss these strategies in detail. However, there is a need to differentiate between the approaches based on target so that in future, delivery strategies can be developed according to the goal of the study and for efficient delivery to the desired site. The goal of this review is to summarize the mechanisms for target specific delivery, list and discuss the formulation strategies used for oral delivery of NA therapies and delineate the similarities and differences between local and systemic targeting oral delivery systems and current challenges.


Assuntos
Sistemas de Liberação de Medicamentos , Ácidos Nucleicos , Humanos , Administração Oral , Trato Gastrointestinal
20.
J Med Chem ; 65(22): 15327-15343, 2022 11 24.
Artigo em Inglês | MEDLINE | ID: mdl-36322935

RESUMO

15-Prostaglandin dehydrogenase (15-PGDH) regulates the concentration of prostaglandin E2 in vivo. Inhibitors of 15-PGDH elevate PGE2 levels and promote tissue repair and regeneration. Here, we describe a novel class of quinoxaline amides that show potent inhibition of 15-PGDH, good oral bioavailability, and protective activity in mouse models of ulcerative colitis and recovery from bone marrow transplantation.


Assuntos
Hidroxiprostaglandina Desidrogenases , Quinoxalinas , Animais , Camundongos , Colite Ulcerativa/tratamento farmacológico , Dinoprostona , Hidroxiprostaglandina Desidrogenases/antagonistas & inibidores , Quinoxalinas/farmacologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...