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1.
Am J Physiol Gastrointest Liver Physiol ; 327(4): G499-G512, 2024 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-39104322

RESUMEN

Apoptosis, inflammation, and wound healing are critical pathophysiological events associated with various liver diseases. Currently, there is a lack of in vivo approaches to study hepatocyte apoptosis-induced liver injury and repair. To address this critical knowledge gap, we developed a unique genetically modified mouse model, namely, 3-Transgene (Tg) with inducible Hepatocyte-Specific Apoptosis Phenotype (3xTg-iHAP) in this study. The 3xTg-iHAP mice possess three transgenes including Alb-Cre, Rosa26-rtTA, and tetO-Fasl on a B6 background. These mice are phenotypically normal, viable, and fertile. After subcutaneous administration of a single dose of doxycycline (5 mg/kg, Dox) to 3xTg-iHAP mice, we observed a complete histological spectrum of sterile liver wound-healing responses: asymptomatic hepatocyte apoptosis at 8 h, necrotic liver injury and sterile inflammation at 48 h, followed by hepatocyte mitosis and regeneration within 7 days. During the injury phase, the mice exhibited an increase in the biomarkers of alanine aminotransferase (ALT), chemokine (C-X-C motif) ligand 1 (CXCL1), and IL-6 in peripheral blood, as well as α-smooth muscle actin (α-SMA) protein in liver tissues. Conversely, the mice displayed a decrease in these markers in the recovery phase. Remarkably, this model shows that the sterile liver injury following elevated hepatocyte apoptosis is associated with an increase in myeloid cells in the liver. Within 7 days post-Dox administration, the liver of Dox-treated 3xTg-iHAP mice displays a normal histological structure, indicating the completion of wound healing. Together, we established a novel mouse model of injury and regeneration induced by hepatocyte apoptosis. This tool provides a robust in vivo platform for studying the pathophysiology of sterile liver inflammation, regeneration, and new therapeutic interventions for liver diseases.NEW & NOTEWORTHY Bu et al. present a triple-transgenic mouse model, namely, 3xTg-iHAP mice that are engineered to explore hepatocyte apoptosis-triggered sterile liver injury and regeneration. This model demonstrates a full spectrum of liver wound-healing responses from asymptomatic apoptosis to injury, myeloid cell-dominant sterile inflammation, and repair after induction of hepatocyte-specific apoptosis. The robust nature of this model makes it an invaluable in vivo tool for studying sterile liver inflammation, regeneration, and new therapeutic strategies.


Asunto(s)
Apoptosis , Modelos Animales de Enfermedad , Hepatocitos , Regeneración Hepática , Ratones Transgénicos , Células Mieloides , Animales , Hepatocitos/metabolismo , Hepatocitos/patología , Ratones , Células Mieloides/metabolismo , Hígado/metabolismo , Hígado/patología , Cicatrización de Heridas , Ratones Endogámicos C57BL , Quimiocina CXCL1/metabolismo , Quimiocina CXCL1/genética
2.
Inorg Chem ; 62(37): 14959-14970, 2023 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-37672483

RESUMEN

Metallogels formed from supramolecular interactions of low-molecular-weight gelators (LMWGs) combine the qualities of heterogeneous catalysts and offer the advantages of multifunctionality owing to the facile installation of desired task-specific moieties on the surface and along the channels of the gels. We discuss the applications of a triazole-based Ni(II) gel-derived xerogel (NiXero) having a high density of Ni(II)-nodes and appended primary amines as a recyclable heterogeneous catalyst for Knoevenagel condensation of aldehyde and malononitrile in water and the solvent-free cycloaddition of CO2 to form a series of cyclic carbonates with near-quantitative conversion of the respective epoxides, with low catalyst loading (0.59 mol %), high catalyst stability, and recyclability. The structural advantages of NiXero, due to the concurrent presence of bifunctional Lewis acid-base sites on the channels, open Ni(II) nodes, Ntriazole, pendant -NH2 and its chemical stability, are conducive to the cooperative heterogeneous catalytic activity under mild conditions. This work emphasizes the effective amalgamation of metals with purpose-built ligand systems for the construction of metallogels and their utility as heterogeneous catalysts for desired organic transformations.

3.
Proc Natl Acad Sci U S A ; 117(28): 16174-16180, 2020 07 14.
Artículo en Inglés | MEDLINE | ID: mdl-32571947

RESUMEN

Urban mining of precious metals from electronic waste, such as printed circuit boards (PCB), is not yet feasible because of the lengthy isolation process, health risks, and environmental impact. Although porous polymers are particularly effective toward the capture of metal contaminants, those with porphyrin linkers have not yet been considered for precious metal recovery, despite their potential. Here, we report a porous porphyrin polymer that captures precious metals quantitatively from PCB leachate even in the presence of 63 elements from the Periodic Table. The nanoporous polymer is synthesized in two steps from widely available monomers without the need for costly catalysts and can be scaled up without loss of activity. Through a reductive capture mechanism, gold is recovered with 10 times the theoretical limit, reaching a record 1.62 g/g. With 99% uptake taking place in the first 30 min, the metal adsorbed to the porous polymer can be desorbed rapidly and reused for repetitive batches. Density functional theory (DFT) calculations indicate that energetically favorable multinuclear-Au binding enhances adsorption as clusters, leading to rapid capture, while Pt capture remains predominantly at single porphyrin sites.

4.
Am J Physiol Gastrointest Liver Physiol ; 323(3): G205-G218, 2022 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-35819158

RESUMEN

Feeding modes influence the gut microbiome, immune system, and intestinal barrier homeostasis in neonates; how feeding modes impact susceptibility to neonatal gastrointestinal (GI) diseases is still uncertain. Here, we investigated the impact of dam feeding (DF) and formula feeding (FF) on features of the gut microbiome and physiological inflammation during the first 2 days of postnatal development and on the susceptibility to intestinal injury related to the inflammatory state in neonatal mouse pups. 16S rRNA sequencing data revealed microbiome changes, lower α-diversity, and a distinct pattern of ß-diversity including expansion of f_Enterobacteriaceae and f_Enterococcaceae in the ileum of FF pups compared with DF pups by postnatal day (P)2. Together with gut dysbiosis, the FF cohort also had greater ileal mucosa physiological inflammatory activity compared with DF pups by P2 but maintained normal histological features. Interestingly, FF but not DF mouse pups developed necrotizing enterocolitis (NEC)-like intestinal injury within 24 h after anti-CD3 mAb treatment, suggesting that FF influences the susceptibility to intestinal injury in neonates. We further found that NEC-like incidence in anti-CD3 mAb-treated FF neonatal pups was attenuated by antibiotic treatment. Collectively, our data suggest that FF predisposes mouse pups to anti-CD3 mAb-induced intestinal injury due to abnormal f_Enterobacteriaceae and f_Enterococcaceae colonization. These findings advance our understanding of FF-associated microbial colonization and intestinal inflammation, which may help inform the development of new therapeutic approaches to GI diseases like NEC in infants.NEW & NOTEWORTHY This report shows that a feeding mode profoundly affects gut colonization in neonatal mice. Furthermore, our results demonstrate that formula feeding predisposes mouse pups to anti-CD3 mAb-induced necrotizing enterocolitis (NEC)-like intestinal injury upon inadequate microbial colonization. The study suggests the role of the combined presence of formula feeding-associated dysbiosis and mucosal inflammation in the pathogenesis of NEC and provides a new mouse model to study this disease.


Asunto(s)
Enterocolitis Necrotizante , Microbioma Gastrointestinal , Animales , Animales Recién Nacidos , Disbiosis , Enterocolitis Necrotizante/tratamiento farmacológico , Humanos , Inflamación/patología , Mucosa Intestinal/patología , Ratones , ARN Ribosómico 16S
5.
Int J Med Sci ; 19(5): 842-857, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35693733

RESUMEN

Background: Complement component 1 Q subcomponent binding protein (C1QBP) plays a vital role in the progression and metabolism of cancer. Studies have shown that xanthine dehydrogenase (XDH)-derived reactive oxygen species (ROS) accelerates tumor growth, and also induces mutations or produces cytotoxic effects concurrently. However, the role of C1QBP in metabolism, oxidative stress, and apoptosis of renal cell carcinoma (RCC) cells have not yet been explored. Methods: Metabolomics assay was applied to investigate the role of C1QBP in RCC metabolism. C1QBP knockdown and overexpression cells were established via lentiviral infection and subjected to apoptosis and ROS assay in vitro. RNA stability assay was applied to characterize the mechanism of C1QBP regulating XDH transcription. In vivo, orthotopic tumor xenografts assay was performed to investigate the role of C1QBP in RCC progression. Results: Metabolomics investigation revealed that C1QBP dramatically diminished the hypoxanthine content in RCC cells. C1QBP promoted the mRNA and protein expression of hypoxanthine catabolic enzyme XDH. Meanwhile, C1QBP may affect XDH transcription by regulating the mRNA level of XDH transcriptional stimulators IL-6, TNF-α, and IFN-γ. Moreover, the expression of C1QBP and XDH was lower in RCC tumors compared with the tumor-associated normal tissues, and their down-regulation was associated with higher Fuhrman grade. C1QBP significantly increased ROS level, apoptosis, and the expression of apoptotic proteins such as cleaved caspase-3 and bax/bcl2 via regulating XDH. Conclusion: C1QBP promotes the catabolism of hypoxanthine and elevates the apoptosis of RCC cells by modulating XDH-mediated ROS generation.


Asunto(s)
Carcinoma de Células Renales , Neoplasias Renales , Apoptosis/genética , Carcinoma de Células Renales/patología , Proteínas Portadoras/metabolismo , Humanos , Hipoxantinas , Neoplasias Renales/patología , Proteínas Mitocondriales/genética , ARN Mensajero , Especies Reactivas de Oxígeno/metabolismo , Xantina Deshidrogenasa/genética , Xantina Deshidrogenasa/metabolismo
6.
Exp Eye Res ; 211: 108749, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34464609

RESUMEN

Infrared thermography provides functional imaging by picturing the temperature pattern of the region imaged. The temperature correlates to the blood flow pattern and is used in the diagnosis of diseases like breast cancer, peripheral vascular disorders, diabetic neuropathy and fever screening. In the present study, the usage of ocular thermography for diagnosis of diabetic retinopathy is explored. Ocular thermograms using infrared imaging camera were obtained for normal subjects (80 volunteers - 40 males and 40 females) age groups 21-30, 31-40, 41-50 and 51-60 years, non-proliferative diabetic retinopathy (NPDR) patients (50 volunteers -25 males and 25 females) and proliferative diabetic retinopathy (PDR) patients (20 volunteers -10 males and 10 females) belonging to age group of 51-60 years. The temperature at various points of interest (POIs) and horizontal temperature profiles were studied. Ocular surface temperature (OST) and effect of eye dilation on OST was studied for control, age matched NPDR and PDR. Statistical analyses were carried out to find the significance of correlation between OST of controls and NPDR and PDR. The global minimum temperature on the ocular surface for controls (21-60 years) was found to be at cornea which is about 34.79 ± 0.68 °C, and maximum at the inner canthus viz. 36.08 ± 0.62 °C. Dilation studies showed an average increase of 0.82 ± 0.13 °C in cornea and 0.75 ± 0.14 °C in conjunctiva and limbus (p < 0.001). The temperature of cornea is around 33.22 ± 0.12 °C and 32.64 ± 0.12 °C for NPDR and PDR patients respectively, in the age group of 51-60 years. OST of NPDR patients was 0.60 ± 0.15 °C lesser than that of age matched normal eyes (p < 0.001) at cornea and limbus regions and 0.71 ± 0.20 °C at inner canthus. The OST of PDR patients was lesser than age matched controls by 1.18 ± 0.12 °C at cornea, 0.9 ± 0.13 °C at inner canthus and 1.0 ± 0.14 °C at other POIs. During dilation studies a positive variation of 0.61 ± 0.12 °C in cornea and 0.48 ± 0.13 °C in conjunctiva and limbus was observed (p < 0.001) in NPDR eyes. Similarly an average increase of 0.62 ± 0.11 °C in cornea and an average increase of 0.47 ± 0.15 °C in conjunctiva and limbus were observed (p < 0.001) in PDR eyes. The OST of NPDR and PDR patients was less compared with age matched counterparts in both pre and post dilation studies. Dilation of eye showed increase in OST for both controls and diabetic retinopathy patients. The degree of increase is less compared with controls. The variation in OST observed during pre and post dilatation studies of diabetic retinopathy patients is a functional marker of pathology, and can be used as a parameter for diagnosis.


Asunto(s)
Temperatura Corporal/fisiología , Retinopatía Diabética/fisiopatología , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Midriáticos/administración & dosificación , Pupila/efectos de los fármacos , Flujo Sanguíneo Regional/fisiología , Termografía , Tropicamida/administración & dosificación , Adulto Joven
7.
J Transl Med ; 18(1): 197, 2020 05 13.
Artículo en Inglés | MEDLINE | ID: mdl-32404201

RESUMEN

An amendment to this paper has been published and can be accessed via the original article.

8.
Org Biomol Chem ; 18(15): 2962, 2020 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-32255143

RESUMEN

Correction for 'Carbazole based Electron Donor Acceptor (EDA) catalysis for the synthesis of biaryl and aryl-heteroaryl compounds' by Rajendhiran Saritha et al., Org. Biomol. Chem., 2020, DOI: 10.1039/d0ob00282h.

9.
Sheng Li Xue Bao ; 72(3): 308-324, 2020 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-32572429

RESUMEN

Gut injury continues to be the devastating and unpredictable critical illness associated with increased cell death of intestinal epithelial cells (IECs). The IECs, immune system and microbiome are the interrelated entities to maintain normal intestinal homeostasis and barrier integrity. In response to microbial invasion, IEC cell death occurs to maintain intestinal epithelium function and retain the continuous renewal and tissue homeostasis. But the imbalance of IEC cell death results in increased intestinal permeability and barrier dysfunction that leads to several acute and chronic intestinal diseases, such as intestinal ischemia/reperfusion (I/R), sepsis, inflammatory bowel diseases (IBD), necrotizing enterocolitis (NEC), etc. During the pathophysiological state, the excessive IEC apoptotic cell death leads to a chronic inflammatory condition, later switches to necroptotic cell death mechanism that induces more pathological features than apoptosis and may also induce other lytic cell death mechanisms like pyroptosis and ferroptosis to increase the pathogenesis of the intestinal diseases. But still, there remains gaps in the fundamental knowledge about the IEC cell death mechanisms in chronic intestinal diseases. Together, a deep understanding of the specific cell death mechanisms underlying chronic intestinal diseases, including sepsis, IBD, NEC, and intestinal I/R, is desperately needed to develop emerging novel promising therapeutic strategies. This review aims to show how the acute and critical illness in the gut are driven by IEC cell death mechanism, such as apoptosis, necrosis, necroptosis, pyroptosis, and ferroptosis.


Asunto(s)
Células Epiteliales , Mucosa Intestinal , Apoptosis , Muerte Celular , Humanos , Recién Nacido , Necrosis
10.
Rep Pract Oncol Radiother ; 24(1): 80-85, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30505237

RESUMEN

AIM: The aim of this study is to analyse the dosimetry to the pelvic lymph nodes and its correlation to point B using CT based high dose rate brachytherapy of carcinoma cervix. BACKGROUND: Conventionally, dose to pelvic lymph nodes from intracavitary brachytherapy was reported by point B and by the reference points of the lymphatic trapezoid. MATERIALS AND METHODS: 30 consecutive CT based high dose rate applications were reviewed between February and March 2016. The high risk clinical target volume and the organs at risk and the pelvic nodal groups were contoured. DVH parameters for the right and left obturator nodal group, right and left external iliac nodal group and right and left internal iliac nodal group were recorded. Right and left point B doses were also recorded. RESULTS: On analysis of the combined dose, it was found that all the DVH parameters were significantly different from point B, except the D100 obturator and D2cc internal iliac lymph node. There was a significant correlation between all DVH parameters and point B, except D2cc, D1cc and D0.1cc of external iliac. The obturator group received the highest dose contribution from brachytherapy. The mean D90 dose received per fraction for the obturator, external iliac and internal iliac nodes was 2.7 Gy, 1.17 Gy and 1.41 Gy, respectively. CONCLUSIONS: There is a significant dose contribution to the pelvic lymph nodal groups during intracavitary brachytherapy. There is a low degree of correlation between point B dose and dosimetric parameters of the individual nodal groups. Hence, it is important to analyse the dose delivered to individual nodal groups during intracavitary brachytherapy, at least in patients with enlarged lymph nodes to calculate the cumulative dose delivered.

11.
J Transl Med ; 15(1): 85, 2017 04 28.
Artículo en Inglés | MEDLINE | ID: mdl-28454543

RESUMEN

BACKGROUND: TREM-1 acts as an amplifier of inflammation expressed on macrophages. The objective of this study was to evaluate the relationship between TREM-1 and macrophage polarization, and association of TREM-1 and M1 macrophage polarization with insulin resistance (IR) in obese population compared to non-obese population. METHODS: We enrolled 38 patients after obtaining IRB approval for this study. We evaluated the mRNA and protein expression levels of general macrophage marker (CD68), M1 marker (CD86, CCR7, iNOS, IFNγ, TNF-α and IL-6,), M2 marker (CD206, CD163, IL-10, IL-4) and chemokine axis (MCP-1, CCR2 and CCR5) along with TREM-1 and TREM-2 in omentum fat, subcutaneous fat, and liver biopsy tissues of non-obese (N = 5), obese non-diabetics, (N = 16) and obese diabetics (N = 17). RESULTS: The results of our study showed over-expression of TREM-1, M1 markers and down-regulation of TREM-2 and M2 markers in the omentum, subcutaneous and liver biopsies of obese patients (diabetics and non-diabetics) compared to non-obese patients. Overall, the obese diabetic group showed a significant (p < 0.05) higher number of patients with over expression of M1 markers (TREM-1, CD68, CD86, CCR-7, iNOS, IFN-γ, TNF-α, IL-6, MCP-1, CCR-2 and CCR-5) and down-regulation of M2 markers (CD206, CD163 and IL-4) in liver biopsy compared to obese non-diabetics. CONCLUSIONS: TREM-1 expression is significantly increased along with the M1 markers in liver biopsy of obese diabetic (17/17) and obese non-diabetic patients (9/16). Our data suggests that TREM-1 overexpression and M1 macrophage polarization are associated with obesity-induced IR.


Asunto(s)
Polaridad Celular , Resistencia a la Insulina , Macrófagos/patología , Obesidad/patología , Receptor Activador Expresado en Células Mieloides 1/metabolismo , Adulto , Antígenos CD/metabolismo , Biomarcadores/metabolismo , Biopsia , Comorbilidad , Citocinas/metabolismo , Demografía , Diabetes Mellitus/genética , Diabetes Mellitus/patología , Femenino , Fluorescencia , Humanos , Hígado/patología , Masculino , Persona de Mediana Edad , Óxido Nítrico Sintasa de Tipo II/metabolismo , Obesidad/genética , Epiplón/patología , ARN Mensajero/genética , ARN Mensajero/metabolismo , Receptores de Quimiocina/metabolismo
12.
Mol Cell Biochem ; 426(1-2): 27-45, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27868170

RESUMEN

Obesity-induced low-grade inflammation (metaflammation) impairs insulin receptor signaling. This has been implicated in the development of insulin resistance. Insulin signaling in the target tissues is mediated by stress kinases such as p38 mitogen-activated protein kinase, c-Jun NH2-terminal kinase, inhibitor of NF-kB kinase complex ß (IKKß), AMP-activated protein kinase, protein kinase C, Rho-associated coiled-coil containing protein kinase, and RNA-activated protein kinase. Most of these kinases phosphorylate several key regulators in glucose homeostasis. The phosphorylation of serine residues in the insulin receptor and IRS-1 molecule results in diminished enzymatic activity in the phosphatidylinositol 3-kinase (PI3K)/Akt pathway. This has been one of the key mechanisms observed in the tissues that are implicated in insulin resistance especially in type 2 diabetes mellitus (T2-DM). Identifying the specific protein kinases involved in obesity-induced chronic inflammation may help in developing the targeted drug therapies to minimize the insulin resistance. This review is focused on the protein kinases involved in the inflammatory cascade and molecular mechanisms and their downstream targets with special reference to obesity-induced T2-DM.


Asunto(s)
Resistencia a la Insulina , Obesidad/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Quinasas/metabolismo , Transducción de Señal , Animales , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/patología , Humanos , Inflamación/metabolismo , Inflamación/patología , Obesidad/patología
13.
Artículo en Inglés | MEDLINE | ID: mdl-38554082

RESUMEN

Fluoride is widely present in nature, and human exposure to it is generally regarded as inevitable. High levels of fluoride intake induce acute and chronic illnesses. To reduce potential harm to the general public, it is essential to create selective fluoride detectors capable of providing a colorimetric response for naked-eye detection without the need for sophisticated equipment. Here, we report a one-pot synthesis of four different diaminomaleonitrile-derived Schiff base sensors. The terephthalaldehyde adduct provided a strong color change visible to the naked eye at a F- concentration level as low as 2 ppm. From the evaluation against other anions, such as CN-, I-, Br-, Cl-, NO3-, PO43-, OAc-, and HSO4-, the molecular sensor displayed a visible color change exclusively upon exposure to fluoride, underscoring exceptional selectivity. As a key intermediate for understanding the mechanism, HF2- was confirmed by 19F nuclear magnetic resonance. Theoretical calculations suggested a deprotonation-triggered bathochromic shift brought about by the unique electronic structure of the sensor. Furthermore, the simple synthetic protocol from economically accessible materials allowed for the preparation of the compound on a large scale, rendering it a highly practical visual fluoride sensor.

14.
Cell Mol Gastroenterol Hepatol ; 18(3): 101364, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38788898

RESUMEN

BACKGROUND & AIMS: Necrotizing enterocolitis (NEC) is a life-threatening disease affecting mostly the ileum of preemies. Intestinal epithelial cell (IEC) apoptosis contributes to NEC pathogenesis. However, how scattered crypt IEC apoptosis leads to NEC with excessive villus epithelial necrosis remains unclear. METHODS: A novel triple-transgenic mouse model, namely, 3xTg-iAPcIEC (inducible apoptosis phenotype in crypt-IEC), was developed to induce IEC-specific overexpression of Fasl transgene using doxycycline (Dox)-inducible tetO-rtTA system and villin-cre technology. The 3-days-old neonatal 3xTg-iAPcIEC mice and their littermate controls were subcutaneously (s.c.) challenged with a single dose of Dox. Intestinal tissues were processed at different time points to examine scattered crypt IEC apoptosis-mediated NEC development. Gene knockout technology, antibody-mediated cell depletion, and antibiotic-facilitated Gram-positive bacteria depletion were used to study mechanisms. RESULTS: Treatment of 3xTg-iAPcIEC mouse pups with Dox induces scattered crypt IEC apoptosis followed by crypt inflammation and excessive villous necrosis resembling NEC. This progression correlated with elevated Ifng, Rip3, CD8+ T cells, and Gram-positive bacteria in the ileum. Mechanistically, IFN-γ and RIP3-activated signals mediate the effect of scattered crypt IEC apoptosis on the induction of intestinal crypt inflammation and villous necrosis. Meanwhile, pathophysiological events of CD8+ T cell infiltration and dysbiosis with Gram-positive bacteria primarily contribute to excessive villous inflammation and necrosis. Notably, blocking any of these events protects against NEC development in 3xTg-iAPcIEC mouse pups, underlining their central roles in NEC pathogenesis. CONCLUSIONS: Scattered crypt IEC apoptosis induces NEC in mouse pups via IFN-γ, RIP3, CD8+ T cells, and Gram-positive bacteria-mediated comprehensive pathophysiological events. Our findings may advance knowledge in the prevention and treatment of NEC.


Asunto(s)
Apoptosis , Modelos Animales de Enfermedad , Enterocolitis Necrotizante , Proteína Ligando Fas , Interferón gamma , Mucosa Intestinal , Ratones Transgénicos , Animales , Enterocolitis Necrotizante/patología , Enterocolitis Necrotizante/metabolismo , Ratones , Mucosa Intestinal/patología , Mucosa Intestinal/microbiología , Mucosa Intestinal/inmunología , Interferón gamma/metabolismo , Proteína Ligando Fas/metabolismo , Proteína Serina-Treonina Quinasas de Interacción con Receptores/metabolismo , Proteína Serina-Treonina Quinasas de Interacción con Receptores/genética , Células Epiteliales/patología , Células Epiteliales/metabolismo , Linfocitos T CD8-positivos/inmunología , Necrosis , Animales Recién Nacidos , Doxiciclina/farmacología , Humanos , Íleon/patología , Íleon/inmunología
15.
bioRxiv ; 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38746153

RESUMEN

Noroviruses are the leading global cause of acute gastroenteritis, responsible for 685 million annual cases. While all age groups are susceptible to noroviruses, children are vulnerable to more severe infections than adults, underscored by 200 million pediatric cases and up to 200,000 deaths in children annually. Understanding the basis for the increased vulnerability of young hosts is critical to developing effective treatments. The pathogenic outcome of any enteric virus infection is governed by a complex interplay between the virus, intestinal microbiota, and host immune factors. A central mediator in these complex relationships are host- and microbiota-derived metabolites. Noroviruses bind a specific class of metabolites, bile acids, which are produced by the host and then modified by commensal bacterial enzymes. Paradoxically, bile acids can have both proviral and antiviral roles during norovirus infections. Considering these opposing effects, the microbiota-regulated balance of the bile acid pool may be a key determinant of the pathogenic outcome of a norovirus infection. The bile acid pool in newborns is unique due to immaturity of host metabolic pathways and developing gut microbiota, which could underlie the vulnerability of these hosts to severe norovirus infections. Supporting this concept, we demonstrate herein that microbiota and their bile acid metabolites protect from severe norovirus diarrhea whereas host-derived bile acids promote disease. Remarkably, we also report that maternal bile acid metabolism determines neonatal susceptibility to norovirus diarrhea during breastfeeding by delivering proviral bile acids to the newborn. Finally, directed targeting of maternal and neonatal bile acid metabolism can protect the neonatal host from norovirus disease. Altogether, these data support the conclusion that metabolic immaturity in newborns and ingestion of proviral maternal metabolites in breast milk are the central determinants of heightened neonatal vulnerability to norovirus disease.

16.
Cell Host Microbe ; 32(9): 1488-1501.e5, 2024 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-39214086

RESUMEN

The pathogenic outcome of enteric virus infections is governed by a complex interplay between the virus, intestinal microbiota, and host immune factors, with metabolites serving as a key mediator. Noroviruses bind bile acid metabolites, which are produced by the host and then modified by commensal bacteria. Paradoxically, bile acids can have both proviral and antiviral roles during norovirus infections. Working in an infant mouse model of norovirus infection, we demonstrate that microbiota and their bile acid metabolites protect from norovirus diarrhea, whereas host bile acids promote disease. We also find that maternal bile acid metabolism determines the susceptibility of newborn mice to norovirus diarrhea during breastfeeding. Finally, targeting maternal and neonatal bile acid metabolism can protect newborn mice from norovirus disease. In summary, neonatal metabolic immaturity and breastmilk bile acids are central determinants of heightened newborn vulnerability to norovirus disease.


Asunto(s)
Animales Recién Nacidos , Ácidos y Sales Biliares , Infecciones por Caliciviridae , Diarrea , Modelos Animales de Enfermedad , Microbioma Gastrointestinal , Leche Humana , Norovirus , Animales , Ratones , Ácidos y Sales Biliares/metabolismo , Infecciones por Caliciviridae/metabolismo , Infecciones por Caliciviridae/virología , Leche Humana/virología , Leche Humana/metabolismo , Diarrea/virología , Diarrea/metabolismo , Femenino , Humanos , Ratones Endogámicos C57BL
17.
Cell Host Microbe ; 2024 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-39293437

RESUMEN

Microbiota and feeding modes influence the susceptibility of premature newborns to necrotizing enterocolitis (NEC) through mechanisms that remain unknown. Here, we show that microbiota colonization facilitated by breastmilk feeding promotes NOD-like receptor family CARD domain containing 5 (Nlrc5) gene expression in mouse intestinal epithelial cells (IECs). Notably, inducible knockout of the Nlrc5 gene in IECs predisposes neonatal mice to NEC-like injury in the small intestine upon viral inflammation in an NK1.1+ cell-dependent manner. By contrast, formula feeding enhances neonatal gut colonization with environment-derived tilivalline-producing Klebsiella spp. Remarkably, tilivalline disrupts microbiota-activated STAT1 signaling that controls Nlrc5 gene expression in IECs through a PPAR-γ-mediated mechanism. Consequently, this dysregulation hinders the resistance of neonatal intestinal epithelium to self-NK1.1+ cell cytotoxicity upon virus infection/colonization, promoting NEC development. Together, we discover the underappreciated role of intestinal microbiota colonization in shaping a disease tolerance program to viral inflammation and elucidate the mechanisms impacting NEC development in neonates.

18.
Cureus ; 15(7): e42753, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37654914

RESUMEN

Introduction The knee joint is a complex system containing various hard and soft tissue components necessary for functioning in a coordinated manner. The menisci help to deepen the tibial plateau. Knowledge of the dimension of menisci in the knee joint is of paramount importance in arthroscopic surgery and the management of injuries due to sports or degeneration. The present study aims to describe the morphometric data of the medial meniscus and document the morphometric variation in the medial menisci. Methodology This study was conducted in the department of anatomy in two medical colleges under MGR University by measuring the dimensions of 100 medial menisci taken from 50 formalin-fixed embalmed cadavers. The width and thickness of the medial menisci were measured using digital vernier calipers. The outer and inner circumferences were measured using a measuring tape, non-elastic threads, and metallic pins. The area of the medial meniscus and the tibial plateau was measured by counting the small squares present in the circumference of the menisci drawn over the graph paper. The weight of the medial menisci was measured using the electronic weigh scale. Results The widest part of the medial meniscus was the posterior one-third, and the narrowest part was the anterior one-third. The thickest part was the middle one-third, followed by the anterior one-third. The average inner and outer circumferences of the menisci were 6.25 cm and 10.05 cm, respectively. The medial meniscus covers more than half of the area of the tibial plateau. Conclusion The present study provides a good understanding of the morphometric features of the medial menisci and will be of great help for managing knee joint pathologies and designing prostheses.

19.
Chem Sci ; 14(3): 540-549, 2023 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-36741513

RESUMEN

One of the fundamental aims in catalysis research is to understand what makes a certain scaffold perform better as a catalyst than another. For instance, in nature enzymes act as versatile catalysts, providing a starting point for researchers to understand how to achieve superior performance by positioning the substrate close to the catalyst using non-covalent interactions. However, translating this information to a non-biological catalyst is a challenging task. Here, we report a simple and scalable electrostatically tuned phenol (ETP) as an organocatalyst for transfer hydrogenation of N-arenes using the Hantzsch ester as a hydride source. The biomimetic catalyst (1-5 mol%) displays potential catalytic activity to prepare diverse tetrahydroquinoline derivatives with good to excellent conversion under ambient reaction conditions. Kinetic studies reveal that the ETP is 130-fold faster than the uncharged counterpart, towards completion of the reaction. Control experiments and NMR spectroscopic investigations elucidate the role of the charged environment in the catalytic transformation.

20.
Int J Appl Basic Med Res ; 13(1): 23-28, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37266531

RESUMEN

Background: Saliva has the potential to be used as a noninvasive sample for testing hyperglycemia in diabetes mellitus. Serum 1,5-anhydroglucitol (1,5-AG) decreases with an increase in blood sugar >180 mg/dl. We hypothesized that salivary 1,5-AG can be used to identify blood sugar higher than 180 mg/dl using a novel biochemical method. Aim: This study aimed to develop a novel biochemical method for serum and salivary assessment of 1,5-AG and assess its correlation with postprandial blood sugar (PPBS) >180 mg/dl. Methodology: The study comprised 45 controls (healthy individuals) and 45 cases (type 2 diabetic patients with PPBS >180 mg/dl). Blood and salivary samples were collected according to the study protocol. A new method was developed for the quantification of 1,5-AG in serum and saliva using liquid chromatography-mass spectrometry. Results: The value of serum (mean -22.19 µg/ml and median -22.12 µg/ml) and salivary (mean -0.124 µg/ml and median -0.088 µg/ml) 1,5-AG was higher in healthy individuals compared to corresponding serum (mean -3.89 µg/ml and median -2.52 µg/ml) and salivary (mean -0.025 µg/ml and median - 0.025 µg/ml) levels in diabetics with PPBS >180 mg/dl. In diabetics, a significant negative correlation was noticed with PPBS levels and 1,5-AG levels in serum and saliva. Salivary 1,5-AG level <0.054 µg/ml had an 86.4% sensitivity and 87.2% specificity in predicting a blood sugar value >180 mg/dl. Conclusion: The results of our study suggest that the short-term glycemic marker 1,5-AG can be detected in saliva and can be useful as an adjunct marker in monitoring of glycemic status in diabetic patients.

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