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1.
Heliyon ; 10(16): e36496, 2024 Aug 30.
Article in English | MEDLINE | ID: mdl-39247357

ABSTRACT

Raw mango peel (RMP) was first saponified to yield saponified mango peel (SMP), which was then loaded with Zr(IV) ions to form a biosorbent for As(III) scavenging.The biosorption behaviors and mechanisms of As(III) scavenging using RMP and Zr(IV)-loaded saponified mango peel (Zr(IV)-SMP) were investigated batchwise. The As(III) scavenging efficiency of RMP increased from 20.13 % to 87.32 % after Zr(IV) loading. Optimum contact time of 6 h has been investigated for As(III) scavenging by Zr(IV)-SMP, and the data on kinetics is well fitted to the pseudo-second-order (PSO) model. Similarly, isotherm data of Zr(IV)-SMP fitted well to the Langmuir isotherm model with the maximum As(III) scavenging potential of 45.52 mg/g. Chloride (Cl-) and nitrate (NO3 -) have negligible influence on As(III) scavenging, but sulphate (SO4 2-) interferes significantly. The exhausted Zr(IV)-SMP could be easily regenerated by treating with 2MNaOH. A mechanistic study indicates that As(III) scavenging is primarily contributed to electrostatic interaction and ligand exchange, which is confirmed from both instrumental and chemical characterizations techniques. Tubewell underground water polluted with a trace amount of arsenic (98.63 µg/L) could be successfully lowered down to the WHO standard (10 µg/L) by applying a small amount of Zr(IV)-SMP. Therefore, the Zr(IV)-SMP investigated in this work can be a low-cost, environmentally benign, and promising alternative for scavenging trace levels of arsenic from contaminated water.

2.
Heliyon ; 10(17): e37382, 2024 Sep 15.
Article in English | MEDLINE | ID: mdl-39296029

ABSTRACT

The occurrence of arsenic in the surroundings raises apprehension because its detrimental impacts on both human health and the ecology. Since adsorption is an effective, affordable method that can be adjusted to specific environmental circumstances, it is a sustainable solution for the removal of arsenic from the aquatic environment. Utilizing biomass that has been chemically activated may be a viable way to increase the adsorption capacity of the material, reduce arsenic pollution, and protect the environment and human health. In the proposed research, Fe(III) loaded saponified Punica granatum peel (Fe(III)-SPGP) has been synthesized to remove arsenic from aqueous solutions. FTIR and SEM analysis were utilized to carry out the characterization of the biosorbents. Batch experiments were carried out by altering several factors including pH and contact time, in addition to initial concentration and desorption. The most effective pH for As(III) adsorption using Fe(III)-SPGP was discovered to be 9.0. After determining that a pseudo-second-order kinetic model was the one that provided the greatest fit for the results of the experiment, the model developed by Langmuir was applied. It was discovered that the maximum adsorption of As(III) that could be adsorbed by Fe(III)-SPGP was 63.29 mg/g. The spent biosorbent may easily be reused again in subsequent applications. Based on these findings, Fe(III)-SPGP shows promise as a cheap effective sorbent for excising contaminants of As(III).

3.
J Vis Exp ; (202)2023 Dec 01.
Article in English | MEDLINE | ID: mdl-38108391

ABSTRACT

Skeletal muscle regeneration is a dynamic process driven by adult muscle stem cells and their progeny. Mostly quiescent at a steady state, adult muscle stem cells become activated upon muscle injury. Following activation, they proliferate, and most of their progeny differentiate to generate fusion-competent muscle cells while the remaining self-renews to replenish the stem cell pool. While the identity of muscle stem cells was defined more than a decade ago, based on the co-expression of cell surface markers, myogenic progenitors were identified only recently using high-dimensional single-cell approaches. Here, we present a single-cell mass cytometry (cytometry by time of flight [CyTOF]) method to analyze stem cells and progenitor cells in acute muscle injury to resolve the cellular and molecular dynamics that unfold during muscle regeneration. This approach is based on the simultaneous detection of novel cell surface markers and key myogenic transcription factors whose dynamic expression enables the identification of activated stem cells and progenitor cell populations that represent landmarks of myogenesis. Importantly, a sorting strategy based on detecting cell surface markers CD9 and CD104 is described, enabling prospective isolation of muscle stem and progenitor cells using fluorescence-activated cell sorting (FACS) for in-depth studies of their function. Muscle progenitor cells provide a critical missing link to study the control of muscle stem cell fate, identify novel therapeutic targets for muscle diseases, and develop cell therapy applications for regenerative medicine. The approach presented here can be applied to study muscle stem and progenitor cells in vivo in response to perturbations, such as pharmacological interventions targeting specific signaling pathways. It can also be used to investigate the dynamics of muscle stem and progenitor cells in animal models of muscle diseases, advancing our understanding of stem cell diseases and accelerating the development of therapies.


Subject(s)
Adult Stem Cells , Muscular Diseases , Animals , Muscle, Skeletal , Stem Cells , Cell Division
4.
Sci Transl Med ; 15(717): eadd2387, 2023 10 11.
Article in English | MEDLINE | ID: mdl-37820008

ABSTRACT

Diabetes is a global public health burden and is characterized clinically by relative or absolute insulin deficiency. Therapeutic agents that stimulate insulin secretion and improve insulin sensitivity are in high demand as treatment options. CD47 is a cell surface glycoprotein implicated in multiple cellular functions including recognition of self, angiogenesis, and nitric oxide signaling; however, its role in the regulation of insulin secretion remains unknown. Here, we demonstrate that CD47 receptor signaling inhibits insulin release from human as well as mouse pancreatic ß cells and that it can be pharmacologically exploited to boost insulin secretion in both models. CD47 depletion stimulated insulin granule exocytosis via activation of the Rho GTPase Cdc42 in ß cells and improved glucose clearance and insulin sensitivity in vivo. CD47 blockade enhanced syngeneic islet transplantation efficiency and expedited the return to euglycemia in streptozotocin-induced diabetic mice. Further, anti-CD47 antibody treatment delayed the onset of diabetes in nonobese diabetic (NOD) mice and protected them from overt diabetes. Our findings identify CD47 as a regulator of insulin secretion, and its manipulation in ß cells offers a therapeutic opportunity for diabetes and islet transplantation by correcting insulin deficiency.


Subject(s)
Diabetes Mellitus, Experimental , Insulin Resistance , Insulin-Secreting Cells , Islets of Langerhans Transplantation , Islets of Langerhans , Animals , Humans , Mice , CD47 Antigen/metabolism , Diabetes Mellitus, Experimental/therapy , Insulin/metabolism , Insulin Secretion , Insulin-Secreting Cells/metabolism , Islets of Langerhans/metabolism , Mice, Inbred NOD
5.
Heliyon ; 9(5): e15698, 2023 May.
Article in English | MEDLINE | ID: mdl-37159700

ABSTRACT

We studied the sequestration of hexavalent chromium Cr(VI) from an aqueous solution using chemically modified pomegranate peel (CPP) as an efficient bio-adsorbent. The synthesized material was characterized by X-ray diffraction spectroscopy (XRD), Fourier-transform infrared spectroscopy (FTIR), energy dispersive spectroscopy (EDS), and scanning electron microscopy (SEM). The impacts of parameters like solution pH, Cr(VI) concentration, contact time, and adsorbent dosage were investigated. Experimental results of the isotherm studies and adsorption kinetics were found agreeing to the Langmuir isotherm model and pseudo-second-order kinetics, respectively. The CPP showed appreciable Cr(VI) remediation capacity with a maximal loading capacity of 82.99 mg/g at pH 2.0, which was obtained in 180 min at room temperature. Thermodynamic studies revealed the biosorption process as spontaneous, feasible, and thermodynamically favorable. The spent adsorbent was eventually regenerated and reused, and the safe disposal of Cr(VI) was ensured. The study revealed that the CPP can be effectively employed as an affordable sorbent for the excision of Cr(VI) from water.

6.
Environ Sci Pollut Res Int ; 30(19): 54682-54693, 2023 Apr.
Article in English | MEDLINE | ID: mdl-36881243

ABSTRACT

The newly developed aminated maize stalk (AMS) was prepared by a chemical process using charred maize stalk (CMS). The AMS was used for the removal of nitrate and nitrite ions from aqueous media. The effects of initial anion concentration, contact time, and pH were studied by the batch method. The prepared adsorbent was characterized by FT-IR, XRD, FE-SEM , and elemental analysis. The concentration of the nitrate and nitrite solution before and after was determined with the help of a UV-Vis spectrophotometer. The maximum adsorption capacities were found to be 294.11 mg/g for nitrate and 232.55 mg/g for nitrite, respectively, at pH 5 for both ions attaining equilibrium within 60 min. The BET surface area of AMS was found to be 25.3 m2/g with a pore volume of 0.02cc/g. The pseudo-second-order kinetics model fit well, and the adsorption data supported the Langmuir isotherm. The findings revealed that AMS has a high capability for removing nitrate (NO3-) and nitrite (NO2-) ions from their aqueous solutions.


Subject(s)
Nitrates , Water Pollutants, Chemical , Nitrates/chemistry , Nitrites/chemistry , Zea mays , Adsorption , Spectroscopy, Fourier Transform Infrared , Solutions , Anions , Water/chemistry , Kinetics , Hydrogen-Ion Concentration , Water Pollutants, Chemical/chemistry
7.
Heliyon ; 9(2): e13465, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36816270

ABSTRACT

Pomelo, Citrus maxima, peel was chemically modified with lime water and then loaded with Fe(III) to develop anion exchange sites for effective sequestration of As(V) from water. Biosorbent characterizations were done by using FTIR, SEM, XRD, EDX, and Boehm's titration. The batch biosorption studies were carried out at various pHs using modified and non-modified biosorbents and optimum biosorption of As(V) occurred at acidic pH (3.0-5.0) for both the biosorbents. A kinetic study showed a fast biosorption rate and obtained results fitted well with the pseudo-second-order (PSO) model. When isotherm data were modeled using the Langmuir and Freundlich isotherm models, the Langmuir isotherm model fit the data better and produced maximal As(V) biosorption capacities of 0.72 ± 03, 0.86 ± 06, and 0.95 ± 05 mmol/g at temperatures 293± 1K, 298± 1K and 303± 1K, respectively. Desorptionof As(V) was effective using 0.1 M NaOH in batch mode. Negative values of ΔG° for all temperatures with positive ΔH° confirmed the spontaneous and endothermic nature of As(V) biosorption. The existence of co-existing chloride (Cl-), nitrate (NO3 -), sodium (Na+), and calcium (Ca2+) showed insignificant interference whereas a high concentration of sulphate (SO4 2-) and phosphate (PO4 3-) significantly lowered As(V) biosorption percentage. Arsenic concentrations in actual arsenic polluted groundwater could be reduced to the WHO drinking water standard (10 µg/L) by using only 1 g/L of investigated Fe(III)-SPP. The dynamic biosorption of As(V) in a fixed bed system showed that Fe(III)-SPP was effective also in continuous mode and different design parameters for fixed bed system were determined using Thomas, Adams-Bohart, BDST, and Yoon-Nelson models. Therefore, from all of these results it is suggested that Fe(III)-SPP investigated in this study can be a potential, low cost and environmentally benign biosorbent material for an effective removal of trace amounts of arsenic from polluted water.

8.
RSC Adv ; 12(46): 29865-29877, 2022 Oct 17.
Article in English | MEDLINE | ID: mdl-36321102

ABSTRACT

The main target of this study was to evaluate the efficiency of charred xanthated sugarcane bagasse (CXSB) and charred sugarcane bagasse (CSB) in the removal of Hg(ii) ions from aqueous media. Batch experiments were performed to study the experimental parameters such as effects of pH, concentration, contact time and temperature. The adsorption velocity of Hg(ii) onto CSB and CXSB was fast and reached equilibrium within 60 minutes. Isotherm and kinetic studies showed that Hg(ii) uptake using both the biosorbents followed Langmuir isotherm and pseudo second order kinetics. The maximum adsorption capacity of Hg(ii) at optimum pH 4.5 onto CSB and CXSB was found to be 125 mg g-1 and 333.34 mg g-1, respectively. A negative value of ΔG° and positive ΔS° value (0.24 kJ mol-1 for CSB and 0.18 kJ mol-1 for CXSB) for both the biosorbents confirm the spontaneous nature of Hg(ii) adsorption. A positive value of ΔH° (52.06 kJ mol-1 for CSB and 30.82 kJ mol-1 for CXSB) suggests the endothermic nature of biosorption. The investigated results shows that CXSB compared to CSB can be used as a low cost and environmentally benign bio-adsorbent for the removal of Hg(ii) ions from aqueous solutions.

9.
Heliyon ; 8(8): e10305, 2022 Aug.
Article in English | MEDLINE | ID: mdl-36090219

ABSTRACT

A new biosorbent for Cr(VI) sequestration was investigated from betel nut waste (BNW), Areca catechu, by H2SO4 charring. Aqueous insolubility and Cr(VI) uptake capacity of native BNW were potentially improved after H2SO4 modification due to cross-linking reaction of betel nut cellulose, thereby creating suitable complexation sites for Cr(VI) ion removal. Langmuir isotherm and pseudo second order (PSO) kinetic models described well with the experimental data. A trace amount of Cr(VI) was effectively removed below the safe drinking water standard (WHO, 0.05 mg/L) using charred BNW (CBNW). The negative value of ΔG° evaluated for all the temperatures suggested the spontaneous nature of Cr(VI) sequestration and positive value of ΔH° (42.43±0.13 kJ/mol) confirmed an endothermic reaction. Co-existing NO 3 - , Cl-, Na+ and Zn2+ ions showed negligible interferences, whereas SO 4 2 - and PO 4 3 - notably reduced Cr(VI) uptake capacity of CBNW. More than 98% of adsorbed Cr(VI) was desorbed using 1M NaOH solution. A light yellow precipitate of BaCrO4 was recovered from the desorbed solution after precipitation with BaCl2 solution. Therefore, the CBNW biosorbent investigated in this work is expected to be a promising material for Cr(VI) sequestration and its recovery from polluted water.

10.
Biomolecules ; 12(9)2022 09 04.
Article in English | MEDLINE | ID: mdl-36139075

ABSTRACT

Pancreatic beta cells are highly susceptible to oxidative stress, which plays a crucial role in diabetes outcomes. Progress has been slow to identify molecules that could be utilized to enhance cell survival and function under oxidative stress. Itaconate, a byproduct of the tricarboxylic acid cycle, has both anti-inflammatory and antioxidant properties. The effects of itaconate on beta cells under oxidative stress are relatively unknown. We explored the effects of 4-octyl itaconate-a cell-permeable derivative of itaconate-on MIN6 (a beta cell model) under oxidative stress conditions caused by hypoxia, along with its mechanism of action. Treatment with 4-OI reversed hypoxia-induced cell death, reduced ROS production, and inhibited cell death pathway activation and inflammatory cytokine secretion in MIN6 cells. The 4-OI treatment also suppressed lactate dehydrogenase A (LDHA)activity, which increases under hypoxia. Treatment of cells with the ROS scavenger NAC and LDHA-specific inhibitor FX-11 reproduced the beneficial effects of 4-OI on MIN6 cell viability under oxidative stress conditions, confirming its role in regulating ROS production. Conversely, overexpression of LDHA reduced the beneficial effects exerted by 4-OI on cells. Our findings provide a strong rationale for using 4-OI to prevent the death of MIN6 cells under oxidative stress.


Subject(s)
Antioxidants , Oxidative Stress , Antioxidants/metabolism , Antioxidants/pharmacology , Cytokines/metabolism , Humans , Hypoxia , Lactate Dehydrogenase 5 , Reactive Oxygen Species/metabolism , Succinates
11.
Clin Exp Immunol ; 208(3): 255-267, 2022 06 23.
Article in English | MEDLINE | ID: mdl-35439818

ABSTRACT

FOXP3+ regulatory T cells (Tregs) are central to maintaining peripheral tolerance and immune homeostasis. They have the potential to be developed as a cellular therapy to treat various clinical ailments such as autoimmune disorders, inflammatory diseases and to improve transplantation outcomes. However, a major question remains whether Tregs can persist and exert their function effectively in a disease state, where a broad spectrum of inflammatory mediators could inactivate Tregs. In this study, we investigated the potential of mesenchymal stem cell (MSC)-derived exosomes to promote and sustain Tregs function. MSC-conditioned media (MSC-CM) cultured Tregs were more suppressive in both polyclonal and allogeneic responses and were resistant to inflammatory stimulation in vitro compared with the controls. A similar enhancement of Treg function was also observed by culturing Tregs with MSC-derived exosomes alone. The enhanced suppressive activity and stability of Treg cultured in MSC-CM was reduced when exosomes were depleted from MSC-CM. We identified that MSC-derived exosomes could upregulate the expression of LC3(II/I), phosphorylate Jak3 and Stat5 to promote Treg survival, and regulate FOXP3 expression in Tregs. Overall, our study demonstrates that MSC-derived exosomes are capable of enhancing Hucb-Tregs function and stability by activating autophagy and Stat5 signalling pathways. Our findings provide a strong rationale for utilizing MSC-derived exosomes as an effective strategy to enhance Treg function, and improve the overall Tregs-based cell therapy landscape.


Subject(s)
Exosomes , Mesenchymal Stem Cells , Exosomes/metabolism , Fetal Blood , Forkhead Transcription Factors/metabolism , Humans , STAT5 Transcription Factor/metabolism , T-Lymphocytes, Regulatory
12.
Cell Transplant ; 30: 9636897211046556, 2021.
Article in English | MEDLINE | ID: mdl-34570631

ABSTRACT

The role of Regulatory T cells (Tregs) in tolerance induction post-transplantation is well-established, but Tregs adoptive transfer alone without combined immunosuppressants have failed so far in achieving clinical outcomes. Here we applied a set of well-designed criteria to test the influence of commonly used immunosuppressants (belatacept, tacrolimus, and mycophenolate) on cord blood-derived Tregs (CB-Tregs). Our study shows that while none of these immunosuppressants modulated the stability and expression of homing molecules by CB-Tregs, belatacept met all other selective criteria, shown by its ability to enhance CB-Tregs-mediated in vitro suppression of the allogeneic response without affecting their viability, proliferation, mitochondrial metabolism and expression of functional markers. In contrast, treatment with tacrolimus or mycophenolate led to reduced expression of functional molecule GITR in CB-Tregs, impaired their viability, proliferation and mitochondrial metabolism. These findings indicate that belatacept could be considered as a candidate in Tregs-based clinical immunomodulation regimens to induce transplant tolerance.


Subject(s)
Abatacept/therapeutic use , Fetal Blood/immunology , Immune Tolerance/immunology , Immunosuppressive Agents/therapeutic use , T-Lymphocytes, Regulatory/immunology , Abatacept/pharmacology , Humans , Immunosuppressive Agents/pharmacology
13.
Cell Adh Migr ; 15(1): 126-139, 2021 12.
Article in English | MEDLINE | ID: mdl-33823745

ABSTRACT

MAGI1 is an intracellular adaptor protein that stabilizes cell junctions and regulates epithelial and endothelial integrity. Here, we report that that in endothelial cells MAGI1 colocalizes with paxillin, ß3-integrin, talin 1, tensin 3 and α-4-actinin at mature focal adhesions and actin stress fibers, and regulates their dynamics. Downregulation of MAGI1 reduces focal adhesion formation and maturation, cell spreading, actin stress fiber formation and RhoA/Rac1 activation. MAGI1 silencing increases phosphorylation of paxillin at Y118, an indicator of focal adhesion turnover. MAGI1 promotes integrin-dependent endothelial cells adhesion to ECM, reduces invasion and tubulogenesisin vitro and suppresses angiogenesis  in vivo. Our results identify MAGI1 as anovel component of focal adhesions, and regulator of focal adhesion dynamics, cell adhesion, invasion and angiogenesis.


Subject(s)
Adaptor Proteins, Signal Transducing/metabolism , Cell Adhesion Molecules/metabolism , Cell Adhesion/physiology , Endothelial Cells/metabolism , Focal Adhesions/metabolism , Guanylate Kinases/metabolism , Neovascularization, Physiologic , Actinin/metabolism , Animals , Cell Movement , Focal Adhesion Protein-Tyrosine Kinases/metabolism , Humans , Integrin beta3/metabolism , Mice , Mice, Transgenic , Paxillin/metabolism , Phosphorylation , Stress, Mechanical , Talin/metabolism , Tensins/metabolism , rac1 GTP-Binding Protein/metabolism , rhoA GTP-Binding Protein/metabolism
14.
Int J Mol Sci ; 22(8)2021 Apr 14.
Article in English | MEDLINE | ID: mdl-33920030

ABSTRACT

Recent advances provide evidence that the cellular signalling pathway comprising the ligand-receptor duo of thrombospondin-1 (TSP1) and CD47 is involved in mediating a range of diseases affecting renal, vascular, and metabolic function, as well as cancer. In several instances, research has barely progressed past pre-clinical animal models of disease and early phase 1 clinical trials, while for cancers, anti-CD47 therapy has emerged from phase 2 clinical trials in humans as a crucial adjuvant therapeutic agent. This has important implications for interventions that seek to capitalize on targeting this pathway in diseases where TSP1 and/or CD47 play a role. Despite substantial progress made in our understanding of this pathway in malignant and cardiovascular disease, knowledge and translational gaps remain regarding the role of this pathway in kidney and metabolic diseases, limiting identification of putative drug targets and development of effective treatments. This review considers recent advances reported in the field of TSP1-CD47 signalling, focusing on several aspects including enzymatic production, receptor function, interacting partners, localization of signalling, matrix-cellular and cell-to-cell cross talk. The potential impact that these newly described mechanisms have on health, with a particular focus on renal and metabolic disease, is also discussed.


Subject(s)
CD47 Antigen/genetics , Cell Communication/genetics , Kidney/metabolism , Thrombospondin 1/genetics , Humans , Kidney/pathology , Kidney Diseases/genetics , Metabolic Diseases/genetics , Neoplasms/genetics , Signal Transduction/genetics , Vascular Diseases/genetics
16.
Sci Rep ; 10(1): 21968, 2020 12 15.
Article in English | MEDLINE | ID: mdl-33319836

ABSTRACT

Acute kidney injury (AKI) is a major health problem affecting millions of patients globally. There is no effective treatment for AKI and new therapies are urgently needed. Novel drug development, testing and progression to clinical trials is overwhelmingly expensive. Drug repurposing is a more cost-effective measure. We identified 2 commonly used drugs (colchicine and metformin) that alter inflammatory cell function and signalling pathways characteristic of AKI, and tested them in models of acute and chronic kidney injury to assess therapeutic benefit. We assessed the renoprotective effects of colchicine or metformin in C57BL/6 mice challenged with renal ischemia reperfusion injury (IRI), treated before or after injury. All animals underwent analysis of renal function and biomolecular phenotyping at 24 h, 48 h and 4 weeks after injury. Murine renal tubular epithelial cells were studied in response to in vitro mimics of IRI. Pre-emptive treatment with colchicine or metformin protected against AKI, with lower serum creatinine, improved histological changes and decreased TUNEL staining. Pro-inflammatory cytokine profile and multiple markers of oxidative stress were not substantially different between groups. Metformin augmented expression of multiple autophagic proteins which was reversed by the addition of hydroxychloroquine. Colchicine led to an increase in inflammatory cells within the renal parenchyma. Chronic exposure after acute injury to either therapeutic agent in the context of reduced renal mass did not mitigate the development of fibrosis, with colchicine significantly worsening an ischemic phenotype. These data indicate that colchicine and metformin affect acute and chronic kidney injury differently. This has significant implications for potential drug repurposing, as baseline renal disease must be considered when selecting medication.


Subject(s)
Acute Kidney Injury/prevention & control , Colchicine/administration & dosage , Drug Repositioning , Kidney Failure, Chronic/prevention & control , Metformin/administration & dosage , Animals , Humans , Mice , Mice, Inbred C57BL
17.
Cells ; 9(7)2020 07 15.
Article in English | MEDLINE | ID: mdl-32679764

ABSTRACT

The aged population is currently at its highest level in human history and is expected to increase further in the coming years. In humans, aging is accompanied by impaired angiogenesis, diminished blood flow and altered metabolism, among others. A cellular mechanism that impinges upon these manifestations of aging can be a suitable target for therapeutic intervention. Here we identify cell surface receptor CD47 as a novel age-sensitive driver of vascular and metabolic dysfunction. With the natural aging process, CD47 and its ligand thrombospondin-1 were increased, concurrent with a reduction of self-renewal transcription factors OCT4, SOX2, KLF4 and cMYC (OSKM) in arteries from aged wild-type mice and older human subjects compared to younger controls. These perturbations were prevented in arteries from aged CD47-null mice. Arterial endothelial cells isolated from aged wild-type mice displayed cellular exhaustion with decreased proliferation, migration and tube formation compared to cells from aged CD47-null mice. CD47 suppressed ex vivo sprouting, in vivo angiogenesis and skeletal muscle blood flow in aged wild-type mice. Treatment of arteries from older humans with a CD47 blocking antibody mitigated the age-related deterioration in angiogenesis. Finally, aged CD47-null mice were resistant to age- and diet-associated weight gain, glucose intolerance and insulin desensitization. These results indicate that the CD47-mediated signaling maladapts during aging to broadly impair endothelial self-renewal, angiogenesis, perfusion and glucose homeostasis. Our findings provide a strong rationale for therapeutically targeting CD47 to minimize these dysfunctions during aging.


Subject(s)
Aging/pathology , CD47 Antigen/metabolism , Glucose/metabolism , Homeostasis , Neovascularization, Physiologic , Animals , Arteries/pathology , Cell Movement/genetics , Cell Proliferation/genetics , Cell Self Renewal , Endothelial Cells/metabolism , Endothelial Cells/pathology , Gene Expression Regulation , Humans , Kruppel-Like Factor 4 , Male , Matrix Metalloproteinases/metabolism , Metabolic Syndrome/pathology , Mice, Inbred C57BL , Neovascularization, Physiologic/genetics , Regional Blood Flow , Thrombospondin 1/metabolism , Transcription Factors/metabolism
18.
Lab Invest ; 100(9): 1184-1196, 2020 09.
Article in English | MEDLINE | ID: mdl-32366943

ABSTRACT

Acute kidney injury triggers a complex cascade of molecular responses that can culminate in maladaptive repair and fibrosis. We have previously reported that the matrix protein thrombospondin-1 (TSP1), binding its high affinity its receptor CD47, promotes acute kidney injury. However, the role of this pathway in promoting fibrosis is less clear. Hypothesizing that limiting TSP1-CD47 signaling is protective against fibrosis, we interrogated this pathway in a mouse model of chronic ischemic kidney injury. Plasma and renal parenchymal expression of TSP1 in patients with chronic kidney disease was also assessed. We found that CD47-/- mice or wild-type mice treated with a CD47 blocking antibody showed clear amelioration of fibrotic histological changes compared to control animals. Wild-type mice showed upregulated TSP1 and pro-fibrotic markers which were significantly abrogated in CD47-/- and antibody-treated cohorts. Renal tubular epithelial cells isolated from WT mice showed robust upregulation of pro-fibrotic markers following hypoxic stress or exogenous TSP1, which was mitigated in CD47-/- cells. Patient sera showed a proportionate correlation between TSP1 levels and worsening glomerular filtration rate. Immunohistochemistry of human kidney tissue demonstrated tubular and glomerular matrix localization of TSP1 expression in patients with CKD. These data suggest that renal tubular epithelial cells contribute to fibrosis by activating TSP1-CD47 signaling, and point to CD47 as a potential target to limit fibrosis following ischemic injury.


Subject(s)
CD47 Antigen/metabolism , Kidney/metabolism , Signal Transduction , Thrombospondin 1/metabolism , Animals , CD47 Antigen/genetics , Cells, Cultured , Disease Models, Animal , Epithelial Cells/metabolism , Fibrosis , Humans , Ischemia , Kidney/blood supply , Kidney/pathology , Kidney Tubules/cytology , Kidney Tubules/metabolism , Mice, Inbred C57BL , Mice, Knockout
19.
Sci Rep ; 10(1): 6930, 2020 04 24.
Article in English | MEDLINE | ID: mdl-32332767

ABSTRACT

Normothermic machine perfusion (NMP) is an emerging modality for kidney preservation prior to transplantation. NMP may allow directed pharmacomodulation of renal ischemia-reperfusion injury (IRI) without the need for systemic donor/recipient therapies. Three proven anti-IRI agents not in widespread clinical use, CD47-blocking antibody (αCD47Ab), soluble complement receptor 1 (sCR1), and recombinant thrombomodulin (rTM), were compared in a murine model of kidney IRI. The most effective agent was then utilized in a custom NMP circuit for the treatment of isolated porcine kidneys, ascertaining the impact of the drug on perfusion and IRI-related parameters. αCD47Ab conferred the greatest protection against IRI in mice after 24 hours. αCD47Ab was therefore chosen as the candidate agent for addition to the NMP circuit. CD47 receptor binding was demonstrated by immunofluorescence. Renal perfusion/flow improved with CD47 blockade, with a corresponding reduction in oxidative stress and histologic damage compared to untreated NMP kidneys. Tubular and glomerular functional parameters were not significantly impacted by αCD47Ab treatment during NMP. In a murine renal IRI model, αCD47Ab was confirmed as a superior anti-IRI agent compared to therapies targeting other pathways. NMP enabled effective, direct delivery of this drug to porcine kidneys, although further efficacy needs to be proven in the transplantation setting.


Subject(s)
Antibodies/pharmacology , Kidney/pathology , Perfusion , Reperfusion Injury/pathology , Temperature , Animals , Blood Urea Nitrogen , CD47 Antigen/immunology , Chemokines/genetics , Chemokines/metabolism , Complement C3/metabolism , Complement C9/metabolism , Creatinine/blood , Drug Delivery Systems , Epithelial Cells/drug effects , Epithelial Cells/metabolism , Epithelial Cells/pathology , Female , Hepatitis A Virus Cellular Receptor 1/genetics , Hepatitis A Virus Cellular Receptor 1/metabolism , Hydrogen Peroxide/metabolism , Inflammation Mediators/metabolism , Kidney Tubules/pathology , Male , Mice , Mice, Inbred C57BL , Neutrophils/drug effects , Neutrophils/metabolism , Oxidative Stress/drug effects , RNA, Messenger/genetics , RNA, Messenger/metabolism , Receptors, Complement/metabolism , Reperfusion Injury/blood , Swine
20.
Nat Commun ; 10(1): 5012, 2019 11 01.
Article in English | MEDLINE | ID: mdl-31676764

ABSTRACT

Peptides and biologics provide unique opportunities to modulate intracellular targets not druggable by conventional small molecules. Most peptides and biologics are fused with cationic uptake moieties or formulated into nanoparticles to facilitate delivery, but these systems typically lack potency due to low uptake and/or entrapment and degradation in endolysosomal compartments. Because most delivery reagents comprise cationic lipids or polymers, there is a lack of reagents specifically optimized to deliver cationic cargo. Herein, we demonstrate the utility of the cytocompatible polymer poly(propylacrylic acid) (PPAA) to potentiate intracellular delivery of cationic biomacromolecules and nano-formulations. This approach demonstrates superior efficacy over all marketed peptide delivery reagents and enhances delivery of nucleic acids and gene editing ribonucleoproteins (RNPs) formulated with both commercially-available and our own custom-synthesized cationic polymer delivery reagents. These results demonstrate the broad potential of PPAA to serve as a platform reagent for the intracellular delivery of cationic cargo.


Subject(s)
Acrylates/chemistry , Endosomes/chemistry , Macromolecular Substances/chemistry , Nanoparticles/chemistry , Peptides/chemistry , Polymers/chemistry , Animals , Anions/chemistry , Cations/chemistry , Cell Line , Cells, Cultured , Drug Delivery Systems/methods , Endosomes/metabolism , HEK293 Cells , Humans , Intracellular Space/metabolism , MCF-7 Cells , Macromolecular Substances/administration & dosage , Mice , NIH 3T3 Cells , Nanoparticles/administration & dosage , Peptides/administration & dosage , RAW 264.7 Cells , Rats , Reproducibility of Results
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