N,N-Dimethylacetamide Significantly Attenuates LPS- and TNFα-Induced Proinflammatory Responses Via Inhibition of the Nuclear Factor Kappa B Pathway

N,N-dimethylacetamide targets neuroinflammation in Alzheimer's disease in in-vitro and ex-vivo models

Alzheimer's disease (AD) is a chronic degenerative brain disorder with no clear pathogenesis or effective cure, accounting for 60-80% of cases of dementia. In recent years, the importance of neuroinflammation in the pathogenesis of AD and other neurodegenerative disorders has come into focus. Previously, we made the serendipitous discovery that the widely used drug excipient N,N-dimethylacetamide (DMA) attenuates endotoxin-induced inflammatory responses in vivo. In the current work, we investigate the effect of DMA on neuroinflammation and its mechanism of action in in-vitro and ex-vivo models of AD. We show that DMA significantly suppresses the production of inflammatory mediators, such as reactive oxygen species (ROS), nitric oxide (NO) and various cytokines and chemokines, as well as amyloid-β (Aβ), in cultured microglia and organotypic hippocampal slices induced by lipopolysaccharide (LPS). We also demonstrate that DMA inhibits Aβ-induced inflammation. Finally, we show that the mechanism of DMA's effect on neuroinflammation is inhibition of the nuclear factor kappa-B (NF-κB) signaling pathway and we show how DMA dismantles the positive feedback loop between NF-κB and Aβ synthesis. Taken together, our findings suggest that DMA, a generally regarded as safe compound that crosses the blood brain barrier, should be further investigated as a potential therapy for Alzheimer's disease and neuroinflammatory disorders.

N,N-Dimethylformamide Delays LPS-Induced Preterm Birth in a Murine Model by Suppressing the Inflammatory Response

Preterm birth accounts for the majority of perinatal mortality worldwide, and there remains no FDA-approved drug to prevent it. Recently, we discovered that the common drug excipient, N,N-dimethylacetamide (DMA), delays inflammation-induced preterm birth in mice by inhibiting NF-κB. Since we reported this finding, it has come to light that a group of widely used, structurally related aprotic solvents, including DMA, N-methyl-2-pyrrolidone (NMP) and dimethylformamide (DMF), have anti-inflammatory efficacy. We show here that DMF suppresses LPS-induced TNFα secretion from RAW 264.7 cells and IL-6 and IL-8 secretion from HTR-8 cells at concentrations that do not significantly affect cell viability. Like DMA, DMF protects IκBα from degradation and prevents the p65 subunit of NF-κB from translocating to the nucleus. In vivo, DMF decreases LPS-induced inflammatory cell infiltration and expression of TNFα and IL-6 in the placental labyrinth, all to near baseline levels. Finally, DMF decreases the rate of preterm birth in LPS-induced pregnant mice (P<.0001) and the rate at which pups are spontaneously aborted (P<.0001). In summary, DMF, a widely used solvent structurally related to DMA and NMP, delays LPS-induced preterm birth in a murine model without overt toxic effects. Re-purposing the DMA/DMF/NMP family of small molecules as anti-inflammatory drugs is a promising new approach to delaying or reducing the incidence of inflammation-induced preterm birth and potentially attenuating other inflammatory disorders as well.

Vaginal Nanoformulations for the Management of Preterm Birth

Preterm birth (PTB) is a leading cause of infant morbidity and mortality in the world. In 2020, 1 in 10 infants were born prematurely in the United States. The World Health Organization estimates that a total of 15 million infants are born prematurely every year. Current therapeutic interventions for PTB have had limited replicable success. Recent advancements in the field of nanomedicine have made it possible to utilize the vaginal administration route to effectively and locally deliver drugs to the female reproductive tract. Additionally, studies using murine models have provided important insights about the cervix as a gatekeeper for pregnancy and parturition. With these recent developments, the field of reproductive biology is on the cusp of a paradigm shift in the context of treating PTB. The present review focuses on the complexities associated with treating the condition and novel therapeutics that have produced promising results in preclinical studies.

FDA-Approved Excipient N, N-Dimethylacetamide Attenuates Inflammatory Bowel Disease in In Vitro and In Vivo Models

Inflammatory bowel disease (IBD) affects almost 7 million people worldwide and is increasing in incidence. While the precise pathogenesis of IBD remains unknown, the production of inflammatory cytokines and chemokines play a central role. We have previously found that N, N-dimethylacetamide (DMA), a widely used non-toxic drug excipient, suppresses cytokine and chemokine secretion in vitro and prevents inflammation-induced preterm birth in vivo. Using sandwich enzyme-linked immunosorbent assays (ELISAs), we tested whether DMA attenuates cytokine and chemokine secretion from LPS- or TNFα-stimulated human intestinal epithelial cells and human monocytes and HMGB1 release from RAW 264.7 cells. To test our hypothesis that the mechanism of DMA's effects in in vitro and in vivo models of IBD is inhibition of the NF-κB pathway, we used western blotting to track levels of the nuclear factor kappa B (NF-κB) inhibitory molecule I kappa B alpha (IκBα) in THP-1 human monocytes in the absence or presence of DMA. Finally, we induced colitis in C57Bl/6 mice with dextran sodium sulfate (DSS) and then tested whether i.p injections of DMA at 2.1 g/kg/day attenuates clinical and histopathologic signs of colitis. DMA attenuated cytokine and chemokine release from human intestinal epithelial cells and human monocytes and HMGB1 release from RAW 264.7 cells. Importantly, DMA prevented degradation of IκBα in THP-1 cells, thereby suggesting one mechanism for DMA's effects. Finally, we show here, for the first time, that DMA attenuates clinical and histologic features of DSS-induced colitis. Based on these data, DMA should be further explored in preclinical and clinical trials for its potential as novel drug therapy for IBD.

Exosomal delivery of NF-κB inhibitor delays LPS-induced preterm birth and modulates fetal immune cell profile in mouse models

Accumulation of immune cells and activation of the pro-inflammatory transcription factor NF-κB in feto-maternal uterine tissues is a key feature of preterm birth (PTB) pathophysiology. Reduction of the fetal inflammatory response and NF-κB activation are key strategies to minimize infection-associated PTB. Therefore, we engineered extracellular vesicles (exosomes) to contain an NF-κB inhibitor, termed super-repressor (SR) IκBα. Treatment with SR exosomes (1 × 1010 per intraperitoneal injection) after lipopolysaccharide (LPS) challenge on gestation day 15 (E15) prolonged gestation by over 24 hours (PTB ≤ E18.5) and reduced maternal inflammation (n ≥ 4). Furthermore, using a transgenic model in which fetal tissues express the red fluorescent protein tdTomato while maternal tissues do not, we report that LPS-induced PTB in mice is associated with influx of fetal innate immune cells, not maternal, into feto-maternal uterine tissues. SR packaged in exosomes provides a stable and specific intervention for reducing the inflammatory response associated with PTB.

Sodium Hydrogen Exchanger Regulatory Factor-1 (NHERF1) Regulates Fetal Membrane Inflammation

The fetal inflammatory response, a key contributor of infection-associated preterm birth (PTB), is mediated by nuclear factor kappa B (NF-kB) activation. Na⁺/H⁺ exchanger regulatory factor-1 (NHERF1) is an adapter protein that can regulate intracellular signal transduction and thus influence NF-kB activation. Accordingly, NHERF1 has been reported to enhance proinflammatory cytokine release and amplify inflammation in a NF-kB-dependent fashion in different cell types. The objective of this study was to examine the role of NHERF1 in regulating fetal membrane inflammation during PTB. We evaluated the levels of NHERF1 in human fetal membranes from term labor (TL), term not in labor (TNIL), and PTB and in a CD1 mouse model of PTB induced by lipopolysaccharide (LPS). Additionally, primary cultures of fetal membrane cells were treated with LPS, and NHERF1 expression and cytokine production were evaluated. Gene silencing methods using small interfering RNA targeting NHERF1 were used to determine the functional relevance of NHERF1 in primary cultures. NHERF1 expression was significantly (p < 0.001) higher in TL and PTB membranes compared to TNIL membranes, and this coincided with enhanced (p < 0.01) interleukin (IL)-6 and IL-8 expression levels. LPS-treated animals delivering PTB had increased levels of NHERF1, IL-6, and IL-8 compared to phosphate-buffered saline (PBS; control) animals. Silencing of NHERF1 expression resulted in a significant reduction in NF-kB activation and IL-6 and IL-8 production as well as increased IL-10 production. In conclusion, downregulation of NHERF1 increased anti-inflammatory IL-10, and reducing NHERF1 expression could be a potential therapeutic strategy to reduce the risk of infection/inflammation associated with PTB.

The emerging role of exosomes as novel therapeutics: Biology, technologies, clinical applications, and the next

The extracellular vesicles (EVs) research area has grown rapidly because of their pivotal roles in intercellular communications and maintaining homeostasis of individual organism. As a subtype of EVs, exosomes are made via unique biogenesis pathway and exhibit disparate functional and phenotypic characteristics. Functionally, exosomes transfer biological messages from donor cell to recipient cell, which makes exosomes as a novel therapeutic platform delivering therapeutic materials to the target tissue/cell. Currently, both academia and industry try to develop exosome platform‐based therapeutics for disease management, some of which are already in clinical trials. In this review, we will discuss focusing on therapeutic values of exosomes, recent advances in therapeutic exosome platform development, and late development of exosome therapeutics in diverse therapeutic areas.

Upregulation of TNF-α and IL-6 induces preterm premature rupture of membranes by activation of ADAMTS-9 in embryonic membrane cells

AIM

To investigate the role of thrombospondin motifs 9 (ADAMTS9) in preterm premature rupture of membranes (pPROM).

MATERIALS AND METHODS

ADAMTS9 levels were measured in amnion cells from 24 patients of different groups (preterm vs. full-term birth, with vs. without PROM). ADAMTS9 was suppressed in human amnioblasts to investigate its effects on embryonic membrane cells and inflammation-induced cell damage. Pregnant mouse models were used to assess whether inflammation regulates ADAMTS9 by upregulating TNF-α and IL-6, contributing to the preterm birth occurrence.

KEY FINDINGS

We found that ADAMTS9 protein and gene expression levels significantly differed among various groups (pPROM > full-term PROM > preterm non-PROM > full-term non-PROM). After ADAMTS9 suppression in human amnioblast WISH cells, TNF-α- and IL-6-induced apoptosis was decreased. In addition, TNF-α, IL-6, and ADAMTS9 protein and gene expression levels were increased in the embryos of mice treated with LPS compared with controls. In agreement, the rate of preterm birth was higher in the LPS group compared with controls.

SIGNIFICANCE

Taken together, these in vitro and in vivo findings suggest that TNF-α and IL-6 secreted by macrophages during inflammation regulate ADAMTS9 and induce pPROM.

Erythropoietin prevents LPS-induced preterm birth and increases offspring survival

Problem

Preterm delivery is the leading cause of neonatal mortality and contributes to delayed physical and cognitive development in children. At present, there is no efficient therapy to prevent preterm labor. A large body of evidence suggests that infections might play a significant and potentially preventable cause of premature birth. This work assessed the effects of erythropoietin (EPO) in a murine model of inflammation‐associated preterm delivery, which mimics central features of preterm infections in humans.

Method of study

BALB/c mice were injected i.p. with 20 000 IU/kg EPO or normal saline twice on gestational day (GD) 15, with a 3 hours time interval between injections. An hour after the first EPO or normal saline injection, all mice received two injections of 50 μg/kg LPS, also given 3 hours apart.

Results

EPO significantly prevented preterm labor and increased offspring survival in an LPS induced preterm delivery model. EPO prevented LPS‐induced leukocyte infiltration into the placenta. Moreover, EPO inhibited the expression of pro‐inflammatory cytokines, interleukin‐1β (IL‐1β), interleukin‐6 (IL‐6), and tumour necrosis factor‐α (TNF‐α) in maternal serum and amniotic fluid. EPO also prevented LPS‐induced increase in placental prostaglandin (PG)E2 and uterine inducible nitric oxide synthase (iNOS) production, while decreasing nuclear factor kappa‐B (NF‐κβ) activity in the myometrium. EPO also increased the gene expression of placental programmed cell death ligand 1 (PD‐L1) in LPS‐treated mice.

Conclusions

Our results suggest that EPO could be a potential novel therapeutic strategy to tackle infection‐related preterm labor.

The Release of the Bromodomain Ligand N,N-Dimethylacetamide Adds Bioactivity to a Resorbable Guided Bone Regeneration Membrane in a Rabbit Calvarial Defect Model

N,N-Dimethylacetamide (DMA) is FDA approved as an excipient and is used as drug-delivery vehicle. Due to its amphipathic nature and diverse bioactivities, it appears to be a good combination of biodegradable poly-lactide-co-glycolide (PLGA)-based guided bone regeneration membranes. Here we show that the solvent DMA can be loaded to PLGA membranes by different regimes, leading to distinct release profiles, and enhancing the bone regeneration in vivo. Our results highlight the potential therapeutic benefits of DMA in guided bone regeneration procedures, in combination with biodegradable PLGA membranes.

A vaginal nanoformulation of a SphK inhibitor attenuates lipopolysaccharide-induced preterm birth in mice

Aim: Previously, we have shown that inhibition of SphK by the SphK inhibitor-II (SKI II) prevents lipopolysaccharide-induced preterm birth in mice. The aim of this study was to develop a vaginal self-nanoemulsifying drug-delivery system (SNEDDS) for SKI II. Materials & methods: A SKI II-loaded SNEDDS was characterized and tested in a murine preterm birth model. Results: The SNEDDS immediately formed a gel and then slowly emulsified to nanoglobules with over 500-fold enhancement of SKI II solubility at vaginal pH. Intravaginal administration of the SKI II SNEDDS significantly decreased lipopolysaccharide-induced preterm birth in mice. Conclusion: A vaginal nanoformulation of SKI II represents a novel, noninvasive approach to prevent preterm birth.

N,N-Dimethlyacetamide Prevents the High-Fat Diet-Induced Increase in Body Weight

Increased body weight caused by visceral fat accumulation is on the rise and is reaching epidemic proportions worldwide. Hence, means and ways to tackle the problem of increased adiposity is of utmost importance. In this work, we report the effect of a water-soluble small molecule N,N-Dimethlyacetamide (DMA) on weight gain and adiposity in vitro and in vivo. To monitor the in vitro effect of DMA on adipogenesis, 3T3-L1 preadipocytes and pluripotent C2C12 cells were differentiated to adipocytes in the presence of DMA (5 mM and 10 mM). Oil red O staining and reverse transcriptase polymerase chain reaction (RT-PCR) were performed to evaluate the differentiation to adipocytes. To study the in vivo effect of DMA on body weight, experiments were done with C57BL/6J male mice (6 weeks old). The mice were randomly assigned to receive either high-fat diet (HFD; 45% fat) or a normal diet (7% fat) and were either intraperitoneally injected with DMA or phosphate-buffered saline (PBS) once a week for 20 weeks. Glucose tolerance test was performed on living mice. Post-experiment, the epididymal and subcutaneous adipose tissue were excised from the sacrificed animal, and histology, RT-PCR and plasma triglyceride assay were performed. DMA had no inhibitory effect on adipocyte differentiation when applied only once. However, sustained treatment with DMA inhibited the adipocyte differentiation in both 3T3-L1 and C2C12 cells, and significantly lowered the expression of adipocyte markers, in particular, fatty acid-binding protein 4 (fabp4). Under HFD, C57BL/6J mice treated with DMA had lower body weight compared with PBS treatment. Moreover, the HFD-induced higher body weight was controlled when the mice were switched from PBS to DMA treatment. Further, the HFD-mediated adipocyte hypertrophy from epididymal and subcutaneous adipose tissue was significantly reduced with DMA treatment. Interestingly, the glucose clearance and triglyceride levels in the plasma were improved in mice when DMA treatment was initiated early. Taken together, our results show that DMA exhibits a clear potential to prevent weight gain and restricts adiposity in response to high-fat feeding.

17-α Hydroxyprogesterone Nanoemulsifying Preconcentrate-Loaded Vaginal Tablet: A Novel Non-Invasive Approach for the Prevention of Preterm Birth

Preterm birth (PTB) is a major cause of infant mortality in the United States and around the globe. Makena^®—once-a-week intramuscular injection of 17-α Hydroxyprogesterone caproate (17P)—is the only FDA approved treatment for the prevention of PTB. Invasive delivery of 17P requires hospitalization and expert personnel for injection. Vaginal delivery of 17P would be preferable, because of high patient compliance, reduced systemic exposure, fewer side effects, and no need for hospitalization. The objective of the present study was to prepare and evaluate a self-nanoemulsifying vaginal tablet of 17P. A solid self-nanoemulsifying preconcentrate (S-SNEDDS) of 17P and dimethylacetamide (DMA) was developed using medium chain triglycerides, a non- immunogenic surfactant, and co-processed excipient (PVA-F100). The tablet prepared was characterized for emulsification time, particle size, solid state properties, and drug release. The formulation showed >50% inhibition of TNF-α release from LPS-stimulated RAW 264.7 cells. Importantly, there were significant differences in rates of PTB and average time to delivery between control and vaginal 17P-treated groups in LPS-stimulated timed pregnant E15.5 mice. Considering the lacuna of therapeutic approaches in this area, vaginal delivery of 17P for the prevention of preterm birth has significant clinical relevance.

Anti-inflammatory effect of diterpenes-enriched fractions from Pterodon polygalaeflorus through inhibition of macrophage migration and cytokine production

Objectives

To evaluate the anti-inflammatory potential of Pterodon polygalaeflorus hexane extract (HE) and its fractions on macrophage migration in vitro and in vivo.

Methods

Hexane extract from P. polygalaeflorus fruits was fractionated and yielded four fractions. RAW 264.7 cells were treated with samples to evaluate cell viability (MTT assay), cell migration (wound healing and transwell assays), CD14 expression (flow cytometry), iNOS and cytokine mRNA expression (RT-qPCR), NO (Griess reaction) and cytokine (ELISA) production. In vivo migration was evaluated on the thioglycollate-induced peritonitis model. Qualitative analysis was performed by GC-MS.

Key findings

All fractions inhibited the NO production by LPS-stimulated RAW 264.7 cells. Fr3 and Fr4 presented the lowest IC50 values. The expressions of iNOS and IL-1β, TNF-α and IL-10 cytokines were inhibited by Fr3 and Fr4, whereas the CD14 expression was only inhibited by Fr3. All the samples inhibited RAW 264.7 migration in the wound healing and transwell assays. Fr3 and Fr4 reduced the migration of Mac-1+Gr-1− cells to the peritoneum and presented in their compositions: 6α-hydroxy-7β-acetoxyvouacapan-17β-oate, methyl 6α,7β-dihydroxyvouacapan-17β-oate, methyl 6α-acetoxy-7β-hydroxyvouacapan-17β-oate, geranylgeraniol and 14,15-epoxy-geranylgeraniol.

Conclusions

The anti-inflammatory effects of Fr3 and Fr4 involve inhibition of cell migration, iNOS expression and NO production, cytokine expression (mRNA and proteins) and CD14 expression (Fr3).