Dexamethasone and pentoxifylline inhibit endotoxin-induced cachectin/tumor necrosis factor synthesis at separate points in the signaling pathway

Hypoxia-adenosine axis as therapeutic targets for acute respiratory distress syndrome

The human respiratory and circulatory systems collaborate intricately to ensure oxygen delivery to all cells, which is vital for ATP production and maintaining physiological functions and structures. During limited oxygen availability, hypoxia-inducible factors (HIFs) are stabilized and play a fundamental role in maintaining cellular processes for hypoxia adaptation. First discovered during investigations of erythropoietin production regulation, HIFs influence physiological and pathological processes, including development, inflammation, wound healing, and cancer. HIFs promote extracellular adenosine signaling by enhancing adenosine generation and receptor signaling, representing an endogenous feedback mechanism that curbs excessive inflammation, supports injury resolution, and enhances hypoxia tolerance. This is especially important for conditions that involve tissue hypoxia, such as acute respiratory distress syndrome (ARDS), which globally poses significant health challenges without specific treatment options. Consequently, pharmacological strategies to amplify HIF-mediated adenosine production and receptor signaling are of great importance.

Pentoxifylline and Vitamin E Can Restrict Radiation Necrosis via Vascular Pathways, Experimental Study in an Animal Model

OBJECTIVE

Radiation necrosis (RN) is a long-term side effect of Gamma Knife stereotactic radiosurgery that may require surgical intervention. Pentoxifylline and vitamin E have previously been shown to be effective in the treatment of RN in the published literature, but there are no data on the prophylactic use of these molecules or, more importantly, whether prophylaxis is required.

METHODS

The iatrogenic RN model included 50 Sprague-Dawley rats of both sexes. There were 7 treatment subgroups established. Gamma-Plan 8.32 was used to plan after magnetic resonance scans were performed in a specially designed frame. The injection doses used in the treatment groups were vitamin E (30 mg/kg/day in a single dose) and pentoxifylline (50 mg/kg/day in 2 doses). Control magnetic resonance scans were performed at the end of a 16-week treatment, and the subjects were decapitated for pathological evaluations.

RESULTS

The intensity of hypoxia - inducible factor 1α immunoreactivity is statistically significantly lower in the therapeutic vitamin E, prophylactic pentoxifylline and vitamin E, and therapeutic pentoxifylline and vitamin E groups than in the other groups. Similarly, the intensity of vascular endothelial growth factor immunoreactivity was reduced in the therapeutic vitamin E and prophylactic pentoxifylline and vitamin E treatment modality groups. When compared with other groups, the therapeutic pentoxifylline group had significantly fewer vascular endothelial growth factor-immunoreactive cells in the perinecrotic area, with an accompanying decreased contrast enhancement pattern.

CONCLUSIONS

Both vitamin E and pentoxifylline are effective for the treatment and/or restriction of RN, either alone or in combination. The use of these molecules as a preventive measure did not outperform the therapeutic treatment.

TNFR1 links TNF exocytosis to TNF production in allergen-activated RBL-2H3 cells

We previously reported that the maximal production of Tumor Necrosis Factor (TNF or TNFα) in antigen-activated RBL-2H3 cells (a tumor analog of mucosal mast cells) requires Munc13-4, a regulator of exocytic fusion. In this study, we investigated the involvement of various fusion catalysts in TNF production. We observed a strong correlation between the total TNF level and TNF exocytosis in RBL-2H3 cells. RT-qPCR shows that TNFR1 (TNF receptor 1) is the sole TNFR expressed in these cells, and that its transcription is upregulated upon allergen-mediated activation. Importantly, the addition of soluble TNFR1 inhibits antigen-elicited TNF production in a dosage-dependent fashion. Likewise, TNF production is diminished in the presence of TACE (TNFα Converting Enzyme) inhibitor KP-457, which prevents the generation of soluble TNF (sTNF). Together, these findings indicate that sTNF and TNFR1 function as autocrine agent and receptor respectively at the mast cell surface to boost TNF proliferation during allergic inflammation.

Repurposing drugs for highly prevalent diseases: pentoxifylline, an old drug and a new opportunity for diabetic kidney disease

Diabetic kidney disease is one of the most frequent complications in patients with diabetes and constitutes a major cause of end-stage kidney disease. The prevalence of diabetic kidney disease continues to increase as a result of the growing epidemic of diabetes and obesity. Therefore, there is mounting urgency to design and optimize novel strategies and drugs that delay the progression of this pathology and contain this trend. The new approaches should go beyond the current therapy focussed on the control of traditional risk factors such as hyperglycaemia and hypertension. In this scenario, drug repurposing constitutes an economic and feasible approach based on the discovery of useful activities for old drugs. Pentoxifylline is a nonselective phosphodiesterase inhibitor currently indicated for peripheral artery disease. Clinical trials and meta-analyses have shown renoprotection secondary to anti-inflammatory and antifibrotic effects in diabetic patients treated with this old known drug, which makes pentoxifylline a candidate for repurposing in diabetic kidney disease.

Diabetic Nephropathy: Pathogenesis to Cure

Diabetic nephropathy (DN) is a leading cause of end-stage renal disorder (ESRD). It is defined as the increase in urinary albumin excretion (UAE) when no other renal disease is present. DN is categorized into microalbuminuria and macroalbuminuria. Factors like high blood pressure, high blood sugar levels, genetics, oxidative stress, hemodynamic and metabolic changes affect DN. Hyperglycemia causes renal damage through activating protein kinase C (PKC), producing advanced end glycation products (AGEs) and reactive oxygen species (ROS). Growth factors, chemokines, cell adhesion molecules, inflammatory cytokines are found to be elevated in the renal tissues of the diabetic patient. Many different and new diagnostic methods and treatment options are available due to the increase in research efforts and progression in medical science. However, until now, no permanent cure is available. This article aims to explore the mechanism, diagnosis, and therapeutic strategies in current use for increasing the understanding of DN.

Alcohol-Related Liver Disease: An Overview on Pathophysiology, Diagnosis and Therapeutic Perspectives

Alcohol-related liver disease (ALD) refers to a spectrum of liver manifestations ranging from fatty liver diseases, steatohepatitis, and fibrosis/cirrhosis with chronic inflammation primarily due to excessive alcohol use. Currently, ALD is considered as one of the most prevalent causes of liver disease-associated mortality worldwide. Although the pathogenesis of ALD has been intensively investigated, the present understanding of its biomarkers in the context of early clinical diagnosis is not complete, and novel therapeutic targets that can significantly alleviate advanced forms of ALD are limited. While alcohol abstinence remains the primary therapeutic intervention for managing ALD, there are currently no approved medications for treating ALD. Furthermore, given the similarities and the differences between ALD and non-alcoholic fatty liver disease in terms of disease progression and underlying molecular mechanisms, numerous studies have demonstrated that many therapeutic interventions targeting several signaling pathways, including oxidative stress, inflammatory response, hormonal regulation, and hepatocyte death play a significant role in ALD treatment. Therefore, in this review, we summarized several key molecular targets and their modes of action in ALD progression. We also described the updated therapeutic options for ALD management with a particular emphasis on potentially novel signaling pathways.

Immune responses in diabetic nephropathy: Pathogenic mechanisms and therapeutic target

Diabetic nephropathy (DN) is a chronic, inflammatory disease affecting millions of diabetic patients worldwide. DN is associated with proteinuria and progressive slowing of glomerular filtration, which often leads to end-stage kidney diseases. Due to the complexity of this metabolic disorder and lack of clarity about its pathogenesis, it is often more difficult to diagnose and treat than other kidney diseases. Recent studies have highlighted that the immune system can inadvertently contribute to DN pathogenesis. Cells involved in innate and adaptive immune responses can target the kidney due to increased expression of immune-related localization factors. Immune cells then activate a pro-inflammatory response involving the release of autocrine and paracrine factors, which further amplify inflammation and damage the kidney. Consequently, strategies to treat DN by targeting the immune responses are currently under study. In light of the steady rise in DN incidence, this timely review summarizes the latest findings about the role of the immune system in the pathogenesis of DN and discusses promising preclinical and clinical therapies.

Added to pre-existing inflammation, mRNA-lipid nanoparticles induce inflammation exacerbation (IE)

Current nucleoside-modified RNA lipid nanoparticle (modmRNA-LNP) technology has successfully paved the way for the highest clinical efficacy data from next-generation vaccinations against SARS-CoV-2 during the COVID-19 pandemic. However, such modmRNA-LNP technology has not been characterized in common pre-existing inflammatory or immune-challenged conditions, raising the risk of adverse clinical effects when administering modmRNA-LNPs in such cases. Herein, we induce an acute-inflammation model in mice with lipopolysaccharide (LPS) intratracheally (IT), 1 mg kg-1, or intravenously (IV), 2 mg kg-1, and then IV administer modmRNA-LNP, 0.32 mg kg-1, after 4 h, and screen for inflammatory markers, such as pro-inflammatory cytokines. ModmRNA-LNP at this dose caused no significant elevation of cytokine levels in naive mice. In contrast, shortly after LPS immune stimulation, modmRNA-LNP enhanced inflammatory cytokine responses, Interleukin-6 (IL-6) in serum and Macrophage Inflammatory Protein 2 (MIP-2) in liver significantly. Our report identifies this phenomenon as inflammation exacerbation (IE), which was proven to be specific to the LNP, acting independent of mRNA cargo, and was demonstrated to be time- and dose-dependent. Macrophage depletion as well as TLR3 -/- and TLR4-/- knockout mouse studies revealed macrophages were the immune cells involved or responsible for IE. Finally, we show that pretreatment with anti-inflammatory drugs, such as corticosteroids, can partially alleviate IE response in mice. Our findings characterize the importance of LNP-mediated IE phenomena in gram negative bacterial inflammation, however, the generalizability of modmRNA-LNP in other forms of chronic or acute inflammatory and immune contexts needs to be addressed.

A Dual Anti-Inflammatory and Anti-Proliferative 3-Styrylchromone Derivative Synergistically Enhances the Anti-Cancer Effects of DNA-Damaging Agents on Colon Cancer Cells by Targeting HMGB1-RAGE-ERK1/2 Signaling

The current anti-cancer treatments are not enough to eradicate tumors, and therefore, new modalities and strategies are still needed. Most tumors generate an inflammatory tumor microenvironment (TME) and maintain the niche for their development. Because of the critical role of inflammation via high-mobility group box 1 (HMGB1)–receptor for advanced glycation end-products (RAGE) signaling pathway in the TME, a novel compound possessing both anti-cancer and anti-inflammatory activities by suppressing the HMGB1-RAGE axis provides an effective strategy for cancer treatment. A recent work of our group found that some anti-cancer 3-styrylchromones have weak anti-inflammatory activities via the suppression of this axis. In this direction, we searched such anti-cancer molecules possessing potent anti-inflammatory activities and discovered 7-methoxy-3-hydroxy-styrylchromone (C6) having dual suppressive activities. Mechanism-of-action studies revealed that C6 inhibited the increased phosphorylation of extracellular signal-regulated kinases 1 and 2 (ERK1/2) under the stimulation of HMGB1-RAGE signaling and thereby suppressed cytokine production in macrophage-like RAW264.7 cells. On the other hand, in colorectal cancer HCT116 cells, C6 inhibited the activation of ERK1/2, cyclin-dependent kinase 1, and AKT, down-regulated the protein level of XIAP, and up-regulated pro-apoptotic Bax and caspase-3/7 expression. These alterations are suggested to be involved in the C6-induced suppression of cell cycle/proliferation and initiation of apoptosis in the cancer cells. More importantly, in cancer cells, the treatment of C6 potentiates the anti-cancer effects of DNA-damaging agents. Thus, C6 may be a promising lead for the generation of a novel class of cancer therapeutics.

Repositioning of pentoxifylline as an immunomodulator and regulator of the renin-angiotensin system in the treatment of COVID-19

Pentoxifylline (PTX) is a phosphodiesterase inhibitor that increases cyclic adenosine monophosphate levels, which in turn activate protein kinase, leading to a reduction in the synthesis of proinflammatory cytokines to ultimately influence the renin-angiotensin system (RAS) in vitro by inhibiting angiotensin 1 receptor (AT1R) expression. The rheological, anti-inflammatory, and renin-angiotensin axis properties of PTX highlight this drug as a therapeutic treatment alternative for patients with COVID-19 by helping reduce the production of the inflammatory cytokines without deleterious effects on the immune system to delay viral clearance. Moreover, PTX can restore the balance of the immune response, reduce damage to the endothelium and alveolar epithelial cells, improve circulation, and prevent microvascular thrombosis. There is further evidence that PTX can improve ventilatory parameters. Therefore, we propose repositioning PTX in the treatment of COVID-19. The main advantage of repositioning PTX is that it is an affordable drug that is already available worldwide with an established safety profile, further offering the possibility of immediately analysing the result of its use and associated success rates. Another advantage is that PTX selectively reduces the concentration of TNF-α mRNA in cells, which, in the case of an acute infectious state such as COVID-19, would seem to offer a more strategic approach.

Immune Modulatory Treatments for Autism Spectrum Disorder

Several lines of evidence from family history studies, immunogenetics, maternal immune activation, neuroinflammation, and systemic inflammation support an immune subtype of autism spectrum disorder (ASD). Current Food and Drug Administration-approved medications for ASD do not address the underlying pathophysiology of ASD, have not consistently been shown to address the core symptoms of ASD, and are currently only approved for treating irritability in children and adolescents. In this article, we review the immune modulatory effects of the 2 currently Food and Drug Administration-approved treatments for ASD. We then provide an overview of current data on emerging treatments for ASD from multiple fields of medicine with immune modulatory effects. Although further research is needed to more clearly establish the efficacy and safety of immune modulatory treatments, early data on repurposing medications used to treat systemic inflammation for ASD demonstrate potential benefit and further research is warranted.

Inflammatory Targets in Diabetic Nephropathy

One of the most frequent complications in patients with diabetes mellitus is diabetic nephropathy (DN). At present, it constitutes the first cause of end stage renal disease, and the main cause of cardiovascular morbidity and mortality in these patients. Therefore, it is clear that new strategies are required to delay the development and the progression of this pathology. This new approach should look beyond the control of traditional risk factors such as hyperglycemia and hypertension. Currently, inflammation has been recognized as one of the underlying processes involved in the development and progression of kidney disease in the diabetic population. Understanding the cascade of signals and mechanisms that trigger this maladaptive immune response, which eventually leads to the development of DN, is crucial. This knowledge will allow the identification of new targets and facilitate the design of innovative therapeutic strategies. In this review, we focus on the pathogenesis of proinflammatory molecules and mechanisms related to the development and progression of DN, and discuss the potential utility of new strategies based on agents that target inflammation.

Cerebral Radiation Necrosis: Incidence, Pathogenesis, Diagnostic Challenges, and Future Opportunities

PURPOSE OF REVIEW

Cerebral radiation necrosis (CRN) is a major dose-limiting adverse event of radiotherapy. The incidence rate of RN varies with the radiotherapy modality, total dose, dose fractionation, and the nature of the lesion being targeted. In addition to these known and controllable features, there is a stochastic component to the occurrence of CRN-the genetic profile of the host or the lesion and their role in the development of CRN.

RECENT FINDINGS

Recent studies provide some insight into the genetic mechanisms underlying radiation-induced brain injury. In addition to these incompletely understood host factors, the diagnostic criteria for CRN using structural and functional imaging are also not clear, though multiple structural and functional imaging modalities exist, a combination of which may prove to be the ideal diagnostic imaging approach. As the utilization of novel molecular therapies and immunotherapy increases, the incidence of CNR is expected to increase and its diagnosis will become more challenging. Tissue biopsies can be insensitive and suffer from sampling biases and procedural risks. Liquid biopsies represent a promising, accurate, and non-invasive diagnostic strategy, though this modality is currently in its infancy. A better understanding of the pathogenesis of CRN will expand and optimize the diagnosis and management of CRN by better utilizing existing treatment options including bevacizumab, pentoxifylline, hyperbaric oxygen therapy, and laser interstitial thermal therapy.

Pentoxifylline for Renal Protection in Diabetic Kidney Disease. A Model of Old Drugs for New Horizons

Diabetic kidney disease is one of the most relevant complications in diabetes mellitus patients, which constitutes the main cause of end-stage renal disease in the western world. Delaying the progression of this pathology requires new strategies that, in addition to the control of traditional risk factors (glycemia and blood pressure), specifically target the primary pathogenic mechanisms. Nowadays, inflammation is recognized as a critical novel pathogenic factor in the development and progression of renal injury in diabetes mellitus. Pentoxifylline is a nonspecific phosphodiesterase inhibitor with rheologic properties clinically used for more than 30 years in the treatment of peripheral vascular disease. In addition, this compound also exerts anti-inflammatory actions. In the context of diabetic kidney disease, pentoxifylline has shown significant antiproteinuric effects and a delay in the loss of estimated glomerular filtration rate, although at the present time there is no definitive evidence regarding renal outcomes. Moreover, recent studies have reported that this drug can be associated with a positive impact on new factors related to kidney health, such as Klotho. The use of pentoxifylline as renoprotective therapy for patients with diabetic kidney disease represents a new example of drug repositioning.

Immune Effects of Corticosteroids in Sepsis

Sepsis, a life-threatening organ dysfunction, results from a dysregulated host response to invading pathogens that may be characterized by overwhelming systemic inflammation or some sort of immune paralysis. Sepsis remains a major cause of morbidity and mortality. Treatment is nonspecific and relies on source control and organ support. Septic shock, the most severe form of sepsis is associated with the highest rate of mortality. Two large multicentre trials, undertaken 15 years apart, found that the combination of hydrocortisone and fludrocortisone significantly reduces mortality in septic shock. The corticosteroids family is composed of several molecules that are usually characterized according to their glucocorticoid and mineralocorticoid power, relative to hydrocortisone. While the immune effects of glucocorticoids whether mediated or not by the intracellular glucocorticoid receptor have been investigated for several decades, it is only very recently that potential immune effects of mineralocorticoids via non-renal mineralocorticoid receptors have gained popularity. We reviewed the respective role of glucocorticoids and mineralocorticoids in counteracting sepsis-associated dysregulated immune systems.

Cancer cachexia: Diagnosis, assessment, and treatment

Cancer cachexia is a multi-factorial syndrome, which negatively affects quality of life, responsiveness to chemotherapy, and survival in advanced cancer patients. Our understanding of cachexia has grown greatly in recent years and the roles of many tumor-derived and host-derived compounds have been elucidated as mediators of cancer cachexia. However, cancer cachexia remains an unmet medical need and attempts towards a standard treatment guideline have been unsuccessful. This review covers the diagnosis, assessment, and treatment of cancer cachexia; the elements impeding the formulation of a standard management guideline; and future directions of research for the improvement and standardization of current treatment procedures.

Pentoxifylline, dexamethasone and azithromycin demonstrate distinct age-dependent and synergistic inhibition of TLR- and inflammasome-mediated cytokine production in human newborn and adult blood in vitro

Introduction

Neonatal inflammation, mediated in part through Toll-like receptor (TLR) and inflammasome signaling, contributes to adverse outcomes including organ injury. Pentoxifylline (PTX), a phosphodiesterase inhibitor which potently suppresses cytokine production in newborn cord blood, is a candidate neonatal anti-inflammatory agent. We hypothesized that combinations of PTX with other anti-inflammatory agents, the steroid dexamethasone (DEX) or the macrolide azithromycin (AZI), may exert broader, more profound and/or synergistic anti-inflammatory activity towards neonatal TLR- and inflammasome-mediated cytokine production.

Methods

Whole newborn and adult blood was treated with PTX (50–200 μM), DEX (10⁻¹⁰–10⁻⁷ M), or AZI (2.5–20 μM), alone or combined, and cultured with lipopolysaccharide (LPS) (TLR4 agonist), R848 (TLR7/8 agonist) or LPS/adenosine triphosphate (ATP) (inflammasome induction). Supernatant and intracellular cytokines, signaling molecules and mRNA were measured by multiplex assay, flow cytometry and real-time PCR. Drug interactions were assessed based on Loewe's additivity.

Results

PTX, DEX and AZI inhibited TLR- and/or inflammasome-mediated cytokine production in newborn and adult blood, whether added before, simultaneously or after TLR stimulation. PTX preferentially inhibited pro-inflammatory cytokines especially TNF. DEX inhibited IL-10 in newborn, and TNF, IL-1β, IL-6 and interferon-α in newborn and adult blood. AZI inhibited R848-induced TNF, IL-1β, IL-6 and IL-10, and LPS-induced IL-1β and IL-10. (PTX+DEX) synergistically decreased LPS- and LPS/ATP-induced TNF, IL-1β, and IL-6, and R848-induced IL-1β and interferon-α, while (PTX+AZI) synergistically decreased induction of TNF, IL-1β, and IL-6. Synergistic inhibition of TNF production by (PTX+DEX) was especially pronounced in newborn vs. adult blood and was accompanied by reduction of TNF mRNA and enhancement of IL10 mRNA.

Conclusions

Age, agent, and specific drug-drug combinations exert distinct anti-inflammatory effects towards TLR- and/or inflammasome-mediated cytokine production in human newborn blood in vitro. Synergistic combinations of PTX, DEX and AZI may offer benefit for prevention and/or treatment of neonatal inflammatory conditions while potentially limiting drug exposure and toxicity.

Suppression of LPS-induced inflammatory responses by the hydroxyl groups of dexamethasone

The innate immune response is a central process that is activated during pathogenic infection in order to maintain physiological homeostasis. It is well known that dexamethasone (Dex), a synthetic glucocorticoid, is a potent immunosuppressant that inhibits the cytokine production induced by bacterial lipopolysaccharides (LPS). Nevertheless, the extent to which the functional groups of Dex control the excessive activation of inflammatory reactions remains unknown. Furthermore, importantly, the role of Dex in the innate immune response remains unclear. Here we explore the mechanism of LPS-induced TNF-α secretion and reveal p38 MAPK signaling as a target of Dex that is involved in control of tumor necrosis factor-α (TNF-α)-converting enzyme (TACE) activity; that later mediates the shedding of TNF-α that allows its secretion. We further demonstrate that the 11-hydroxyl and 21-hydroxyl groups of Dex are the main groups that are involved in reducing LPS-induced TNF-α secretion by activated macrophages. Blockage of the hydroxyl groups of Dex inhibits immunosuppressant effect of Dex during LPS-induced TNF-α secretion and mouse mortality. Our findings demonstrate Dex signaling is involved in the control of innate immunity.

Pentoxifylline and Methylprednisolone Additively Alleviate Kidney Failure and Prolong Survival of Rats after Renal Warm Ischemia-Reperfusion

Renal ischemia-reperfusion injury (IRI) induces local inflammation leading to kidney damage. Since pentoxifylline (PTX) and steroids have distinct immunomodulatory properties, we aimed to evaluate for the first time their combined use in IRI-induced acute kidney injury (AKI) and chronic kidney disease (CKD) in rats. In two experiments, PTX (100 mg/kg body weight subcutaneously) was administered 90 min prior to renal IRI or/and methylprednisolone (MP; 100 mg/kg body weight intramuscularly) was infused 60 min after reperfusion of a solitary kidney (AKI model: 45 min ischemia, 48 male Sprague-Dawley rats) or one kidney with excision of contralateral kidney 2 weeks later (CKD model: 90 min ischemia, 38 rats). Saline was infused in place of PTX or/and MP depending on the group. Renal function (diuresis, serum creatinine, creatinine clearance, sodium and potassium excretion, and urine protein/creatinine) was assessed at 48 h and 120 h post-IRI (AKI model) or 4, 16 and 24 weeks after IRI, along with survival analysis (CKD model). More evidently at early stages of AKI or CKD, treated animals showed higher glomerular filtration and diminished tubular loss of electrolytes, more so with PTX + MP than PTX or MP (serum creatinine (μmol/L) at 48 h of AKI: 60.9 ± 19.1 vs. 131.1 ± 94.4 vs. 233.4 ± 137.0, respectively, vs. 451.5 ± 114.4 in controls, all p < 0.05; and at 4 weeks of CKD: 89.0 ± 31.9 vs. 118.1 ± 64.5 vs. 156.9 ± 72.6, respectively, vs. 222.9 ± 91.4 in controls, p < 0.05 for PTX or PTX + MP vs. controls and PTX + MP vs. MP). Survival was better by >2-fold with PTX + MP (89%) vs. controls (40%; p < 0.05). PTX + MP largely protect from IRI-induced AKI and CKD and subsequent mortality in rats. This calls for clinical investigations, especially in kidney transplantation.

Up-regulation of OLR1 expression by TBC1D3 through activation of TNFα/NF-κB pathway promotes the migration of human breast cancer cells

Metastatic spread of cancer cells is the most life-threatening aspect of breast cancer and involves multiple steps including cell migration. We recently found that the TBC1D3 oncogene promotes the migration of breast cancer cells, and its interaction with CaM enhances the effects of TBC1D3. However, little is known regarding the mechanism by which TBC1D3 induces the migration of cancer cells. Here, we demonstrated that TBC1D3 stimulated the expression of oxidized low density lipoprotein receptor 1 (OLR1), a stimulator of cell migration, in breast cancer cells at the transcriptional level. Depletion of OLR1 by siRNAs or down-regulation of OLR1 expression using pomalidomide, a TNFα inhibitor, significantly decreased TBC1D3-induced migration of these cells. Notably, TBC1D3 overexpression activated NF-κB, a major effector of TNFα signaling, while inhibition of TNFα signaling suppressed the effects of TBC1D3. Consistent with this, NF-κB inhibition using its specific inhibitor caffeic acid phenethyl ester decreased both TBC1D3-induced OLR1 expression and cell migration, suggesting a critical role for TNFα/NF-κB signaling in TBC1D3-induced migration of breast cancer cells. Mechanistically, TBC1D3 induced activation of this signaling pathway on multiple levels, including by increasing the release of TNFα, elevating the transcription of TNFR1, TRAF1, TRAF5 and TRAF6, and decreasing the degradation of TNFR1. In summary, these studies identify the TBC1D3 oncogene as a novel regulator of TNFα/NF-κB signaling that mediates this oncogene-induced migration of human breast cancer cells by up-regulating OLR1.

New paradigms in management of alcoholic hepatitis: a review

Severe alcoholic hepatitis (SAH) is defined by modified Maddrey discriminant function ≥32 or Model for End-Stage Liver Disease (MELD) >21 and/or hepatic encephalopathy. It has a 3-month mortality rate ≥30-70 %. Patients with severe alcoholic hepatitis need combined, i.e., static (MELD score) and dynamic (Lille's score), prognostication. Systemic inflammation and poor regeneration are hallmarks of SAH, rather than intrahepatic inflammation. SAH is characterized by dysregulated and uncontrolled systemic inflammatory response followed by weak compensatory antiinflammatory response that leads to increased susceptibility to infection and multiple organ failure. Massive necrosis of hepatocytes exceeds the proliferative capacity of hepatocytes. Liver progenitor cells proliferate to form narrow ductules which radiate out into the damaged liver parenchyma. Corticosteroids have been the standard-of-care therapy, albeit controversial. However, the recent Steroids or Pentoxifylline for Alcoholic Hepatitis (STOPAH) trial revealed that prednisolone was not associated with a significant reduction in 28-day mortality, with no improvement in outcomes at 90 days or 1 year. A paradigm shift from antiinflammatory therapy such as corticosteroids to liver regeneration treatment, e.g., granulocyte-colony stimulating factor, molecular targeted treatments, and fecal microbiota transplantation, for severe alcoholic hepatitis is taking place. Liver transplantation should be offered to select patients with severe alcoholic hepatitis who are nonresponsive to medical treatment.

Novel avenues for treating diabetic nephropathy: new investigational drugs

At present, treatment of diabetic kidney disease (DKD) is still mainly based on drugs acting on glycemic and blood pressure control, as there is no validated therapy able to halt the progression of renal failure. Because of the high incidence of DKD, due to the increase of diabetes mellitus in general population, new therapeutic strategies are needed. Areas covered: We analysed ongoing and already completed clinical trials, from clinicaltrials.gov and PubMed, dealing with new therapies for DKD. Expert opinion: Among the drugs currently being explored, the most promising molecules are those that interfere with glucose-dependent pathways, in particular polyol, protein kinase, hexosamine and AGEs metabolic pathways, and impaired renal vascular regulation. One of the recent goals achieved by molecular biology is the development of monoclonal antibodies able to interfere with extracellular matrix accumulation and fibrosis. Other interesting therapies are under investigation and further studies with a greater number of patients will establish a better approach for diabetic nephropathy.

Treatment of Severe Alcoholic Hepatitis With Corticosteroid, Pentoxifylline, or Dual Therapy: A Systematic Review and Meta-Analysis

BACKGROUND AND AIMS

Although both corticosteroids and pentoxifylline are currently recommended drugs for the treatment of patients with severe alcoholic hepatitis, their effectiveness in reducing mortality remains unclear. In this systematic review, we aimed to evaluate the therapeutic and adverse effects of corticosteroids, pentoxifylline, and combination by using Cochrane methodology and therefore determine optimal treatment for severe alcoholic hepatitis.

METHODS

We searched MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials from their inauguration until October 2015. Combinations of the following keywords and controlled vocabularies were searched: alcoholic hepatitis, corticosteroid, and pentoxifylline.

RESULTS

A total of 2639 patients from 25 studies were included. The treatment groups did not differ significantly in terms of overall mortality. Analysis of 1-month mortality revealed corticosteroid monotherapy reduced mortality compared with placebo (OR=0.58; 95% CI, 0.34-0.98; P=0.04), but pentoxifylline monotherapy did not. The mortality with dual therapy was similar to corticosteroid monotherapy (OR=0.91; 95% CI, 0.62-1.34; P=0.63). However, dual therapy decreased the incidences of hepatorenal syndrome or acute kidney injury (OR=0.47; 95% CI, 0.26-0.86; P=0.01) and the infection risk (OR=0.63; 95% CI, 0.41-0.97; P=0.04) significantly more than corticosteroid monotherapy did. None of the treatments conferred any medium-term or long-term survival benefits in the present study.

CONCLUSIONS

Dual therapy was not inferior to corticosteroid monotherapy and could reduce the incidence of hepatorenal syndrome or acute kidney injury and risk of infection. Therefore, dual therapy might be considered in treatment of patients with severe alcoholic hepatitis.

Experimental Bothrops atrox envenomation: Efficacy of antivenom therapy and the combination of Bothrops antivenom with dexamethasone

Bothrops atrox snakes are the leading cause of snake bites in Northern Brazil. The venom of this snake is not included in the antigen pool used to obtain the Bothrops antivenom. There are discrepancies in reports on the effectiveness of this antivenom to treat victims bitten by B. atrox snakes. However, these studies were performed using a pre-incubation of the venom with the antivenom and, thus, did not simulate a true case of envenomation treatment. In addition, the local lesions induced by Bothrops venoms are not well resolved by antivenom therapy. Here, we investigated the efficacy of the Bothrops antivenom in treating the signs and symptoms caused by B. atrox venom in mice and evaluated whether the combination of dexamethasone and antivenom therapy enhanced the healing of local lesions induced by this envenomation. In animals that were administered the antivenom 10 minutes after the envenomation, we observed an important reduction of edema, dermonecrosis, and myonecrosis. When the antivenom was given 45 minutes after the envenomation, the edema and myonecrosis were reduced, and the fibrinogen levels and platelet counts were restored. The groups treated with the combination of antivenom and dexamethasone had an enhanced decrease in edema and a faster recovery of the damaged skeletal muscle. Our results show that Bothrops antivenom effectively treats the envenomation caused by Bothrops atrox and that the use of dexamethasone as an adjunct to the antivenom therapy could be useful to improve the treatment of local symptoms observed in envenomation caused by Bothrops snakes.

Bothrops atrox is the dominant species responsible for accidental human snake bites in Northern Brazil. The efficacy of antivenom therapy to correct the systemic disturbances, including hemostatic disorders, caused by Brazilian Bothrops is well known. However, two fundamental issues need to be addressed in this region. (1) There are concerns regarding the effectiveness of the antivenom to treat Bothrops snake bites in this region since Bothrops atrox venom is not used as an antigen to obtain the Bothrops antivenom in Brazil, and (2) the efficacy of the antivenom therapy in reversing local injuries induced by Bothrops venoms is low. Thus, our study aimed to assess the effectiveness of antivenom therapy alone or in combination with dexamethasone to treat experimental envenomation induced by Bothrops atrox venom in mice. Our results showed that the Brazilian Bothrops antivenom effectively reversed the systemic disturbances caused by this envenomation and combining the antivenom therapy with dexamethasone accelerated the regression of inflammatory edema and the regeneration of skeletal muscle that was damaged by the venom.

Pentoxifylline Alleviates Early Brain Injury in a Rat Model of Subarachnoid Hemorrhage

BACKGROUND

Subarachnoid hemorrhage (SAH) is a severe cerebrovascular disease frequently caused by ruptured aneurysms. Early brain injury (EBI) is the primary cause of morbidity and mortality in patients diagnosed with SAH and is associated with increased intracranial pressure, decreased cerebral blood flow and cerebral ischemia. Pentoxifylline (PTX) is a methylxanthine derivative clinically proven to improve perfusion in the peripheral microcirculation and has been shown to have neuroprotective effects in brain trauma and global cerebral ischemia in experimental animal models. This study aimed to determine the effect of PTX in experimental SAH, which has not been investigated yet.

METHODS

An experimental SAH model was induced in male Wistar rats by autologous blood injection into the prechiasmatic cistern, and PTX was injected intraperitoneally immediately after SAH. The effects of PTX were evaluated 24 h after SAH via assessing the cerebral ultrastructure via transmission electron microscopy (TEM). Brain edema, blood-brain barrier (BBB) permeability, red blood cell deformability, tumor necrosis factor-alpha (TNF-alpha), nitrite-nitrate levels and apoptotic neuron death were also determined 24 h after SAH. The BBB permeability was measured by Evans blue (EB) extravasation, erythrocyte deformability was determined by filtration technique, and TNF-alpha and reactive nitrogen metobolites were analyzed in brain tissue by ELISA and spectral analysis, respectively. Apoptotic neurons were determined in brain sections by cleaved caspase-3 immunohistochemical analysis, and expression intensity was quantified using image J software.

RESULTS

Cerebral ultrastructure in SAH group animals revealed intense perivascular edema and distortion in the astrocyte foot processes. PTX treatment attenuated structural deterioration due to SAH. Brain water content, BBB permeability, TNF-alpha, nitrite-nitrate levels and apoptotic neuronal death were significantly increased 24 h after SAH and were significantly alleviated by PTX treatment. There was no significant change in red cell deformability after SAH.

CONCLUSIONS

Our results show that PTX reduces brain edema, BBB permeability, TNF-alpha expression, reactive nitrogen metobolites and apopotosis in experimental SAH. Based on our findings we suggest that PTX exerts neuroprotection against SAH-induced EBI, which might be associated with the inhibition of inflammation and apoptotic neuronal cell death.

Dexamethasone Modulates IL-13 and IL-10 Expression

Interleukin (IL-)-10 and IL-13 are Th2-cell-associated cytokines with a variety of biologic activities in immune and inflammatory responses. It is known that glucocorticoids (GCs) modulate inflammatory and immune functions. In fact, GCs are involved to regulate the transcription of cytokines which are relevant in chronic inflammation and cell-mediated immune response.

In the present study we analyzed, in vitro, the effects of DEX on the expression of the IL-10 and IL-13 lymphokines in murine spleen and thymus cells. DEX-stimulation induced down-regulation of the expression of IL-10 and IL-13 mRNA.

This effect was already evident 0.5 hr after treatment and persisted in time, in both resting and activated lymphocytes. These results suggest that GCs could have inhibitory effect on Th2 cytokine production.

Ex vivo host and parasite response to antileishmanial drugs and immunomodulators

Background

Therapeutic response in infectious disease involves host as well as microbial determinants. Because the immune and inflammatory response to Leishmania (Viannia) species defines the outcome of infection and efficacy of treatment, immunomodulation is considered a promising therapeutic strategy. However, since Leishmania infection and antileishmanial drugs can themselves modulate drug transport, metabolism and/or immune responses, immunotherapeutic approaches require integrated assessment of host and parasite responses.

Methodology

To achieve an integrated assessment of current and innovative therapeutic strategies, we determined host and parasite responses to miltefosine and meglumine antimoniate alone and in combination with pentoxifylline or CpG 2006 in peripheral blood mononuclear cells (PBMCs) of cutaneous leishmaniasis patients. Parasite survival and secretion of TNF-α, IFN-γ, IL-10 and IL-13 were evaluated concomitantly in PBMCs infected with Luc-L. (V.) panamensis exposed to meglumine antimoniate (4, 8, 16, 32 and 64 μg Sb^V/mL) or miltefosine (2, 4, 8, 16 and 32 μM HePC). Concentrations of 4 μM of miltefosine and 8 μg Sb^V/mL were selected for evaluation in combination with immunomodulators based on the high but partial reduction of parasite burden by these antileishmanial concentrations without affecting cytokine secretion of infected PBMCs. Intracellular parasite survival was determined by luminometry and cytokine secretion measured by ELISA and multiplex assays.

Principal Findings

Anti- and pro-inflammatory cytokines characteristic of L. (V.) panamensis infection were evaluable concomitantly with viability of Leishmania within monocyte-derived macrophages present in PBMC cultures. Both antileishmanial drugs reduced the parasite load of macrophages; miltefosine also suppressed IL-10 and IL-13 secretion in a dose dependent manner. Pentoxifylline did not affect parasite survival or alter antileishmanial effects of miltefosine or meglumine antimoniate. However, pentoxifylline diminished secretion of TNF-α, IFN-γ and IL-13, cytokines associated with the outcome of infection by species of the Viannia subgenus. Exposure to CpG diminished the leishmanicidal effect of meglumine antimoniate, but not miltefosine, and significantly reduced secretion of IL -10, alone and in combination with either antileishmanial drug. IL-13 increased in response to CpG plus miltefosine.

Conclusions and Significance

Human PBMCs allow integrated ex vivo assessment of antileishmanial treatments, providing information on host and parasite determinants of therapeutic response that may be used to tailor therapeutic strategies to optimize clinical resolution.

Host determinants of the response to infection have increasingly been recognized as therapeutically relevant targets. Despite the pathogenesis of dermal leishmaniasis being mediated by the immune and inflammatory response, in vitro anti-leishmanial drug screening has been based on antimicrobial effect without consideration of effects on the host response. The results of this study show that peripheral blood mononuclear cells from patients allow an integrated evaluation of both antimicrobial efficacy and host response to drugs, immunomodulatory agents, and their combinations. This integrated approach to defining treatment strategies based on host and parasite responses opens the way for the optimization and tailoring of treatment to different clinical circumstances.

The PPAR-γ antagonist GW9662 elicits differentiation of M2c-like cells and upregulation of the MerTK/Gas6 axis: a key role for PPAR-γ in human macrophage polarization

Background

The nuclear receptors PPAR-γ and LXRs regulate macrophage lipid metabolism and macrophage mediated inflammation. We examined the influence of these molecules on macrophage alternative activation, with particular focus on differentiation of “M2c” anti-inflammatory cells.

Methods

We cultured human monocytes in M0, M1, M2a or M2c macrophage differentiating conditions, in the presence or absence of PPAR-γ and LXR ligands. Flow cytometry was used to analyze membrane expression of phenotypic markers. Basal and LPS-stimulated production of soluble mediators was measured by ELISA. Efferocytosis assays were performed by coincubating monocytes/macrophages with apoptotic neutrophils.

Results

We found that PPAR-γ inhibition, using the PPAR-γ antagonist GW9662, elicits differentiation of M2c-like (CD206⁺ CD163⁺ CD16⁺) cells and upregulation of the MerTK/Gas6 axis. Exposure of differentiating macrophages to IFN-γ, GM-CSF or LPS (M1 conditions), however, hampers GW9662 induction of MerTK and Gas6. When macrophages are differentiated with IL-4 (M2a conditions), addition of GW9662 results into an M2a (CD206⁺ CD209⁺ CD163⁻ MerTK⁻) to M2c (CD206^high CD209⁻ CD163⁺ MerTK⁺) polarization shift. Conversely, in the presence of dexamethasone (M2c conditions), the PPAR-γ agonist rosiglitazone attenuates CD163 and MerTK upregulation. The LXR agonist T0901317 induces MerTK independently of M2c polarization; indeed, CD206, CD163 and CD16 are downregulated. GW9662-differentiated M2c-like cells secrete high levels of Gas6 and low amounts of TNF-α and IL-10, mimicking dexamethasone effects in vitro. However, unlike conventional M2c cells, GW9662-differentiated cells do not show enhanced efferocytic ability.

Conclusions

Our results provide new insights into the role of PPAR-γ and LXR receptors in human macrophage activation and reveal the existence of different patterns regulating MerTK expression. Unexpectedly, PPAR-γ appears to negatively control the expansion of a discrete subset of M2c-like anti-inflammatory macrophages.

Alcoholic liver disease: mechanisms of injury and targeted treatment

Alcoholic liver disease (ALD) is a complex process that includes a wide spectrum of hepatic lesions, from steatosis to cirrhosis. Cell injury, inflammation, oxidative stress, regeneration and bacterial translocation are key drivers of alcohol-induced liver injury. Alcoholic hepatitis is the most severe form of all the alcohol-induced liver lesions. Animal models of ALD mainly involve mild liver damage (that is, steatosis and moderate inflammation), whereas severe alcoholic hepatitis in humans occurs in the setting of cirrhosis and is associated with severe liver failure. For this reason, translational studies using humans and human samples are crucial for the development of new therapeutic strategies. Although multiple attempts have been made to improve patient outcome, the treatment of alcoholic hepatitis is still based on abstinence from alcohol and brief exposure to corticosteroids. However, nearly 40% of patients with the most severe forms of alcoholic hepatitis will not benefit from treatment. We suggest that future clinical trials need to focus on end points other than mortality. This Review discusses the main pathways associated with the progression of liver disease, as well as potential therapeutic strategies targeting these pathways.

Novel agents for the medical treatment of endometriosis

PURPOSE OF REVIEW

Current medical treatments for endometriosis-associated pain, including oral contraceptives, progestins and GnRH agonists, are partially effective and have significant side-effects. The purpose of this review is to present new hormonal and nonhormonal treatment for endometriosis.

RECENT FINDINGS

At present, the ideal drug that can prevent, inhibit or stop development of endometriosis, reduce associated pain or infertility and allow conception does not exist. New drugs in development for endometriosis modulate GnRH, estrogen and/or progesterone receptors, or target endometriosis-associated inflammation, angiogenesis, adhesion and/or tissue invasion. Most have been tested in rodents, and have been evaluated in more relevant animal models like nonhuman primates (baboons), but only a few, that is GnRH antagonists, have been tested in human randomized controlled trials. Important safety and efficacy issues remain a concern, as steroid receptors, inflammation, adhesion, angiogenesis and tissue invasion are key factors in physiological events like ovulation, menstruation and embryo implantation.

SUMMARY

New drugs for the medical treatment of endometriosis targeting both hormonal (GnRH, estrogen and progesterone receptors) and nonhormonal pathways (inflammation, angiogenesis, adhesions, tissue invasion) are promising, but their efficacy and safety need to be established in randomized human trials before they can be used in clinical practice.

A novel model of megavoltage radiation-induced oral mucositis in hamsters: Role of inflammatory cytokines and nitric oxide

PURPOSE

To design a novel model to study Cobalt-60 (Co-60)-induced radiation mucositis and to describe the pathways involved in its development.

MATERIALS AND METHODS

Hamsters' cheeks were treated with Co-60 radiation (10, 20, 30 or 35 Gy). Three days later, oral mucosa scarification was performed with a needle. The animals were euthanized at day 13 (D + 13) after irradiation. Gross and microscopic alterations were evaluated by a new score system that we developed. Also, neutrophil infiltration, tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-10, inducible nitric oxide synthase (iNOS), nitric oxide (NO) and nitrite were assessed in oral mucosa. We also tried to establish the roles of TNF-α and IL-1β and iNOS in our model using pharmacological approaches with pentoxiphylline (PTX) and aminoguanidine (AMG), respectively.

RESULTS

We found that a single administration of 35 Gy of Co-60, followed by mechanical scratches 3 days later, induced oral mucositis in hamsters. Animals with mucositis lost weight and had a survival median of 13 days, the time at which peak inflammation occurs. We noticed increased levels of NO, iNOS, TNF-α and IL-1β and a reduced concentration of IL-10. PTX partially prevented the mucositis phenotype by reducing the levels of inflammatory mediators and iNOS expression. Additionally, AMG, a selective inhibitor of iNOS, reduced Co-60-induced oral mucositis through reducing NO production.

CONCLUSION

We described a novel model of megavoltage radiation-induced oral mucositis in hamsters. TNF-α, IL-1β and NO seem to play a role in the pathophysiology of this model.

Inflammatory cytokines in diabetic nephropathy

Probably, the most paradigmatic example of diabetic complication is diabetic nephropathy, which is the largest single cause of end-stage renal disease and a medical catastrophe of worldwide dimensions. Metabolic and hemodynamic alterations have been considered as the classical factors involved in the development of renal injury in patients with diabetes mellitus. However, the exact pathogenic mechanisms and the molecular events of diabetic nephropathy remain incompletely understood. Nowadays, there are convincing data that relate the diabetes inflammatory component with the development of renal disease. This review is focused on the inflammatory processes that develop diabetic nephropathy and on the new therapeutic approaches with anti-inflammatory effects for the treatment of chronic kidney disease in the setting of diabetic nephropathy.

Pathogenesis of alcoholic liver disease: Role of oxidative metabolism

Alcohol consumption is a predominant etiological factor in the pathogenesis of chronic liver diseases, resulting in fatty liver, alcoholic hepatitis, fibrosis/cirrhosis, and hepatocellular carcinoma (HCC). Although the pathogenesis of alcoholic liver disease (ALD) involves complex and still unclear biological processes, the oxidative metabolites of ethanol such as acetaldehyde and reactive oxygen species (ROS) play a preeminent role in the clinical and pathological spectrum of ALD. Ethanol oxidative metabolism influences intracellular signaling pathways and deranges the transcriptional control of several genes, leading to fat accumulation, fibrogenesis and activation of innate and adaptive immunity. Acetaldehyde is known to be toxic to the liver and alters lipid homeostasis, decreasing peroxisome proliferator-activated receptors and increasing sterol regulatory element binding protein activity via an AMP-activated protein kinase (AMPK)-dependent mechanism. AMPK activation by ROS modulates autophagy, which has an important role in removing lipid droplets. Acetaldehyde and aldehydes generated from lipid peroxidation induce collagen synthesis by their ability to form protein adducts that activate transforming-growth-factor-β-dependent and independent profibrogenic pathways in activated hepatic stellate cells (HSCs). Furthermore, activation of innate and adaptive immunity in response to ethanol metabolism plays a key role in the development and progression of ALD. Acetaldehyde alters the intestinal barrier and promote lipopolysaccharide (LPS) translocation by disrupting tight and adherent junctions in human colonic mucosa. Acetaldehyde and LPS induce Kupffer cells to release ROS and proinflammatory cytokines and chemokines that contribute to neutrophils infiltration. In addition, alcohol consumption inhibits natural killer cells that are cytotoxic to HSCs and thus have an important antifibrotic function in the liver. Ethanol metabolism may also interfere with cell-mediated adaptive immunity by impairing proteasome function in macrophages and dendritic cells, and consequently alters allogenic antigen presentation. Finally, acetaldehyde and ROS have a role in alcohol-related carcinogenesis because they can form DNA adducts that are prone to mutagenesis, and they interfere with methylation, synthesis and repair of DNA, thereby increasing HCC susceptibility.

Post-translational regulation of mitogen-activated protein kinase phosphatase (MKP)-1 and MKP-2 in macrophages following lipopolysaccharide stimulation: the role of the C termini of the phosphatases in determining their stability

MAPK phosphatases (MKPs) are critical modulators of the innate immune response, and yet the mechanisms regulating their accumulation remain poorly understood. In the present studies, we investigated the role of post-translational modification in the accumulation of MKP-1 and MKP-2 in macrophages following LPS stimulation. We found that upon LPS stimulation, MKP-1 and MKP-2 accumulated with different kinetics: MKP-1 level peaked at ∼1 h, while MKP-2 levels continued to rise for at least 6 h. Accumulation of both MKP-1 and MKP-2 were attenuated by inhibition of the ERK cascade. Interestingly, p38 inhibition prior to LPS stimulation had little effect on MKP-1 and MKP-2 protein levels, but hindered their detection by an M-18 MKP-1 antibody. Studies of the epitope sequence recognized by the M-18 MKP-1 antibody revealed extensive phosphorylation of two serine residues in the C terminus of both MKP-1 and MKP-2 by the ERK pathway. Remarkably, the stability of both MKP-1 and MKP-2 was markedly decreased in macrophages in the presence of an ERK pathway inhibitor. Mutation of the two C-terminal serine residues in MKP-1 and MKP-2 to alanine decreased their half-lives, while mutating these residues to aspartate dramatically increased their half-lives. Deletion of the C terminus from MKP-1 and MKP-2 also considerably increased their stabilities. Surprisingly, enhanced stabilities of the MKP-1 and MKP-2 mutants were not associated with decreased ubiquitination. Degradation of both MKP-1 and MKP-2 was attenuated by proteasomal inhibitors. Our studies suggest that MKP-1 and MKP-2 stability is regulated by ERK-mediated phosphorylation through a degradation pathway independent of polyubiquitination.

Targeting inflammation in diabetes: Newer therapeutic options

Inflammation has been recognised to both decrease beta cell insulin secretion and increase insulin resistance. Circulating cytokines can affect beta cell function directly leading to secretory dysfunction and increased apoptosis. These cytokines can also indirectly affect beta cell function by increasing adipocyte inflammation.The resulting glucotoxicity and lipotoxicity further enhance the inflammatory process resulting in a vicious cycle. Weight reduction and drugs such as metformin have been shown to decrease the levels of C-Reactive Protein by 31% and 13%, respectively. Pioglitazone, insulin and statins have anti-inflammatory effects. Interleukin 1 and tumor necrosis factor-α antagonists are in trials and NSAIDs such as salsalate have shown an improvement in insulin sensitivity. Inhibition of 12-lipo-oxygenase, histone de-acetylases, and activation of sirtuin-1 are upcoming molecular targets to reduce inflammation. These therapies have also been shown to decrease the conversion of pre-diabetes state to diabetes. Drugs like glicazide, troglitazone, N-acetylcysteine and selective COX-2 inhibitors have shown benefit in diabetic neuropathy by decreasing inflammatory markers. Retinopathy drugs are used to target vascular endothelial growth factor, angiopoietin-2, various proteinases and chemokines. Drugs targeting the proteinases and various chemokines are pentoxifylline, inhibitors of nuclear factor-kappa B and mammalian target of rapamycin and are in clinical trials for diabetic nephropathy. Commonly used drugs such as insulin, metformin, peroxisome proliferator-activated receptors, glucagon like peptide-1 agonists and dipeptidyl peptidase-4 inhibitors also decrease inflammation. Anti-inflammatory therapies represent a potential approach for the therapy of diabetes and its complications.

Inflammation in diabetic kidney disease

Diabetes mellitus entails significant health problems worldwide. The pathogenesis of diabetes is multifactorial, resulting from interactions of both genetic and environmental factors that trigger a complex network of pathophysiological events, with metabolic and hemodynamic alterations. In this context, inflammation has emerged as a key pathophysiology mechanism. New pathogenic pathways will provide targets for prevention or future treatments. This review will focus on the implications of inflammation in diabetes mellitus, with special attention to inflammatory cytokines.

Microinflammation in the pathogenesis of diabetic nephropathy

Diabetic nephropathy is the leading cause of end‐stage renal failure in developed countries. Furthermore, diabetic nephropathy is related to the risk of cardiovascular diseases and an increase in mortality of diabetic patients. Several factors are involved in the development of nephropathy, including glomerular hyperfiltration, oxidative stress, accumulation of advanced glycation end‐products, activation of protein kinase C, acceleration of the polyol pathway and over‐expression of transforming growth factor‐β. Recently, accumulated data have emphasized the critical roles of chronic low‐grade inflammation, ‘microinflammation’, in the pathogenesis of diabetic nephropathy, suggesting that microinflammation is a common mechanism in the development of diabetic vascular complications. Expression of cell adhesion molecules, chemokines and pro‐inflammatory cytokines are increased in the renal tissues of diabetic patients and animals. Deficiency of pro‐inflammatory molecules results in amelioration of renal injuries after induction of diabetes in mice. Plasma and urinary levels of cytokines, chemokines and cell adhesion molecules, are elevated and correlated with albuminuria. Several kinds of drugs that have anti‐inflammatory actions as their pleiotropic effects showed renoprotective effects on diabetic animals. Modulation of the inflammatory process prevents renal insufficiency in diabetic animal models, suggesting that microinflammation is one of the promising therapeutic targets for diabetic nephropathy, as well as for cardiovascular diseases.

Role of pentoxifylline and sparfloxacin in prophylaxis of spontaneous bacterial peritonitis in cirrhotic patients

This study was directed to evaluate the role of sparfloxacin and pentoxifylline in the prophylaxis of spontaneous bacterial peritonitis in cirrhotic patients. Forty cirrhotic patients with ascites were included in the study. Patients were randomized into four groups in a blind fashion; each group consists of ten patients. Group one received ciprofloxacin (control group), group two received sparfloxacin, group three received pentoxifylline, and group four received a combination of sparfloxacin and pentoxifylline. Treatment duration was six months. Serum TNF-α level was the primary inflammatory marker of the study to evaluate the effect of the used medications. In group two, TNF-α level showed a statistically significant decrease in comparison with group one (P = 0.001), while in group three, TNF-α level showed nonsignificant difference in comparison with the control group (P > 0.05). In addition, group four showed a statistically significant decrease in TNF-α level compared to the other three groups (P < 0.05). The finding from our study indicates that sparfloxacin as well as pentoxifylline could be used in prophylaxis of spontaneous bacterial peritonitis. Combination of sparfloxacin and pentoxifylline showed some of synergism which may be useful in decreasing emergence of resistant strains.

Role of protein tyrosine phosphatase non-receptor type 7 in the regulation of TNF-α production in RAW 264.7 macrophages

Protein tyrosine phosphatases play key roles in a diverse range of cellular processes such as differentiation, cell proliferation, apoptosis, immunological signaling, and cytoskeletal function. Protein tyrosine phosphatase non-receptor type 7 (PTPN7), a member of the phosphatase family, specifically inactivates mitogen-activated protein kinases (MAPKs). Here, we report that PTPN7 acts as a regulator of pro-inflammatory TNF-α production in RAW 264.7 cells that are stimulated with lipopolysaccharide (LPS) that acts as an endotoxin and elicits strong immune responses in animals. Stimulation of RAW 264.7 cells with LPS leads to a transient decrease in the levels of PTPN7 mRNA and protein. The overexpression of PTPN7 inhibits LPS-stimulated production of TNF-α. In addition, small interfering RNA (siRNA) analysis showed that knock-down of PTPN7 in RAW 264.7 cells increased TNF-α production. PTPN7 has a negative regulatory function to extracellular signal regulated kinase 1/2 (ERK1/2) and p38 that increase LPS-induced TNF-α production in macrophages. Thus, our data presents PTPN7 as a negative regulator of TNF-α expression and the inflammatory response in macrophages.

Implications of treatment that target protective mechanisms against diabetic nephropathy

Diabetes results in vascular changes and dysfunction, and vascular complications are the leading cause of morbidity and mortality in diabetic patients. There has been a continual increase in the number of diabetic nephropathy patients and epidemic increases in the number of patients progressing to end-stage renal diseases. To identify targets for therapeutic intervention, most studies have focused on understanding how abnormal levels of glucose metabolites cause diabetic nephropathy, which is of paramount importance in devising strategies to combat the development and progression of diabetic nephropathy. However, less studied than the systemic toxic mechanisms, hyperglycemia and dyslipidemia might inhibit the endogenous vascular protective factors such as insulin, vascular endothelial growth factor, and platelet-derived growth factor. In this review, we highlight the importance of enhancing endogenous protective factors to prevent or delay diabetic nephropathy.

Cerebral radiation necrosis: a review of the pathobiology, diagnosis and management considerations

Radiation therapy forms one of the building blocks of the multi-disciplinary management of patients with brain tumors. Improved survival following radiation therapy may come with a cost, including the potential complication of radiation necrosis. Radiation necrosis impacts the quality of life in cancer survivors, and it is essential to detect and effectively treat this entity as early as possible. Significant progress in neuro-radiology and molecular pathology facilitate more straightforward diagnosis and characterization of cerebral radiation necrosis. Several therapeutic interventions, both medical and surgical, may halt the progression of radiation necrosis and diminish or abrogate its clinical manifestations, but there are still no definitive guidelines to follow explicitly that guide treatment of radiation necrosis. We discuss the pathobiology, clinical features, diagnosis, available treatment modalities, and outcomes in the management of patients with intracranial radiation necrosis that follows radiation used to treat brain tumors.

Inflammation and oxidative stress in diabetic nephropathy: new insights on its inhibition as new therapeutic targets

Diabetes and insulin resistance can greatly increase microvascular complications of diabetes including diabetic nephropathy (DN). Hyperglycemic control in diabetes is key to preventing the development and progression of DN. However, it is clinically very difficult to achieve normal glucose control in individual diabetic patients. Many factors are known to contribute to the development of DN. These include diet, age, lifestyle, or obesity. Further, inflammatory- or oxidative-stress-induced basis for DN has been gaining interest. Although anti-inflammatory or antioxidant drugs can show benefits in rodent models of DN, negative evidence from large clinical studies indicates that more effective anti-inflammatory and antioxidant drugs need to be studied to clear this question. In addition, our recent report showed that potential endogenous protective factors could decrease inflammation and oxidative stress, showing great promise for the treatment of DN.

Molecular targets in the treatment of alcoholic hepatitis

Alcohol related costs to health and society are high. One of the most serious complications of alcohol misuse to the individual is the development of alcoholic hepatitis (AH), a clinical syndrome of jaundice and progressive inflammatory liver injury in patients with a history of recent heavy alcohol use. It has a poor outcome and few existing successful therapies. The use of glucocorticoids in patients with severe AH is still controversial and there remains a group of patients with glucocorticoid-resistant disease. However, as our understanding of the pathogenesis of the condition improves there are opportunities to develop new targeted therapies with specific actions to control liver inflammation without having a detrimental effect on the immune system as a whole. In this article we review the molecular mechanisms of AH concentrating on the activation of the innate and adaptive immune response. We consider existing treatments including glucocorticoids, anti-tumor necrosis factor therapy and pentoxifylline and their limitations. Using our knowledge of the disease pathogenesis we discuss possible novel therapeutic approaches. New targets include pro-inflammatory cytokines such as interleukin (IL)-17, chemokines and their receptors (for example IL-8, CXCL9 and CXCR3) and augmentation of anti-inflammatory molecules such as IL-10 and IL-22. And there is also future potential to consider combination therapy to selectively modulate the immune response and gain control of disease.

Hepatic immunosuppressive effects of systemically administered novel dextran-methylprednisolone prodrugs with peptide linkers in rats

The hepatic immunosuppressive activities of two novel dextran prodrugs of methylprednisolone (MP) containing one (DMP1) or five (DMP5) amino acids as linkers were studied in rats. At various times (0-2 weeks) after intravenous administration of single 5 mg/kg (MP equivalent) doses of each prodrug or MP succinate (MPS), livers were isolated and immunologically stimulated ex vivo with lipopolysaccharide. The concentrations of tumor necrosis factor (TNF)-α in the outlet perfusate were then quantitated to assess immune response. Additionally, the concentrations of DMP1, DMP5, and/or MP were measured in the liver. MPS, DMP5, or DMP1 injections caused a maximum of 48.9%, 63.5%, or 85.7% decrease in the TNF-α secretion into the perfusate, with the time above the 50% inhibitory effect being <5, <24, or 120 h, respectively. Additionally, the area under the effect-time curve for DMP1 was 11-fold or fourfold higher than that after the administration of MPS or DMP5, respectively. Relatively high concentrations of DMP1 were present in the liver even at the last sampling time of 2 weeks. These data suggest that a single intravenous dose of DMP1 produces an intense and sustained immunosuppression in the liver for a relatively long time, which may be useful in liver transplantation.