Mitochondrial function and regulation of macrophage sterol metabolism and inflammatory responses

Recent progress of endoplasmic reticulum stress in the mechanism of atherosclerosis

The research progress of endoplasmic reticulum (ER) stress in atherosclerosis (AS) is of great concern. The ER, a critical cellular organelle, plays a role in important biological processes including protein synthesis, folding, and modification. Various pathological factors may cause ER stress, and sustained or excessive ER stress triggers the unfolded protein response, ultimately resulting in apoptosis and disease. Recently, researchers have discovered the importance of ER stress in the onset and advancement of AS. ER stress contributes to the occurrence of AS through different pathways such as apoptosis, inflammatory response, oxidative stress, and autophagy. Therefore, this review focuses on the mechanisms of ER stress in the development of AS and related therapeutic targets, which will contribute to a deeper understanding of the disease's pathogenesis and provide novel strategies for preventing and treating AS.

Effects of mitochondrial dysfunction on cellular function: Role in atherosclerosis

Atherosclerosis, an immunoinflammatory disease of medium and large arteries, is associated with life-threatening clinical events, such as acute coronary syndromes and stroke. Chronic inflammation and impaired lipoprotein metabolism are considered to be among the leading causes of atherosclerosis, while numerous risk factors, including arterial hypertension, diabetes mellitus, obesity, and aging, can contribute to the development of the disease. In recent years, emerging evidence has underlined the key role of mitochondrial dysfunction in the pathogenesis of atherosclerosis. Mitochondrial dysfunction is believed to result in an increase in reactive oxygen species, leading to oxidative stress, chronic inflammation, and intracellular lipid deposition, all of which can contribute to the pathogenesis of atherosclerosis. Critical cells, including endothelial cells, vascular smooth muscle cells, and macrophages, play an important role in atherosclerosis. Mitochondrial function is also involved in maintaining the normal function of these cells. To better understand the relationship between mitochondrial dysfunction and atherosclerosis, this review summarizes the findings of recent studies and discusses the role of mitochondrial dysfunction in the risk factors and critical cells of atherosclerosis. FACTS: OPEN QUESTIONS.

Phytol from Scoparia dulcis prevents NF-κB-mediated inflammatory responses during macrophage polarization

Macrophages are primary immune cells that mediate a wide range of inflammatory diseases through their polarization potential. In this study, phytol isolated from Scoparia dulcis has been explored against 7-ketocholesterol and bacterial lipopolysaccharide-induced macrophage polarization in IC-21 cells. Isolated phytol has been characterized using GC-MS, TLC, HPTLC, FTIR, 1H-NMR, and HPLC analyses. The immunomodulatory effects of viable concentrations of phytol were tested on oxidative stress, arginase activity, nuclear and mitochondrial membrane potentials in IC-21 cells in addition to the modulation of calcium and lipids. Further, gene and protein expression of atherogenic markers were studied. Results showed that the isolated phytol at a viable concentration of 400 µg/ml effectively reduced the production of nitric oxide, superoxide anion (ROS generation), calcium and lipid accumulation, stabilized nuclear and mitochondrial membranes, and increased arginase activity. The atherogenic markers including iNOS, COX-2, IL-6, IL-1β, MMP-9, CD36, and NF-κB were significantly downregulated at the levels of gene and protein expression, while macrophage surface and nuclear receptor markers (CD206, CD163, and PPAR-γ) were significantly upregulated by phytol pre-treatment in macrophages. Therefore, the present pharmacognostic study supports the role of phytol isolated from Scoparia dulcis in preventing M2-M1 macrophage polarization under inflammatory conditions, making it a promising compound.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-024-03924-9.

Relaxin-3 Ameliorates Diabetic Cardiomyopathy by Inhibiting Endoplasmic Reticulum Stress

Background

This study is aimed at investigating whether relaxin-3 exhibits protective effects against cardiomyopathy in diabetic rats by suppressing ERS.

Methods

Eighty male SD rats were randomly divided into two groups: controls (n = 20) and diabetes (n = 60). The streptozotocin-treated rats were randomly divided into three groups: diabetic group (DM), low-dose relaxin-3 group (0.2 μg/kg/d), and high-dose relaxin-3 group (2 μg/kg/d). The myocardial tissues and collagen fiber were observed by hematoxylin and eosin (H&E) and Masson staining. Serum brain natriuretic peptide (BNP), troponin (TNI), myoglobin, interleukin (IL-17), interleukin (IL)-1α, and tumor necrosis factor (TNF)-α were determined by ELISA. The protein expression of glucose regulatory protein 78 (GRP78) and C/EBP homologous protein (CHOP) in the heart tissue of each group was detected by Western blot analysis.

Results

(1) HE and Masson staining indicated that relaxin-3 could attenuate myocardial lesions and myocardial collagen volume fraction. (2) BNP, TnI, and myoglobin in the DM group at four and eight weeks were significantly higher than in the controls (P < 0.01). The relaxin-3-treated groups showed significantly reduced serum BNP, TnI, and myoglobin levels compared with the DM group (P < 0.05). (3) IL-17, IL-1α, and TNF-α levels in the DM rats at 4 weeks were higher than in the controls (P < 0.05). Low or high dose of relaxin-3-treated groups showed reduced serum IL-17 and TNF-α levels compared with the DM group at four and eight weeks (P < 0.05). (4) CHOP and GRP78 protein expression was increased in the DM group at four and eight weeks compared with the controls (P < 0.01), and small and large doses of relaxin-3 significantly reduced GRP78 and CHOP protein expression.

Conclusions

Exogenous relaxin-3 ameliorates diabetic cardiomyopathy by inhibiting ERS in diabetic rats.

Hydroxychloroquine Effects on THP-1 Macrophage Cholesterol Handling: Cell Culture Studies Corresponding to the TARGET Cardiovascular Trial

Background and Objectives: Cardiovascular (CV) risk is elevated in rheumatoid arthritis (RA). RA patient plasma causes pro-atherogenic derangements in cholesterol transport leading to macrophage foam cell formation (FCF). The TARGET randomized clinical trial compares CV benefits of 2 RA drug regimens. Hydoxychloroquine (HCQ) is a key medication used in TARGET. This study examines effects of HCQ on lipid transport to elucidate mechanisms underlying TARGET outcomes and as an indicator of likely HCQ effects on atherosclerosis in RA. Materials and Methods: THP1 human macrophages were exposed to media alone, IFNγ (atherogenic cytokine), HCQ, or HCQ + IFNγ. Cholesterol efflux protein and scavenger receptor mRNA levels were quantified by qRT-PCR and corresponding protein levels were assessed by Western blot. FCF was evaluated via Oil-Red-O and fluorescent-oxidized LDL. Intracellular cholesterol and efflux were quantified with Amplex Red assay. Results: With the exception of a decrease in the efflux protein cholesterol 27-hydroxylase in the presence IFNγ at all HCQ concentrations, no significant effect on gene or protein expression was observed upon macrophage exposure to HCQ and this was reflected in the lack of change in FCF and oxidized LDL uptake. Conclusions: HCQ did not significantly affect THP1 macrophage cholesterol transport. This is consistent with TARGET, which postulates superior effects of anti-TNF agents over sulfasalazine + HCQ.

Ganoderma lucidum spore ethanol extract attenuates atherosclerosis by regulating lipid metabolism via upregulation of liver X receptor alpha

CONTEXT

Ganoderma lucidum (Leyss.ex Fr.) Karst (Ganodermataceae) is a fungus that has been used in traditional Chinese medicine.

OBJECTIVE

This is the first investigation of the lipid-lowering and anti-atherosclerotic effects of Ganoderma lucidum spore ethanol extract (EEG) in hyperlipidemic rabbits.

MATERIALS AND METHODS

Fifty-four Japanese rabbits were randomly divided into six groups (n = 9): control, model, atorvastatin and three EEG groups (6, 24 and 96 mg/kg/day, p.o.). Control group was administered a normal diet and other groups were administered a high-fat diet to induce hyperlipidaemia and atherosclerosis for 14 weeks. During this time, lipid profiles were recorded; lipid testing and histopathological examination of aorta and liver were conducted. LXRα and its downstream genes expression in the liver and small intestine were examined. The effect of EEG on macrophage cholesterol efflux and ABCA1/G1 expression was observed under silenced LXRα expression.

RESULTS

EEG reduced serum cholesterol (20.33 ± 3.62 mmol/L vs 34.56 ± 8.27 mmol/L for the model group) and LDL-C, reduced the area of arterial plaques (24.8 ± 10% vs 53.9 ± 15.2% for the model group) and Intima/Medium thickness ratio, increased faecal bile acid content, upregulated LXRα, CYP7A1, ABCA1/G1, ABCG5/G8 expression in the liver, small intestine and macrophages. After silencing LXRα in macrophages, the ability of EEG to promote cholesterol efflux was inhibited.

DISCUSSION AND CONCLUSION

EEG exert lipid-lowering and anti-atherosclerotic effects via upregulating expression of LXRα and downstream genes associated with reverse cholesterol transport and metabolism. However, whether PPARα/γ are involved in the up-regulation of LXR expression by EEG remains to be elucidated.

Novel insights: Dynamic foam cells derived from the macrophage in atherosclerosis

Atherosclerosis can be regarded as a chronic disease derived from the interaction between disordered lipoproteins and an unsuitable immune response. The evolution of foam cells is not only a significant pathological change in the early stage of atherosclerosis but also a key stage in the occurrence and development of atherosclerosis. The formation of foam cells is mainly caused by the imbalance among lipids uptake, lipids treatment, and reverse cholesterol transport. Although a large number of studies have summarized the source of foam cells and the mechanism of foam cells formation, we propose a new idea about foam cells in atherosclerosis. Rather than an isolated microenvironment, the macrophage multiple lipid uptake pathways, lipid internalization, lysosome, mitochondria, endoplasmic reticulum, neutral cholesterol ester hydrolase (NCEH), acyl-coenzyme A-cholesterol acyltransferase (ACAT), and reverse cholesterol transport are mutually influential, and form a dynamic process under multi-factor regulation. The macrophage takes on different uptake lipid statuses depending on multiple uptake pathways and intracellular lipids, lipid metabolites versus pro-inflammatory factors. Except for NCEH and ACAT, the lipid internalization of macrophages also depends on multicellular organelles including the lysosome, mitochondria, and endoplasmic reticulum, which are associated with each other. A dynamic balance between esterification and hydrolysis of cholesterol for macrophages is essential for physiology and pathology. Therefore, we propose that the foam cell in the process of atherosclerosis may be dynamic under multi-factor regulation, and collate this study to provide a holistic and dynamic idea of the foam cell.

Mitochondria orchestrate macrophage effector functions in atherosclerosis

Macrophages are pivotal in the initiation and development of atherosclerotic cardiovascular diseases. Recent studies have reinforced the importance of mitochondria in metabolic and signaling pathways to maintain macrophage effector functions. In this review, we discuss the past and emerging roles of macrophage mitochondria metabolic diversity in atherosclerosis and the potential avenue as biomarker. Beyond metabolic functions, mitochondria are also a signaling platform integrating epigenetic, redox, efferocytic and apoptotic regulations, which are exquisitely linked to their dynamics. Indeed, mitochondria functions depend on their density and shape perpetually controlled by mitochondria fusion/fission and biogenesis/mitophagy balances. Mitochondria can also communicate with other organelles such as the endoplasmic reticulum through mitochondria-associated membrane (MAM) or be secreted for paracrine actions. All these functions are perturbed in macrophages from mouse or human atherosclerotic plaques. A better understanding and integration of how these metabolic and signaling processes are integrated and dictate macrophage effector functions in atherosclerosis may ultimately help the development of novel therapeutic approaches.

Modeling cerebellar limb dysmetria and impaired spatial memory in rats using lamivudine: A preliminary study

BACKGROUND AND AIM

Neurodegeneration has been associated with the use of combination antiretroviral therapy (cART). This study is aimed at determining if any constituent of cART can induce cerebellar limb dysmetria and spatial memory impairments.

MATERIALS AND METHODS

Forty adult male Wistar rats were randomly grouped into four (n = 10): control (distilled water 0.5 mL); Tenofovir (6 mg/kg); Lamivudine (6 mg/kg) and Efavirenz (12 mg/kg). The following neurobehavioral studies were conducted: open field, beam walk, and Morris water maze. Immunohistochemistry of CD 68 and GFAP were used to test for neuroinflammation and neurodegeneration.

RESULTS

There was marked increase in pyknotic pyramidal cells of the hippocampus and ghost Purkinje cells in the cerebellum of treatment groups. There was also a significant increase in oxidative stress in lamivudine and efavirenz groups. In addition, Lamivudine caused a significant increase of microglial and astrocytic activity (p < 0.001, 0.05 respectively) compared to control. The open field test showed a significant decrease (p < 0.0001) of the line crossing performance in the efavirenz, lamivudine and tenofovir (with means: 26.4, 4.6, 17.4 respectively) compared to control (50.6). There was also a significant decrease in the grooming (p < 0.05) and rearing (p < 0.01) in lamivudine group. Whereas, walk latency increased in efavirenz (p < 0.01), and lamivudine (p < 0.0001) compared to control. While hind limb slips significantly increased in efavirenz (p < 0.05) and lamivudine (p < 0.0001) compared with control group. Likewise, Lamivudine and Tenofovir exposed groups experienced a significant delay in the time to identify the hidden platform in compared to control (p < 0.05).

CONCLUSION

Lamivudine altered efferent stimuli along the cerebellospinal tracts thereby causing motor impairments. The degenerating Purkinje fibers may have induced marked neurodegeneration in the hippocampus resulting in impaired spatial memory.

Immunometabolic function of cholesterol in cardiovascular disease and beyond

Inflammation represents the driving feature of many diseases, including atherosclerosis, cancer, autoimmunity and infections. It is now established that metabolic processes shape a proper immune response and within this context the alteration in cellular cholesterol homeostasis has emerged as a culprit of many metabolic abnormalities observed in chronic inflammatory diseases. Cholesterol accumulation supports the inflammatory response of myeloid cells (i.e. augmentation of toll-like receptor signalling, inflammasome activation, and production of monocytes and neutrophils) which is beneficial in the response to infections, but worsens diseases associated with chronic metabolic inflammation including atherosclerosis. In addition to the innate immune system, cells of adaptive immunity, upon activation, have also been shown to undergo a reprogramming of cellular cholesterol metabolism, which results in the amplification of inflammatory responses. Aim of this review is to discuss (i) the molecular mechanisms linking cellular cholesterol metabolism to specific immune functions; (ii) how cellular cholesterol accumulation sustains chronic inflammatory diseases such as atherosclerosis; (iii) the immunometabolic profile of patients with defects of genes affecting cholesterol metabolism including familial hypercholesterolaemia, cholesteryl ester storage disease, Niemann-Pick type C, and immunoglobulin D syndrome/mevalonate kinase deficiency. Available data indicate that cholesterol immunometabolism plays a key role in directing immune cells function and set the stage for investigating the repurposing of existing 'metabolic' drugs to modulate the immune response.

Lipid-based gene delivery to macrophage mitochondria for atherosclerosis therapy

Atherosclerosis with associated cardiovascular diseases remains one of the main causes of disability and death worldwide, requiring development of new solutions for prevention and treatment. Macrophages are the key effectors of a series of events involved in atherogenesis, such as inflammation, plaque formation, and changes in lipid metabolism. Some of these events were shown to be associated with mitochondrial dysfunction and excessive mitochondrial DNA (mtDNA) damage. Moreover, macrophages represent a promising target for novel therapeutic approaches that are based on the expression of various receptors and nanoparticle uptake. Lipid-based gene delivery to mitochondria is considered to be an interesting strategy for mtDNA damage correction. To date, several nanocarriers and their modifications have been developed that demonstrate high transfection efficiency and low cytotoxicity. This review discusses the possibilities of lipid-based gene delivery to macrophage mitochondria for atherosclerosis therapy.

Changes in neurosteroidogenesis during demyelination and remyelination in cuprizone-treated mice

Changes of neurosteroids may be involved in the pathophysiology of multiple sclerosis (MS). The present study investigated whether changes of neurosteroidogenesis also occurred in the grey and white matter regions of the brain in mice subjected to cuprizone-induced demyelination. Accordingly, we compared the expression of neurosteroidogenic proteins, including steroidogenic acute regulatory protein (StAR), voltage-dependent anion channel (VDAC) and 18 kDa translocator protein (TSPO), as well as neurosteroidogenic enzymes, including the side chain cleavage enzyme (P450scc), 3β-hydroxysteroid dehydrogenase/isomerase and 5α-reductase (5α-R), during the demyelination and remyelination periods. Using immunohistochemistry and a quantitative polymerase chain reaction, we demonstrated a decreased expression of StAR, P450scc and 5α-R with respect to an increase astrocytic and microglial reaction and elevated levels of tumor necrosis factor (TNF)α during the cuprizone demyelination period in the hippocampus, cortex and corpus callosum. These parameters, as well as the glial reaction, were normalised after 2 weeks of spontaneous remyelination in regions containing grey matter. Conversely, persistent elevated levels of TNFα and low levels of StAR and P450scc were observed during remyelination in corpus callosum white matter. We conclude that neurosteroidogenesis/myelination status and glial reactivity are inversely related in the hippocampus and neocortex. Establishing a cause and effect relationship for the measured variables remains a future challenge for understanding the pathophysiology of MS.

A Mouse Model of Schnyder Corneal Dystrophy with the N100S Point Mutation

Schnyder corneal dystrophy (SCD) is a rare autosomal dominant disease in humans, characterized by abnormal deposition of cholesterol and phospholipids in cornea caused by mutations in the UbiA prenyltransferase domain containing 1 (UBIAD1) gene. In this study, we generated a mouse line carrying Ubiad1 N100S point mutation using the CRISPR/Cas9 technique to investigate the pathogenesis of SCD. In vivo confocal microscopy revealed hyper-reflective dot-like deposits in the anterior cornea in heterozygotes and homozygotes. No significant change was found in corneal epithelial barrier function or wound healing. Electron microscopy revealed abnormal mitochondrial morphology in corneal epithelial, stromal, and endothelial cells. Mitochondrial DNA copy number assay showed 1.27 ± 0.07 fold change in homozygotes versus 0.98 ± 0.05 variation in wild type mice (P < 0.05). Lipidomic analysis indicated abnormal metabolism of glycerophosphoglycerols, a lipid class found in mitochondria. Four (34:1, 34:2, 36:2, and 44:8) of the 11 glycerophosphoglycerols species identified by mass spectrometry showed a significant increase in homozygous corneas compared with heterozygous and wild-type mouse corneas. Unexpectedly, we did not find a difference in the corneal cholesterol level between different genotypes by filipin staining or lipidomic analysis. The Ubiad1^N100S mouse provides a promising animal model of SCD revealing that mitochondrial dysfunction is a prominent component of the disease. The different phenotype in human and mouse may due to difference in cholesterol metabolism between species.

High Cholesterol Diet-Induced Changes in Oxysterol and Scavenger Receptor Levels in Heart Tissue

Involvement of high cholesterol and oxidative stress in cardiovascular diseases is well studied, as it can be hypothesized that various products originated from lipid peroxidation, such as oxysterols, or affected protein expression might lead to cardiomyocyte damage followed by the pathological modifications. Although oxidation of excessive cholesterol to oxysterols in elevated stress conditions is identified by a number of studies, the role of a high cholesterol diet in regulating fatty acid and oxysterol accumulation, together with scavenger receptor mRNA levels, in the heart remains little investigated. Our study provides a detailed analysis of the changes in fatty acid, oxysterol, and scavenger receptor profiles and its relation with histological alterations in the heart tissue. We evaluated alterations of fatty acid composition, by the GC-MS method, while 4β-, 25-, and 27-hydroxycholesterol and 7-ketocholesterol levels by means of LC-MS/MS in high cholesterol diet-fed rabbits. Additionally, a number of proteins related to lipid metabolism and scavenger receptor mRNA expressions were evaluated by Western blotting and RT-PCR. According to our in vivo results, a high cholesterol diet enhances a number of unsaturated fatty acids, oxysterols, and LXRα, in addition to CD36, CD68, CD204, and SR-F1 expressions while α-tocopherol supplementation decreases LXRα and SR expressions together with an increase in 27-hydroxycholesterol and ABCA1 levels. Our results indicated that the high cholesterol diet modulates proteins related to lipid metabolism, which might result in the malfunction of the heart and α-tocopherol shows its beneficial effects. We believe that this work will lead the generation of different theories in the development of heart diseases.

The Minimal Unit of Infection: Mycobacterium tuberculosis in the Macrophage

The interaction between Mycobacterium tuberculosis and its host cell is highly complex and extremely intimate. Were it not for the disease, one might regard this interaction at the cellular level as an almost symbiotic one. The metabolic activity and physiology of both cells are shaped by this coexistence. We believe that where this appreciation has greatest significance is in the field of drug discovery. Evolution rewards efficiency, and recent data from many groups discussed in this review indicate that M. tuberculosis has evolved to utilize the environmental cues within its host to control large genetic programs or regulons. But these regulons may represent chinks in the bacterium's armor because they include off-target effects, such as the constraint of the metabolic plasticity of M. tuberculosis. A prime example is how the presence of cholesterol within the host cell appears to limit the ability of M. tuberculosis to fully utilize or assimilate other carbon sources. And that is the reason for the title of this review. We believe firmly that, to understand the physiology of M. tuberculosis and to identify new drug targets, it is imperative that the bacterium be interrogated within the context of its host cell. The constraints induced by the environmental cues present within the host cell need to be preserved and exploited. The M. tuberculosis-infected macrophage truly is the "minimal unit of infection."

27-hydroxycholesterol: A novel player in molecular carcinogenesis of breast and prostate cancer

Several studies have suggested an etiological role for hypercholesterolemia in the pathogenesis of breast cancer and prostate cancer (PCa). However, the molecular mechanisms that underlie and mediate the hypercholesterolemia-fostered increased risk for breast cancer and PCa are yet to be determined. The discovery that the most abundant cholesterol oxidized metabolite in the plasma, 27 hydroxycholesterol (27-OHC), is a selective estrogen receptor modulator (SERM) and an agonist of Liver X receptors (LXR) partially fills the void in our understanding and knowledge of the mechanisms that may link hypercholesterolemia to development and progression of breast cancer and PCa. The wide spectrum and repertoire of SERM and LXR-dependent effects of 27-OHC in the context of all facets and aspects of breast cancer and prostate cancer biology are reviewed in this manuscript in a very comprehensive manner. This review highlights recent findings pertaining to the role of 27-OHC in breast cancer and PCa and delineates the signaling mechanisms involved in the governing of different facets of tumor biology, that include tumor cell proliferation, epithelial-mesenchymal transition (EMT), as well as tumor cell invasion, migration, and metastasis. We also discuss the limitations of contemporary studies and lack of our comprehension of the entire gamut of effects exerted by 27-OHC that may be relevant to the pathogenesis of breast cancer and PCa. We unveil and propose potential future directions of research that may further our understanding of the role of 27-OHC in breast cancer and PCa and help design therapeutic interventions against endocrine therapy-resistant breast cancer and PCa.

ABCA1 agonist peptides for the treatment of disease

PURPOSE OF REVIEW

The review summarizes information pertaining to the preclinical development of new apolipoprotein (apo) E mimetic peptides that stimulate cellular cholesterol efflux.

RECENT FINDINGS

Small α-helical peptides based on the C-terminal domain of apoE have been developed for therapeutic applications. These peptides stimulate cellular cholesterol efflux via the ATP-binding cassette transporter A1 (ABCA1) with high potency, like native apolipoproteins on a molar basis. This potent activity has been related to the unique ability of these peptides to maintain α-helix structure upon dilution. Recent structure-activity studies improving the safety features of these mimetic peptides have greatly improved their potential for clinical use. These studies have identified structural features of the class A α-helix motif that induce muscle toxicity and hypertriglyceridemia, which may have implications for the design of other HDL mimetic peptides.

SUMMARY

ABCA1 is an integral membrane protein that plays a central role in biology. Its principal function is to mediate the efflux of cholesterol and phospholipid from cells to extracellular apo, preventing a build-up of excess cholesterol in membranes. This process generates HDL particles that perform a variety of functions to protect against disease. A number of these functions can be viewed as directly or indirectly supporting ABCA1 activity, thus constituting a positive feedback system to optimize cellular lipid efflux responses and disease prevention. Consequently, therapeutic approaches that mimic the activities of apos may prove highly effective to combat disease. One such approach involves the use of peptides. The broad biological relevance of ABCA1 suggests these apo mimetic peptides may be useful for the treatment of a number of diseases, such as atherosclerosis, diabetes, and Alzheimer's disease.

An altered peripheral IL6 response in major depressive disorder

Major depressive disorder (MDD) is one of the most prevalent major psychiatric disorders with a lifetime prevalence of 17%. Recent evidence suggests MDD is not only a brain dysfunction, but a systemic disease affecting the whole body. Central and peripheral inflammatory changes seem to be a centerpiece of MDD pathology: a subset of patients show elevated blood cytokine and chemokine levels that partially normalize with symptom improvement over the course of anti-depressant treatment. As this inflammatory process in MDD is poorly understood, we hypothesized that the peripheral tissues of MDD patients will respond differently to inflammatory stimuli, resulting in an aberrant transcriptional response to elevated pro-inflammatory cytokines. To test this, we used MDD patient- and control-derived dermal fibroblast cultures to investigate their response to an acute treatment with IL6, IL1β, TNFα, or vehicle. Following RNA isolation and subsequent cDNA synthesis, quantitative PCR was used to determine the relative expression level of several families of inflammation-responsive genes. Our results showed comparable expression of the tested genes between MDD patients and controls at baseline. In contrast, MDD patient fibroblasts had a diminished transcriptional response to IL6 in all the gene sets tested (oxidative stress response, mitochondrial function, and lipid metabolism). We also found a significant increase in baseline and IL6 stimulated transcript levels of the IL6 receptor gene. This IL6 receptor transcript increase in MDD fibroblasts was accompanied by an IL6 stimulated increase in induction of SOCS3, which dampens IL6 receptor signaling. Altogether our results demonstrate that there is an altered transcriptional response to IL6 in MDD, which may represent one of the molecular mechanisms contributing to disease pathophysiology. Ultimately we hope that these studies will lead to validation of novel MDD drug targets focused on normalizing the altered IL6 response in patients.