Thalidomide interaction with inflammation in idiopathic pulmonary fibrosis.

The "Thalidomide tragedy" is a landmark in the history of the pharmaceutical industry. Despite limited clinical trials, there is a continuous effort to investigate thalidomide as a drug for cancer and inflammatory diseases such as rheumatoid arthritis, lepromatous leprosy, and COVID-19. This review focuses on the possibilities of targeting inflammation by repurposing thalidomide for the treatment of idiopathic pulmonary fibrosis (IPF). Articles were searched from the Scopus database, sorted, and selected articles were reviewed. The content includes the proven mechanisms of action of thalidomide relevant to IPF. Inflammation, oxidative stress, and epigenetic mechanisms are major pathogenic factors in IPF. Transforming growth factor-ß (TGF-ß) is the major biomarker of IPF. Thalidomide is an effective anti-inflammatory drug in inhibiting TGF-ß, interleukins (IL-6 and IL-1ß), and tumour necrosis factor-α (TNF-α). Thalidomide binds cereblon, a process that is involved in the proposed mechanism in specific cancers such as breast cancer, colon cancer, multiple myeloma, and lung cancer. Cereblon is involved in activating AMP-activated protein kinase (AMPK)-TGF-ß/Smad signalling, thereby attenuating fibrosis. The past few years have witnessed an improvement in the identification of biomarkers and diagnostic technologies in respiratory diseases, partly because of the COVID-19 pandemic. Hence, investment in clinical trials with a systematic plan can help repurpose thalidomide for pulmonary fibrosis.

Thalidomide alleviates neuropathic pain through microglial IL-10/ß-endorphin signaling pathway.

Thalidomide is an antiinflammatory, antiangiogenic and immunomodulatory agent which has been used for the treatment of erythema nodosum leprosum and multiple myeloma. It has also been employed in treating complex regional pain syndromes. The current study aimed to reveal the molecular mechanisms underlying thalidomide-induced pain antihypersensitive effects in neuropathic pain. Thalidomide gavage, but not its more potent analogs lenalidomide and pomalidomide, inhibited mechanical allodynia and thermal hyperalgesia in neuropathic pain rats induced by tight ligation of spinal nerves, with ED50 values of 44.9 and 23.5 mg/kg, and Emax values of 74% and 84% MPE respectively. Intrathecal injection of thalidomide also inhibited mechanical allodynia and thermal hyperalgesia in neuropathic pain. Treatment with thalidomide, lenalidomide and pomalidomide reduced peripheral nerve injury-induced proinflammatory cytokines (TNFα, IL-1ß and IL-6) in the ipsilateral spinal cords of neuropathic rats and LPS-treated primary microglial cells. In contrast, treatment with thalidomide, but not lenalidomide or pomalidomide, stimulated spinal expressions of IL-10 and ß-endorphin in neuropathic rats. Particularly, thalidomide specifically stimulated IL-10 and ß-endorphin expressions in microglia but not astrocytes or neurons. Furthermore, pretreatment with the IL-10 antibody blocked upregulation of ß-endorphin in neuropathic rats and cultured microglial cells, whereas it did not restore thalidomide-induced downregulation of proinflammatory cytokine expression. Importantly, pretreatment with intrathecal injection of the microglial metabolic inhibitor minocycline, IL-10 antibody, ß-endorphin antiserum, and preferred or selective µ-opioid receptor antagonist naloxone or CTAP entirely blocked thalidomide gavage-induced mechanical antiallodynia. Our results demonstrate that thalidomide, but not lenalidomide or pomalidomide, alleviates neuropathic pain, which is mediated by upregulation of spinal microglial IL-10/ß-endorphin expression, rather than downregulation of TNFα expression.

Constitutive TNF-α signaling in neonates is essential for the development of tissue-resident leukocyte profiles at barrier sites.

Newborn infants have a high disposition to develop systemic inflammatory response syndromes (SIRSs) upon inflammatory or infectious challenges. Moreover, there is a considerable trafficking of hematopoietic cells to tissues already under noninflammatory conditions. These age-specific characteristics suggest a hitherto unappreciated crucial role of the vascular endothelium during the neonatal period. Here, we demonstrate that healthy neonates showed already strong endothelial baseline activation, which was mediated by a constitutively increased production of TNF-α. In mice, pharmacological inhibition of TNF-α directly after birth prevented subsequent fatal SIRS but completely abrogated the recruitment of leukocytes to sites of infection. Importantly, in healthy neonates, blocking TNF-α at birth disrupted the physiologic leukocyte trafficking, which resulted in persistently altered leukocyte profiles at barrier sites. Collectively, these data suggest that constitutive TNF-α-mediated sterile endothelial activation in newborn infants contributes to the increased risk of developing SIRS but is needed to ensure the postnatal recruitment of leukocytes to organs and interfaces.-Bickes, M. S., Pirr, S., Heinemann, A. S., Fehlhaber, B., Halle, S., Völlger, L., Willers, M., Richter, M., Böhne, C., Albrecht, M., Langer, M., Pfeifer, S., Jonigk, D., Vieten, G., Ure, B., von Kaisenberg, C., Förster, R., von Köckritz-Blickwede, M., Hansen, G., Viemann, D. Constitutive TNF-α signaling in neonates is essential for the development of tissue-resident leukocyte profiles at barrier sites.

CD38+ M-MDSC expansion characterizes a subset of advanced colorectal cancer patients.

BACKGROUND: Myeloid-derived suppressor cells (MDSCs) are a population of immature immune cells with several protumorigenic functions. CD38 is a transmembrane receptor-ectoenzyme expressed by MDSCs in murine models of esophageal cancer. We hypothesized that CD38 could be expressed on MDSCs in human colorectal cancer (CRC), which might allow for a new perspective on therapeutic targeting of human MDSCs with anti-CD38 monoclonal antibodies in this cancer. METHODS: Blood samples were collected from 41 CRC patients and 8 healthy donors, followed by peripheral blood mononuclear cell (PBMC) separation. Polymorphonuclear (PMN-) and monocytic (M-) MDSCs and CD38 expression levels were quantified by flow cytometry. The immunosuppressive capacity of M-MDSCs from 10 CRC patients was validated in a mixed lymphocyte reaction (MLR) assay. RESULTS: A significant expansion of CD38+ M-MDSCs and a trend of expansion of CD38+ PMN-MDSCs (accompanied by a trend of increased CD38 expression on both M- and PMN-MDSCs) were observed in PBMCs of CRC patients when compared with healthy donors. The CD38+ M-MDSCs from CRC patients were found to be immunosuppressive when compared with mature monocytes. CD38+ M- and PMN-MDSC frequencies were significantly higher in CRC patients who previously received treatment when compared with treatment-naive patients. CONCLUSIONS: This study provides a rationale for an attempt to target M-MDSCs with an anti-CD38 monoclonal antibody in metastatic CRC patients. FUNDING: NCI P01-CA14305603, the American Cancer Society, Scott and Suzi Lustgarten Family Colon Cancer Research Fund, Hansen Foundation, and Janssen Research and Development.

IL-27 Suppresses Antimicrobial Activity in Human Leprosy.

The mechanisms by which intracellular pathogens trigger immunosuppressive pathways are critical for understanding the pathogenesis of microbial infection. One pathway that inhibits host defense responses involves the induction of type I interferons and subsequently IL-10, yet the mechanism by which type I IFN induces IL-10 remains unclear. Our studies of gene expression profiles derived from leprosy skin lesions suggested a link between IL-27 and the IFN-ß induced IL-10 pathway. Here, we demonstrate that the IL-27p28 subunit is upregulated following treatment of monocytes with IFN-ß and Mycobacterium leprae, the intracellular bacterium that causes leprosy. The ability of IFN-ß and M. leprae to induce IL-10 was diminished by IL-27 knockdown. Additionally, treatment of monocytes with recombinant IL-27 was sufficient to induce the production of IL-10. Functionally, IL-27 inhibited the ability of IFN-γ to trigger antimicrobial activity against M. leprae in infected monocytes. At the site of disease, IL-27 was more strongly expressed in skin lesions of patients with progressive lepromatous leprosy, correlating and colocalizing with IFN-ß and IL-10 in macrophages. Together, these data provide evidence that in the human cutaneous immune responses to microbial infection, IL-27 contributes to the suppression of host antimicrobial responses.

CD4+CD25+ T regs with acetylated FoxP3 are associated with immune suppression in human leprosy.

Leprosy is a chronic human disease that results from infection of Mycobacterium leprae. T reg cells have been shown to have important implications in various diseases. However, in leprosy, it is still unclear whether T regs can mediate immune suppression during progression of the disease. In the present study, we have proposed the putative mechanism leading to high proportion of T reg cells and investigated its significance in human leprosy. High levels of TGF-ß followed by adaptation of FoxP3(+) naive and memory (CD4(+)CD45RA(+)/RO(+)) T cells were observed as the principal underlying factors leading to higher generation of T reg cells during disease progression. Furthermore, TGF-ß was found to be associated with increased phosphorylation-mediated-nuclear-import of SMAD3 and NFAT towards BL/LL pole to facilitate FoxP3 expression in these cells, the same as justified after using nuclear inhibitors of SMAD3 (SIS3) and NFAT (cyclosporin A) in CD4(+)CD25(+) cells in the presence of TGF-ß and IL-2. Interestingly, low ubiquitination of FoxP3 in T reg cells of BL/LL patients was revealed to be a major driving force in conferring stability to FoxP3 which in turn is linked to suppressive potential of T regs. The present study has also pinpointed the presence of CD4(+)CD25(+)IL-10(+) sub class of T regs (Tr1) in leprosy.

Thalidomide inhibited the synthesis of IgM and IgG whereas Thalidomide+Dexamethasone and Dexamethasone alone acted as co-stimulants with pokeweed and enhanced their synthesis.

Thalidomide (Thal) provides effective treatment for erythema nodosum leprosum (ENL). In combination with Dexamethasome (Dex) it is an effective treatment for multiple myeloma (MM) and Waldenström's macroglobulinemia (WM). Thal's mechanism(s) of action in the treatment of these diverse medical conditions is not known, but it could be suppression of immunoglobulin (Ig) synthesis. Mononuclear cells were stimulated with pokeweed (PWM), and treated with Thal, Thal+Dex or Dex. The cultures were assayed for IgM and IgG. The maximum synthesis was expected to occur in cultures stimulated with PWM at 0.5, 5.0 or 10 microg/ml. The test agents at 15 microM each were expected to alter the response. Compared to cultures stimulated with PWM alone, there was significantly less Ig in the cultures containing Thal+PWM, and significantly more Ig in the cultures containing Thal+Dex+PWM or Dex+PWM (Wilcoxon). The median % of maximum was 57 for cultures treated with Thal+PWM; 184 for cultures treated with Thal+Dex+PWM, and 139 for cultures treated with Dex+PWM. Thal also acted as a co-stimulant with PWM and enhanced the synthesis of IL-2, IL-6 and DNA; whereas, Thal+Dex or Dex enhanced Ig synthesis, but suppressed IL-2, IL-6 and cell proliferation. Thal's ability to suppress Ig may explain its activity in ENL, MM and WM. The enhancement of Ig by Dex does not help to explain a role for Dex alone or in combination with Thal for the treatment of MM and WM.

Thalidomide suppressed IL-1beta while enhancing TNF-alpha and IL-10, when cells in whole blood were stimulated with lipopolysaccharide.

Thalidomide is used to treat erythema nodosum leprosum (ENL). The events that precipitate this inflammatory reaction, which may occur in multibacillary leprosy patients, and the mechanism by which thalidomide arrest ENL, are not known. Thalidomide's ability to inhibit tumor necrosis factor alpha (TNF-alpha) in vitro has been proposed as a partial explanation of its effective treatment of ENL. In in vitro assays, thalidomide can enhance or suppress TNF-alpha. This is dependent on the stimulant used to evoke TNF-alpha; the procedure used to isolate the mononuclear cells from blood, and the predominant mononuclear cell type in the culture. To avoid artifacts that may occur during isolation of mononuclear cells from blood, we stimulated normal human blood with LPS and evaluated the effect of thalidomide and dexamethasone on TNF-alpha, and other inflammatory cytokines and biomarkers. Thalidomide suppressed interleukin 1 beta (IL-1beta) (p = 0.007), and it enhanced TNF-alpha (p = 0.007) and interleukin 10 (IL-10) (p = 0.031). Dexamethasone enhanced IL-10 (p = 0.013) and suppressed IL-1beta, TNF-alpha, interleukin 6 (IL-6), and interleukin 8 (IL-8) (p = 0.013). The two drugs did not suppress: C-reactive protein (CRP), Ig-superfamily cell-adhesion molecule 1 (ICAM 1), tumor necrosis factor receptor 1 (TNFR1), tumor necrosis factor receptor 2 (TNFR2), or amyloid A. In vitro and in vivo evidence is accumulating that TNF-alpha is not the primary cytokine targeted by thalidomide in ENL and other inflammatory conditions.

Thalidomide in multiple myeloma--clinical trials and aspects of drug metabolism and toxicity.

BACKGROUND: After the tragic events in the early 1960s, thalidomide has re-emerged as therapeutic for multiple myeloma (MM). It was first approved for the treatment of erythema nodosum leprosum, and is now under evaluation for hematologic and non-hematologic disorders. Its complex mechanism of action is not fully understood; however extensive preclinical studies in MM have revealed its antiangiogenic and immunomodulatory properties. OBJECTIVE: In this review, we focus on the importance and toxicity of thalidomide in today's clinical use. METHODS: Key preclinical and clinical trials available as well as data on the pharmacokinetics and pharmacodynamics of thalidomide in humans are summarized. CONCLUSIONS: Thalidomide is widely used as first-line treatment and in relapsed/refractory MM. The most common side effects are fatigue, constipation and peripheral neuropathy, and careful monitoring is required to avoid fetal exposure.

Response to ciclosporin treatment in Ethiopian and Nepali patients with severe leprosy Type 1 reactions.

Leprosy type 1 reactions (T1R) are immune-mediated events with inflammation of peripheral nerves and skin. We report the clinical outcomes of a closely monitored open prospective trial in which eight Nepali and 33 Ethiopian patients with T1Rs were treated with an Indian generic formulation of ciclosporin (Cn; 5-7.5 mg/kg/day) for 12 weeks and followed up for 24 weeks after starting treatment. Outcomes were measured using a clinical severity score. Among the Nepalis, 75-100% improved in all acute clinical parameters; 67-100% patients maintained improvement, except for those with acute sensory nerve impairment among whom 67% relapsed after stopping treatment. The skin lesions of all Ethiopians on 5 mg/kg/day of Cn improved and 50-60% had peripheral nerve function improvement. Most Ethiopians needed a higher dose of Cn to improve nerve impairment and neuritis, and 50-78% of them developed worse clinical severity scores when Cn was stopped. Four Ethiopians and two Nepalis developed elevated serum creatinine levels on 7.5 mg/kg/day Cn, and three (9%) Ethiopians developed treatable hypertension. This suggests that Cn monotherapy is an effective treatment for severe T1R with few adverse effects. A dose of 5 mg/kg/day seems efficacious in Nepalis, but a higher dose may be required in Ethiopian patients.

Thalidomide analogs from diamines: Synthesis and evaluation as inhibitors of TNF-alpha production.

Fourteen thalidomide analogs bearing two phthalimido units were prepared in high yields (83-94%) by condensation of different diamines with phthalic or 3-nitrophthalic anhydride. An in vitro investigation of the compounds as inhibitors of the TNF-alpha production was performed. The inhibition was higher for compounds bearing amino and nitro groups and was modulated by increasing the size of the spacers between the phthalimide groups.

Cyclosporine A treatment of leprosy patients with chronic neuritis is associated with pain control and reduction in antibodies against nerve growth factor.

OBJECTIVES: Chronic neuritis (CN) is still a major problem in leprosy and is difficult to manage in patients who do not respond well to prednisone. In this study we (i) evaluate the efficacy of cyclosporine A (CyA) in controlling CN patients, and (ii) analyse the presence of anti-NGF antibodies in the sera of leprosy patients, and their behaviour during CyA treatment. DESIGN: This was an open, prospective, non-comparative study. Sixty-seven leprosy patients in three different institutions in Pará, Brazil were studied from January, 2001 to January, 2004. Of these, 47 had no CN and 20 were leprosy patients suffering from CN and taking at least 40 mg/day prednisone to control nerve impairment and pain. Patients received 12 months reducing course CyA starting at 5 mg/kg per day. The outcome measure was sensory impairment, assessed using Semmes-Weinstein monofilament examination (SWME), muscular force and spontaneous or palpation-related pain. RESULTS: Antibodies against NGF were detected in the sera of leprosy patients, which may explain the depletion of NGF in leprosy contributing to neuritis, inflammation and loss of cutaneous nociception. The levels of these antibodies in CN patients were slightly lower than in patients with no CN. However, anti-NGF titres in CN patients treated with CyA were lowered to levels similar to those in the normal subjects. There was also improvement in sensory impairment, muscular force and pain. CONCLUSIONS: These data suggest that anti-NGF antibodies are present in the sera of leprosy patients and may influence the outcome of neuritis, and that CyA might be a useful drug in controlling nerve impairment and pain in leprosy patients.

The promise of thalidomide: evolving indications.

Thalidomide was first used in the late 1950s but it was withdrawn from the market in the 1960s for its notorious teratogenic effects. This drug was more recently rediscovered as a powerful immunomodulatory and antiinflammatory agent and was approved by the FDA in 1998 for treatment of erythema nodosum leprosum. Thalidomide has shown great promise in advanced or refractory multiple myeloma either alone or in combination with other agents. It has also demonstrated benefits in a wide variety of disparate conditions such as aphthous and genital ulcers, cancer cachexia, HIV, tuberculosis and chronic graft versus host disease. Thalidomide is being investigated for treatment of renal cell carcinoma, and liver and thyroid cancers. Better understanding of its many mechanisms of action has provoked great interest in its potential use for treatment of various disorders. This review focuses on thalidomide's mechanisms of action, biochemistry, pharmacokinetics and its use in erythema nodosum leprosum as well as multiple myeloma, graft versus host disease, and renal cell carcinoma.

Thalidomide inhibits tumor necrosis factor-alpha production and antigen presentation by Langerhans cells.

Thalidomide is an effective treatment for several inflammatory and autoimmune disorders including erythema nodosum leprosum, Behcet's syndrome, discoid lupus erythematosus, and Crohn's disease. Thalidomide is believed to exert its anti-inflammatory effects, at least in part, by inhibiting tumor necrosis factor-alpha (TNF-alpha) production by monocytes. We studied the effects of thalidomide on epidermal Langerhans cells (LC). LCs are epidermal antigen-presenting dendritic cells that play important roles in skin immune responses. Using the murine epidermis-derived dendritic cell lines, XS106A from A/J mice and XS52 from BALB/c mice as surrogates for LC, we found that thalidomide inhibited TNF-alpha production in a concentration-dependent manner. Northern blot analysis revealed that thalidomide significantly decreased the peak-induced mRNA level of TNF-alpha in XS106A cells and XS52 cells. We then examined the effect of thalidomide on fresh LC enriched to approximately 98% using positive selection of Ia+ cells with antibodies conjugated to magnetic microspheres. TNF-alpha production was reduced by 67.7% at a thalidomide concentration of 200 microg per mL. Thalidomide also had a profound inhibitory effect on the ability of LC to present antigen to a responsive TH1 clone. Thalidomide inhibits TNF-alpha production and the antigen-presenting ability of epidermal LCs. These mechanisms may contribute to the therapeutic effects observed with this agent.

Thalidomide as an anti-cancer agent.

Thalidomide is a glutamic acid derivative initially introduced as a sedative hypnotic nearly forty years ago. It was withdrawn following numerous reports linking it to a characteristic pattern of congenital abnormalities in babies born to mothers who used the drug for morning sickness. It has gradually been re-introduced into clinical practice over the past two decades, albeit under strict regulation, since it was found to be useful in the management of erythema nodosum leprosum and HIV wasting syndrome. Recognition of its anti-angiogenic effect led to its evaluation in the treatment of various malignancies, where angiogenesis has been shown to play an important role. Numerous clinical trials done over the past four years have confirmed the significant anti-myeloma activity of this drug. It has also shown promise in preliminary trials in the treatment of a variety of different malignant diseases. The mechanisms of its antineoplastic effects continue to be the focus of ongoing research. It has become clear that even though its anti angiogenic effects play a significant role in the anti-tumor activity, there are other properties of this drug which are responsible as well. It also possesses anti-TNF alpha activity, which has led to its evaluation in several inflammatory states. In this concise review, we briefly describe the historical background and pharmacological aspects of this drug. We have concisely reviewed the current knowledge regarding mechanisms of its anti-neoplastic activity and the results of various clinical trials in oncology.

Management of erythema nodosum leprosum by thalidomide: thalidomide analogues inhibit M. leprae-induced TNFalpha production in vitro.

Thalidomide is being successfully used for the treatment of erythema nodosum leprosum (ENL), among other disorders with inflammatory and immunological bases. Although the active molecules responsible for the diverse therapeutic activities of the drug and the sequence of reactions triggered inside the cells remain unclear, it was demonstrated that thalidomide (THAL) inhibits TNFalpha mRNA expression and protein production by stimulated monocytes and activated T lymphocytes. Patients treated with THAL experienced a reduction in serum TNFalpha levels and it diminished cytokine gene expression at the lesion site, with a concomitant abrogation of clinical symptoms. It has been reported that thalidomide as well as some its analogues decrease M. leprae-induced TNFalpha and IL-12 mRNA in vitro. THAL also reduced monocyte apoptosis in the cultures. The present data further support thalidomide's effects on TNFa synthesis and the growing need to search for new specific TNFalpha inhibitors (non-teratogenic compounds) that might be potentially used in clinical disorders such as leprosy.

Triptolide, a novel immunosuppressive and anti-inflammatory agent purified from a Chinese herb Tripterygium wilfordii Hook F.

Triptolide is a diterpenoid triepoxide purified from a Chinese herb Tripterygium Wilfordii Hook F (TWHF). TWHF has been used in traditional Chinese medicine for more than two thousand years. However, its potential value was recognized by the western medicine only after investigators observed the effectiveness of TWHF in the treatment of leprosy and rheumatoid arthritis. Triptolide has been identified as the major component responsible for the immunosuppressive and anti-inflammatory effects of TWHF. Triptolide inhibits both Ca(2+)-dependent and Ca(2+)-independent pathways and affects T cell activation through inhibition of interleukin-2 transcription at a site different from the target of cyclosporin A. Triptolide also has inhibitory effects on a variety of proinflammatory cytokines and mediators and on the expression of adhesion molecules by endothelial cells. Triptolide is effective for the treatment of a variety of autoimmune diseases and in prevention of allograft rejection and graft-versus-host disease in both animals and humans. Moreover, triptolide possesses antitumor and male anti-fertility effect. However, the toxicities of triptolide may be associated with renal, cardiac, hematopoietic and reproductive systems. Currently available data suggest that triptolide is a promising immunosuppressive and anti-inflammatory agent and should be explored further in autoimmune diseases and transplantation.