Regulation of tumour necrosis factor signalling: live or let die. Nat Rev Immunol. 2015;15:362-374. [PMID: 26008591 DOI: 10.1038/nri3834]

Neuroprotection of Human Umbilical Cord-Derived Mesenchymal Stem Cells (hUC-MSCs) in Alleviating Ischemic Stroke-Induced Brain Injury by Regulating Inflammation and Oxidative Stress

Brain injury caused by stroke has a high rate of mortality and remains a major medical challenge worldwide. In recent years, there has been significant attention given to the use of human Umbilical cord-derived Mesenchymal Stem Cells (hUC-MSCs) for the treatment of stroke in different adult and neonate animal models of stroke. However, using hUC-MSCs by systemic administration to treat ischemic stroke has not been investigated sufficiently. In this study, we conducted various experiments to explore the neuroprotection of hUC-MSCs in rats. Our findings demonstrate that an intravenous injection of a high dose of hUC-MSCs at 2 × 10^7 cells/kg markedly ameliorated brain injury resulting from ischemic stroke. This improvement was observed one day after inducing transient middle cerebral artery occlusion (MCAO) and subsequent reperfusion in rats. Notably, the efficacy of this single administration of hUC-MSCs surpassed that of edaravone, even when the latter was used continuously over three days. Mechanistically, secretory factors derived from hUC-MSCs, such as HGF, BDNF, and TNFR1, ameliorated the levels of MDA and T-SOD to regulate oxidative stress. In particular, TNFR1 also improved the expression of NQO-1 and HO-1, important proteins associated with oxidative stress. More importantly, TNFR1 played a significant role in reducing inflammation by modulating IL-6 levels in the blood. Furthermore, TNFR1 was observed to influence the permeability of the blood-brain barrier (BBB) as demonstrated in the evan's blue experiment and protein expression of ZO-1. This study represented a breakthrough in traditional methods and provided a novel strategy for clinical medication and trials.

Microglia signaling in health and disease - Implications in sex-specific brain development and plasticity

Microglia, the intrinsic neuroimmune cells residing in the central nervous system (CNS), exert a pivotal influence on brain development, homeostasis, and functionality, encompassing critical roles during both aging and pathological states. Recent advancements in comprehending brain plasticity and functions have spotlighted conspicuous variances between male and female brains, notably in neurogenesis, neuronal myelination, axon fasciculation, and synaptogenesis. Nevertheless, the precise impact of microglia on sex-specific brain cell plasticity, sculpting diverse neural network architectures and circuits, remains largely unexplored. This article seeks to unravel the present understanding of microglial involvement in brain development, plasticity, and function, with a specific emphasis on microglial signaling in brain sex polymorphism. Commencing with an overview of microglia in the CNS and their associated signaling cascades, we subsequently probe recent revelations regarding molecular signaling by microglia in sex-dependent brain developmental plasticity, functions, and diseases. Notably, C-X3-C motif chemokine receptor 1 (CX3CR1), triggering receptors expressed on myeloid cells 2 (TREM2), calcium (Ca2+), and apolipoprotein E (APOE) emerge as molecular candidates significantly contributing to sex-dependent brain development and plasticity. In conclusion, we address burgeoning inquiries surrounding microglia's pivotal role in the functional diversity of developing and aging brains, contemplating their potential implications for gender-tailored therapeutic strategies in neurodegenerative diseases.

Decoy peptides that inhibit TNF signaling by disrupting the TNF homotrimeric oligomer

Tumor necrosis factor (TNF) is a pro-inflammatory cytokine and its functional homotrimeric form interacts with the TNF receptor (TNFR) to activate downstream apoptotic, necroptotic, and inflammatory signaling pathways. Excessive activation of these pathways leads to various inflammatory diseases, which makes TNF a promising therapeutic target. Here, 12-mer peptides were selected from the interface of TNF-TNFR based upon their relative binding energies and were named 'TNF-inhibiting decoys' (TIDs). These decoy peptides inhibited TNF-mediated secretion of cytokines and cell death, as well as activation of downstream signaling effectors. Effective TIDs inhibited TNF signaling by disrupting the formation of TNF's functional homotrimeric form. Among derivatives of TIDs, TID3c showed slightly better efficacy in cell-based assays by disrupting TNF trimer formation. Moreover, TID3c oligomerized TNF to a high molecular weight configuration. In silico modeling and simulations revealed that TID3c and its parent peptide, TID3, form a stable complex with TNF through hydrogen bonds and electrostatic interactions, which makes them the promising lead to develop peptide-based anti-TNF therapeutics.

EGFR inhibits TNF-α-mediated pathway by phosphorylating TNFR1 at tyrosine 360 and 401

Tumour necrosis factor receptor 1 (TNFR1) induces the nuclear factor kappa-B (NF-κB) signalling pathway and regulated cell death processes when TNF-α ligates with it. Although mechanisms regulating the downstream pathways of TNFR1 have been elucidated, the direct regulation of TNFR1 itself is not well known. In this study, we showed that the kinase domain of the epidermal growth factor receptor (EGFR) regulates NF-κB signalling and TNF-α-induced cell death by directly phosphorylating TNFR1 at Tyr 360 and 401 in its death domain. In contrast, EGFR inhibition by EGFR inhibitors, such as erlotinib and gefitinib, prevented their interaction. Once TNFR1 is phosphorylated, its death domain induces the suppression of the NF-κB pathways, complex II-mediated apoptosis, or necrosome-dependent necroptosis. Physiologically, in mouse models, EGF treatment mitigates TNF-α-dependent necroptotic skin inflammation induced by treatment with IAP and caspase inhibitors. Our study revealed a novel role for EGFR in directly regulating TNF-α-related pathways.

Effect of Exogenous Melatonin on Performance and Mastitis in Dairy Cows

Mastitis is an important factor affecting the health of cows that leads to elevated somatic cell counts in milk, which can seriously affect milk quality and result in huge economic losses for the livestock industry. Therefore, the aim of this trial was to investigate the effect of melatonin on performance and mastitis in dairy cows. Forty-eight Holstein cows with a similar body weight (470 ± 10 kg), parity (2.75 ± 1.23), number of lactation days (143 ± 43 days), BCS (3.0-3.5), milk yield (36.80 ± 4.18 kg), and somatic cell count (300,000-500,000 cells/mL) were selected and randomly divided into four groups: control (CON group), trial Ⅰ (T80 group), trial Ⅱ (T120 group), and trial Ⅲ (T160 group). Twelve cows in trial groups I, II, and III were pre-dispensed 80, 120, and 160 mg of melatonin in edible glutinous rice capsules along with the basal ration, respectively, while the control group was fed an empty glutinous rice capsule along with the ration. The trial period was 37 days, which included a 7-day adaptive phase followed by a 30-day experimental period. At the end of the trial period, feeding was ended and the cows were observed for 7 days. Milk samples were collected on days 0, 7, 14, 21, 28, and 37 to determine the somatic cell number and milk composition. Blood samples were collected on days 0, 15, 30, and 37 of the trial to determine the serum biochemical indicators, antioxidant and immune indicators, and the amount of melatonin in the blood. The results showed that the somatic cell counts of lactating cows in the CON group were lower than those in the T120 group on days 14 (p < 0.05) and 28 (p < 0.01) at 1 week after melatonin cessation. The milk protein percentage and milk fat percentage of cows in the T120 group were higher than those in the CON group (p < 0.01). The total protein and globulin content in the T120 group were higher than those in the CON group (p < 0.01). In terms of antioxidant capacity and immunity, the cows 1 week after melatonin cessation showed higher superoxide dismutase activity and interleukin-10 contents (p < 0.01) compared with the CON group and lower malondialdehyde and tumor necrosis factor-alpha contents (p < 0.01) compared with the T120 group. The melatonin content in the T120 group was increased relative to that in the other groups. In conclusion, exogenous melatonin can increase the content of milk components, reduce the somatic cell count, and improve the antioxidant capacity and immune responses to a certain extent. Under the experimental conditions, 120 mg/day melatonin is recommended for mid- to late-lactation cows.

Modulation of extrinsic apoptotic pathway by intracellular glycosylation

The importance of post-translational modifications (PTMs), particularly O-GlcNAcylation, of cytoplasmic proteins in apoptosis has been neglected for quite a while. Modification of cytoplasmic proteins by a single N-acetylglucosamine sugar is a dynamic and reversible PTM exhibiting properties more like phosphorylation than classical O- and N-linked glycosylation. Due to the sparse information existing, we have only limited understanding of how GlcNAcylation affects cell death. Deciphering the role of GlcNAcylation in cell fate may provide further understanding of cell fate decisions. This review focus on the modulation of extrinsic apoptotic pathway via GlcNAcylation carried out by O-GlcNAc transferase (OGT) or by other bacterial effector proteins.

FNDC4 reduces hepatocyte inflammatory cell death via AMPKα in metabolic dysfunction-associated steatotic liver disease

BACKGROUND

The molecular mediators responsible for the progression of metabolic dysfunction-associated steatotic liver disease (MASLD) to steatohepatitis (MASH) have not yet been completely disentangled. We sought to analyze whether FNDC4, an hepatokine and adipokine with anti-inflammatory properties, is involved in TNF-α-induced inflammatory cell death in patients with MASLD.

METHODS

Plasma FNDC4 (n = 168) and hepatic FNDC4 and inflammatory cell death (n = 65) were measured in samples from patients with severe obesity with available liver biopsy-proven MASLD diagnosis. The effect of FNDC4 on TNF-α-induced pyroptosis, apoptosis and necroptosis (PANoptosis) and mitochondrial dysfunction was studied in vitro using human HepG2 hepatocytes.

RESULTS

Compared with individuals with normal liver, patients with type 2 diabetes and MASLD exhibited decreased hepatic FNDC4 mRNA and protein levels, which were related to liver inflammation. An overexpression of TNF-α, its receptor TNF-R1 and factors involved in inflammatory cell death was also found in the liver of these patients. FNDC4-knockdown in HepG2 hepatocytes increased apoptotic cell death, while FNDC4 treatment blunted NLRP3 inflammasome-induced pyroptosis, apoptosis and necroptosis in TNF-α-stimulated hepatocytes. Moreover, FNDC4 improved TNF-α-induced hepatocyte mitochondrial dysfunction by enhancing mitochondrial DNA (mtDNA) copy number and OXPHOS complex subunits I, II, III and V protein expression. Mechanistically, AMP-activated protein kinase α (AMPKα) was required for the FNDC4-mediated inhibition of cell death and increase in mtDNA content.

CONCLUSIONS

FNDC4 acts as a hepatocyte survival factor favouring mitochondrial homeostasis and decreasing inflammatory cell death via AMPKα. Collectively, our study identifies FNDC4 as an attractive target to prevent hepatocellular damage in patients with MASLD.

Signaling molecules in the microenvironment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a major fatal cancer that is known for its high recurrence and metastasis. An increasing number of studies have shown that the tumor microenvironment is closely related to the metastasis and invasion of HCC. The HCC microenvironment is a complex integrated system composed of cellular components, the extracellular matrix (ECM), and signaling molecules such as chemokines, growth factors, and cytokines, which are generally regarded as crucial molecules that regulate a series of important processes, such as the migration and invasion of HCC cells. Considering the crucial role of signaling molecules, this review aims to elucidate the regulatory effects of chemokines, growth factors, and cytokines on HCC cells in their microenvironment to provide important references for clarifying the development of HCC and exploring effective therapeutic targets.

Neurological Side Effects of TNF-α Inhibitors Revisited: A Review of Case Reports

Over the past two decades, the use of tumor necrosis factor alpha (TNF-α) inhibitors has significantly improved the treatment of patients with immune-mediated inflammatory diseases. Firstly, introduced for rheumatoid arthritis, these inhibitors are currently approved and used for a variety of conditions, including ankylosing spondylitis, Crohn's disease, juvenile idiopathic arthritis, psoriasis, psoriatic arthritis, ulcerative colitis, and chronic uveitis. Despite their immense therapeutic efficacy, TNF-α inhibitors have been associated with neurological adverse effects that bring new clinical challenges. The present review collects data from multiple studies to evaluate the incidence and the relationship between TNF-α inhibitors and neurological side effects and to explore the potential underlying mechanisms of this association. Moreover, it highlights the importance of patient selection, particularly in the case of individuals with a history of demyelinating diseases, raises awareness for clinicians, and calls for ongoing research that will improve TNF-α targeting strategies and offer safer and more effective therapeutic options.

Interferon-I modulation and natural products: Unraveling mechanisms and therapeutic potential in severe COVID-19

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to pose a significant global public health threat, particularly to older adults, pregnant women, and individuals with underlying chronic conditions. Dysregulated immune responses to SARS-CoV-2 infection are believed to contribute to the progression of COVID-19 in severe cases. Previous studies indicates that a deficiency in type I interferon (IFN-I) immunity accounts for approximately 15 %-20 % of patients with severe pneumonia caused by COVID-19, highlighting the potential therapeutic importance of modulating IFN-I signals. Natural products and their derivatives, due to their structural diversity and novel scaffolds, play a crucial role in drug discovery. Some of these natural products targeting IFN-I have demonstrated applications in infectious diseases and inflammatory conditions. However, the immunomodulatory potential of IFN-I in critical COVID-19 pneumonia and the natural compounds regulating the related signal pathway remain not fully understood. In this review, we offer a comprehensive assessment of the association between IFN-I and severe COVID-19, exploring its mechanisms and integrating information on natural compounds effective for IFN-I regulation. Focusing on the primary targets of IFN-I, we also summarize the regulatory mechanisms of natural products, their impact on IFNs, and their therapeutic roles in viral infections. Collectively, by synthesizing these findings, our goal is to provide a valuable reference for future research and to inspire innovative treatment strategies for COVID-19.

The C-reactive protein-albumin-lymphocyte (CALLY) index is a useful predictor of postoperative complications in patients with a colonic stent for obstructive colorectal cancer: a Japanese multicenter study

PURPOSE

The C-reactive protein-albumin-lymphocyte (CALLY) index is a novel score that offers a good reflection of nutritional status, inflammatory response, and immune system status. The CALLY index is reported to correlate with the prognosis of various carcinomas. The purpose of the present study was to investigate the association between the CALLY index and the short-term prognosis of obstructive colorectal cancer managed with a colonic stent.

METHODS

The subjects of this retrospective study were 263 patients who underwent colorectal resection after colonic stenting for obstructive colorectal cancer between 2016 and 2023. Patients were classified into a group with a low CALLY index (CALLY-L group, n = 85) and a group with a high (CALLY-H group, n = 178) CALLY index.

RESULTS

The CALLY-L group had greater blood loss (53 mL vs 20 mL, p = 0.002) and higher poor performance status (PS3; 20% vs 10.1%, p = 0.033), open surgery (21.2% vs 7.3%, p = 0.001), distant metastases (41.2% vs 20.8%, p = 0.01), and postoperative complications (30.6% vs. 18.5%, p = 0.039) than the CALLY-H group. Multivariate analysis identified a prolonged operative time (odds ratio 1.983, 95% confidence interval 1.013-3.881; p = 0.045), greater blood loss (odds ratio 2.572, 95% confidence interval 1.291-5.129; p = 0.007) and a low CALLY index (odds ratio 1.961, 95% confidence interval 1.013-3.795; p = 0.045) as independent predictors of complications.

CONCLUSION

The CALLY index may be a useful predictor of postoperative complications of obstructive colorectal cancer.

Prognostic significance of the preoperative C-reactive protein-albumin-lymphocyte (CALLY) index on outcomes after gastrectomy for gastric cancer

PURPOSE

Systemic inflammatory response markers are reported to be prognostic for patients with cancer. The C-reactive protein (CRP)-albumin-lymphocyte (CALLY) index has been established as an immuno-nutritional scoring system. The aim of this study was to clarify the impact of the preoperative CALLY index on the outcome of patients undergoing gastrectomy for gastric cancer.

METHODS

We analyzed the data of 826 patients who underwent gastrectomy for stage I, II, or III gastric cancer between 2010 and 2017. The CALLY index was defined as (albumin × lymphocyte)/(CRP × 104).

RESULTS

The cut-off of the CALLY index was 2. The 147 patients with a preoperative CALLY index < 2 had significantly worse overall survival (OS) and relapse-free survival (RFS) than those with a CALLY index ≥ 2 (P < 0.01, P < 0.01, respectively). Multivariate analysis identified that a CALLY index < 2 (P = 0.02), intraoperative blood loss (P < 0.01), and stage II or III disease (P < 0.01) were independent and significant predictors of worse RFS. A CALLY index < 2 (P = 0.01), intraoperative blood loss (P < 0.01), postoperative complications (P = 0.02), and stage II or III disease (P < 0.01) were independent and significant predictors of worse OS.

CONCLUSION

The preoperative CALLY index was independently associated with a poor prognosis for patients after gastrectomy for gastric cancer.

Progranulin: A promising biomarker and therapeutic target for fibrotic diseases

Progranulin (PGRN), a multifunctional growth factor-like protein expressed by a variety of cell types, serves an important function in the physiologic and pathologic processes of fibrotic diseases, including wound healing and the inflammatory response. PGRN was discovered to inhibit pro-inflammation effect by competing with tumor necrosis factor-alpha (TNF-α) binding to TNF receptors. Notably, excessive tissue repair in the development of inflammation causes tissue fibrosis. Previous investigations have indicated the significance of PGRN in regulating inflammatory responses. Recently, multiple studies have shown that PGRN was linked to fibrogenesis, and was considered to monitor the formation of fibrosis in multiple organs, including liver, cardiovascular, lung and skin. This paper is a comprehensive review summarizing our current knowledge of PGRN, from its discovery to the role in fibrosis. This is followed by an in-depth look at the characteristics of PGRN, consisting of its structure, basic function and intracellular signaling. Finally, we will discuss the potential of PGRN in the diagnosis and treatment of fibrosis.

The miR-29-3p family suppresses inflammatory osteolysis

Osteoclasts are the cells primarily responsible for inflammation-induced bone loss, as is particularly seen in rheumatoid arthritis. Increasing evidence suggests that osteoclasts formed under homeostatic versus inflammatory conditions may differ in phenotype. While microRNA-29-3p family members (miR-29a-3p, miR-29b-3p, miR-29c-3p) promote the function of RANKL-induced osteoclasts, the role of miR-29-3p during inflammatory TNF-α-induced osteoclastogenesis is unknown. We used bulk RNA-seq, histology, qRT-PCR, reporter assays, and western blot analysis to examine bone marrow monocytic cell cultures and tissue from male mice in which the function of miR-29-3p family members was decreased by expression of a miR-29-3p tough decoy (TuD) competitive inhibitor in the myeloid lineage (LysM-cre). We found that RANKL-treated monocytic cells expressing the miR-29-3p TuD developed a hypercytokinemia/proinflammatory gene expression profile in vitro, which is associated with macrophages. These data support the concept that miR-29-3p suppresses macrophage lineage commitment and may have anti-inflammatory effects. In correlation, when miR-29-3p activity was decreased, TNF-α-induced osteoclast formation was accentuated in an in vivo model of localized osteolysis and in a cell-autonomous manner in vitro. Further, miR-29-3p targets mouse TNF receptor 1 (TNFR1/Tnfrsf1a), an evolutionarily conserved regulatory mechanism, which likely contributes to the increased TNF-α signaling sensitivity observed in the miR-29-3p decoy cells. Whereas our previous studies demonstrated that the miR-29-3p family promotes RANKL-induced bone resorption, the present work shows that miR-29-3p dampens TNF-α-induced osteoclastogenesis, indicating that miR-29-3p has pleiotropic effects in bone homeostasis and inflammatory osteolysis. Our data supports the concept that the knockdown of miR-29-3p activity could prime myeloid cells to respond to an inflammatory challenge and potentially shift lineage commitment toward macrophage, making the miR-29-3p family a potential therapeutic target for modulating inflammatory response.

New compatible pair of TCM: Paeoniae Radix Alba effectively alleviate Psoraleae Fructus-induced liver injury by suppressing NLRP3 inflammasome activation

Objective

Drug-induced liver injury (DILI), a type of acute inflammation, has sparked significant concern owing to its unpredictability and severity. Psoraleae Fructus (PF), an edible Chinese herb widely used in traditional Chinese medicine (TCM), causes liver injury. Therefore, the elucidation of the mechanism underlying PF-induced liver injury and the search for more effective means of detoxification using herbal compatibility has become an urgent issue. This study evaluated the hepatoprotective effects of Paeoniae Radix Alba (PRA), a hepatoprotective Chinese medicine, on PF-induced liver injury and explored the underlying mechanisms.

Methods

A rat model of lipopolysaccharide (LPS)-induced immune stress was established to evaluate the hepatotoxicity of PF and the detoxifying effect of PRA. Subsequently, inflammatory pathways were identified using network pharmacology. Finally, the molecular mechanism by which PRA alleviates PF-induced liver injury was validated using an inflammasome activation model in bone marrow-derived macrophages (BMDMs).

Results

In vivo, hepatocytes in rats treated with LPS + PF exhibited massive inflammatory infiltration and apoptosis, and the expression of liver injury indicators and inflammatory factors was significantly upregulated, which was reversed by PRA pretreatment. Network pharmacology showed that PRA alleviated PF-induced liver injury and was associated with the NOD-like receptor signaling pathway. Moreover, PF directly induced inflammasome activation in LPS-primed BMDMs which in turn induced caspase-1 activation and the secretion of downstream effector cytokines such as IL-1β. PRA pretreatment inhibited PF-induced activation of the NLRP3 inflammasome by mitigating the accumulation of mitochondrial reactive oxygen species (mtROS).

Conclusions

The present study demonstrates that PRA alleviated PF induced-liver injury by inhibiting NLRP3 inflammasome activation. The results of this study are expected to inform the prevention and control of PF-induced hepatotoxicity in clinical practice.

Synthetic lethal connectivity and graph transformer improve synthetic lethality prediction

Synthetic lethality (SL) has shown great promise for the discovery of novel targets in cancer. CRISPR double-knockout (CDKO) technologies can only screen several hundred genes and their combinations, but not genome-wide. Therefore, good SL prediction models are highly needed for genes and gene pairs selection in CDKO experiments. However, lack of scalable SL properties prevents generalizability of SL interactions to out-of-sample data, thereby hindering modeling efforts. In this paper, we recognize that SL connectivity is a scalable and generalizable SL property. We develop a novel two-step multilayer encoder for individual sample-specific SL prediction model (MLEC-iSL), which predicts SL connectivity first and SL interactions subsequently. MLEC-iSL has three encoders, namely, gene, graph, and transformer encoders. MLEC-iSL achieves high SL prediction performance in K562 (AUPR, 0.73; AUC, 0.72) and Jurkat (AUPR, 0.73; AUC, 0.71) cells, while no existing methods exceed 0.62 AUPR and AUC. The prediction performance of MLEC-iSL is validated in a CDKO experiment in 22Rv1 cells, yielding a 46.8% SL rate among 987 selected gene pairs. The screen also reveals SL dependency between apoptosis and mitosis cell death pathways.

Reciprocal suppression between TGFβ signaling and TNF stimulation finetunes the macrophage inflammatory response

Inflammation plays a crucial role in the development of various disease conditions or is closely associated with them. Inflammatory cytokines like TNF often engage in interactions with other cytokines and growth factors, including TGFβ, to orchestrate inflammatory process. Basal/endogenous TGFβ signaling is a universal presence, yet the precise way TNF communicates with TGFβ signaling to regulate inflammation and influence inflammatory levels in macrophages has remained elusive. To address this question, this study utilized genetic approaches and a combination of molecular and cellular methods, including conditional TGFβ receptor knockout mice, human cells, RNAseq, ATACseq and Cut & Run-seq. The results reveal that the TGFβ signaling functions as a vital homeostatic pathway, curtailing uncontrolled inflammation in macrophages in response to TNF. Conversely, TNF employs two previously unrecognized mechanisms to suppress the TGFβ signaling. These mechanisms encompass epigenetic inhibition and RBP-J-mediated inhibition of the TGFβ signaling pathway by TNF. These mechanisms empower TNF to diminish the antagonistic influence exerted by the TGFβ signaling pathway, ultimately enhancing TNF's capacity to induce heightened levels of inflammation. This reciprocal suppression dynamic between TNF and the TGFβ signaling pathway holds unique physiopathological significance, as it serves as a crucial "braking" mechanism. The balance between TNF levels and the activity of the endogenous TGFβ signaling pathway plays a pivotal role in determining the overall extent of inflammation. The potential for therapeutically augmenting the TGFβ signaling pathway presents an intriguing avenue for countering the impact of TNF and, consequently, developing innovative strategies for inflammation control.

Mitochondrial Quality Control Processes at the Crossroads of Cell Death and Survival: Mechanisms and Signaling Pathways

Biological aging results from an accumulation of damage in the face of reduced resilience. One major driver of aging is cell senescence, a state in which cells remain viable but lose their proliferative capacity, undergo metabolic alterations, and become resistant to apoptosis. This is accompanied by complex cellular changes that enable the development of a senescence-associated secretory phenotype (SASP). Mitochondria, organelles involved in energy provision and activities essential for regulating cell survival and death, are negatively impacted by aging. The age-associated decline in mitochondrial function is also accompanied by the development of chronic low-grade sterile inflammation. The latter shares some features and mediators with the SASP. Indeed, the unloading of damage-associated molecular patterns (DAMPs) at the extracellular level can trigger sterile inflammatory responses and mitochondria can contribute to the generation of DAMPs with pro-inflammatory properties. The extrusion of mitochondrial DNA (mtDNA) via mitochondrial outer membrane permeabilization under an apoptotic stress triggers senescence programs. Additional pathways can contribute to sterile inflammation. For instance, pyroptosis is a caspase-dependent inducer of systemic inflammation, which is also elicited by mtDNA release and contributes to aging. Herein, we overview the molecular mechanisms that may link mitochondrial dyshomeostasis, pyroptosis, sterile inflammation, and senescence and discuss how these contribute to aging and could be exploited as molecular targets for alleviating the cell damage burden and achieving healthy longevity.

Breaking Down Barriers: Epithelial Contributors to Monogenic IBD Pathogenesis

Monogenic causes of inflammatory bowel diseases (IBD) are increasingly being discovered. To date, much attention has been placed in those resulting from inborn errors of immunity. Therapeutic efforts have been largely focused on offering personalized immune modulation or curative bone marrow transplant for patients with IBD and underlying immune disorders. To date, less emphasis has been placed on monogenic causes of IBD that pertain to impairment of the intestinal epithelial barrier. Here, we provide a comprehensive review of monogenic causes of IBD that result in impaired intestinal epithelial barrier that are categorized into 6 important functions: (1) epithelial cell organization, (2) epithelial cell intrinsic functions, (3) epithelial cell apoptosis and necroptosis, (4) complement activation, (5) epithelial cell signaling, and (6) control of RNA degradation products. We illustrate how impairment of any of these categories can result in IBD. This work reviews the current understanding of the genes involved in maintaining the intestinal barrier, the inheritance patterns that result in dysfunction, features of IBD resulting from these disorders, and pertinent translational work in this field.

USP36 inhibits apoptosis by deubiquitinating cIAP1 and survivin in colorectal cancer cells

Chemotherapeutic agents for treating colorectal cancer (CRC) primarily induce apoptosis in tumor cells. The ubiquitin-proteasome system is critical for apoptosis regulation. Deubiquitinating enzymes (DUBs) remove ubiquitin from substrates to reverse ubiquitination. Although over 100 DUB members have been discovered, the biological functions of only a small proportion of DUBs have been characterized. Here, we aimed to systematically identify the DUBs that contribute to the development of CRC. Among the DUBs, ubiquitin-specific protease 36 (USP36) is upregulated in CRC. We showed that the knockdown of USP36 induces intrinsic and extrinsic apoptosis. Through gene silencing and coimmunoprecipitation techniques, we identified survivin and cIAP1 as USP36 targets. Mechanistically, USP36 binds and removes lysine-11-linked ubiquitin chains from cIAP1 and lysine-48-linked ubiquitin chains from survivin to abolish protein degradation. Overexpression of USP36 disrupts the formation of the XIAP-second mitochondria-derived activator of caspase complex and promotes receptor-interacting protein kinase 1 ubiquitination, validating USP36 as an inhibitor to intrinsic and extrinsic apoptosis through deubiquitinating survivin and cIAP1. Therefore, our results suggest that USP36 is involved in CRC progression and is a potential therapeutic target.

Engineering antigen-presenting cells for immunotherapy of autoimmunity

Autoimmune diseases are burdensome conditions that affect a significant fraction of the global population. The hallmark of autoimmune disease is a host's immune system being licensed to attack its tissues based on specific antigens. There are no cures for autoimmune diseases. The current clinical standard for treating autoimmune diseases is the administration of immunosuppressants, which weaken the immune system and reduce auto-inflammatory responses. However, people living with autoimmune diseases are subject to toxicity, fail to mount a sufficient immune response to protect against pathogens, and are more likely to develop infections. Therefore, there is a concerted effort to develop more effective means of targeting immunomodulatory therapies to antigen-presenting cells, which are involved in modulating the immune responses to specific antigens. In this review, we highlight approaches that are currently in development to target antigen-presenting cells and improve therapeutic outcomes in autoimmune diseases.

Biomaterials-Based Technologies in Skeletal Muscle Tissue Engineering

For many clinically prevalent severe injuries, the inherent regenerative capacity of skeletal muscle remains inadequate. Skeletal muscle tissue engineering (SMTE) seeks to meet this clinical demand. With continuous progress in biomedicine and related technologies including micro/nanotechnology and 3D printing, numerous studies have uncovered various intrinsic mechanisms regulating skeletal muscle regeneration and developed tailored biomaterial systems based on these understandings. Here, the skeletal muscle structure and regeneration process are discussed and the diverse biomaterial systems derived from various technologies are explored in detail. Biomaterials serve not merely as local niches for cell growth, but also as scaffolds endowed with structural or physicochemical properties that provide tissue regenerative cues such as topographical, electrical, and mechanical signals. They can also act as delivery systems for stem cells and bioactive molecules that have been shown as key participants in endogenous repair cascades. To achieve bench-to-bedside translation, the typical effect enabled by biomaterial systems and the potential underlying molecular mechanisms are also summarized. Insights into the roles of biomaterials in SMTE from cellular and molecular perspectives are provided. Finally, perspectives on the advancement of SMTE are provided, for which gene therapy, exosomes, and hybrid biomaterials may hold promise to make important contributions.

Low-dose TNF-α promotes angiogenesis of oral squamous cell carcinoma cells via TNFR2/Akt/mTOR axis

OBJECTIVES

To assess the role of TNF-α/TNFR2 axis on promoting angiogenesis in oral squamous cell carcinoma (OSCC) cells and uncover the underlying mechanisms.

MATERIALS AND METHODS

The expression of TNFR2 and CD31 in OSCC tissues was examined; gene expression relationship between TNF-α/TNFR2 and angiogenic markers or signaling molecules was analyzed; the expression of angiogenic markers, signaling molecules, TNFR1, and TNFR2 in TNF-α-stimulated OSCC cells treated with or without TNFR2 neutralizing antibody (TNFR2 Nab) were assessed; the concentration of angiogenic markers in the supernatant of OSCC cells was detected; conditioned mediums of OSCC cells treated with TNF-α or TNF-α + TNFR2 Nab were applied to human umbilical vein endothelial cells (HUVECs), followed by tube formation and cell migration assays.

RESULTS

Significantly elevated expression of TNFR2 and CD31 in OSCC tissues was observed. A positive gene expression correlation was identified between TNF-α/TNFR2 and angiogenic markers or signaling molecules. TNFR2 Nab inhibited the effects of TNF-α on enhancing the expression of angiogenic factors and TNFR2, the phosphorylation of the Akt/mTOR signaling pathway, HUVECs migration, and tube formation.

CONCLUSIONS

TNFR2 Nab counteracts the effect of TNF-α on OSCC cells through the TNFR2/Akt/mTOR axis, indicating that blocking TNFR2 might be a promising strategy against cancer.

Interleukin-10 induces TNF-driven apoptosis and ROS production in salivary gland cancer cells

Treatment resistance after chemo-/immunotherapy occurs in patients with head and neck squamous cell cancers (HNSCs), including salivary gland cancers (SGCs). Interleukin-10 (IL-10), a cytokine with pro- and anti-cancer effects, has an unclear impact on HNSC/SGC cells. We show that HNSC patients exhibiting high expression of IL-10 and its receptor IL-10Rα experience have prolonged overall survival. Immunoreactive IL-10 was low in ductal cells of human SGC biopsies. Human (A253) and murine WR21-SGC cells expressed IL-10Rβ, but only A253 cells expressed IL-10 and IL-10Rα. The addition of recombinant IL-10 impaired SGC cell proliferation and induced apoptosis in vitro. N-acetylcysteine restored IL-10-induced reactive oxygen species (ROS) production but did not prevent IL-10-mediated viability loss. Mechanistically, recIL-10 delayed cell cycle progression from G0/G1 to the S phase with cyclin D downregulation and upregulation of NF-kB. IL-10 increased tumor necrosis factor-α (TNF-α) in A253 and WR21 and FasL in WR21 cells. Neutralizing antibodies against TNF-α and NF-kB inhibition restored SGC proliferation after IL-10 treatment, emphasizing the critical role of TNF-α and NF-kB in IL-10-mediated anti-tumor effects. These findings underscore the potential of IL-10 to impede SGC cell growth through apoptosis induction, unraveling potential therapeutic targets for intervention in salivary gland carcinomas.

Relieving Macrophage Dysfunction by Inhibiting SREBP2 Activity: A Hypoxic Mesenchymal Stem Cells-Derived Exosomes Loaded Multifunctional Hydrogel for Accelerated Diabetic Wound Healing

Macrophage dysfunction is one of the primary factors leading to the delayed healing of diabetic wounds. Hypoxic bone marrow mesenchymal stem cells-derived exosomes (hyBMSC-Exos) have been shown to play an active role in regulating cellular function through the carried microRNAs. However, the administration of hyBMSC-Exos alone in diabetic wounds usually brings little effect, because the exosomes are inherently unstable and have a short retention time at the wounds. In this study, a multifunctional hydrogel based on gallic acid (GA) conjugated chitosan (Chi-GA) and partially oxidized hyaluronic acid (OHA) is prepared for sustained release of hyBMSC-Exos. The hydrogel not only exhibits needs-satisfying physicochemical properties, but also displays outstanding biological performances such as low hemolysis rate, strong antibacterial capacity, great antioxidant ability, and excellent biocompatibility. It has the ability to boost the stability of hyBMSC-Exos, leading to a continuous and gradual release of the exosomes at wound locations, ultimately enhancing the exosomes' uptake efficiency by target cells. Most importantly, hyBMSC-Exos loaded hydrogel shows an excellent ability to promote diabetic wound healing by regulating macrophage polarization toward M2 phenotype. This may be because exosomal miR-4645-5p and antioxidant property of the hydrogel synergistically inhibit SREBP2 activity in macrophages. This study presents a productive approach for managing diabetic wounds.

Direct Interaction of Minocycline to p47phox Contributes to its Attenuation of TNF-α-Mediated Neuronal PC12 Cell Death: Experimental and Simulation Validation

Minocycline, a repurposed approved medication, shows promise in treating neurodegeneration. However, the specific pathways targeted by minocycline remain unclear despite the identification of molecular targets. This study explores minocycline's potential protective effects against TNF-α-mediated neuronal death in PC12 cells, with a focus on unraveling its interactions with key molecular targets. The study begins by exploring minocycline's protective role against TNF-α-mediated neuronal death in PC12 cells, showcasing a substantial reduction in cleaved caspase-3 expression, DNA fragmentation, and intracellular ROS levels following minocycline pretreatment. Subsequently, a comprehensive analysis utilizing pull-down assays, computational docking, mutation analysis, molecular dynamics simulations, and free energy calculations is conducted to elucidate the direct interaction between minocycline and p47phox-the organizer subunit of NADPH oxidase-2 (NOX2) complex. Computational insights, including a literature survey and analysis of key amino acid residues, reveal a potential binding site for minocycline around Trp193 and Cys196. In silico substitutions of Trp193 and Cys196 further confirm their importance in binding with minocycline. These integrated findings underscore minocycline's protective mechanisms, linking its direct interaction with p47phox to the modulation of NOX2 activity and attenuation of NOX-derived ROS generation. Minocycline demonstrates protective effects against TNF-α-induced PC12 cell death, potentially linked to its direct interaction with p47phox. This interaction leads to a reduction in NOX2 complex assembly, ultimately attenuating NOX-derived ROS generation. These findings hold significance for researchers exploring neuroprotection and the development of p47phox inhibitors.

Natural Product-Derived Compounds Targeting Keratinocytes and Molecular Pathways in Psoriasis Therapeutics

Psoriasis is a chronic autoimmune inflammatory skin disorder that affects approximately 2-3% of the global population due to significant genetic predisposition. It is characterized by an uncontrolled growth and differentiation of keratinocytes, leading to the formation of scaly erythematous plaques. Psoriasis extends beyond dermatological manifestations to impact joints and nails and is often associated with systemic disorders. Although traditional treatments provide relief, their use is limited by potential side effects and the chronic nature of the disease. This review aims to discuss the therapeutic potential of keratinocyte-targeting natural products in psoriasis and highlight their efficacy and safety in comparison with conventional treatments. This review comprehensively examines psoriasis pathogenesis within keratinocytes and the various related signaling pathways (such as JAK-STAT and NF-κB) and cytokines. It presents molecular targets such as high-mobility group box-1 (HMGB1), dual-specificity phosphatase-1 (DUSP1), and the aryl hydrocarbon receptor (AhR) for treating psoriasis. It evaluates the ability of natural compounds such as luteolin, piperine, and glycyrrhizin to modulate psoriasis-related pathways. Finally, it offers insights into alternative and sustainable treatment options with fewer side effects.

Soluble Plasma Proteins of Tumor Necrosis Factor and Immunoglobulin Superfamilies Reveal New Insights into Immune Regulation in People with HIV and Opioid Use Disorder

People with HIV (PWH) frequently suffer from Opioid (OP) Use Disorder (OUD). In an investigation of the impact of OUD on underlying immune dysfunction in PWH, we previously reported that OP use exacerbates inflammation in virally controlled PWH followed in the Infectious Diseases Elimination Act (IDEA) Syringe Services Program (SSP). Unexpectedly, Flu vaccination-induced antibody responses in groups with OUD were superior to PWH without OUD. Here, we investigated the profile of 48 plasma biomarkers comprised of TNF and Ig superfamily (SF) molecules known to impact interactions between T and B cells in 209 participants divided into four groups: (1) HIV+OP+, (2) HIV-OP+, (3) HIV+OP-, and (4) HIV-OP-. The differential expression of the top eight molecules ranked by median values in individual Groups 1-3 in comparison to Group 4 was highly significant. Both OP+ groups 1 and 2 had higher co-stimulatory TNF SF molecules, including 4-1BB, OX-40, CD40, CD30, and 4-1BBL, which were found to positively correlate with Flu Ab titers. In contrast, HIV+OP- exhibited a profile dominant in Ig SF molecules, including PDL-2, CTLA-4, and Perforin, with PDL-2 showing a negative correlation with Flu vaccine titers. These findings are relevant to vaccine development in the fields of HIV and OUD.

Deciphering DED assembly mechanisms in FADD-procaspase-8-cFLIP complexes regulating apoptosis

Fas-associated protein with death domain (FADD), procaspase-8, and cellular FLICE-inhibitory proteins (cFLIP) assemble through death-effector domains (DEDs), directing death receptor signaling towards cell survival or apoptosis. Understanding their three-dimensional regulatory mechanism has been limited by the absence of atomic coordinates for their ternary DED complex. By employing X-ray crystallography and cryogenic electron microscopy (cryo-EM), we present the atomic coordinates of human FADD-procaspase-8-cFLIP complexes, revealing structural insights into these critical interactions. These structures illustrate how FADD and cFLIP orchestrate the assembly of caspase-8-containing complexes and offer mechanistic explanations for their role in promoting or inhibiting apoptotic and necroptotic signaling. A helical procaspase-8-cFLIP hetero-double layer in the complex appears to promote limited caspase-8 activation for cell survival. Our structure-guided mutagenesis supports the role of the triple-FADD complex in caspase-8 activation and in regulating receptor-interacting protein kinase 1 (RIPK1). These results propose a unified mechanism for DED assembly and procaspase-8 activation in the regulation of apoptotic and necroptotic signaling across various cellular pathways involved in development, innate immunity, and disease.

CPT-11 mitigates autoimmune diseases by suppressing effector T cells without affecting long-term anti-tumor immunity

The incidence of autoimmune diseases has significantly increased over the past 20 years. Excessive host immunoreactions and disordered immunoregulation are at the core of the pathogenesis of autoimmune diseases. The traditional anti-tumor chemotherapy drug CPT-11 is associated with leukopenia. Considering that CPT-11 induces leukopenia, we believe that it is a promising drug for the control of autoimmune diseases. Here, we show that CPT-11 suppresses T cell proliferation and pro-inflammatory cytokine production in healthy C57BL/6 mice and in complete Freund's adjuvant-challenged mice. We found that CPT-11 effectively inhibited T cell proliferation and Th1 and Th17 cell differentiation by inhibiting glycolysis in T cells. We also assessed CPT-11 efficacy in treating autoimmune diseases in models of experimental autoimmune encephalomyelitis and psoriasis. Finally, we proved that treatment of autoimmune diseases with CPT-11 did not suppress long-term immune surveillance for cancer. Taken together, these results show that CPT-11 is a promising immunosuppressive drug for autoimmune disease treatment.

Signaling controversy and future therapeutical perspectives of targeting sphingolipid network in cancer immune editing and resistance to tumor necrosis factor-α immunotherapy

Anticancer immune surveillance and immunotherapies trigger activation of cytotoxic cytokine signaling, including tumor necrosis factor-α (TNF-α) and TNF-related apoptosis-inducing ligand (TRAIL) pathways. The pro-inflammatory cytokine TNF-α may be secreted by stromal cells, tumor-associated macrophages, and by cancer cells, indicating a prominent role in the tumor microenvironment (TME). However, tumors manage to adapt, escape immune surveillance, and ultimately develop resistance to the cytotoxic effects of TNF-α. The mechanisms by which cancer cells evade host immunity is a central topic of current cancer research. Resistance to TNF-α is mediated by diverse molecular mechanisms, such as mutation or downregulation of TNF/TRAIL receptors, as well as activation of anti-apoptotic enzymes and transcription factors. TNF-α signaling is also mediated by sphingosine kinases (SphK1 and SphK2), which are responsible for synthesis of the growth-stimulating phospholipid, sphingosine-1-phosphate (S1P). Multiple studies have demonstrated the crucial role of S1P and its transmembrane receptors (S1PR) in both the regulation of inflammatory responses and progression of cancer. Considering that the SphK/S1P/S1PR axis mediates cancer resistance, this sphingolipid signaling pathway is of mechanistic significance when considering immunotherapy-resistant malignancies. However, the exact mechanism by which sphingolipids contribute to the evasion of immune surveillance and abrogation of TNF-α-induced apoptosis remains largely unclear. This study reviews mechanisms of TNF-α-resistance in cancer cells, with emphasis on the pro-survival and immunomodulatory effects of sphingolipids. Inhibition of SphK/S1P-linked pro-survival branch may facilitate reactivation of the pro-apoptotic TNF superfamily effects, although the role of SphK/S1P inhibitors in the regulation of the TME and lymphocyte trafficking should be thoroughly assessed in future studies.

Molecular Insights into the Relationship Between Platelet Activation and Endothelial Dysfunction: Molecular Approaches and Clinical Practice

Platelets are one of the coagulation cells. When platelet activation occurs, many mediators are released and affect endothelial cells (ECs) and lead to endothelial dysfunction (ED). ED plays an important role in the pathogenesis of many diseases, including cardiovascular disease (CVD). Platelet are of important factors in ED. The release of mediators by platelets causes the stimulation of inflammatory pathways, oxidative stress, and apoptosis, which ultimately result in ED.On the other hand, platelet activation in CVD patients can be associated with a bad prognosis. Platelet activation can increase the level of markers such as p-selectin in the serum. Also, in this study, we have discussed the role of platelet as a diagnostic factor, as well as its use as a treatment option. In addition, we discussed some of the molecular pathways that are used to target platelet activation.

Reverse Genetics Applied to Immunobiology of Tumor Necrosis Factor, a Multifunctional Cytokine

Tumor necrosis factor (TNF) is one of many cytokines - protein molecules responsible for communication between the cells of immune system. TNF was discovered and given its grand name because of its striking antitumor effects in experimental systems, but its main physiological functions in the context of whole organism turned out to be completely unrelated to protection against tumors. This short review discusses "man-made" mouse models generated by early genome-editing technologies, which enabled us to establish true functions of TNF in health and certain diseases as well as to unravel potential strategies for improving therapy of TNF-dependent diseases.

Mitochondria-Derived Vesicles, Sterile Inflammation, and Pyroptosis in Liver Cancer: Partners in Crime or Innocent Bystanders?

Alterations in cellular signaling, chronic inflammation, and tissue remodeling contribute to hepatocellular carcinoma (HCC) development. The release of damage-associated molecular patterns (DAMPs) upon tissue injury and the ensuing sterile inflammation have also been attributed a role in HCC pathogenesis. Cargoes of extracellular vesicles (EVs) and/or EVs themselves have been listed among circulating DAMPs but only partially investigated in HCC. Mitochondria-derived vesicles (MDVs), a subpopulation of EVs, are another missing link in the comprehension of the molecular mechanisms underlying the onset and progression of HCC biology. EVs have been involved in HCC growth, dissemination, angiogenesis, and immunosurveillance escape. The contribution of MDVs to these processes is presently unclear. Pyroptosis triggers systemic inflammation through caspase-dependent apoptotic cell death and is implicated in tumor immunity. The analysis of this process, together with MDV characterization, may help capture the relationship among HCC development, mitochondrial quality control, and inflammation. The combination of immune checkpoint inhibitors (i.e., atezolizumab and bevacizumab) has been approved as a synergistic first-line systemic treatment for unresectable or advanced HCC. The lack of biomarkers that may allow prediction of treatment response and, therefore, patient selection, is a major unmet need. Herein, we overview the molecular mechanisms linking mitochondrial dysfunction, inflammation, and pyroptosis, and discuss how immunotherapy targets, at least partly, these routes.

Positive selection CRISPR screens reveal a druggable pocket in an oligosaccharyltransferase required for inflammatory signaling to NF-κB

Nuclear factor κB (NF-κB) plays roles in various diseases. Many inflammatory signals, such as circulating lipopolysaccharides (LPSs), activate NF-κB via specific receptors. Using whole-genome CRISPR-Cas9 screens of LPS-treated cells that express an NF-κB-driven suicide gene, we discovered that the LPS receptor Toll-like receptor 4 (TLR4) is specifically dependent on the oligosaccharyltransferase complex OST-A for N-glycosylation and cell-surface localization. The tool compound NGI-1 inhibits OST complexes in vivo, but the underlying molecular mechanism remained unknown. We did a CRISPR base-editor screen for NGI-1-resistant variants of STT3A, the catalytic subunit of OST-A. These variants, in conjunction with cryoelectron microscopy studies, revealed that NGI-1 binds the catalytic site of STT3A, where it traps a molecule of the donor substrate dolichyl-PP-GlcNAc2-Man9-Glc3, suggesting an uncompetitive inhibition mechanism. Our results provide a rationale for and an initial step toward the development of STT3A-specific inhibitors and illustrate the power of contemporaneous base-editor and structural studies to define drug mechanism of action.

Metabolic reprogramming of the retinal pigment epithelium by cytokines associated with age-related macular degeneration

The complex metabolic relationship between the retinal pigment epithelium (RPE) and photoreceptors is essential for maintaining retinal health. Recent evidence indicates the RPE acts as an adjacent lactate sink, suppressing glycolysis in the epithelium in order to maximize glycolysis in the photoreceptors. Dysregulated metabolism within the RPE has been implicated in the pathogenesis of age-related macular degeneration (AMD), a leading cause of vision loss. In the present study, we investigate the effects of four cytokines associated with AMD, TNFα, TGF-β2, IL-6, and IL-1β, as well as a cocktail containing all four cytokines, on RPE metabolism using ARPE-19 cells, primary human RPE cells, and ex vivo rat eyecups. Strikingly, we found cytokine-specific changes in numerous metabolic markers including lactate production, glucose consumption, extracellular acidification rate, and oxygen consumption rate accompanied by increases in total mitochondrial volume and ATP production. Together, all four cytokines could potently override the constitutive suppression of glycolysis in the RPE, through a mechanism independent of PI3K/AKT, MEK/ERK, or NF-κB. Finally, we observed changes in glycolytic gene expression with cytokine treatment, including in lactate dehydrogenase subunit and glucose transporter expression. Our findings provide new insights into the metabolic changes in the RPE under inflammatory conditions and highlight potential therapeutic targets for AMD.

TNF-α signals through ITK-Akt-mTOR to drive CD4+ T cell metabolic reprogramming, which is dysregulated in rheumatoid arthritis

Upon activation, T cells undergo metabolic reprogramming to meet the bioenergetic demands of clonal expansion and effector function. Because dysregulated T cell cytokine production and metabolic phenotypes coexist in chronic inflammatory disease, including rheumatoid arthritis (RA), we investigated whether inflammatory cytokines released by differentiating T cells amplified their metabolic changes. We found that tumor necrosis factor-α (TNF-α) released by human naïve CD4+ T cells upon activation stimulated the expression of a metabolic transcriptome and increased glycolysis, amino acid uptake, mitochondrial oxidation of glutamine, and mitochondrial biogenesis. The effects of TNF-α were mediated by activation of Akt-mTOR signaling by the kinase ITK and did not require the NF-κB pathway. TNF-α stimulated the differentiation of naïve cells into proinflammatory T helper 1 (TH1) and TH17 cells, but not that of regulatory T cells. CD4+ T cells from patients with RA showed increased TNF-α production and consequent Akt phosphorylation upon activation. These cells also exhibited increased mitochondrial mass, particularly within proinflammatory T cell subsets implicated in disease. Together, these findings suggest that T cell-derived TNF-α drives their metabolic reprogramming by promoting signaling through ITK, Akt, and mTOR, which is dysregulated in autoinflammatory disease.

Molecular insights into clinical trials for immune checkpoint inhibitors in colorectal cancer: Unravelling challenges and future directions

Colorectal cancer (CRC) is a complex disease with diverse etiologies and clinical outcomes. Despite considerable progress in development of CRC therapeutics, challenges remain regarding the diagnosis and management of advanced stage metastatic CRC (mCRC). In particular, the five-year survival rate is very low since mCRC is currently rarely curable. Over the past decade, cancer treatment has significantly improved with the introduction of cancer immunotherapies, specifically immune checkpoint inhibitors. Therapies aimed at blocking immune checkpoints such as PD-1, PD-L1, and CTLA-4 target inhibitory pathways of the immune system, and thereby enhance anti-tumor immunity. These therapies thus have shown promising results in many clinical trials alone or in combination. The efficacy and safety of immunotherapy, either alone or in combination with CRC, have been investigated in several clinical trials. Clinical trials, including KEYNOTE-164 and CheckMate 142, have led to Food and Drug Administration approval of the PD-1 inhibitors pembrolizumab and nivolumab, respectively, for the treatment of patients with unresectable or metastatic microsatellite instability-high or deficient mismatch repair CRC. Unfortunately, these drugs benefit only a small percentage of patients, with the benefits of immunotherapy remaining elusive for the vast majority of CRC patients. To this end, primary and secondary resistance to immunotherapy remains a significant issue, and further research is necessary to optimize the use of immunotherapy in CRC and identify biomarkers to predict the response. This review provides a comprehensive overview of the clinical trials involving immune checkpoint inhibitors in CRC. The underlying rationale, challenges faced, and potential future steps to improve the prognosis and enhance the likelihood of successful trials in this field are discussed.

Uncovering the pharmacological mechanism of Shou Tai Wan on recurrent spontaneous abortion: A integrated pharmacology strategy-based research

ETHNOPHARMACOLOGICAL RELEVANCE

Shou Tai Wan (STW), a traditional Chinese medicine formula, has been historically used for the treatment of recurrent spontaneous abortion (RSA). Despite its long-standing usage, the exact mechanism underlying the therapeutic effects of STW remains unclear in the existing literature.

AIMS OF THIS STUDY

To explore the Pharmacological Mechanism of STW on RSA.

METHODS

A network pharmacological methodology was utilized to predict the active compounds and potential targets of STW, collect the RSA targets and other human proteins of STW, and analyze the STW related networks. The animal experiments were also performed to validate the effect of STW on RSA.

RESULTS

The results of network analysis showed that STW may regulate PI3K/AKT, MAPK, FoxO signaling pathways and so on. Animal experiment established the RSA model with CBA/J × DBA/2 mice. It was found that STW can reduce the embryo absorption rate of RSA group (p < 0.05) and balance the expression of Th 1/Th2 type cytokines compared with the model group. After 14 days of administration, the decidual and placental tissues were taken and the CD4+ T cells were isolated, and the phosphorylation level of signaling pathway was detected by Springbio720 antibody microarray. This experiment found that STW can significantly up-regulate the phosphorylation levels of STAT3 and STAT6 proteins in the STAT signaling pathway, and down-regulating the phosphorylation level of STAT1 protein. STW also significantly up-regulated the phosphorylation levels of Raf1, A-Raf, Ask1, Mek1, Mek2, JKK1, ERK1, ERK2, c-fos, c-Jun and CREB proteins in the MAPK signaling pathway, and down-regulate the phosphorylation levels of MEK6 and IKKb proteins. Compared with the RSA group, the STW group increased the expression levels of ERK1/2 mRNA and proteins and p-ERK1/2 proteins, and there was a statistical difference (p < 0.05). This is consistent with the chip results.

CONCLUSION

STW may achieve therapeutic effects by interfering with the signaling pathways, biological processes and targets discovered in this study. It provides a new perspective for revealing the immunological mechanism of STW in the treatment of RSA, and also provides a theoretical basis for the clinical use of STW in the treatment of RSA.

Peptide-based allosteric inhibitor targets TNFR1 conformationally active region and disables receptor-ligand signaling complex

Tumor necrosis factor (TNF) receptor 1 (TNFR1) plays a pivotal role in mediating TNF induced downstream signaling and regulating inflammatory response. Recent studies have suggested that TNFR1 activation involves conformational rearrangements of preligand assembled receptor dimers and targeting receptor conformational dynamics is a viable strategy to modulate TNFR1 signaling. Here, we used a combination of biophysical, biochemical, and cellular assays, as well as molecular dynamics simulation to show that an anti-inflammatory peptide (FKCRRWQWRMKK), which we termed FKC, inhibits TNFR1 activation allosterically by altering the conformational states of the receptor dimer without blocking receptor-ligand interaction or disrupting receptor dimerization. We also demonstrated the efficacy of FKC by showing that the peptide inhibits TNFR1 signaling in HEK293 cells and attenuates inflammation in mice with intraperitoneal TNF injection. Mechanistically, we found that FKC binds to TNFR1 cysteine-rich domains (CRD2/3) and perturbs the conformational dynamics required for receptor activation. Importantly, FKC increases the frequency in the opening of both CRD2/3 and CRD4 in the receptor dimer, as well as induces a conformational opening in the cytosolic regions of the receptor. This results in an inhibitory conformational state that impedes the recruitment of downstream signaling molecules. Together, these data provide evidence on the feasibility of targeting TNFR1 conformationally active region and open new avenues for receptor-specific inhibition of TNFR1 signaling.

Emerging polymeric materials for treatment of oral diseases: design strategy towards a unique oral environment

Oral diseases are prevalent but challenging diseases owing to the highly movable and wet, microbial and inflammatory environment. Polymeric materials are regarded as one of the most promising biomaterials due to their good compatibility, facile preparation, and flexible design to obtain multifunctionality. Therefore, a variety of strategies have been employed to develop materials with improved therapeutic efficacy by overcoming physicobiological barriers in oral diseases. In this review, we summarize the design strategies of polymeric biomaterials for the treatment of oral diseases. First, we present the unique oral environment including highly movable and wet, microbial and inflammatory environment, which hinders the effective treatment of oral diseases. Second, a series of strategies for designing polymeric materials towards such a unique oral environment are highlighted. For example, multifunctional polymeric materials are armed with wet-adhesive, antimicrobial, and anti-inflammatory functions through advanced chemistry and nanotechnology to effectively treat oral diseases. These are achieved by designing wet-adhesive polymers modified with hydroxy, amine, quinone, and aldehyde groups to provide strong wet-adhesion through hydrogen and covalent bonding, and electrostatic and hydrophobic interactions, by developing antimicrobial polymers including cationic polymers, antimicrobial peptides, and antibiotic-conjugated polymers, and by synthesizing anti-inflammatory polymers with phenolic hydroxy and cysteine groups that function as immunomodulators and electron donors to reactive oxygen species to reduce inflammation. Third, various delivery systems with strong wet-adhesion and enhanced mucosa and biofilm penetration capabilities, such as nanoparticles, hydrogels, patches, and microneedles, are constructed for delivery of antibiotics, immunomodulators, and antioxidants to achieve therapeutic efficacy. Finally, we provide insights into challenges and future development of polymeric materials for oral diseases with promise for clinical translation.

Choosing the right biologic treatment for moderate-to-severe plaque psoriasis: the impact of comorbidities

INTRODUCTION

Psoriasis is a chronic inflammatory skin disease often associated with several comorbidities, such as psoriatic arthritis, inflammatory bowel disease, obesity, diabetes mellitus or cardiovascular diseases, infections, or cancer, among others. With the progressive aging of the population, a growing number of patients with psoriasis can be expected to present multiple comorbidities. Currently, there is a wide range of biological treatments available for moderate to severe psoriasis, including tumor necrosis alpha (TNF) inhibitors, IL12/23 inhibitor, IL17 inhibitors, and IL23 inhibitors.

AREAS COVERED

This review aims to describe the specific characteristics of these drugs in relation to psoriasis comorbidities, in order to facilitate decision-making in clinical practice.

EXPERT OPINION

Some of the biological treatments can influence comorbidities, in some cases even improving them. Therefore, comorbidities are a key factor when deciding on one biological treatment over another. The development of new drugs is expanding the therapeutic arsenal for psoriasis. A high level of expertise in the field with a detailed knowledge of the characteristics of every drug is imperative to provide personalized medicine.

Recombinant 60-kDa heat shock protein from Paracoccidioides brasiliensis induces the death of mouse lymphocytes in a mechanism dependent on Toll-like receptor 4 and tumor necrosis factor

Paracoccidioides fungi are thermodimorphic microorganisms that cause paracoccidioidomycosis (PCM), an autochthonous disease from Latin America, with most cases in Brazil. Humans become infected by inhaling conidia or mycelial fragments that transform into yeast at body temperature. These fungi cause chronic-granulomatous inflammation, which may promote fibrosis and parenchyma destruction in the lungs. In response to stress imposed by the host, fungi Paracoccidioides spp. increase the expression of heat shock proteins (HSP), which protect them by sustaining cellular proteostasis. Our group has studied the role of HSP60 in PCM, and previous data show that the recombinant HSP60 (rHSP60) has a deleterious effect when used in a single dose as therapy for experimental PCM. Here, we investigated the mechanism by which rHSP60 could worsen the disease. We found that rHSP60 caused the viability loss of splenic or lymph node cells from both immunized and non-immunized mice, including in splenic T lymphocytes under polyclonal stimulation with concanavalin A, probably by undergoing apoptosis. Among analyzed splenic cells, lymphocytes were indeed the main cells to die. When we investigated the death mechanisms, remarkably, we found that there was no viability loss in rHSP60-stimulated splenic cells from mice deficient in Toll-like receptor 4, TRIF adapter protein, and TNF receptor 1(TNFR1), as well as rHSP60-stimulated WT cells incubated with anti-TNF antibody. Besides, caspase-8 inhibitor IETD-CHO blocked the rHSP60 effect on splenic cells, suggesting that rHSP60 induces the extrinsic apoptosis pathway dependent on signaling via TLR4/TRIF and TNFR1.

Photoaffinity labeling coupled with proteomics identify PDI-ADAM17 module is targeted by (-)-vinigrol to induce TNFR1 shedding and ameliorate rheumatoid arthritis in mice

Various biological agents have been developed to target tumor necrosis factor alpha (TNF-α) and its receptor TNFR1 for the rheumatoid arthritis (RA) treatment, whereas small molecules modulating such cytokine receptors are rarely reported in comparison to the biologicals. Here, by revealing the mechanism of action of vinigrol, a diterpenoid natural product, we show that inhibition of the protein disulfide isomerase (PDI, PDIA1) by small molecules activates A disintegrin and metalloprotease 17 (ADAM17) and then leads to the TNFR1 shedding on mouse and human cell membranes. This small-molecule-induced receptor shedding not only effectively blocks the inflammatory response caused by TNF-α in cells, but also reduces the arthritic score and joint damage in the collagen-induced arthritis mouse model. Our study indicates that targeting the PDI-ADAM17 signaling module to regulate the shedding of cytokine receptors by the chemical approach constitutes a promising strategy for alleviating RA.

Pulmonary RNA interference against acute lung injury mediated by mucus- and cell-penetrating nanocomplexes

Trans-mucosal delivery of anti-inflammatory siRNA into alveolar macrophages represents a promising modality for the treatment of acute lung injury (ALI). However, its therapeutic efficacy is often hurdled by the lack of effective carriers that can simultaneously overcome the mucosal barrier and cell membrane barrier. Herein, we developed mucus/cell membrane dual-penetrating, macrophage-targeting polyplexes which enabled efficient intratracheal delivery of TNF-α siRNA (siTNF-α) to attenuate pulmonary inflammation against lipopolysaccharide (LPS)-induced ALI. P-G@Zn, a cationic helical polypeptide bearing both guanidine and zinc dipicolylamine (Zn-DPA) side charged groups, was designed to condense siTNF-α and promote macrophage internalization due to its helicity-dependent membrane activity. Coating of the polyplexes with charge-neutralizing carboxylated mannan (Man-COOH) greatly enhanced the mucus penetration potency due to shielding of the electrostatic adhesive interactions with the mucus, and it cooperatively enabled active targeting to alveolar macrophages to potentiate the intracellular delivery efficiency of siTNF-α. As such, intratracheally administered Man-COOH/P-G@Zn/siTNF-α polyplexes provoked notable TNF-α silencing by ∼75 % in inflamed lung tissues at 500 μg siRNA/kg, and demonstrated potent anti-inflammatory performance to treat ALI. This study provides an effective tool for the synchronized trans-mucosal delivery of siRNA into macrophages, and the unique properties of the polyplexes render remarkable potentials for anti-inflammatory therapy against ALI. STATEMENT OF SIGNIFICANCE: siRNA-mediated anti-inflammatory management of acute lung injury (ALI) is greatly challenged by the insufficient delivery across the mucus layer and cell membrane. To address such critical issue, mucus/cell membrane dual-penetrating, macrophage-targeting polyplexes are herein developed, which are comprised of an outer shell of carboxylated mannan (Man-COOH) and an inner nanocore formed by TNF-α siRNA (siTNF-α) and a cationic helical polypeptide P-G@Zn. Man-COOH coating endowed the polyplexes with high mucus-penetrating capability and macrophage-targeting ability, while P-G@Zn bearing both guanidine and zinc dipicolylamine afforded potent siTNF-α condensation capacity and high intracellular delivery efficiency with reduced cytotoxicity. Intratracheally administered polyplexes solicit pronounced TNF-α silencing and anti-inflammatory efficiencies in ALI mice. This study renders an effective example for overcoming the multiple barriers against trans-mucosal delivery of siRNA into macrophages, and holds profound potentials for gene therapy against ALI.

Cellular heterogeneity in TNF/TNFR1 signalling: live cell imaging of cell fate decisions in single cells

Cellular responses to TNF are inherently heterogeneous within an isogenic cell population and across different cell types. TNF promotes cell survival by activating pro-inflammatory NF-κB and MAPK signalling pathways but may also trigger apoptosis and necroptosis. Following TNF stimulation, the fate of individual cells is governed by the balance of pro-survival and pro-apoptotic signalling pathways. To elucidate the molecular mechanisms driving heterogenous responses to TNF, quantifying TNF/TNFR1 signalling at the single-cell level is crucial. Fluorescence live-cell imaging techniques offer real-time, dynamic insights into molecular processes in single cells, allowing for detection of rapid and transient changes, as well as identification of subpopulations, that are likely to be missed with traditional endpoint assays. Whilst fluorescence live-cell imaging has been employed extensively to investigate TNF-induced inflammation and TNF-induced cell death, it has been underutilised in studying the role of TNF/TNFR1 signalling pathway crosstalk in guiding cell-fate decisions in single cells. Here, we outline the various opportunities for pathway crosstalk during TNF/TNFR1 signalling and how these interactions may govern heterogenous responses to TNF. We also advocate for the use of live-cell imaging techniques to elucidate the molecular processes driving cell-to-cell variability in single cells. Understanding and overcoming cellular heterogeneity in response to TNF and modulators of the TNF/TNFR1 signalling pathway could lead to the development of targeted therapies for various diseases associated with aberrant TNF/TNFR1 signalling, such as rheumatoid arthritis, metabolic syndrome, and cancer.

B-cell lymphoma-2 family proteins in the crosshairs: Small molecule inhibitors and activators for cancer therapy

The B-cell lymphoma-2 (BCL-2) family of proteins plays a crucial role in the regulation of apoptosis, offering a dual mechanism for its control. Numerous studies have established a strong association between gene disorders of these proteins and the proliferation of diverse cancer cell types. Consequently, the identification and development of drugs targeting BCL-2 family proteins have emerged as a prominent area in antitumor therapy. Over the last two decades, several small-molecules have been designed to modulate the protein-protein interactions between anti- and proapoptotic BCL-2 proteins, effectively suppressing tumor growth and metastasis in vivo. The primary focus of research has been on developing BCL-2 homology 3 (BH3) mimetics to target antiapoptotic BCL-2 proteins, thereby competitively releasing proapoptotic BCL-2 proteins and restoring the blocked intrinsic apoptotic program. Additionally, for proapoptotic BCL-2 proteins, exogenous small molecules have been explored to activate cell apoptosis by directly interacting with executioner proteins such as BCL-2-associated X protein (BAX) or BCL-2 homologous antagonist/killer protein (BAK). In this comprehensive review, we summarize the inhibitors and activators (sensitizers) of BCL-2 family proteins developed over the past decades, highlighting their discovery, optimization, preclinical and clinical status, and providing an overall landscape of drug development targeting these proteins for therapeutic purposes.

EFHD2 suppresses intestinal inflammation by blocking intestinal epithelial cell TNFR1 internalization and cell death

TNF acts as one pathogenic driver for inducing intestinal epithelial cell (IEC) death and substantial intestinal inflammation. How the IEC death is regulated to physiologically prevent intestinal inflammation needs further investigation. Here, we report that EF-hand domain-containing protein D2 (EFHD2), highly expressed in normal intestine tissues but decreased in intestinal biopsy samples of ulcerative colitis patients, protects intestinal epithelium from TNF-induced IEC apoptosis. EFHD2 inhibits TNF-induced apoptosis in primary IECs and intestinal organoids (enteroids). Mice deficient of Efhd2 in IECs exhibit excessive IEC death and exacerbated experimental colitis. Mechanistically, EFHD2 interacts with Cofilin and suppresses Cofilin phosphorylation, thus blocking TNF receptor I (TNFR1) internalization to inhibit IEC apoptosis and consequently protecting intestine from inflammation. Our findings deepen the understanding of EFHD2 as the key regulator of membrane receptor trafficking, providing insight into death receptor signals and autoinflammatory diseases.

Plants with Anti-Ulcer Activity and Mechanism: A Review of Preclinical and Clinical Studies

Ulcer disorders including the oral mucosa, large intestine, and stomach mucosa, cause significant global health burdens. Conventional treatments such as non-steroid anti-inflammatory drugs (NSAIDs), proton pump inhibitors (PPIs), histamine H2 receptor antagonists (H2RAs), and cytoprotective agents have drawbacks like mucosal injury, diminish gastric acid secretion, and interact with concurrent medications. Therefore, alternative therapeutic approaches are needed to tackle this health concern. Plants are rich in active metabolites in the bark, roots, leaves, fruits, and seeds, and have been utilized for medicinal purposes since ancient times. The use of herbal therapy is crucial, and regulations are necessary to ensure the quality of products, particularly in randomized studies, to assess their efficacy and safety in treating ulcer disorders. This study aims to explore the anti-ulcer activity of medicinal plants in treating peptic ulcer disease, ulcerative colitis, and aphthous ulcers. Articles were searched in Scopus and PubMed, and filtered for publication from 2013 to 2023, resulting in a total of 460 from Scopus and 239 from PubMed. The articles were further screened by title and abstract and resulted in 55 articles. Natural products, rich in active metabolites, were described to manage ulcer disease by protecting the mucosa, reducing ulcer effects, inhibiting pro-inflammatory factors, and reducing bacterial load, thus improving patients' quality of life. Natural extracts have proven effective in managing other health problems, including ulcers by reducing pain and decreasing lesions. This review provides an overview of preclinical and clinical studies on medicinal plants, focusing on their effectiveness in treating conditions like peptic ulcers, ulcerative colitis, and aphthous ulcers.

Molecular mechanisms of tumour necrosis factor signalling via TNF receptor 1 and TNF receptor 2 in the tumour microenvironment

Tumour necrosis factor (TNF) is a primary mediator of inflammatory processes by facilitating cell death, immune cell activation and triggering of inflammation. In the cancer context, research has revealed TNF as a multifaceted cytokine that can be both pro- or anti-tumorigenic depending on what context is observed. We explore the plethora of ways that TNF and its receptors manipulate the functional and phenotypic characteristics in the tumour microenvironment (TME) on both tumour cells and immune cells, promoting either tumour elimination or progression. Here, we discuss the latest cutting-edge TNF-focused biologics currently in clinical translation that modifies the TME to derive greater immune responses and therapeutic outcomes, and further give perspectives on the future of targeting TNF in the context of cancer by emerging technological approaches.