CD8 + T-cell deficiency protects mice from abdominal aortic aneurysm formation in response to calcium chloride 2.

OBJECTIVE: Abdominal aortic aneurysm (AAA) is an aneurysm-like dilated and highly fatal cardiovascular disease. CD8 + T cells have been shown to be critical for vascular pathological processes, but the contribution of these lymphocytes to vascular diseases remains elusive. METHODS AND RESULTS: Eight-week-old male wildtype (CD8 +/+ ) and Cd8a knockout (CD8 -/- ) mice were used in a calcium chloride 2 (CaCl 2 )-induced experimental AAA model. At 6 weeks after surgery, CD8 + T-cell deletion prevented the formation of AAA, accompanied by reductions of the levels of inflammatory (interferon-γ [IFN-γ], interleukin-1ß, monocyte chemoattractant protein-1, intracellular adhesion molecule-1, vascular cell adhesion molecule-1, NOD-like receptor protein 3, caspase-1), oxidative stress [NADPH oxidase and gp91 phox ], and proteolysis (cathepsin S, cathepsin K, matrix metalloproteinase-2 [MMP-2] and MMP-9) proteins and/or genes in plasma and/or AAA tissues. Immunoreactivities of MMP-2 and MMP-9 were observed in macrophages. An injection of IFN-γ and adoptive transfer of CD8 + T cells of IFN-γ +/+ mice diminished CD8 -/- -mediated vasculoprotective actions in the AAA mice. In vitro, IFN-γ enhanced MMP-2 and MMP-9 gelatinolytic activities in macrophage and/or vascular smooth muscle cells. CONCLUSION: The vasculoprotective effects of CD8 + T-cell deletion in a mouse CaCl 2 -induced AAA model were likely attributable to, at least in part, the attenuation of IFN-γ-dependent inflammation action, oxidative stress production, and proteolysis, suggesting a novel therapeutic target for AAA formation by regulating CD8 + T-cell-derived IFN-γ secretion.

Efficacy and advantage of immunotherapy for melanoma via intramuscular co-expression of plasmid-encoded PD-1 and CTLA-4 scFvs.

Immunotherapy, in the shape of immune checkpoint inhibitors (ICIs), has completely changed the treatment of cancer. However, the increasing expense of treatment and the frequency of immune-related side effects, which are frequently associated with combination antibody therapies and Fc fragment of antibody, have limited the patient's ability to benefit from these treatments. Herein, we presented the therapeutic effects of the plasmid-encoded PD-1 and CTLA-4 scFvs (single-chain variable fragment) for melanoma via an optimized intramuscular gene delivery system. After a single injection, the plasmid-encoded ICI scFv in mouse sera continued to be above 150 ng/mL for 3 weeks and reached peak amounts of 600 ng/mL. Intramuscular delivery of plasmid encoding PD-1 and CTLA-4 scFvs significantly changed the tumor microenvironment, delayed tumor growth, and prolonged survival in melanoma-bearing mice. Furthermore, no significant toxicity was observed, suggesting that this approach could improve the biosafety of ICIs combination therapy. Overall, the expression of ICI scFvs in vivo using intramuscular plasmid delivery could potentially develop into a reliable, affordable, and safe immunotherapy technique, expanding the range of antibody-based gene therapy systems that are available.

Cathepsin K deficiency prevented stress-related thrombosis in a mouse FeCl3 model.

BACKGROUND: Exposure to chronic psychological stress (CPS) is a risk factor for thrombotic cardiocerebrovascular diseases (CCVDs). The expression and activity of the cysteine cathepsin K (CTSK) are upregulated in stressed cardiovascular tissues, and we investigated whether CTSK is involved in chronic stress-related thrombosis, focusing on stress serum-induced endothelial apoptosis. METHODS AND RESULTS: Eight-week-old wild-type male mice (CTSK+/+) randomly divided to non-stress and 3-week restraint stress groups received a left carotid artery iron chloride3 (FeCl3)-induced thrombosis injury for biological and morphological evaluations at specific timepoints. On day 21 post-stress/injury, the stress had enhanced the arterial thrombi weights and lengths, in addition to harmful alterations of plasma ADAMTS13, von Willebrand factor, and plasminogen activation inhibitor-1, plus injured-artery endothelial loss and CTSK protein/mRNA expression. The stressed CTSK+/+ mice had increased levels of injured arterial cleaved Notch1, Hes1, cleaved caspase8, matrix metalloproteinase-9/-2, angiotensin type 1 receptor, galactin3, p16IN4A, p22phox, gp91phox, intracellular adhesion molecule-1, TNF-α, MCP-1, and TLR-4 proteins and/or genes. Pharmacological and genetic inhibitions of CTSK ameliorated the stress-induced thrombus formation and the observed molecular and morphological changes. In cultured HUVECs, CTSK overexpression and silencing respectively increased and mitigated stressed-serum- and H2O2-induced apoptosis associated with apoptosis-related protein changes. Recombinant human CTSK degraded γ-secretase substrate in a dose-dependent manor and activated Notch1 and Hes1 expression upregulation. CONCLUSIONS: CTSK appeared to contribute to stress-related thrombosis in mice subjected to FeCl3 stress, possibly via the modulation of vascular inflammation, oxidative production and apoptosis, suggesting that CTSK could be an effective therapeutic target for CPS-related thrombotic events in patients with CCVDs.

Targeting tumor-infiltrating tregs for improved antitumor responses.

Immunotherapies have revolutionized the landscape of cancer treatment. Regulatory T cells (Tregs), as crucial components of the tumor immune environment, has great therapeutic potential. However, nonspecific inhibition of Tregs in therapies may not lead to enhanced antitumor responses, but could also trigger autoimmune reactions in patients, resulting in intolerable treatment side effects. Hence, the precision targeting and inhibition of tumor-infiltrating Tregs is of paramount importance. In this overview, we summarize the characteristics and subpopulations of Tregs within tumor microenvironment and their inhibitory mechanisms in antitumor responses. Furthermore, we discuss the current major strategies targeting regulatory T cells, weighing their advantages and limitations, and summarize representative clinical trials targeting Tregs in cancer treatment. We believe that developing therapies that specifically target and suppress tumor-infiltrating Tregs holds great promise for advancing immune-based therapies.

MNK: A Novel Promising Target for Cancer Immunotherapy.

Cancer immunotherapy has demonstrated remarkable success in the treatment of multiple advanced malignancies, especially approaches to target the immune checkpoint. Nonetheless, the limited response rate remains a barrier to broader application. Identifying other ways to extend the beneficiaries to a large extent is needed. Emerging evidence has shown that mitogen-activated protein kinase-interacting kinases (MNKs) could be regarded as a novel, attractive target for cancer immunotherapy that is closely correlated with cancer biology and therapies. A comprehensive understanding of the role and mechanism of MNKs in cancer will shed light on the discovery of novel therapeutic strategies for cancer treatment. In this review, we outlined the structure of MNKs, their function and expression, and how MNKs affect tumor progression and elucidated the evidence supporting MNKs as a new promising treatment modality in human cancers.

Perspectives for immunotherapy of EBV-associated GLELC: A relatively "hot" tumor microenvironment.

BACKGROUND: Epstein-Barr virus (EBV)-associated gastric lymphoepithelioma-like carcinoma (EBVaGLELC) represents a small number of gastric cancer (GC), and research on tumor microenvironment (TME) and treatment strategy are still lacking. AIMS: Here, we aim to elucidate the immune features of this rare disease and further help to develop more effective treatment options. MATERIALS & METHODS: A retrospective analysis was conducted between 2019 to 2022 in West China Hospital to reveal the immunological characteristics of EBV-positive GLELC. The difference of immune cell subset and tumor vascular structure between gastric denocarcinoma (GAC) and EBVaGLELC will be pointed out. DISCUSSION: 13 patients with GELEC and 8 patients with GAC were retrospectively studied. The heterogeneity of the immune cell profile was then confirmed through multiplexed immunofluorescence staining (mIF), which revealed a higher proportion of CD3+ T cells, CD8+ T cells, and Treg cells in the EBV-associated GLELC group. Such a distinct TME may provide therapeutic advantages, and patients with this rare subtype of GC could be good candidates for immune checkpoint inhibitors (ICIs). Angiogenesis in EBV-positive GLELC may be less intense than that in gastric adenocarcinoma (GAC), a feature that might decrease their susceptibility to antiangiogenic therapy. Furthermore, we reported a 52-year-old male with advanced EBV-positive GLELC who showed a favorable response to the combined therapy with . A repeat evaluation showed sustained partial response (PR), and the progression-free survival (PFS) was more than 34 months until now. CONCLUSION: Compared with GAC, EBVaGLELC revealed higher T cell infiltration and less intense of angiogenesis. It displays relatively "hot" TME that may provide the rationality to treat with immunotherapy in EBV-related GLELC.

Cathepsin S deficiency improves muscle mass loss and dysfunction via the modulation of protein metabolism in mice under pathological stress conditions.

Cathepsin S (CTSS) is a widely expressed cysteinyl protease that has garnered attention because of its enzymatic and non-enzymatic functions under inflammatory and metabolic pathological conditions. Here, we examined whether CTSS participates in stress-related skeletal muscle mass loss and dysfunction, focusing on protein metabolic imbalance. Eight-week-old male wildtype (CTSS+/+ ) and CTSS-knockout (CTSS-/- ) mice were randomly assigned to non-stress and variable-stress groups for 2 weeks, and then processed for morphological and biochemical studies. Compared with non-stressed mice, stressed CTSS+/+ mice showed significant losses of muscle mass, muscle function, and muscle fiber area. In this setting, the stress-induced harmful changes in the levels of oxidative stress-related (gp91phox and p22phox ,), inflammation-related (SDF-1, CXCR4, IL-1ß, TNF-α, MCP-1, ICAM-1, and VCAM-1), mitochondrial biogenesis-related (PPAR-γ and PGC-1α) genes and/or proteins and protein metabolism-related (p-PI3K, p-Akt, p-FoxO3α, MuRF-1, and MAFbx1) proteins; and these alterations were rectified by CTSS deletion. Metabolomic analysis revealed that stressed CTSS-/- mice exhibited a significant improvement in the levels of glutamine metabolism pathway products. Thus, these findings indicated that CTSS can control chronic stress-related skeletal muscle atrophy and dysfunction by modulating protein metabolic imbalance, and thus CTSS was suggested to be a promising new therapeutic target for chronic stress-related muscular diseases.

gC1qR: A New Target for Cancer Immunotherapy.

Although breakthroughs in cancer treatment have been achieved, immunotherapy yields only modest benefits in most patients. There is still a gap in clarifying the immune evasiveness and immune-resistance mechanisms. Identifying other candidate targets for cancer immunotherapy is therefore a clear unmet clinical need. The complement system, a pillar of innate immunity, has recently entered the limelight due to its immunoregulatory functions in the tumor microenvironment (TME). In particular, gC1qR, a receptor for globular heads of C1q, serves as a promising new target and has attracted more attention. gC1qR, also named P32/C1qBP/HABP1, is a multifunctional protein that is overexpressed in various cancers and holds prognostic value. It regulates the tumorigenic, progression and metastatic properties of tumor cells through several downstream signaling pathways, including the Wnt/ß-catenin, PKC-NF-κB and Akt/PKB pathways. A few preclinical experiments conducted through gC1qR interventions, such as monoclonal antibody, chimeric antigen receptor T-cell (CAR-T) therapy, and tumor vaccination, have shown encouraging results in anticancer activity. The efficacy may rely on the regulatory role on the TME, induction of tumor cells apoptosis and antiangiogenic activity. Nevertheless, the current understanding of the relationship between cancer immunotherapy and gC1qR remains elusive and often contradictory, posing both opportunities and challenges for therapeutic translation in the clinic. In this review, we focus on the current understanding of gC1qR function in cancer immunology and highlight the vital roles in regulating the TME. We also examines the rationale behind targeting gC1qR and discusses the potential for translating into clinical practice.

Glypican-3: A Novel and Promising Target for the Treatment of Hepatocellular Carcinoma.

Glypican-3 (GPC3) is a membrane-associated proteoglycan that is specifically up-regulated in hepatocellular carcinoma (HCC) although rarely or not expressed in normal liver tissues, making it a perfect diagnostic and treatment target for HCC. Several GPC3-based clinical trials are ongoing and recently several innovative GPC3-targeted therapeutic methods have emerged with exciting results, including GPC3 vaccine, anti-GPC3 immunotoxin, combined therapy with immune checkpoint blockades (ICBs), and chimeric antigen receptor (CAR) T or NK cells. Here, we review the value of GPC3 in the diagnosis and prognosis of HCC, together with its signaling pathways, with a specific focus on GPC3-targeted treatments of HCC and some prospects for the future GPC3-based therapeutic strategies in HCC.

Characteristics and survival outcomes of primary splenic cancers: A SEER population-based study.

ABSTRACT: Primary splenic cancers represent a small number of cancer cases and studies on its clinicopathological features and outcomes are limited. Splenic lymphomas and primary splenic angiosarcoma (PSA) are the 2 most common histological types of splenic cancers. This population-based study aimed to investigate the clinical characteristics and survival outcomes of patients with splenic lymphomas or PSA.Patients diagnosed with splenic lymphomas or PSA between 2000 and 2015 were identified from the Surveillance Epidemiology and End Results database of the National Cancer Institutes. Overall survival (OS) and cancer-specific survival (CSS) rates were calculated using the Kaplan-Meier method. A Cox proportional hazard models were used to identify independent predictors of cancer-specific mortality.A total of 700 patients with splenic lymphoma and 48 patients with PSA were included in this study. The median age of patients with splenic lymphoma was 65 years and 57 years for patients with PSA. For patients with splenic lymphoma, the most prevalent histological subtypes were splenic marginal zone lymphoma and diffuse large B-cell lymphoma. A total of 52.6% of the cases had stage IV disease based on the Ann Arbor staging system. Five-year OS and CSS were 76.9% and 83.4%, respectively. Multivariate analysis revealed that independent predictors of splenic lymphoma CSS included race, stage, chemotherapy, and histological subtype. However, a much shorter OS time was seen in the PSA cohort which had a 5-year OS of 11.8%, a median OS of 10.0 months and the 5-year CSS of 12.4%. Chemotherapy was correlated with better outcomes in patients with PSA. However, the survival benefits of surgery for splenic cancer were not statistically significant in our study.The current study is the largest cohort of primary splenic cancer presented in literature based on the Surveillance Epidemiology and End Results database and our large series describe the characteristics and survival outcomes of such rare diseases which may provide reliable information for further studies and clinicians.

A Distinct Clinicopathological Feature and Prognosis of Young Gastric Cancer Patients Aged ≤ 45 Years Old.

PURPOSE: The aim of this retrospective study was to probe into clinicopathological features and prognosis of early-onset gastric cancer (EOGC) patients aged ≤ 45 years old. METHODS: This study selected 154 young gastric cancer patients aged ≤ 45 years old and 158 elderly gastric cancer patients aged > 50 years old admitted to West China Hospital of Sichuan University in 2009-2019 as the research object. These patients were further divided into two groups according to whether tumor can be resected radically. The following parameters were analyzed: age, gender, helicobacter pylori (HP) infection status, Her-2 status, pathological type and stage, chemotherapy, tumor differentiation degree, overall survival (OS). RESULTS: More than 3,000 patients with gastric carcinoma were screened, and 154 young gastric cancer patients aged ≤ 45 years old were identified as EOGC. Among them, the number of female patients in EOGC group was significantly higher than that of males, accounting for 63.6%. In addition, EOGC were associated with diffuse Laur´en type and poorly differentiated tumors. Interestingly, the Kaplan-Meier method showed that the OS of unresectable EOGC group was significantly lower than that of unresectable LOGC group (P = 0.0005) and chemotherapy containing paclitaxel tended to be more effective in the young people (P = 0.0511). Nevertheless, there was no significant difference in OS between young and elderly patients with gastric cancer in the radical resection group (P = 0.3881). CONCLUSION: EOGC patients have a worse prognosis than late-onset gastric cancer (LOGC) patients with advanced unresectable gastric cancer. Palliative surgery or chemotherapy containing paclitaxel may improve the OS of unresectable young individuals with gastric cancer. Additional randomized controlled trials are required for guiding clinical practice.

Unexpected Favorable Outcome to PD-1 Antibody Plus Lenvatinib in a Patient With Recurrent Intestinal Follicular Dendritic Cell Sarcoma: A Case Report and Literature Review.

Background: Follicular dendritic cell sarcoma (FDCS) is an uncommon malignant cancer, and there is no standard treatment to date. Resection followed by adjuvant chemotherapy or radiation is considered the most commonly used strategy for treatment. However, the treatment for patients who have progressed after systemic treatment is more controversial. Case summary: In this case report, we describe a 57-year-old man with primary small intestine FDCS where surgery and second-line systemic chemotherapy failed. After disease progression (PD), the patient received sintilimab plus lenvatinib as third-line treatment and achieved a progression-free survival (PFS) with 7 months. Conclusion: This is the first report of a FDCS patient treated with immune checkpoint inhibitors (ICIs) and antiangiogenic agents, sintilimab and lenvatinib, as third-line therapy. Our case provides a potential therapeutic option for patients with FDCS who progressed after multiline therapy.

Locally advanced gastroesophageal junction cancer with pathological complete response to neoadjuvant therapy: a case report and literature review.

Most gastric cancer and gastroesophageal junction carcinoma (GEJ) patients are already in the advanced stage at the time of diagnosis. Thus, the probability of radical gastrectomy is low, and surgical treatment alone has a poor prognosis due to the high recurrence rate. In order to reduce the recurrence and distant metastasis after surgery, there have been many attempts made to improve the perioperative treatment of advanced localized gastric cancer, but no uniform criteria exist. Over recent years, immunotherapy has revolutionized cancer treatment, and immune checkpoint inhibitors (ICIs) have shown excellent efficacy across various types of tumors, becoming a potential treatment after surgery, chemotherapy, radiotherapy, and targeted therapy. However, the efficacy of single-agent ICIs for gastric cancer is still unsatisfactory. As comprehensive, chemotherapy-based treatment has become the standard care for locally advanced gastric cancer, exploring combination treatment with immune checkpoint inhibitors (ICIs) may be valuable to improving survival outcomes. Here, we report a 66-year-old male with dysphagia diagnosed with GEJ and was defined as clinical stage (cT4N2M0) and Siewert type II, characterized as mismatch repair proficient (pMMR) and programmed cell death ligand-1 (PD-L1) negative; surprisingly, with anti-PD-1 antibody plus SOX (S-1: a combination of tegafur, gimeracil, and oteracil+ oxaliplatin) as perioperative therapy, the patient achieved pathological complete remission (pCR), which indicates that the addition of ICIs to chemotherapy as a perioperative comprehensive treatment might provide a promising strategy option for GEJ. In addition, we review the current status of perioperative comprehensive treatment, in hope that this may provide some reference value for clinical decision-making.

Progress and Challenges of Predictive Biomarkers for Immune Checkpoint Blockade.

Over the past decade, immune checkpoint blockade (ICB) therapy has revolutionized the outlook for oncology with significant and sustained improvement in the overall patient survival. Unlike traditional cancer therapies, which target the cancer cells directly, ICB acts on the immune system to enhance anti-tumoral immunity. However, the response rate is still far from satisfactory and most patients are refractory to such treatment. Unfortunately, the mechanisms underlying such heterogeneous responses between patients to ICB therapy remain unclear. In addition, escalating costs of cancer care and unnecessary immune-related adverse events also are pertinent considerations with applications of ICB. Given these issues, identifying explicit predictive biomarkers for patient selection is an urgent unmet need to increase the efficacy of ICB therapy. The markers can be classified as tumor related and non-tumor-related biomarkers. Although substantial efforts have been put into investigating various biomarkers, none of them has been found to be sufficient for effectively stratifying patients who may benefit from immunotherapy. The present write up is an attempt to review the various emerging clinically relevant biomarkers affecting the efficacy of immune checkpoint inhibitors, as well as the limitations associated with their clinical application.

A Highlight of the Mechanisms of Immune Checkpoint Blocker Resistance.

In recent years, as our understanding of tumor immunology is continuously improved, immunotherapy has come to the center stage of cancer therapy and is deemed as the most promising approach for cancer control. Although immunotherapy, particularly immune checkpoint blockade (ICB), has achieved a milestone in several types of tumors, the majority of cancer patients do not benefit from immunotherapy. The dismal outcome of cancer immunotherapy is mainly due to primary or acquired resistance arising from tumor immune evasion. Exploring the mechanisms of tumor immune evasion in the course of immunotherapy may identify biological targets to conquer tumor resistance to immunotherapy. In this review, we highlight tumor cell-intrinsic and -extrinsic factors that may underlie tumor resistance to immune checkpoint blockers. Targeting these factors in combination with immune checkpoint blockers points to the future direction of cancer immunotherapy.

[Anti-inflammatory effects of penehyclidine hydrochloride on acute respiratory distress syndrome in rats].

OBJECTIVE: To investigate the anti-inflammatory effect of penehyclidine hydrochloride on oleic acid-induced acute respiratory distress syndrome (ARDS) in rats. METHODS: According to randomize number table method, 30 adult male Sprague-Dawley (SD) rats were divided into control group, model group and treatment group. Catheters were placed in femoral vein in each group. The control group was injected with 1.1 mL/kg physiological saline; the model group was injected with 0.1 mL/kg oleic acid and then injected with 1.0 mL/kg normal saline to establish ARDS model; the treatment group was injected with 0.1 mL/kg oleic acid and then injected with 1.0 mL/kg penehyclidine hydrochloride. At 3 hours after the model was established, blood gas analysis was carried out in each group, oxygenation index (PaO2/FiO2) was calculated, and the levels of serum interleukins (IL-1, IL-6) were measured by enzyme linked immunosorbent assay (ELISA). Rats were sacrificed to harvest lung tissue, and the lung wet/dry ratio (W/D) was calculated; the morphological changes of lung tissue was observed under microscope; the superoxide dismutase (SOD) activity and malondialdehyde (MDA) levels were detected by colorimetry; the expression of tumor necrosis factor -α (TNF-α) in lung tissue was detected by immunohistochemical method. The correlations between lung W/D ratio and various indicators were analyzed using Pearson correlation test. RESULTS: Compared with the control group, PaO2/FiO2 in model group was significantly decreased, lung W/D ratio was significantly increased, serum IL-1, IL-6 levels and lung tissue MDA content were significantly increased, lung tissue SOD activity was significantly decreased; the alveolar space was filled with exudate, neutrophils and red blood cells, and there were obvious edema and broadening in pulmonary interstitial and alveolar under light microscope; the type II alveolar epithelial cells were partly destroyed, accompanied by lamellar body degeneration and emptying phenomenon under electron microscope; and immunohistochemistry showed that the positive expression of TNF-α in lung tissue was significantly increased. Compared with the model group, PaO2/FiO2 in the treatment group was significantly improved [mmHg (1 mmHg = 0.133 kPa): 204.42±31.61 vs. 113.91±47.78, P < 0.05], the lung W/D ratio was significantly decreased (5.80±0.44 vs. 6.82±0.59, P < 0.01), serum IL-1, IL-6 levels and lung tissue MDA content were significantly decreased [IL-1 (µg/L): 18.38±0.28 vs. 20.04±0.39, IL-6 (µg/L): 12.64±0.67 vs. 14.28±1.33, MDA (nmol/mg): 3.95±0.28 vs. 5.17±0.29, all P < 0.05], the activity of SOD in lung tissue was significantly increased (U/mg: 48.75±2.41 vs. 45.09±1.69, P < 0.01), histological and pathological changes were significantly reduced, and the positive expression of TNF-α in lung tissue was significantly reduced [positive cell rate: (25.80±3.44)% vs. (38.82±3.59)%, P < 0.01]. CONCLUSIONS: Penehyclidine hydrochloride can effectively improve the oxygenation, alleviate lung injury and reduce pulmonary edema in oleic acid induced ARDS rat by decreasing lung W/D ratio, inhibiting oxidative stress and inflammatory response.

Adiponectin/AdiopR1 signal inactivation contributes to impaired angiogenesis in mice of advanced age.

BACKGROUND: The mechanism by which angiogenesis declines with aging remains largely unknown. Given that the plasma levels of adiponectin (APN) are decreased in the presence of ischemic cardiovascular disease, we explore the possible mechanisms by which APN/adiponectin receptor1 (AdipoR1) axis inactivation contributes to the decline in vascular regeneration capacity in elderly animals. METHODS AND RESULTS: To study aging-related changes in the APN/AdipoR1 axis and its impact on ischemia-induced angiogenesis, a hindlimb ischemia model was applied to young and aged mice. Aging impaired ischemia-induced blood flow recovery. An ELISA showed that the aged mice had decreased plasma APN levels. Immunostaining showed lesser capillary formation in the aged mice. The aged ischemic muscles had decreased levels of AdipoR1, peroxisome proliferator activated receptor-γ (PPAR-γ), PPAR-γ co-activator 1α (PGC-1α), phospho-AMP-activated protein kinase α (p-AMPK-α), and B cell lymphoma-2 (Bcl-2) and increased levels of cleaved caspase-8 (C-caspase-8) and gp91phox/p22phox genes or/and proteins, nicotinamide adenine dinucleotide phosphate oxidase activity, superoxide production, and matrix metalloproteinase-2/-9 activity as well as increased numbers of infiltrated macrophages and leucocytes. In in vitro experiments, aged endothelial cells had negative changes in the levels of PPAR-γ, PGC-1α, p-AMPK-α, Bcl-2, and C-caspase-8 proteins in response to oxidative stress. Genetic interventions targeted toward APN and AdipoR1 negatively affected the targeted angiogenic protein levels in aged muscles and angiogenic actions and/or aged endothelial events. CONCLUSION: These findings indicate that aging can reduce angiogenesis in response to hypoxia via an impaired APN-AdipoR1-dependent mechanism that may be mediated by PPAR-γ/PGC-1α signaling inactivation in advanced age.

Cathepsin K activity controls cardiotoxin-induced skeletal muscle repair in mice.

BACKGROUND: Cathepsin K (CatK) is a widely expressed cysteine protease that has gained attention because of its enzymatic and non-enzymatic functions in signalling. Here, we examined whether CatK-deficiency (CatK-/- ) would mitigate injury-related skeletal muscle remodelling and fibrosis in mice, with a special focus on inflammation and muscle cell apoptosis. METHODS: Cardiotoxin (CTX, 20 µM/200 µL) was injected into the left gastrocnemius muscle of male wild-type (CatK+/+ ) and CatK-/- mice, and the mice were processed for morphological and biochemical studies. RESULTS: On post-injection Day 14, CatK deletion ameliorated muscle interstitial fibrosis and remodelling and performance. At an early time point (Day 3), CatK-/- reduced the lesion macrophage and leucocyte contents and cell apoptosis, the mRNA levels of monocyte chemoattractant protein-1, toll-like receptor-2 and toll-like receptor-4, and the gelatinolytic activity related to matrix metalloproteinase-2/-9. CatK deletion also restored the protein levels of caspase-3 and cleaved caspase-8 and the ratio of the BAX to the Bcl-2. Moreover, CatK deficiency protected muscle fibre laminin and desmin disorder in response to CTX injury. These beneficial muscle effects were mimicked by CatK-specific inhibitor treatment. In vitro experiments demonstrated that pharmacological CatK inhibition reduced the apoptosis of C2C12 mouse myoblasts and the levels of BAX and caspase-3 proteins induced by CTX. CONCLUSIONS: These results demonstrate that CatK plays an essential role in skeletal muscle loss and fibrosis in response to CTX injury, possibly via a reduction of inflammation and cell apoptosis, suggesting a novel therapeutic strategy for the control of skeletal muscle diseases by regulating CatK activity.