Because of its simplicity, reliability, and replicability, the Masquelet induced membrane technique (IMT) has become one of the preferred methods for critical bone defect reconstruction in extremities. Although it is now used worldwide, few studies have been published about IMT in military practice. Bone reconstruction is particularly challenging in this context of care due to extensive soft-tissue injury, early wound infection, and even delayed management in austere conditions. Based on our clinical expertise, recent research, and a literature analysis, this narrative review provides an overview of the IMT application to combat-related bone defects. It presents technical specificities and future developments aiming to optimize IMT outcomes, including for the management of massive multi-tissue defects or bone reconstruction performed in the field with limited resources.

Background: Abnormal myocardial voltage-gated sodium channel 1.5 (Na_v1.5) expression and function cause lethal ventricular arrhythmias during myocardial ischemia–reperfusion (I/R). Protein inhibitor of activated STAT Y (PIASy)-mediated caveolin-3 (Cav-3) small ubiquitin-related modifier (SUMO) modification affects Cav-3 binding to the Na_v1.5. PIASy activity is increased after myocardial I/R, but it is unclear whether this is attributable to plasma membrane Na_v1.5 downregulation and ventricular arrhythmias.

Methods: Using recombinant adeno-associated virus subtype 9 (AAV9), rat cardiac PIASy was silenced using intraventricular injection of PIASy short hairpin RNA (shRNA). After two weeks, rat hearts were subjected to I/R and electrocardiography was performed to assess malignant arrhythmias. Tissues from peri-infarct areas of the left ventricle were collected for molecular biological measurements.

Results: PIASy was upregulated by I/R (P<0.01), with increased SUMO2/3 modification of Cav-3 and reduced membrane Na_v1.5 density (P<0.01). AAV9-PIASy shRNA intraventricular injection into the rat heart down-regulated PIASy after I/R, at both mRNA and protein levels (P<0.05 vs. Scramble-shRNA+I/R group), decreased SUMO-modified Cav-3 levels, enhanced Cav-3 binding to Na_v1.5, and prevented I/R-induced decrease of Na_v1.5 and Cav-3 co-localization in the intercalated disc and lateral membrane. PIASy silencing in rat hearts reduced I/R-induced fatal arrhythmias, which was reflected by a modest decrease in the duration of ventricular fibrillation (VF; P<0.05 vs. Scramble-shRNA+I/R group) and a significantly reduced arrhythmia score (P<0.01 vs. Scramble-shRNA+I/R group). The anti-arrhythmic effects of PIASy silencing were also evidenced by decreased episodes of ventricular tachycardia (VT), sustained VT and VF, especially at the time 5–10 min after ischemia (P<0.05 vs. Scramble-shRNA+IR group). Using in vitro human embryonic kidney 293 T (HEK293T) cells and isolated adult rat cardiomyocyte models exposed to hypoxia/reoxygenation (H/R), we confirmed that increased PIASy promoted Cav-3 modification by SUMO2/3 and Na_v1.5/Cav-3 dissociation after H/R. Mutation of SUMO consensus lysine sites in Cav-3 (K38R or K144R) altered the membrane expression levels of Na_v1.5 and Cav-3 before and after H/R in HEK293T cells.

Conclusions: I/R-induced cardiac PIASy activation increased Cav-3 SUMOylation by SUMO2/3 and dysregulated Na_v1.5-related ventricular arrhythmias. Cardiac-targeted PIASy silencing mediated Cav-3 deSUMOylation and partially prevented I/R-induced Na_v1.5 downregulation in the plasma membrane of cardiomyocytes, and subsequent ventricular arrhythmias in rats. PIASy was identified as a potential therapeutic target for life-threatening arrhythmias in patients with ischemic heart diseases.

Background: Data on severe and extensive burns in China are limited, as is data on the prevalence of a range of related gastrointestinal (GI) disorders [such as stress ulcers, delayed defecation, opioid-related bowel immotility, and abdominal compartment syndrome (ACS)]. We present a multicentre analysis of coincident GI dysfunction and its effect on burn-related mortality.

Methods: This retrospective analysis was conducted on patients with severe [≥ 20% total burn surface area (TBSA)] and extensive (>50% TBSA or >25% full-thickness TBSA) burns admitted to three university teaching institutions in China between January 1, 2011 and December 31, 2020. Both 30- and 90-day mortality were assessed by collating demographic data, burn causes, admission TBSA, % full-thickness TBSA, Baux score, Abbreviated Burn Severity Index (ABSI) score, and Sequential Organ Failure Assessment (SOFA) score, shock at admission and the presence of an inhalation injury. GI dysfunction included abdominal distension, nausea/vomiting, diarrhoea/constipation, GI ulcer/haemorrhage, paralytic ileus, feeding intolerance and ACS. Surgeries, length of intensive care unit (ICU) stay, pain control [in morphine milligram equivalents (MME)] and overall length of hospital stay (LOHS) were recorded.

Results: We analyzed 328 patients [75.6% male, mean age: (41.6±13.6) years] with a median TBSA of 62.0% (41.0%–80.0%); 256(78.0%) patients presented with extensive burns. The 90-day mortality was 23.2%(76/328), with 64(84.2%) of these deaths occurring within 30 d and 25(32.9%) occurring within 7 d. GI dysfunction was experienced by 45.4% of patients and had a significant effect on 90-day mortality [odds ratio (OR)=14.070, 95% confidence interval (CI) 5.886–38.290, P<0.001]. Multivariate analysis showed that GI dysfunction was associated with admission SOFA score and % full-thickness TBSA. Overall, 88.2%(67/76) of deceased patients had GI dysfunction [hazard ratio (HR) for death of GI dysfunction=5.951], with a survival advantage for functional disorders (diarrhoea, constipation, or nausea/vomiting) over GI ulcer/haemorrhage (P<0.001).

Patients with severe burns have an unfavourable prognosis, as nearly one-fifth died within 90 d. Half of our patients had comorbidities related to GI dysfunction, among which GI ulcers and haemorrhages were independently correlated with 90-day mortality. More attention should be given to severe burn patients with GI dysfunction.

Non-muscle invasive bladder cancer (NMIBC) is a major type of bladder cancer with a high incidence worldwide, resulting in a great disease burden. Treatment and surveillance are the most important part of NIMBC management. In 2018, we issued "Treatment and surveillance for non-muscle-invasive bladder cancer in China: an evidence-based clinical practice guideline". Since then, various studies on the treatment and surveillance of NMIBC have been published. There is a need to incorporate these materials and also to take into account the relatively limited medical resources in primary medical institutions in China. Developing a version of guideline which takes these two issues into account to promote the management of NMIBC is therefore indicated. We formed a working group of clinical experts and methodologists. Through questionnaire investigation of clinicians including primary medical institutions, 24 clinically concerned issues, involving transurethral resection of bladder tumor (TURBT), intravesical chemotherapy and intravesical immunotherapy of NMIBC, and follow-up and surveillance of the NMIBC patients, were determined for this guideline. Researches and recommendations on the management of NMIBC in databases, guideline development professional societies and monographs were referred to, and the European Association of Urology was used to assess the certainty of generated recommendations. Finally, we issued 29 statements, among which 22 were strong recommendations, and 7 were weak recommendations. These recommendations cover the topics of TURBT, postoperative chemotherapy after TURBT, Bacillus Calmette–Guérin (BCG) immunotherapy after TURBT, combination treatment of BCG and chemotherapy after TURBT, treatment of carcinoma in situ, radical cystectomy, treatment of NMIBC recurrence, and follow-up and surveillance. We hope these recommendations can help promote the treatment and surveillance of NMIBC in China, especially for the primary medical institutions.

Sepsis is a common complication of combat injuries and trauma, and is defined as a life-threatening organ dysfunction caused by a dysregulated host response to infection. It is also one of the significant causes of death and increased health care costs in modern intensive care units. The use of antibiotics, fluid resuscitation, and organ support therapy have limited prognostic impact in patients with sepsis. Although its pathophysiology remains elusive, immunosuppression is now recognized as one of the major causes of septic death. Sepsis-induced immunosuppression is resulted from disruption of immune homeostasis. It is characterized by the release of anti-inflammatory cytokines, abnormal death of immune effector cells, hyperproliferation of immune suppressor cells, and expression of immune checkpoints. By targeting immunosuppression, especially with immune checkpoint inhibitors, preclinical studies have demonstrated the reversal of immunocyte dysfunctions and established host resistance. Here, we comprehensively discuss recent findings on the mechanisms, regulation and biomarkers of sepsis-induced immunosuppression and highlight their implications for developing effective strategies to treat patients with septic shock.

Background: Autophagy dysfunction plays a crucial role in tau accumulation and neurodegeneration in Alzheimer's disease (AD). This study aimed to investigate whether and how the accumulating tau may in turn affect autophagy.

Methods: The primary hippocampal neurons, N2a and HEK293T cells with tau overexpression were respectively starved and treated with vinblastine to study the effects of tau on the initiating steps of autophagy, which was analysed by Student's two-tailed t-test. The rapamycin and concanamycin A were employed to inhibit the mammalian target of rapamycin kinase complex 1 (mTORC1) activity and the vacuolar H⁺-ATPase (v-ATPase) activity, respectively, which were analysed by One‐way ANOVA with post hoc tests. The Western blotting, co-immunoprecipitation and immunofuorescence staining were conducted to gain insight into the mechanisms underlying the tau effects of mTORC1 signaling alterations, as analysed by Student's two-tailed t-test or One‐way ANOVA with post hoc tests. The autophagosome formation was detected by immunofuorescence staining and transmission electron microscopy. The amino acids (AA) levels were detected by high performance liquid chromatography (HPLC).

Results: We observed that overexpressing human full-length wild-type tau to mimic AD-like tau accumulation induced autophagy deficits. Further studies revealed that the increased tau could bind to the prion-related domain of T cell intracellular antigen 1 (PRD-TIA1) and this association significantly increased the intercellular level of amino acids (Leucine, P=0.0038; Glutamic acid, P=0.0348; Alanine, P=0.0037; Glycine, P=0.0104), with concordant upregulation of mTORC1 activity [phosphorylated eukaryotic translation initiation factor 4E-binding protein 1 (p-4EBP1), P<0.0001; phosphorylated 70 kD ribosomal protein S6 kinase 1 (p-p70S6K1), P=0.0001, phosphorylated unc-51-like autophagy-activating kinase 1 (p-ULK1), P=0.0015] and inhibition of autophagosome formation [microtubuleassociated protein light chain 3 II (LC3 II), P=0.0073; LC3 puncta, P<0.0001]. As expected, this tau-induced deficit of autophagosome formation in turn aggravated tau accumulation. Importantly, we also found that blocking TIA1 and tau interaction by overexpressing PRD-TIA1, downregulating the endogenous TIA1 expression by shRNA, or downregulating tau protein level by a small proteolysis targeting chimera (PROTAC) could remarkably attenuate tau-induced autophagy impairment.

Conclusions: Our findings reveal that AD-like tau accumulation inhibits autophagosome formation and induces autophagy deficits by activating the TIA1/amino acid/mTORC1 pathway, and thus this work reveals new insight into tau-associated neurodegeneration and provides evidence supporting the use of new therapeutic targets for AD treat-ment and that of related tauopathies.

Background: Wear particles-induced osteolysis is a major long-term complication after total joint arthroplasty. Up to now, there is no effective treatment for wear particles-induced osteolysis except for the revision surgery, which is a heavy psychological and economic burden to patients. A metabolite of gut microbiota, short chain fatty acids (SCFAs), has been reported to be beneficial for many chronic inflammatory diseases. This study aimed to investigate the therapeutic effect of SCFAs on osteolysis.

Methods: A model of inflammatory osteolysis was established by applying CoCrMo alloy particles to mouse calvarium. After two weeks of intervention, the anti-inflammatory effects of SCFAs on wear particle-induced osteolysis were evaluated by micro-CT analysis and immunohistochemistry staining. In vitro study, lipopolysaccharide (LPS) primed bone marrow-derived macrophages (BMDMs) and Tohoku hospital pediatrics-1 (THP-1) macrophages were stimulated with CoCrMo particles to activate inflammasome in the presence of acetate (C2), propionate (C3), and butyrate (C4). Western blotting, enzyme-linked immunosorbent assay, and immunofluorescence were used to detect the activation of NLRP3 inflammasome. The effects of SCFAs on osteoclasts were evaluate by qRT-PCR, Western blotting, immunofluorescence, and tartrate-resistant acid phosphatase (TRAP) staining. Additionally, histone deacetylase (HDAC) inhibitors, agonists of GPR41, GPR43, and GPR109A were applied to confirm the underlying mechanism of SCFAs on the inflammasome activation of macrophages and osteoclastogenesis.

Results: C3 and C4 but not C2 could alleviate wear particles-induced osteolysis with fewer bone erosion pits (P<0.001), higher level of bone volume to tissue volume (BV/TV, P<0.001), bone mineral density (BMD, P<0.001), and a lower total porosity (P<0.001). C3 and C4 prevented CoCrMo alloy particles-induced ASC speck formation and nucleation-induced oligomerization, suppressing the cleavage of caspase-1 (P<0.05) and IL-1β (P<0.05) stimulated by CoCrMo alloy particles. C3 and C4 also inhibited the generation of gasdermin D-N-terminal fragment (GSDMD-NT) to regulate pyroptosis. Besides, C3 and C4 have a negative impact on osteoclast differentiation (P<0.05) and its function (P<0.05), affecting the podosome arrangement and morphologically normal podosome belts formation.

Conclusions: Our work showed that C3 and C4 are qualified candidates for the treatment of wear particle-induced osteolysis.

Background: Melatonin, a natural hormone secreted by the pineal gland, has been reported to exhibit antitumor properties through diverse mechanisms of action. However, the oncostatic function of melatonin on esophageal squamous cell carcinoma (ESCC) remains elusive. This study was conducted to investigate the potential effect and underlying molecular mechanism of melatonin as single anticancer agent against ESCC cells.

Methods: ESCC cell lines treated with or without melatonin were used in this study. In vitro colony formation and 5-Ethynyl-2'-deoxyuridine (EdU) incorporation assays, and nude mice tumor xenograft model were used to confirm the proliferative capacities of ESCC cells. RNA-seq, qPCR, Western blotting, recombinant lentivirus-mediated target gene overexpression or knockdown, plasmids transfection and co-IP were applied to investigate the underlying molecular mechanism by which melatonin inhibited ESCC cell growth. IHC staining on ESCC tissue microarray and further survival analyses were performed to explore the relationship between target genes’ expression and prognosis of ESCC.

Results: Melatonin treatment dose-dependently inhibited the proliferative ability and the expression of histone deacetylase 7 (HDAC7), c-Myc and ubiquitin-specific peptidase 10 (USP10) in ESCC cells (P<0.05). The expressions of HDAC7, c-Myc and USP10 in tumors were significantly higher than the paired normal tissues from 148 ESCC patients (P<0.001). Then, the Kaplan-Meier survival analysis suggested that ESCC patients with high HDAC7, c-Myc or USP10 levels predicted worse overall survival (log-rank P<0.001). Co-IP and Western blotting further revealed that HDAC7 physically deacetylated and activated β-catenin thus promoting downstream target c-Myc gene transcription. Notably, our mechanistic study validated that HDAC7/β-catenin/c-Myc could form the positive feedback loop to enhance ESCC cell growth, and USP10 could deubiquitinate and stabilize HDAC7 protein in the ESCC cells. Additionally, we verified that inhibition of the HDAC7/β-catenin/c-Myc axis and USP10/HDAC7 pathway mediated the anti-proliferative action of melatonin on ESCC cells.

Conclusions: Our findings elucidate that melatonin mitigates the HDAC7/β-catenin/c-Myc positive feedback loop and inhibits the USP10-maintained HDAC7 protein stability thus suppressing ESCC cell growth, and provides the reference for identifying biomarkers and therapeutic targets for ESCC.