Reconstruction of foot and ankle defects using the vaccum sealing drainage versus the induced-membrane the elderly: A retrospective comparative study.

The purpose of this study was to compare the reconstructive outcomes of soft-tissue defects around foot and ankle with vaccum sealing drainage (VSD) or induction membrane (IM) of cement formation and attempt to provide an optimal strategy for elderly patients. A retrospective review of all continuous patients with foot and ankle reconstruction using different flaps from October of 2016 and October of 2020 was performed. Based on the different way, the patients were divided into two groups: VSD group (n = 26) and IM group (n = 27). Outcomes were assessed according to the size of the defect, frequency of debridement procedures, hospitalization time, duration of healing, the healing rate, major amputation rate, functional outcomes and complications. Immunohistochemistry (IHC) detection of vascular endothelial growth factor (VEGF) was also be completed. We found that there was no difference in demographic characteristics, size of the defect, debridement times and functional outcomes between the two groups (p > 0.05); however, a significant difference in the wound healing time, hospitalization time and complications were noted between them(p < 0.05). The fresh granulation tissue of both groups showed abundant positive expression of VEGF. Thus, the VSD and IM are both available for foot and ankle reconstruction in elderly patients. However, the IM group offers short hospitalization time, duration of healing and lower frequency of postoperative complications. Thus, we advocate the IM for reconstruction of defects of the foot and ankle region in the elderly patients.

Reconstruction of Composite Soft Tissue Defect in the Distal Finger Using Partial Toenail Flap Transfer.

OBJECTIVE: Composite tissue loss involving the distal finger pulp and the nail is a common but challenging finger injury to restore. This study introduces a reconstruction procedure for a distal finger pulp and nail defect using a partial toenail flap transfer. METHODS: Twenty digits, including 16 thumbs, two index fingers, and two middle fingers, with composite soft tissue defects were treated with a partial toenail flap transfer from October 2015 to January 2020. Shortening revision of the great toe phalanx, a V-Y advancement flap of the toe pulp, and a local pedicle flap from a second toe transfer were used to cover the donor sites, and no skin grafts were required. Functionality was evaluated using the validated Spanish version of the Quick-DASH scale. The aesthetics of both the reconstructed and donor sites were evaluated using the Vancouver Scar Scale (VSS). The static two-point discrimination (2-PD) of the finger pulp was used as a measure of tactile agnosia. RESULTS: All donor site wounds healed well. The average follow-up time was 23.6 months (6-39 months). The mean Quick-DASH functional score was 7.1. The VSS scores were 4.02 ± 0.29 and 4.00 ± 0.38 for the reconstructed and donor sites, respectively. The static 2-PD of finger pulp was 4.5 ± 0.76 mm. The patients were satisfied with finger motion, sensory function, and aesthetic contour. CONCLUSIONS: Partial toenail flap transfer is the recommended treatment to regain motion, sensation, function, and a satisfactory aesthetic appearance when considering repairing a composite soft tissue distal finger defect with accompanying loss of the perionychium, particularly in the thumb, index finger, or middle finger.

Risk factors and nomogram predictive model of surgical site infection in closed pilon fractures.

OBJECTIVES: In this study, we try to investigate the risk factors of postoperative surgical site infection (SSI) in closed pilon fractures and establish a nomogram prediction model. METHODS: From January 2012 to June 2021, 516 closed pilon fracture patients were included in this study. Of these, 387 patients were randomly assigned to the training group and 129 patients were assigned to the validation group (3:1). By univariate and multivariate Cox analysis, we identified independent risk factors for postoperative SSI after Pilon fracture. We established a nomogram model and used receiver operating characteristic (ROC) and calibration chart to evaluate its discriminant and calibration. RESULTS: SSI occurred in 71 patients in the training group and 23 patients in the validation group. Ultimately, age, preoperative blood sugar, operative time, Tscherne classification and fracture classification were identified as independent risk factors for SSI. The AUC values for SSI of the training and validation group were 0.898 and 0.880, and the P value of the Hosmer-Lemeshow test was 0.125. We established a nomogram prediction model based on age, preoperative blood sugar, operative time, Tscherne classification and fracture classification. CONCLUSION: Our nomogram model had good discrimination and calibration power, so it could be used to predict SSI risk in patients with pilon fracture.

Management of wounds with exposed bone structures using an induced-membrane followed by polymethyl methacrylate and second-stage skin grafting in the elderly with a 3-year follow-up.

The treatment of traumatic wounds with exposed bone or tendons is often challenging. An induced membrane (IM) is used to reconstruct bone defects, as it provides an effective and sufficient blood supply for bone and soft-tissue reconstruction. This study explored a novel two-stage strategy for wound management, consisting of initial wound coverage with polymethyl methacrylate (PMMA) and an autologous split-thickness skin graft under the IM. Fifty inpatients were enrolled from December 2016 to December 2019. Each patient underwent reconstruction according to a two-stage process. In the first stage, the defect area was thoroughly debrided, and the freshly treated wound was then covered using PMMA cement. After 4-6 weeks, during the second stage, the PMMA cement was removed to reveal an IM covering the exposed bone and tendon. An autologous split-thickness skin graft was then performed. Haematoxylin and eosin (H&E) staining and immunohistochemical analysis of vascular endothelial growth factor (VEGF), CD31 and CD34 were used to evaluate the IM and compare it with the normal periosteal membrane (PM). The psychological status and the Lower Extremity Function Scale (LEFS) as well as any complications were recorded at follow-up. We found that all skin grafts survived and evidenced no necrosis or infection. H&E staining revealed vascularised tissue in the IM, and immunohistochemistry showed a larger number of VEGF-, CD31- and CD34-positive cells in the IM than in the normal PM. The duration of healing in the group was 5.40 ± 1.32 months with a mean number of debridement procedures of 1.92 ± 0.60. There were two patients with reulceration in the group. The self-rating anxiety scale scores ranged from 35 to 60 (mean 48.02 ± 8.12). Postoperatively, the LEFS score was 50.10 ± 9.77. Finally, our strategy for the management of a non-healing wound in the lower extremities, consisting of an IM in combination with skin grafting, was effective, especially in cases in which bony structures were exposed in the elderly. The morbidity rate was low.

Bone-targeting delivery of platelet lysate exosomes ameliorates glucocorticoid-induced osteoporosis by enhancing bone-vessel coupling.

BACKGROUND: Glucocorticoids (GCs) overuse is associated with decreased bone mass and osseous vasculature destruction, leading to severe osteoporosis. Platelet lysates (PL) as a pool of growth factors (GFs) were widely used in local bone repair by its potent pro-regeneration and pro-angiogenesis. However, it is still seldom applied for treating systemic osteopathia due to the lack of a suitable delivery strategy. The non-targeted distribution of GFs might cause tumorigenesis in other organs. RESULTS: In this study, PL-derived exosomes (PL-exo) were isolated to enrich the platelet-derived GFs, followed by conjugating with alendronate (ALN) grafted PEGylated phospholipid (DSPE-PEG-ALN) to establish a bone-targeting PL-exo (PL-exo-ALN). The in vitro hydroxyapatite binding affinity and in vivo bone targeting aggregation of PL-exo were significantly enhanced after ALN modification. Besides directly modulating the osteogenic and angiogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) and endothelial progenitor cells (EPCs), respectively, PL-exo-ALN also facilitate their coupling under GCs' stimulation. Additionally, intravenous injection of PL-exo-ALN could successfully rescue GCs induced osteoporosis (GIOP) in vivo. CONCLUSIONS: PL-exo-ALN may be utilized as a novel nanoplatform for precise infusion of GFs to bone sites and exerts promising therapeutic potential for GIOP.

Resurfacing the complex finger defect and sensation reconstruction with the free distal ulnar artery perforator flap: a self-controlled case series study.

Background: The purpose of this clinical research is to report our results using the free distal ulnar artery perforator flap for resurfacing complex tissue defects in the finger, and to provide empirical reference for the treatment of subsequent clinical cases. Methods: In our research, eight patients with complex skin defects were treated with free distal ulnar artery perforator flaps. There were 4 index, 3 long, and 2 ring fingers. All the flaps were raised from the ipsilateral ulnar lateral wrist. The donor sites were covered with a full thickness skin graft or closed by direct suture. Results: Comprehensive analysis of the clinical treatment process of eight patients, all flaps survived completely without any necrosis during the 6-18 months follow-up. The patients were satisfied with the finger mobility, the sensation function, and the aesthetic appearance. Conclusions: Resurfacing complex tissue defects in the finger using the free perforator flap in a single stage, especially when the defect is medium in size and accompanied by digit nerve loss, is a valuable technique to achieve satisfaction in both sensation and aesthetic appearance. The ulnar artery perforator flap seems to be a reliable and flexible flap for addressing complex hand injuries with tissue loss.

The efficacy of Schroth exercises combined with the Chêneau brace for the treatment of adolescent idiopathic scoliosis: a retrospective controlled study.

PURPOSE: We aimed to determine the global effects of the Chêneau brace combined with Schroth exercises on adolescent idiopathic scoliosis (AIS). METHODS: We analyzed 192 patients with AIS who underwent the Chêneau brace treatment alone or combined with Schroth best practice (SBP) from June 2013 to October 2019. There were 138 patients in the Brace group and 54 patients in the Brace + SBP group. Radiographs were obtained at various treatment durations. Answers to the health-related quality of life (HRQoL) questionnaire were recorded before the intervention and at the time of treatment wean. RESULTS: The Cobb angle (-3.55°; p < 0.001) and C7-CSVL (-3.03 mm; p < 0.001) significantly decreased in the Brace + SBP group. Thoracic kyphosis (TK) decreased in both the Brace + SBP group (-1.85°; p = 0.0152) and the Brace group (-5.06; p < 0.001). Changes before and after treatment of TK were significantly different between groups (p < 0.001). The 22-item Scoliosis Research Society function score, self-image, mental health, and EuroQol 5-Dimension scores were significantly higher in the Brace + SBP group. The satisfaction score was higher in the Brace + SBP group (3.77 ± 0.63 vs. 3.13 ± 0.79; p < 0.001). CONCLUSIONS: Compared to bracing alone, the Schroth exercises plus bracing had a better effect on coronal balance. Schroth exercises improve flatback deformity caused by bracing and positively influence the HRQoL in AIS patients who received the Chêneau brace treatment.Implications for RehabilitationBracing and physiotherapy are common treatments for adolescent idiopathic scoliosis (AIS).The Chêneau brace treatment causes flatback deformity and muscle stiffness in AIS patients.The Schroth method helps patients increase muscle strength, halt curve progression, increase vital capacity, and maintain improved posture.The Schroth exercises could improve flatback deformity caused by bracing and positively influence the health-related quality of life in AIS patients who received the Chêneau brace treatment.

A nomogram for prediction of deep venous thrombosis risk in elderly femoral intertrochanteric fracture patients: A dual-center retrospective study.

Objective: Deep venous thrombosis (DVT) of the lower extremity is a common perioperative complication of femoral intertrochanteric fracture. This study aimed to identify the risk factors of lower extremity deep vein thrombosis (DVT) in elderly femoral intertrochanteric fracture patients and establish a nomogram model. Methods: From August 2014 to June 2021, a total of 1,652 femoral intertrochanteric fracture patients over the age of 65 were enrolled in our study. We distinguished independent risk factors by univariate and multivariate Cox analyses. A nomogram model was then built, and the discriminative and calibration of the model was evaluated through receiver operating characteristics (ROC) and calibration plots. Results: A total of 378 patients developed DVT (292 in the training group, 86 in the validation group) while the remaining patients did not. According to the univariate and multivariate Cox analyses results, age (OR = 1.07, 95% CI: 1.04-1.10), fibrinogen (OR = 2.09, 95% CI: 1.68-2.60), D-dimer (OR = 1.33, 95% CI: 1.27-1.40), time from injury to admission (OR = 1.78, 95% CI: 1.55-2.05), functional status (OR = 4.21, 95% CI: 2.86-6.20), and diabetes (OR = 1.65, 95% CI: 1.10-2.48) were identified as independent risk factors of DVT. The ROC values for DVT of the training and validation group were 0.862 and 0.912, and the P-value of the Hosmer-Lemeshow calibration test was 0.767. Conclusion: This nomogram model can be used to predict the probability of preoperative DVT in elderly patients with femoral intertrochanteric fracture and guide physician in perioperative thrombosis management.

Comparison of percutaneous cross screw fixation versus open reduction and internal fixation for pelvic Day type II crescent fracture-dislocation: case-control study.

OBJECTIVE: To investigate the clinical outcomes of percutaneous cross screws internal fixation for pelvic Day type II crescent fracture-dislocation. METHODS: We reviewed 66 consecutive patients undergoing surgical treatment for Day type II crescent fracture-dislocation from June 2005 to December 2017. Percutaneous cross screws internal fixation was performed in 40 patients, and open reduction and internal fixation was performed in 26 patients. The patient characteristics, surgical complications, radiographic and clinical outcomes and were compared. RESULTS: There was no statistically difference on the mean time from injury to surgery between the two groups. The time of operation, the amount of blood loss, the length of incision, and the hospital stay were significantly shorter in the percutaneous cross screws internal fixation group. No significant difference on Matta scores and Majeed scores between the two groups. The open reduction and internal fixation group resulted in a higher rate of intraoperative hemorrhage, nerve injury, discomfort, and pain. CONCLUSION: Percutaneous cross screws internal fixation for Day II type pelvic crescent fracture-dislocation was safe and effective. Minimally invasive fixation had the advantages of short operation and hospitalization time, less intraoperative bleeding, and surgical trauma.

Elevating sestrin2 attenuates endoplasmic reticulum stress and improves functional recovery through autophagy activation after spinal cord injury.

Spinal cord injury (SCI) is a devastating neurological trauma that causes losses of motor and sensory function. Sestrin2, also known as hypoxia inducible gene 95, is emerging as a critical determinant of cell homeostasis in response to cellular stress. However, the role of sestrin2 in the neuronal response to endoplasmic reticulum (ER) stress and the potential mechanism remain undefined. In this study, we investigated the effects of sestrin2 on ER stress and delineated an underlying molecular mechanism after SCI. Here, we found that elevated sestrin2 is a protective process in neurons against chemical ER stress induced by tunicamycin (TM) or traumatic invasion, while treatment with PERK inhibitor or knockdown of ATF4 reduces sestrin2 expression upon ER stress. In addition, we demonstrated that overexpression of sestrin2 limits ER stress, promoting neuronal survival and improving functional recovery after SCI, which is associated with activation of autophagy and restoration of autophagic flux mediated by sestrin2. Moreover, we also found that sestrin2 activates autophagy dependent on the AMPK-mTOR signaling pathway. Consistently, inhibition of AMPK abrogates the effect of sestrin2 on the activation of autophagy, and blockage of autophagic flux abolishes the effect of sestrin2 on limiting ER stress and neural death. Together, our data reveal that upregulation of sestrin2 is an important resistance mechanism of neurons to ER stress and the potential role of sestrin2 as a therapeutic target for SCI. Graphical abstract.

Gelatine nanostructured lipid carrier encapsulated FGF15 inhibits autophagy and improves recovery in spinal cord injury.

Gelatine nanostructured lipid carriers (GNLs) have attracted increasing attention due to their biodegradable status and capacity to capture various biologically active compounds. Many studies demonstrated that fibroblast growth factor therapies after spinal cord injury (SCI) can be used in the future for the recovery of neurons. In this study, the therapeutic effects of GNL-encapsulated fibroblast growth factor 15 (FGF15) and FGF15 were compared in SCI. The FGF15-GNLs had 88.17 ± 1.22% encapsulation efficiency and 4.82 ± 0.12% loading capacity. The effects of FGF15-GNLs and FGF15 were assessed based on the Basso-Beattie-Bresnahan (BBB) locomotion scale, inclined plane test and footprint analysis. Immunofluorescent staining was used to identify the expression of autophagy-associated proteins, GFAP (glial fibrillary acidic protein) and neurofilament 200 (NF200). FGF15-GNLs use enhanced the repair after SCI compared to the effect of FGF15. The suppression of autophagy-associated proteins LC3-II and beclin-1, and p62 enhancement by FGF15-GNLs treatment were more pronounced. Thus, the effects of FGF15-GNLs on the recovery after SCI are related to the inhibition of autophagy and glial scar, and promotion of nerve regeneration in SCI.

Nomograms Predict Overall Survival and Cancer-Specific Survival in Patients with Fibrosarcoma: A SEER-Based Study.

PURPOSE: Due to the rarity, it is difficult to predict the survival of patients with fibrosarcoma. This study aimed to apply a nomogram to predict survival outcomes in patients with fibrosarcoma. METHODS: A total of 2235 patients with diagnoses of fibrosarcoma were registered in the Surveillance, Epidemiology, and End Results database, of whom 663 patients were eventually enrolled. Univariate and multivariate Cox analyses were used to identify independent prognostic factors. Nomograms were constructed to predict 3-year and 5-year overall survival and cancer-specific survival of patients with fibrosarcoma. RESULTS: In univariate and multivariate analyses of OS, age, sex, race, tumor stage, pathologic grade, use of surgery, and tumor size were identified as independent prognostic factors. Age, sex, tumor stage, pathologic grade, use of surgery, and tumor size were significantly associated with CSS. These characteristics were further included to establish the nomogram for predicting 3-year and 5-year OS and CSS. For the internal validation of the nomogram predictions of OS and CSS, the C-indices were 0.784 and 0.801. CONCLUSION: We developed the nomograms that estimated 3-year and 5-year OS and CSS. These nomograms not only have good discrimination performance and calibration but also provide patients with better clinical benefits.

A Nomogram for Prediction of Postoperative Pneumonia Risk in Elderly Hip Fracture Patients.

PURPOSE: Pneumonia is one of the common complications of hip fracture. This study aimed to evaluate the risk factors and apply a nomogram to predict postoperative pneumonia in elderly hip fracture patients. MATERIALS AND METHODS: From August 2014 to October 2019, 1113 hip fracture patients who were older than 65 years and underwent surgical treatment in our hospital were subjects of this study. Univariate and multivariate Cox analyses were used to identify independent risk factors. A predictive nomogram model was built, and the discrimination and calibration were determined by receiver operating characteristic and calibration plot. RESULTS: A total of 166 patients developed pneumonia after operation (14.91%, pneumonia group) while the remaining 947 patients did not (85.09%, non-pneumonia group). According to the results, body mass index (OR, 0.76, 95% CI, 0.70 to 0.84, P<0.001), serum albumin (OR, 0.86, 95% CI, 0.79 to 0.93, P<0.001), c-reactive protein (OR, 1.01, 95% CI, 1.00 to 1.92, P=0.011), functional status (OR, 2.94, 95% CI, 1.69 to 5.10, P<0.001) and time to surgery (OR, 4.56, 95% CI, 2.64 to 7.88, P<0.001) were identified as independent risk factors of pneumonia. The area under the curve value for postoperative pneumonia risk was 0.905, and the P-value of the Hosmer-Lemeshow calibration test was 0.529. CONCLUSION: Our nomogram model can be used to predict the risk of pneumonia in elderly hip fractures after surgery and provide clinicians with guidance for better perioperative intervention to improve prognosis and reduce mortality.

CO-Releasing Molecule (CORM)-3 Ameliorates Spinal Cord-Blood Barrier Disruption Following Injury to the Spinal Cord.

Spinal cord injury (SCI) is a clinical tough neurological problem without efficient cure currently. Blood-spinal cord barrier (BSCB) interruption is not only a crucial pathological feature for SCI process but is a possible target for future SCI treatments; however, few treatments have been developed to intervene BSCB. In the present study, we intravenously injected CO-releasing molecule3 (CORM-3), a classical exogenous CO donor, to the rats experiencing SCI and assessed its protection on BSCB integrity in rats. Our results demonstrated that the exogenous increasing of CO by CORM-3 blocked the tight junction (TJ) protein degeneration and neutrophils infiltration, subsequently suppressed the BSCB damage and improved the motor recovery after SCI. And we certified that the CO-induced down-regulation of MMP-9 expression and activity in neutrophil might be associated with the NF-κB signaling. Taken together, our study indicates that CO-releasing molecule (CORM)-3 ameliorates BSCB after spinal cord injury.

Sitagliptin improves functional recovery via GLP-1R-induced anti-apoptosis and facilitation of axonal regeneration after spinal cord injury.

Axon growth and neuronal apoptosis are considered to be crucial therapeutic targets against spinal cord injury (SCI). Growing evidences have reported stimulation of glucagon-like peptide-1 (GLP-1)/GLP-1 receptor (GLP-1R) signalling axis provides neuroprotection in experimental models of neurodegeneration disease. Endogenous GLP-1 is rapidly degraded by dipeptidyl peptidase-IV (DPP4), resulting in blocking of GLP-1/GLP1R signalling process. Sitagliptin, a highly selective inhibitor of DPP4, has approved to have beneficial effects on diseases in which neurons damaged. However, the roles and the underlying mechanisms of sitagliptin in SCI repairing remain unclear. In this study, we used a rat model of SCI and PC12 cells/primary cortical neurons to explore the mechanism of sitagliptin underlying SCI recovery. We discovered the expression of GLP-1R decreased in the SCI model. Administration of sitagliptin significantly increased GLP-1R protein level, alleviated neuronal apoptosis, enhanced axon regeneration and improved functional recovery following SCI. Nevertheless, treatment with exendin9-39, a GLP-1R inhibitor, remarkably reversed the protective effect of sitagliptin. Additionally, we detected the AMPK/PGC-1α signalling pathway was activated by sitagliptin stimulating GLP-1R. Taken together, sitagliptin may be a potential agent for axon regrowth and locomotor functional repair via GLP-1R-induced AMPK/ PGC-1α signalling pathway after SCI.

Stabilization of HIF-1α alleviates osteoarthritis via enhancing mitophagy.

Mitochondrial dysfunction leads to osteoarthritis (OA) and disc degeneration. Hypoxia inducible factor-1α (HIF-1α) mediated mitophagy has a protective role in several diseases. However, the underlying mechanism of HIF-1α mediated mitophagy in OA remains largely unknown. This current study was performed to determine the effect of HIF-1α mediated mitophagy on OA. Therefore, X-ray and tissue staining including HE staining, safranin O-fast green (S-O) and Alcian Blue were used to assess imageology and histomorphology differences of mouse knee joint. Transcriptional analysis was used to find the possible targets in osteoarthritis. Western blot analysis, RT-qPCR and immunofluorescence staining were used to detect the changes in gene and protein levels in the vitro experiment. The expression of HIF-1α was increased in human and mouse OA cartilage. HIF-1α knockdown by siRNA further impair the hypoxia-induced mitochondrial dysfunction; In contrast, HIF-1α mediated protective role was reinforced by prolylhydroxylase (PHD) inhibitor dimethyloxalylglycine (DMOG). In addition, HIF-1α stabilization could alleviate apoptosis and senescence via mitophagy in chondrocytes under hypoxia condition, which could also ameliorate surgery-induced cartilage degradation in mice OA model. In conclusion, HIF-1α mediated mitophagy could alleviate OA, which may serve as a promising strategy for OA treatment.

Paeoniflorin promotes angiogenesis and tissue regeneration in a full-thickness cutaneous wound model through the PI3K/AKT pathway.

The treatment of wounds remains a clinical challenge because of poor angiogenesis under the wound bed, and increasingly, the patients' need for functional and aesthetically pleasing scars. For the wound healing process, new blood vessels which can deliver nutrients and oxygen to the wound area are necessary. In this study, we investigated the pro-angiogenesis ability and mechanism in wound healing of paeoniflorin (PF), which is a traditional Chinese medicine. In our in vitro results, the ability for proliferation, migration and in vitro angiogenesis in human umbilical vein endothelial cells was promoted by coculturing with PF (1.25-5 µM). Meanwhile, molecular docking studies revealed that PF has excellent binding abilities to phosphatidylinositol-3-kinase (PI3K) and protein kinase B (AKT), and consistent with our western blot results, that PF suppressed PI3K and AKT phosphorylation. Furthermore, to investigate the healing effect of PF in vivo, we constructed a full-thickness cutaneous wound model in rats. PF stimulated the cellular proliferation status, collagen matrix deposition and remodeling processes in vitro and new blood vessel formation at the wound bed resulting in efficient wound healing after intragastric administration of 10 mg·kg-1 ·day-1 in vivo. Overall, PF performed the pro-angiogenetic effect in vitro and accelerating wound healing in vivo. In summary, the capacity for angiogenesis in endothelial cells could be enhanced by PF treatment via the PI3K/AKT pathway in vitro and could accelerate the wound healing process in vivo through collagen deposition and angiogenesis in regenerated tissue. This study provides evidence that application of PF represents a novel therapeutic approach for the treatment of cutaneous wounds.

Identification and molecular characterization of a novel anti-lipopolysaccharide factor (ALF) from red swamp crayfish, Procambarus clarkii.

Anti-lipopolysaccharide factors are a group of small proteins with broad spectrum antiviral property and antibacterial activity. Herein, we obtained the genomic sequence of the Procambarus clarkii anti-lipopolysaccharide factor (PcALF) gene by using polymerase chain reaction to investigate its expression pattern in various tissues and in the immune tissues (Hepatopancreas) following exposure to pathogens. The deduced protein of PcALF was conserved; it displayed the signal peptides and putative lipo-polysaccharide binding domain, particularly the two conserved cysteine amino acid residues at both ends of the domain. The recombinant protein of PcALF was successfully expressed in Escherichia coli and rabbit anti-PcALF polyclonal antibodies were prepared. The qRT-PCR analysis showed unequal distribution of PcALF transcript in the examined tissues, however the transcript level was greatest in hepatopancreas. The challenge with peptidoglycan (PGN), lipo-polysaccharide (LPS) and Poly I:C significantly enhanced expression level of PcALF in hepatopancreas when compared with the PBS control. RNA interference of PcALF affected the mRNA expression levels of immune-related genes. Taken together, our data suggested that PcALF is an inducible protein and could play a key biological role in the innate immune defense of P. clarkii.