Establishment of an in vitro model of monocyte-like THP-1 cells for trained immunity induced by bacillus Calmette-Guérin.

BACKGROUND: Mycobacteria bloodstream infections are common in immunocompromised people and usually have disastrous consequences. As the primary phagocytes in the bloodstream, monocytes and neutrophils play critical roles in the fight against bloodstream mycobacteria infections. In contrast to macrophages, the responses of monocytes infected with the mycobacteria have been less investigated. RESULTS: In this study, we first established a protocol for infection of non-adherent monocyte-like THP-1 cells (i.e. without the differentiation induced by phorbol 12-myristate 13-acetate (PMA) by bacillus Calmette-Guérin (BCG). Via the protocol, we were then capable of exploring the global transcriptomic profiles of non-adherent THP-1 cells infected with BCG, and found that NF-κB, MAPK and PI3K-Akt signaling pathways were enhanced, as well as some inflammatory chemokine/cytokine genes (e.g. CCL4, CXCL10, TNF and IL-1ß) were up-regulated. Surprisingly, the Akt-HIF-mTOR signaling pathway was also activated, which induces trained immunity. In this in vitro infection model, increased cytokine responses to lipopolysaccharides (LPS) restimulation, higher cell viability, and decreased Candida albicans loads were observed. CONCLUSIONS: We have first characterized the transcriptomic profiles of BCG-infected non-adherent THP-1 cells, and first developed a trained immunity in vitro model of the cells.

Multi-omics analysis reveals that linoleic acid metabolism is associated with variations of trained immunity induced by distinct BCG strains.

Trained immunity is one of the mechanisms by which BCG vaccination confers persistent nonspecific protection against diverse diseases. Genomic differences between the different BCG vaccine strains that are in global use could result in variable protection against tuberculosis and therapeutic effects on bladder cancer. In this study, we found that four representative BCG strains (BCG-Russia, BCG-Sweden, BCG-China, and BCG-Pasteur) covering all four genetic clusters differed in their ability to induce trained immunity and nonspecific protection. The trained immunity induced by BCG was associated with the Akt-mTOR-HIF1α axis, glycolysis, and NOD-like receptor signaling pathway. Multi-omics analysis (epigenomics, transcriptomics, and metabolomics) showed that linoleic acid metabolism was correlated with the trained immunity-inducing capacity of different BCG strains. Linoleic acid participated in the induction of trained immunity and could act as adjuvants to enhance BCG-induced trained immunity, revealing a trained immunity-inducing signaling pathway that could be used in the adjuvant development.

Mussel inspired sequential protein delivery based on self-healing injectable nanocomposite hydrogel.

Polysaccharide based self-healing and injectable hydrogels with reversible characteristics have widespread potential in protein drug delivery. However, it is a challenge to design the dynamic hydrogel for sequential release of protein drugs. Herein, we developed a novel mussel inspired sequential protein delivery dynamic polysaccharide hydrogel. The nanocomposite hydrogel can be fabricated through doping polydopamine nanoparticles (PDA NPs) into reversible covalent bond (imine bonds) crosslinked polymer networks of oxidized hyaluronic acid (OHA) and carboxymethyl chitosan (CEC), named PDA NPs@OHA-l-CEC. Besides multiple capabilities (i.e., injection, self-healing, and biodegradability), the nanocomposite hydrogel can achieve sustained and sequential protein delivery of vascular endothelial growth factor (VEGF) and bovine serum albumin (BSA). PDA NPs doped in hydrogel matrix serve dual roles, acting as secondary protein release structures and form dynamic non-covalent interactions (i.e., hydrogen bonds) with polysaccharides. Moreover, by adjusting the oxidation degree of OHA, the hydrogels with different crosslinking density could control overall protein release rate. Analysis of different release kinetic models revealed that Fickian diffusion drove rapid VEGF release, while the slower BSA release followed a Super Case II transport mechanism. The novel biocompatible system achieved sequential release of protein drugs has potentials in multi-stage synergistic drug deliver based on dynamic hydrogel.

Pathogen-induced methylglyoxal negatively regulates rice bacterial blight resistance by inhibiting OsCDR1 protease activity.

Xanthomonas oryzae pv. oryzae (Xoo) causes bacterial blight (BB), a globally devastating disease of rice (Oryza sativa) that is responsible for significant crop loss. Sugars and sugar metabolites are important for pathogen infection, providing energy and regulating events associated with defense responses; however, the mechanisms by which they regulate such events in BB are unclear. As an inevitable sugar metabolite, methylglyoxal (MG) is involved in plant growth and responses to various abiotic stresses, but the underlying mechanisms remain enigmatic. Whether and how MG functions in plant biotic stress responses is almost completely unknown. Here, we report that the Xoo strain PXO99 induces OsWRKY62.1 to repress transcription of OsGLY II genes by directly binding to their promoters, resulting in overaccumulation of MG. MG negatively regulates rice resistance against PXO99: osglyII2 mutants with higher MG levels are more susceptible to the pathogen, whereas OsGLYII2-overexpressing plants with lower MG content show greater resistance than the wild type. Overexpression of OsGLYII2 to prevent excessive MG accumulation confers broad-spectrum resistance against the biotrophic bacterial pathogens Xoo and Xanthomonas oryzae pv. oryzicola and the necrotrophic fungal pathogen Rhizoctonia solani, which causes rice sheath blight. Further evidence shows that MG reduces rice resistance against PXO99 through CONSTITUTIVE DISEASE RESISTANCE 1 (OsCDR1). MG modifies the Arg97 residue of OsCDR1 to inhibit its aspartic protease activity, which is essential for OsCDR1-enhanced immunity. Taken together, these findings illustrate how Xoo promotes infection by hijacking a sugar metabolite in the host plant.

Construction of photo-responsive lignin as a broad-spectrum sunscreen agent.

Lignin has potential to serve as promising sunscreen agents as it has good ultraviolet (UV) absorption and antioxidant properties. However, the weak absorption capacity of lignin in the long-wave UV region (UVA, 320-400 nm) limits its further development. In this work, a spiropyran-modified lignin (DLSP) with photo-responsive property was prepared by in-situ construction of spiropyran (SP) structure in the demethylated lignin (DL). Due to the presence of SP moiety, the absorption of DLSP in the UVA region was significantly improved. Under UV irradiation, its absorption peak was redshifted as unconjugated SP form isomerized to conjugated merocyanine (MC) form, and the UVA/UVB ratio increased from 0.62 to 0.74. The free-radical scavenging ability of lignin could protect SP from photodegradation, which provided DLSP excellent fatigue resistance. DLSP were blended into creams to investigate its sunscreen performance. Results indicated that DLSP exhibited radiation-enhanced sunscreen performance, the sun protection factor (SPF) of cream containing 10 wt% of DLSP improved from 20 to 67 after 8 h of UV irradiation. Moreover, DLSP showed low skin penetration and good biocompatibility. These results provide a useful guideline for the rational design of sunscreens with special functionalities.

Discovery of novel 2,3,4,5-tetrahydrospiro[benzo[c]azepine-1,1'-cyclohexan]-5-ol derivatives as PARP-1 inhibitors.

As an essential marker of cancer treatment, PARP-1 inhibitors could effectively kill tumor cells through a mechanism known as synthetic lethality and are used to treat a variety of cancers. In order to explore novel PARP-1 inhibitors, a series of 22 novel erythrina derivatives were reported and preliminarily explored their mechanism of action. The antitumor activities against four human cancer cell lines including A549, OVCAR-3, HCT-116, and MCF-7 were evaluated, and the preliminary SARs were summarized. Among them, compound 11b exhibited better anti-proliferative effects against A549 cells (IC50 = 1.95 µM). The SI results showed that compound 11b had low toxicity. Moreover, compound 11b displayed excellent PARP-1 inhibitory activities with IC50 values of 19.24 nM. In addition, molecular docking studies provided the rational binding modes of compound 11b in complexes with PARP-1. The flow cytometry assays revealed that compound 11b could induce apoptosis of A549 cells (P < 0.001). Simultaneously, compound 11b could effectively reduce the formation of PAR (P < 0.001). The ADMET prediction results indicated compound 11b had similar properties to rucaparib. Collectively, compound 11b has potential research value for further investigation.

Renin-angiotensin system inhibitors improve the survival of cholangiocarcinoma: a propensity score-matched cohort study.

BACKGROUND: Hypertension is a risk factor for cholangiocarcinoma (CCA). The effect of anti-hypertensive drugs on the prognosis of CCA is not clear. METHODS: This is a retrospective study of 102 patients (56.9% males, median age 66 years) diagnosed with CCA and hypertension concurrently and received radical surgery (R0), with a median follow-up of 36.7 months. Kaplan-Meier analysis, Cox regressions, and propensity score (PS) matching were applied for statistical analysis. RESULTS: Results of multivariable cox analysis showed that renin-angiotensin system inhibitors (RASis) usage was a protective factor for progression-free survival (PFS) (hazard ratio [HR] = 0.55, 95% confidence interval [95% CI]: 0.32-0.96) and overall survival (OS) (HR = 0.40, 95% CI: 0.20-0.79), respectively. Calcium channel blockers, diuretics, and ß-blockers didn't show significant associations. The association of RASis usage and PFS and OS was derived by PS matching, with a cohort of 28 RASis users and 56 RASis non-users. The median PFS and OS of RASis users (PFS, 17.6 months (9.2-34.4); OS, 24.8 months (16.5-42.3)) were longer than RASis non-users (PFS, 10.5 months (4.1-24.1); OS, 14.6 months (10.6-28.4)). The 1 year, 2 years, and 3 years' survival rates of RASis users (89.1%, 77.0%, and 65.5%) were higher than RASis non-users (70.9%, 54.0%, and 40.0%). CONCLUSIONS: RASis usage improves the survival of patients with CCA and hypertension concurrently.

Complete chloroplast genome of Lonicera ligustrina Wall. (Caprifoliaceae) and its phylogenetic implications.

Lonicera ligustrina is a folk medicinal herb in China and India with highly potential medicinal value. Here, we reported the complete chloroplast (cp) genome of L. ligustrina (GenBank accession number: ON968694). The cp genome was 155,330 bp long, with a large single-copy region (LSC) of 88,855 bp and a small single-copy region (SSC) of 18,647 bp separated by a pair of inverted repeats (IRs) of 23,914 bp. We also reconstructed the phylogeny of Lonicera using maximum likelihood (ML) method, including our data and previously reported cp genomes of related taxa. The current study indicated that L. ligustrina is sister with the Nintooa clade of subgen. Lonicera.

[Esophageal Angiolipoma:Report of One Case and Literature Review].

Esophageal angiolipoma is a rare disease with unspecific clinical manifestations.This paper reported a case of esophageal angiolipoma confirmed by upper gastrointestinal endoscopy and summarized the clinical manifestations,endoscopic and pathological features,treatment and prognosis of the patients by reviewing the relevant literature,aiming to provide references for clinical diagnosis and treatment of this disease in the future.

SUMO specific peptidase 3 halts pancreatic ductal adenocarcinoma metastasis via deSUMOylating DKC1.

In the past few decades, advances in the outcomes of patients suffering from pancreatic ductal adenocarcinoma (PDAC) have lagged behind these gained in the treatment of many other malignancies. Although the pivotal role of the SUMO pathway in PDAC has been illustrated, the underlying molecule drivers have yet to be fully elucidated. In the present study, we identified SENP3 as a potential suppressor of PDAC progression through an in vivo metastatic model. Further studies revealed that SENP3 inhibited PDAC invasion in a SUMO system dependent fashion. Mechanistically, SENP3 interacted with DKC1 and, as such, catalyzed the deSUMOylation of DKC1, which accepted SUMO3 modifiers at three lysine residues. SENP3-mediated deSUMOylation caused DKC1 instability and disruption of the interaction between snoRNP proteins, which contributed to the impaired migration ability of PDAC. Indeed, overexpression of DKC1 abated the anti-metastasis effect of SENP3, and DKC1 was elevated in PDAC specimens and associated with a poor prognosis in PDAC patients. Collectively, our findings shed light on the essential role of SENP3/DKC1 axis in the progression of PDAC.

Angiotensin receptor blockers retard the progression and fibrosis via inhibiting the viability of AGTR1+ CAFs in intrahepatic cholangiocarcinoma.

BACKGROUND: Intrahepatic cholangiocarcinoma (iCCA) is a highly lethal malignancy characterized by massive fibrosis and has ineffective adjuvant therapies. Here, we demonstrate the potential of angiotensin receptor blockers (ARBs) in targeting iCCA. METHODS: Masson's trichrome staining was used to assess the effect of ARBs in iCCA specimens, CCK8 and gel contraction assays in vitro and in xenograft models in vivo. RNA-seq and ATAC-seq were used for mechanistic investigations. RESULTS: Patients with iCCA who were administered ARBs had a better prognosis and a lower proportion of tumour stroma, indicating alleviated fibrosis. The presence of AGTR1, the ARBs receptor, is associated with a poor prognosis of iCCA and is highly expressed in tumour tissues and cancer-associated fibroblasts (CAFs). The ARBs strongly attenuated the viability of AGTR1+ CAFs in vitro and retarded tumour progression and fibrosis in xenograft models of co-cultured CAFs and iCCA cells. Still, they did not have a significant effect on AGTR1- CAFs. Moreover, ARBs decreased the secretion of AGTR1+ CAF-derived MFAP5 via the Hippo pathway, weakened the interaction between CAFs and iCCA cells, and impaired the aggressiveness of iCCA cells by attenuating the activation of the Notch1 pathway in iCCA cells. CONCLUSIONS: ARBs exhibit anti-fibrotic function by inhibiting the viability of AGTR1+ CAFs. These findings support using ARBs as a novel therapeutic option for targeting iCCA.

Involvement of miR-495 overexpression in the pathogenesis of bronchopulmonary dysplasia in preterm infants via the targeting of NEDD4L-ENaC pathway.

Background: Bronchopulmonary dysplasia (BPD) is a severe pulmonary complication causing morbidity and mortality in preterm infants. A key histopathological feature of BPD is late lung growth retardation, in which the process of alveolarization is hindered and the mechanism of which is unclear. Emerging evidence indicates that microRNAs (miRNAs) promote the development of BPD via the inhibition of their target genes. MiR-495 has been reported to be involved in various lung diseases. However, the physiological function of miR-495 in BPD has not yet been fully understood. Methods: Differentially expressed miRNAs in peripheral blood of patients with BPD were compared with those of normal controls. A dual-luciferase reporter assay was performed to identify the target genes of miR-495. A BPD neonatal rat model was established by injecting lipopolysaccharide (LPS) in the amniotic sac of pregnant rats. The morphology of the lungs was observed using hematoxylin and eosin (HE) staining. The expression of miR-495, neural precursor cell expressed developmentally down-regulated 4-like (NEDD4L), and epithelial Na+ channel (ENaC) was tested using quantitative reverse transcription-polymerase chain reaction (qRT-PCR), Western blot analysis, and immunofluorescent (IF) staining. Results: The expression of miR-495 was significantly increased in the peripheral blood samples of premature infants with BPD and verified using qRT-PCR. NEDD4L was proven to be the target gene of miR-495. Additionally, miR-495 expression was also increased in the lungs of rat pups with BPD at postnatal day (P) 3 compared with the control group. qRT-PCR and Western blot results showed that NEDD4L expression was decreased while ENaC expression was increased at the transcriptional and translational levels. IF staining results showed that NEDD4L level was decreased while ENaC level was increased in the LPS-induced BPD rat model, which was consistent with abnormal changes in alveolar structure. Conclusions: The aberrant overexpression of miR-495 may contribute to the development of BPD by targeting NEDD4L-ENaC pathway, implying an imbalance in lung fluid clearance.

Bacterial infection promotes tumorigenesis of colorectal cancer via regulating CDC42 acetylation.

Increasing evidence highlights the role of bacteria in promoting tumorigenesis. The underlying mechanisms may be diverse and remain poorly understood. Here, we report that Salmonella infection leads to extensive de/acetylation changes in host cell proteins. The acetylation of mammalian cell division cycle 42 (CDC42), a member of the Rho family of GTPases involved in many crucial signaling pathways in cancer cells, is drastically reduced after bacterial infection. CDC42 is deacetylated by SIRT2 and acetylated by p300/CBP. Non-acetylated CDC42 at lysine 153 shows an impaired binding of its downstream effector PAK4 and an attenuated phosphorylation of p38 and JNK, consequently reduces cell apoptosis. The reduction in K153 acetylation also enhances the migration and invasion ability of colon cancer cells. The low level of K153 acetylation in patients with colorectal cancer (CRC) predicts a poor prognosis. Taken together, our findings suggest a new mechanism of bacterial infection-induced promotion of colorectal tumorigenesis by modulation of the CDC42-PAK axis through manipulation of CDC42 acetylation.

Combining Bone Collagen Material with hUC-MSCs for Applicationto Spina Bifida in a Rabbit Model.

Spina bifida is one of the neural tube defects, with a high incidence in human birth defects, which seriously affects the health and quality of life of patients. In the treatment of bone defects, the source of autologous bone is limited and will cause secondary damage to the patient. At the same time, since the bone tissue in animals needs to play a variety of biological functions, its complex structure cannot be replaced by a single material. The combination of mechanical materials and biological materials has become a common choice. Human umbilical cord mesenchymal stem cells (hUC-MSCs) have the advantages of easy access, rapid proliferation, low immunogenicity, and no ethical issues. It is often used in the clinical research of tissue regeneration and repair. Therefore, in this study, we established a spina bifida model using Japanese white rabbits. This model was used to screen the best regenerative repair products for congenital spina bifida, and to evaluate the safety of regenerative repair products. The results showed that the combination of hUC-MSCs with collagen material had better regeneration effect than collagen material alone, and had no negative impact on the health of animals. This study provides a new idea for the clinical treatment of spina bifida, and also helps to speed up the research progress of regenerative repair products.

Salt stress-induced chloroplastic hydrogen peroxide stimulates pdTPI sulfenylation and methylglyoxal accumulation.

High salinity, an adverse environmental factor affecting about 20% of irrigated arable land worldwide, inhibits plant growth and development by causing oxidative stress, damaging cellular components, and disturbing global metabolism. However, whether and how reactive oxygen species disturb the metabolism of salt-stressed plants remain elusive. Here, we report that salt-induced hydrogen peroxide (H2O2) inhibits the activity of plastid triose phosphate isomerase (pdTPI) to promote methylglyoxal (MG) accumulation and stimulates the sulfenylation of pdTPI at cysteine 74. We also show that MG is a key factor limiting the plant growth, as a decrease in MG levels completely rescued the stunted growth and repressed salt stress tolerance of the pdtpi mutant. Furthermore, targeting CATALASE 2 into chloroplasts to prevent salt-induced overaccumulation of H2O2 conferred salt stress tolerance, revealing a role for chloroplastic H2O2 in salt-caused plant damage. In addition, we demonstrate that the H2O2-mediated accumulation of MG in turn induces H2O2 production, thus forming a regulatory loop that further inhibits the pdTPI activity in salt-stressed plants. Our findings, therefore, illustrate how salt stress induces MG production to inhibit the plant growth.

Exosome is involved in liver graft protection after remote ischemia reperfusion conditioning.

BACKGROUND: Remote ischemic perconditioning (RIPerC) has been demonstrated to protect grafts from hepatic ischemia-reperfusion injury (IRI). This study investigated the role of exosomes in RIPerC of liver grafts in rats. METHODS: Twenty-five rats (including 10 donors) were randomly divided into five groups (n = 5 each group): five rats were used as sham-operated controls (Sham), ten rats were for orthotopic liver transplantation (OLT, 5 donors and 5 recipients) and ten rats were for OLT + RIPerC (5 donors and 5 recipients). Liver architecture and function were evaluated. RESULTS: Compared to the OLT group, the OLT + RIPerC group exhibited significantly improved liver graft histopathology and liver function (P < 0.05). Furthermore, the number of exosomes and the level of P-Akt were increased in the OLT + RIPerC group. CONCLUSIONS: RIPerC effectively improves graft architecture and function, and this protective effect may be related to the increased number of exosomes. The upregulation of P-Akt may be involved in underlying mechanisms.

Combining Bone Collagen Matrix with hUC-MSCs for Application to Alveolar Process Cleft in a Rabbit Model.

BACKGROUND: Most materials used clinically for filling severe bone defects either cannot induce bone re-generation or exhibit low bone conversion, therefore, their therapeutic effects are limited. Human umbilical cord mesenchymal stem cells (hUC-MSCs) exhibit good osteoinduction. However, the mechanism by which combining a heterogeneous bone collagen matrix with hUC-MSCs to repair the bone defects of alveolar process clefts remains unclear. METHODS: A rabbit alveolar process cleft model was established by removing the bone tissue from the left maxillary bone. Forty-eight young Japanese white rabbits (JWRs) were divided into normal, control, material and MSCs groups. An equal volume of a bone collagen matrix alone or combined with hUC-MSCs was implanted in the defect. X-ray, micro-focus computerized tomography (micro-CT), blood analysis, histochemical staining and TUNEL were used to detect the newly formed bone in the defect area at 3 and 6 months after the surgery. RESULTS: The bone formation rate obtained from the skull tissue in MSCs group was significantly higher than that in control group at 3 months (P < 0.01) and 6 months (P < 0.05) after the surgery. The apoptosis rate in the MSCs group was significantly higher at 3 months after the surgery (P < 0.05) and lower at 6 months after the surgery (P < 0.01) than those in the normal group. CONCLUSIONS: Combining bone collagen matrix with hUC-MSCs promoted the new bone regeneration in the rabbit alveolar process cleft model through promoting osteoblasts formations and chondrocyte growth, and inducing type I collagen formation and BMP-2 generation.

[Clinical efficacy of Manlyman Spray combined with biofeedback therapy on premature ejaculation].

Objective： To observe the clinical effect of Manlyman Spray combined with biofeedback therapy in the treatment of premature ejaculation (PE)．Methods： A total of 60 primary premature ejaculation patients with stable sexual partners and regular sexual activity (≥１ times per week) from April 2021 to October 2022 were involved in the clinical observation, The patients' age is (34.3 ± 4.9) years old, and the course of the disease is (112.5 ± 65.5) months, and Manlyman Spray combined with biofeedback therapy was used to treat patients for 8 weeks. Manlyman Spray was sprayed 3 times on the surface of the penisqd for 4 weeks, and Biofeedback therapy is treated twice a week according to the AI setting module, for a total of 8 weeks. Before and 8 weeks after medication and at 4 weeks after drug withdrawal, the Intravaginal Ejaculation Latency Time (IELT), Premature Ejaculation Diagnostic Tool (PEDT) scores and Clinical Global Impression of Change (CGIC) scores were Obtained and compared. Results： After 8 weeks of treatment, the IELT of the patients was significantly prolonged (ï¼»351.4 ± 76.7ï¼½ vs ï¼»87 ± 16.8ï¼½,P<0.05) and at 4 weeks after drug withdrawal, the therapeutic effect still existed (ï¼»345.9 ± 80.3ï¼½ vs ï¼»87 ± 16.8ï¼½,P<0.05), the PEDT scores were significantly improved after treatment (ï¼»18.2 ± 1.1ï¼½ vs ï¼»9.0 ± 1.4ï¼½,P<0.05)and at 4 weeks after drug withdrawal(ï¼»18.0 ± 1.2ï¼½ vs ï¼»9.0 ± 1.4ï¼½,P<0.05), and so were the CGIC scores (ï¼»13.4 ± 1.3ï¼½ vs ï¼»3.3 ± 1.4ï¼½,P<0.05, and ï¼»12.6 ± 1.6ï¼½ vs ï¼»3.3 ± 1.4ï¼½,P<0.05). Conclusion： The combination of Manlyman Spray and biofeedback therapy can effectively treat primary premature ejaculation, with a long duration of treatment and good safety, and the specific mechanism needs further study.

Values of a novel pyroptosis-related genetic signature in predicting outcome and immune status of pancreatic ductal adenocarcinoma.

Background: Pyroptosis is an emerging form of programmed cell death associated with progression in malignancies. Yet, there are few studies reporting on the association between pancreatic ductal adenocarcinoma (PDAC) and pyroptosis. Therefore, we aimed to construct a pyroptosis-related genetic signature to predict the clinical outcome and immune status in PDAC patients. Methods: RNA-seq data of 176 PDAC patients from The Cancer Genome Atlas (TCGA) and 167 PDAC patients from the Genotype-Tissue Expression Project were analysed for pyroptosis-related differentially expressed genes (DEGs) between PDAC and normal pancreas. The risk signature of DEGs was analysed using the least absolute shrinkage and selection operator (LASSO) Cox regression analysis and its accuracy was validated in the Gene Expression Omnibus (GEO) cohort (n = 190). Functional enrichment analyses were performed to explore the mechanisms of the DEGs. The immune characteristics were evaluated using single-sample gene set enrichment analysis and ESTIMATE algorithms for each group. Results: A nine-gene risk signature was generated from LASSO Cox regression analysis and classified PDAC patients into either a high- or low-risk group according to the median risk score. The high-risk group had significantly shorter overall survival than the low-risk group and it was verified in the external GEO database. A nomogram based on the risk signature was constructed and showed an ideal prediction performance. Functional enrichment analyses revealed that pyroptosis might regulate the tumor immune microenvironment in PDAC. Immune infiltration evaluation suggested that immune status was more activated in the low-risk group than in the high-risk group. Conclusion: The risk signature encompassing nine pyroptosis-related genes may be a prognostic marker for PDAC. Pyroptosis might affect the prognosis of PDAC patients via regulating the tumor immune microenvironment.