ObjectivePancreatic ductal adenocarcinoma (PDAC) exhibits a limited response to current treatments due to its dense fibrotic stroma and highly immunosuppressive tumor microenvironment. In recent years, advancements in cellular immunotherapy, particularly chimeric antigen receptor macrophage (CAR-M) therapy, have offered new hope for pancreatic cancer treatment. Although CAR-M therapy demonstrates dual potential in directly killing tumor cells and remodeling the immune microenvironment, it still faces challenges such as complex in vitro preparation processes and low in vivo targeting and delivery efficiency. Therefore, developing strategies for efficient and targeted in vivo delivery of CAR genes has become crucial for overcoming current therapeutic limitations. This study aims to develop an orally administrable nano-gene delivery system for the targeted delivery of CAR genes to pancreatic tumor sites. MethodsCore nano-gene particles (PNP/pCAR) were constructed by loading plasmid DNA encoding CAR (pCAR) with cationic polypeptides (PNP). Subsequently, PNP/pCAR was surface-modified with β-glucan to prepare the targeted nanoparticles (βGlus-PNP/pCAR). The loading efficiency of PNP for pCAR was quantitatively assessed by gel retardation assay. The particle size, Zeta potential, morphology, and storage stability of PNP/pCAR were characterized using a Malvern particle size analyzer and transmission electron microscopy. At the cellular level, RAW 264.7 macrophages were selected. The cytotoxicity of PNP/pCAR was evaluated using the CCK-8 assay. The cellular uptake efficiency and lysosomal escape ability of the nanoparticles were assessed via flow cytometry and confocal microscopy. Transfection efficiency was quantitatively evaluated by detecting the expression of the reporter gene GFP using flow cytometry. At the in vivo level, an orthotopic pancreatic cancer mouse model was established. Cy7-labeled βGlus-PNP/pCAR nanoparticles were administered orally, and the fluorescence distribution in mice was dynamically monitored at 1, 2, 4, 8, and 16 h post-administration using a small animal in vivo imaging system. Forty-eight hours after oral gavage, the mice were euthanized, and pancreatic tumor tissues were collected for further analysis of intratumoral fluorescence signals using the imaging system. Additionally, βGlus-PNP/pCAR-GFP nanoparticles loaded with the reporter gene (GFP) were administered orally. Forty-eight hours post-administration, pancreatic tumor tissues were harvested to prepare frozen sections, and GFP expression was observed and analyzed under a fluorescence microscope. ResultsThe PNP carrier exhibited a high loading capacity for pCAR. The successfully prepared PNP/pCAR nanoparticles were regular spheres with a hydrodynamic diameter of approximately (120±10) nm and a Zeta potential of about +(6±1) mV. They maintained good structural stability after incubation in PBS buffer for 7 d. Cell experiments demonstrated that PNP/pCAR exhibited no significant cytotoxicity in RAW 264.7 cells while being efficiently internalized and effectively escaping lysosomal degradation. The transfection positive rate of PNP/pCAR-GFP in RAW 264.7 cells reached (25±3)%, surpassing that of Lipofectamine 2000-loaded pCAR-GFP (Lipo/pCAR-GFP), which was (20±1)%.In vivo experiments revealed that, compared to unmodified PNP/pCAR, βGlus-PNP/pCAR exhibited strongerin situ pancreatic tumor targeting ability after oral administration. Furthermore, oral administration of βGlus-PNP/pCAR-GFP resulted in significant GFP protein expression detectable within pancreatic tumor tissues. ConclusionThis study successfully constructed and validated an orally administrable, pancreatic cancer-targeting polypeptide-based nano-gene delivery system. It provides an important technological foundation in delivery systems and experimental basis for the subsequent development of in situ CAR-M-based therapeutic strategies for pancreatic cancer.

ObjectivePancreatic ductal adenocarcinoma (PDAC) exhibits a limited response to current treatments due to its dense fibrotic stroma and highly immunosuppressive tumor microenvironment. In recent years, advancements in cellular immunotherapy, particularly chimeric antigen receptor macrophage (CAR-M) therapy, have offered new hope for pancreatic cancer treatment. Although CAR-M therapy demonstrates dual potential in directly killing tumor cells and remodeling the immune microenvironment, it still faces challenges such as complex in vitro preparation processes and low in vivo targeting and delivery efficiency. Therefore, developing strategies for efficient and targeted in vivo delivery of CAR genes has become crucial for overcoming current therapeutic limitations. This study aims to develop an orally administrable nano-gene delivery system for the targeted delivery of CAR genes to pancreatic tumor sites. MethodsCore nano-gene particles (PNP/pCAR) were constructed by loading plasmid DNA encoding CAR (pCAR) with cationic polypeptides (PNP). Subsequently, PNP/pCAR was surface-modified with β-glucan to prepare the targeted nanoparticles (βGlus-PNP/pCAR). The loading efficiency of PNP for pCAR was quantitatively assessed by gel retardation assay. The particle size, Zeta potential, morphology, and storage stability of PNP/pCAR were characterized using a Malvern particle size analyzer and transmission electron microscopy. At the cellular level, RAW 264.7 macrophages were selected. The cytotoxicity of PNP/pCAR was evaluated using the CCK-8 assay. The cellular uptake efficiency and lysosomal escape ability of the nanoparticles were assessed via flow cytometry and confocal microscopy. Transfection efficiency was quantitatively evaluated by detecting the expression of the reporter gene GFP using flow cytometry. At the in vivo level, an orthotopic pancreatic cancer mouse model was established. Cy7-labeled βGlus-PNP/pCAR nanoparticles were administered orally, and the fluorescence distribution in mice was dynamically monitored at 1, 2, 4, 8, and 16 h post-administration using a small animal in vivo imaging system. Forty-eight hours after oral gavage, the mice were euthanized, and pancreatic tumor tissues were collected for further analysis of intratumoral fluorescence signals using the imaging system. Additionally, βGlus-PNP/pCAR-GFP nanoparticles loaded with the reporter gene (GFP) were administered orally. Forty-eight hours post-administration, pancreatic tumor tissues were harvested to prepare frozen sections, and GFP expression was observed and analyzed under a fluorescence microscope. ResultsThe PNP carrier exhibited a high loading capacity for pCAR. The successfully prepared PNP/pCAR nanoparticles were regular spheres with a hydrodynamic diameter of approximately (120±10) nm and a Zeta potential of about +(6±1) mV. They maintained good structural stability after incubation in PBS buffer for 7 d. Cell experiments demonstrated that PNP/pCAR exhibited no significant cytotoxicity in RAW 264.7 cells while being efficiently internalized and effectively escaping lysosomal degradation. The transfection positive rate of PNP/pCAR-GFP in RAW 264.7 cells reached (25±3)%, surpassing that of Lipofectamine 2000-loaded pCAR-GFP (Lipo/pCAR-GFP), which was (20±1)%.In vivo experiments revealed that, compared to unmodified PNP/pCAR, βGlus-PNP/pCAR exhibited strongerin situ pancreatic tumor targeting ability after oral administration. Furthermore, oral administration of βGlus-PNP/pCAR-GFP resulted in significant GFP protein expression detectable within pancreatic tumor tissues. ConclusionThis study successfully constructed and validated an orally administrable, pancreatic cancer-targeting polypeptide-based nano-gene delivery system. It provides an important technological foundation in delivery systems and experimental basis for the subsequent development of in situ CAR-M-based therapeutic strategies for pancreatic cancer.

Neurocritical care involves complex pathophysiological mechanisms, and its incidence is higher, injuries are more severe, and treatment is more challenging in high-altitude environments. This consensus, based on the latest domestic and international evidence-based medical data, establishes a standardized, goal-oriented framework for neurocritical care management applicable in high-altitude regions and nationwide. The consensus was developed following international standards for evidence quality assessment and underwent two rounds of Delphi expert consultation, resulting in 32 recommendation statements covering three parts: management systems, monitoring and assessment, and core strategies. Key updates include: advocating for the establishment of independent neurocritical care units and implementing precise tiered diagnosis and treatment based on the "Five Differences in Critical Care" concept; constructing a "trinity" multimodal brain monitoring system centered on cerebral blood flow, cerebral oxygenation, and brain function, emphasizing routine bedside transcranial Doppler ultrasound, cerebral oximetry, and continuous electroencephalography monitoring; shifting management strategies from mild hypothermia therapy to targeted temperature management, and defining the "446" target management pathway for the supercritical stage; emphasizing the assessment of static and dynamic cerebrovascular autoregulation functions through multimodal methods to achieve individualized optimal mean arterial pressure management; elevating cerebrospinal fluid management goals to the level of "glymphatic system" function maintenance; implementing a multidisciplinary collaborative, whole-process management model focusing on patients' long-term neurological functional outcomes; de-escalation criteria include multidimensional indicators such as recovery of brain structure, restoration of cerebrovascular autoregulation, improvement in cerebrospinal fluid dynamics, and reduction in biomarker levels; and integrating cutting-edge technologies like artificial intelligence into post-critical care management and rehabilitation planning. This consensus systematically integrates the entire process of neurocritical care management, reflecting the modern connotation of goal-oriented, dynamic, and multimodal integration in neurocritical care medicine. It aims to adapt to new trends such as deepening understanding of pathophysiological mechanisms, the integration of medicine and engineering, and the empowerment of artificial intelligence, thereby further advancing the discipline of critical care medicine.

Background Regulatory interactions between microRNAs (miRNAs) and messenger RNAs (mRNAs) are involved in the progression of pulmonary fibrosis, which can either promote or inhibit the development of this disease. Objective To explore the miRNA-mRNA regulatory network during the progression of silica (SiO₂)-induced pulmonary fibrosis in mice using integrated mRNA-seq and miRNA-seq analysis. Methods A mouse model of pulmonary fibrosis was established by dynamic SiO₂ dust exposure. The experimental design included a blank control group and four SiO₂-exposed groups (7, 14, 28, and 56 d, n=10 per group). Successful model induction was confirmed by histopathological analysis (HE and Masson staining), hydroxyproline (HYP) quantification, and expression of key fibrosis-related cytokines [fibroblast growth factor (FGF), interleukin-6 (IL-6), transforming growth factor-β (TGF-β), and tumor necrosis factor-α (TNF-α)]. Lung tissues from mice in each group were subjected to sequencing, and Mfuzz was used for time-series gene clustering to identify dynamic progression patterns. DESeq2 was utilized to identify differentially expressed genes (DEGs) and differentially expressed miRNAs. Enrichment analysis of DEGs was performed to identify critical signaling pathways and biological processes underlying pulmonary fibrosis progression. Expression of four selected miRNAs was subsequently validated by real-time quantitative polymerase chain reaction (RT-qPCR). The target mRNAs of key miRNAs were comprehensively predicted by integrating miRBase, starBase, and miRTarBase to construct the regulatory networks and investigate potential functions. Results SiO₂ exposure led to time-dependent aggravation of pulmonary fibrosis in mice, evidenced by increased fibrous deposition, elevated HYP levels (P < 0.01), and up-regulation of four kinds of pro-fibrotic cytokines (P < 0.01) compared with the NT group. Mfuzz clustering revealed the stage-specific characteristics. Compared to controls, 231, 662, 448, and 1020 DEGs were identified after SiO₂ exposure at 7, 14, 28, and 56 d, respectively, primarily enriched in immune responses and chemokine signaling. During critical fibrotic phases—7 d (acute inflammation and initiation) and 28 d (chronic inflammation and establishment)—18 differentially expressed miRNAs were identified; notably mmu-miR-135b-5p was significantly dysregulated at both time points. The expression trends of the four key miRNAs (mmu-miR-135b-5p, mmu-miR-708-5p, mmu-miR-21a-3p, and mmu-miR-205-5p) were consistent with the sequencing results. Furthermore, bioinformatics databases were used to predict the target mRNAs of key miRNAs. The constructed network highlighted critical miRNA-mRNA pairs—including mmu-miR-135b-5p and Meis1, mmu-miR-708-5p and Mmp25, mmu-miR-21a-3p and Cacna1d, mmu-miR-205-5p and Ereg which were closely associated with inflammatory response, extracellular matrix deposition, and fibroblast activation. Conclusion The progression of pulmonary fibrosis is accompanied by dynamic changes in miRNA-mRNA regulatory networks. The identified miRNA-target axes (e.g., miR-135b-5p and Meis1, mmu-miR-708-5p and Mmp25, mmu-miR-21a-3p and Cacna1d, and mmu-miR-205-5p and Ereg—) may play important roles in fibrogenesis and provide potential therapeutic targets for pulmonary fibrosis.

Background Regulatory interactions between microRNAs (miRNAs) and messenger RNAs (mRNAs) are involved in the progression of pulmonary fibrosis, which can either promote or inhibit the development of this disease. Objective To explore the miRNA-mRNA regulatory network during the progression of silica (SiO₂)-induced pulmonary fibrosis in mice using integrated mRNA-seq and miRNA-seq analysis. Methods A mouse model of pulmonary fibrosis was established by dynamic SiO₂ dust exposure. The experimental design included a blank control group and four SiO₂-exposed groups (7, 14, 28, and 56 d, n=10 per group). Successful model induction was confirmed by histopathological analysis (HE and Masson staining), hydroxyproline (HYP) quantification, and expression of key fibrosis-related cytokines [fibroblast growth factor (FGF), interleukin-6 (IL-6), transforming growth factor-β (TGF-β), and tumor necrosis factor-α (TNF-α)]. Lung tissues from mice in each group were subjected to sequencing, and Mfuzz was used for time-series gene clustering to identify dynamic progression patterns. DESeq2 was utilized to identify differentially expressed genes (DEGs) and differentially expressed miRNAs. Enrichment analysis of DEGs was performed to identify critical signaling pathways and biological processes underlying pulmonary fibrosis progression. Expression of four selected miRNAs was subsequently validated by real-time quantitative polymerase chain reaction (RT-qPCR). The target mRNAs of key miRNAs were comprehensively predicted by integrating miRBase, starBase, and miRTarBase to construct the regulatory networks and investigate potential functions. Results SiO₂ exposure led to time-dependent aggravation of pulmonary fibrosis in mice, evidenced by increased fibrous deposition, elevated HYP levels (P < 0.01), and up-regulation of four kinds of pro-fibrotic cytokines (P < 0.01) compared with the NT group. Mfuzz clustering revealed the stage-specific characteristics. Compared to controls, 231, 662, 448, and 1020 DEGs were identified after SiO₂ exposure at 7, 14, 28, and 56 d, respectively, primarily enriched in immune responses and chemokine signaling. During critical fibrotic phases—7 d (acute inflammation and initiation) and 28 d (chronic inflammation and establishment)—18 differentially expressed miRNAs were identified; notably mmu-miR-135b-5p was significantly dysregulated at both time points. The expression trends of the four key miRNAs (mmu-miR-135b-5p, mmu-miR-708-5p, mmu-miR-21a-3p, and mmu-miR-205-5p) were consistent with the sequencing results. Furthermore, bioinformatics databases were used to predict the target mRNAs of key miRNAs. The constructed network highlighted critical miRNA-mRNA pairs—including mmu-miR-135b-5p and Meis1, mmu-miR-708-5p and Mmp25, mmu-miR-21a-3p and Cacna1d, mmu-miR-205-5p and Ereg which were closely associated with inflammatory response, extracellular matrix deposition, and fibroblast activation. Conclusion The progression of pulmonary fibrosis is accompanied by dynamic changes in miRNA-mRNA regulatory networks. The identified miRNA-target axes (e.g., miR-135b-5p and Meis1, mmu-miR-708-5p and Mmp25, mmu-miR-21a-3p and Cacna1d, and mmu-miR-205-5p and Ereg—) may play important roles in fibrogenesis and provide potential therapeutic targets for pulmonary fibrosis.

Despite significant advances in the field of critical care medicine over the past three decades, veno-arterial extracorporeal membrane oxygenation (V-A ECMO) remains the primary temporary mechanical circulatory support modality for patients with acute severe circulatory failure. With the accumulation of clinical experience and the increasing maturity of operational techniques in V-A ECMO, its technical management—particularly hemodynamic management—has become a key factor influencing patient outcomes. To further improve patient survival, the Chinese Critical Care Ultrasound Study Group, in collaboration with the Hemodynamic Therapy of Critical Care Collaborative Group and the Critical Care Medicine Branch of the China International Exchange and Promotive Association for Medical and Health Care, organized experts in critical care medicine to develop the Consensus on Hemodynamic Management in Adult Veno-Arterial Extracorporeal Membrane Oxygenation (2026 Edition). Based on years of clinical experience and the latest evidence-based medical evidence, this consensus formulates 15 systematic recommendations covering the entire process of V-A ECMO, including initiation, management during support, and weaning, aiming to promote standardized application of hemodynamic management in V-A ECMO.

The accumulation of uremic toxins such as urea nitrogen, blood creatinine, and uric acid of patients with renal failure in vivo would lead to aggravated kidney damage. In this study, coated aldehyde oxy-starch (CAO) was used as an adsorbent to investigate its in vitro adsorption performance on renal failure indexes for urea, indoxyl sulfate (INS), monomethylamine (MMA), dimethylamine (DMA), uric acid (UA), and creatinine (Cr). The effects of variables such as pH, temperature, concentration, dosage, and time on the adsorption capacity of CAO were systematically investigated, employing analytical techniques of high-performance liquid chromatography (HPLC) and gas chromatography (GC). The results revealed that CAO exhibited a strong adsorption capacity for urea, INS, and MMA, alongside a moderate adsorption capacity for DMA, UA, and Cr. The adsorption kinetics and thermodynamic studies indicated that the adsorption of urea and UA by CAO were fitted in pseudo-first-order kinetics, and the adsorption isotherm aligned with the Freundlich adsorption model. The enthalpy change ΔH of urea in adsorption was in the range of 40 to 60 kJ·mol^-1, which demonstrated the presence of strong adsorption force due to the interactions of coordinating groups. The ΔH of UA was greater than 80 kJ·mol^-1, indicating the generation of chemical bonds during the adsorption. Both of them, Gibbs free energy ΔG was less than 0, within the range of -20 to 0 kJ·mol^-1, suggested that the adsorption of urea and UA by CAO occurred spontaneously as physical adsorption process. The adsorption entropy ΔS of urea and UA was > 0, which indicated an increase in entropy throughout the adsorption. The infrared spectroscopygram showed the formation of a chemical bond, specifically the imine bond, following the adsorption of urea by CAO, thereby indicating a chemical reaction during the adsorption. This study elucidates the adsorption mechanism of CAO on various indexes of renal failure, providing a scientific basis for its clinical usage.

Objective To investigate the changes in the prevalence of Babesia microti infections, spleen morphology and proportions of splenic immune cells in BALB/c mice following intravenous and intraperitoneal injections, so as to provide insights into unraveling the immune regulatory mechanisms of Babesia infections. Methods Laboratory - maintained B. microti strains were prepared into whole blood samples with 10% prevalence of B. microti infection. A total of 75 BALB/c mice were randomly divided into three groups, including the normal control group, intravenous injection group, and intraperitoneal injection group, of 25 mice in each group. Mice in the intravenous and intraperitoneal injection groups were administered 100 μL of whole blood samples with 10% prevalence of B. microti infection, with the day of injection recorded as d0, and animals in the normal control group were given no treatments. Blood was sampled from mice in each group via the tail tip on d7, d14, d21, d28 and d35, and prepared into thin-film blood smears, and B. microti infection was observed in red blood cells. Five mice were randomly sampled from each group and sacrificed on d7, d14, d21, d28 and d35, and spleen was collected for measurement of spleen size and weight. In addition, splenic cells were isolated, and the proportions of CD3e⁺ T cells, CD45R⁺ B cells, CD49b⁺ nature killer (NK) cells, and F4/80⁺ macrophages were detected in CD45⁺ lymphocytes using flow cytometry. Results The prevalence of B. microti infection in the intravenous (22.80%) and intraperitoneal injection groups (44.82%) peaked on d7 (χ² = 8.141, P < 0.01) and then rapidly decreased, and no parasites were observed on d35. The longest mouse spleen length [(32.91 ± 2.20) mm] and width [(9.82 ± 0.43) mm], and the greatest weight [(0.78 ± 0.10) g] were found on d14 in the intravenous injection group, and the longest spleen length [(32.42 ± 3.21) mm] and width [(10.25 ± 0.73) mm], and the greatest weight [(0.73 ± 0.09) g] were seen in the intra-peritoneal injection group on d21, d7 and d14, respectively. There were significant differences among the intravenous injection group, intraperitoneal injection group and the normal control group in terms of spleen length (F = 10.310, P < 0.05), width (F = 9.824, P < 0.05), and weight (F = 10.672, P < 0.05) on d21, and the mouse spleen length, width and weight were all significantly greater in the intraperitoneal injection group than in the intravenous injection group (allP values < 0.05). The proportions of splenic CD3e⁺ T cells [(60.60 ± 6.20)% and (39.68 ± 7.62)%], CD45R⁺ B cells [(43.32 ± 2.08)% and (49.53 ± 4.90)%], CD49b⁺ NK cells [(6.88 ± 1.34)% and (7.71 ± 1.59)%], and F4/80⁺ macrophages [(2.21 ± 0.29)% and (3.80 ± 0.35)%] peaked on d14, d21, d21 and d14 in the intravenous and intraperitoneal injection groups, respectively. There were significant differences in the proportions of CD3e⁺ T cells (F = 16.730, P < 0.05) and F4/80⁺ macrophages (F = 15.941, P < 0.05) among the intravenous injection group, intraperitoneal injection group and normal control group on d14, and a higher proportion of CD3e⁺ T cells and a lower proportion of F4/80⁺ macrophages were detected in the intravenous injection group than in the intraperitoneal injection group (both P values < 0.01). There were significant differences among the intravenous injection group, intraperitoneal injection group and normal control group on d21 in terms of proportions of splenic CD3e⁺ T cells (F = 9.252, P < 0.05), CD45R⁺ B cells (F = 14.349, P < 0.05), CD49b⁺ NK cells (F = 13.436,P < 0.05), and F4/80⁺ macrophages (F = 8.180, P < 0.05), and a higher proportion of CD3e⁺ T cells and lower proportions of CD45R⁺ B cells and F4/80⁺ macrophages were detected in the intravenous injection group than in the intraperitoneal injection group (all P values < 0.01). In addition, there was a significant difference in the proportion of CD3e⁺ T cells among the intravenous injection group, intraperitoneal injection group and normal control group on d28 (F = 9.772,P < 0.05), and a lower proportion of CD3e⁺ T cells was found in the intravenous injection group than in the intraperitoneal injection group (P < 0.01). Conclusions Both intraperitoneal and intravenous routes are effective to induce B. microti infections in BALB/c mice, and the prevalence of B. microti infections is higher in BALB/c mice through the intraperitoneal route than through the intravenous route. Intraperitoneal and intravenous injections with B. microti cause diverse spleen morphologies and proportions of splenic immune cells in mice, indicating routes of B. microti infections cause different impacts on immune response mechanisms in mice.

ObjectiveTo obtain the gene sequences of major histocompatibility complex (MHC ) Ⅱgenes of Wuzhishan pigs, analyze their genetic information, and explore the biological functions of their MHC system. MethodsSpleen samples were collected from 3 adult male Wuzhishan pigs. Primers were designed according to MHCⅡ gene sequences, and the coding sequences of Wuzhishan pig MHCⅡ genes were amplified by RT-PCR. Sanger sequencing was performed to determine the full-length sequences. Bioinformatics tools were employed to analyze the physicochemical properties, phylogenetic relationships, conserved motifs, structural domains, chromosomal localization, and syntenic relationships of these genes. ResultsEight MHCⅡ genes were identified in Wuzhishan pigs, designated as SLA-DRA, SLA-DQA, SLA-DQB, SLA-DRB, SLA-DOB, SLA-DMB, SLA-DMA and SLA-DOA. The full-length sequences of these genes were determined by Sanger sequencing and subsequently deposited in GenBank under accession numbers PQ182796, PQ182797, PQ182798, PQ182799, PQ182800, PQ182801, PQ182802, and PQ164779. Phylogenetic analysis showed that the six MHCⅡ genes of Wuzhishan pigs clustered separately from their counterparts in Duroc, Meishan, Large White, and Bama pigs, indicating distinct evolutionary trajectories. Bioinformatics analysis demonstrated that most MHC Ⅱ proteins were hydrophobic, with molecular weights ranging from 27 700 to 30 000 Da. Genes within the same subregion shared conserved motifs. Specifically, four MHCⅡ proteins encoded by SLA-DQB, SLA-DRB, SLA-DOB, and SLA-DMB contained the MHCⅡβ conserved domain, while those encoded by the genes SLA-DRA, SLA-DQA, SLA-DMA, and SLA-DOA contained the MHCⅡα conserved domain. The eight MHCⅡ genes were scattered along the long arm of chromosome 7 in the Wuzhishan pigs, exhibiting syntenic relationships with three human genes and five Duroc pig genes. ConclusionThe MHCⅡ genes of Wuzhishan pigs may possess a unique evolutionary origin.

ObjectiveTo obtain the gene sequences of major histocompatibility complex (MHC ) Ⅱgenes of Wuzhishan pigs, analyze their genetic information, and explore the biological functions of their MHC system. MethodsSpleen samples were collected from 3 adult male Wuzhishan pigs. Primers were designed according to MHCⅡ gene sequences, and the coding sequences of Wuzhishan pig MHCⅡ genes were amplified by RT-PCR. Sanger sequencing was performed to determine the full-length sequences. Bioinformatics tools were employed to analyze the physicochemical properties, phylogenetic relationships, conserved motifs, structural domains, chromosomal localization, and syntenic relationships of these genes. ResultsEight MHCⅡ genes were identified in Wuzhishan pigs, designated as SLA-DRA, SLA-DQA, SLA-DQB, SLA-DRB, SLA-DOB, SLA-DMB, SLA-DMA and SLA-DOA. The full-length sequences of these genes were determined by Sanger sequencing and subsequently deposited in GenBank under accession numbers PQ182796, PQ182797, PQ182798, PQ182799, PQ182800, PQ182801, PQ182802, and PQ164779. Phylogenetic analysis showed that the six MHCⅡ genes of Wuzhishan pigs clustered separately from their counterparts in Duroc, Meishan, Large White, and Bama pigs, indicating distinct evolutionary trajectories. Bioinformatics analysis demonstrated that most MHC Ⅱ proteins were hydrophobic, with molecular weights ranging from 27 700 to 30 000 Da. Genes within the same subregion shared conserved motifs. Specifically, four MHCⅡ proteins encoded by SLA-DQB, SLA-DRB, SLA-DOB, and SLA-DMB contained the MHCⅡβ conserved domain, while those encoded by the genes SLA-DRA, SLA-DQA, SLA-DMA, and SLA-DOA contained the MHCⅡα conserved domain. The eight MHCⅡ genes were scattered along the long arm of chromosome 7 in the Wuzhishan pigs, exhibiting syntenic relationships with three human genes and five Duroc pig genes. ConclusionThe MHCⅡ genes of Wuzhishan pigs may possess a unique evolutionary origin.