Objective: In in vitro systems for differentiating and expanding natural killer (NK) cells, feeder cells provide essential cell-cell contact and paracrine signals that drive precursor proliferation and terminal maturation. However, existing xenogeneic feeder cells or tumor-derived genetically modified feeder cells pose risks of residual immunogenicity and malignant transformation, limiting clinical use. This study aims to develop a humanized mesenchymal-like stromal cell (hematopoietic organoid-derived human mesenchymal stromal cells, HO-hMSCs) derived from iPSC-based hematopoietic organoids, and elucidate its mechanisms of NK-supportive activity to enable a safe, efficient platform for clinical-grade NK cell production. Methods: Human induced pluripotent stem cells (iPSCs) were differentiated into hematopoietic organoids, from which HO-hMSCs were isolated. Flow-cytometric phenotyping and bulk RNA-sequencing were performed to compare HO-hMSCs with umbilical cord-derived MSCs (UC-hMSCs). The effect of HO-hMSCs on NK cell differentiation efficiency (CD3 CD56 ) and effector maturation (CD16 expression) were assessed by co-culture experiments, using UC-hMSCs as control. Results: 1) Hematopoietic organoid induction and NK differentiation: iPSCs were induced to form hematopoietic organoids using cytokine cocktails, which further differentiated into high-purity CD45 CD56 NK cells [(82.8%±12.07)% efficiency on day 21]. 2) HO-hMSC characteristics: HO-hMSCs exhibited upregulated expression of Notch pathway ligands (DLL4, JAG1, 4.06-8.04-fold), homeobox genes (HOXA3, HOXA5, log FC=1.28 and 1.44), and key regulators of NK development (GATA3, BCL11A) and cytokine receptors (IL7R, IL27RA, 6.76 to 13.34-fold increase). 3) Functional validation: Compared to UC-hMSCs, HO-hMSCs co-culture significantly enhanced NK cell proportion by 30.5% (P<0.05) and increased CD16 positivity (+20.5%). Conclusion: This study for the first time reveals that human hematopoietic organoid-derived HO-hMSCs possess potent hematopoietic niche-supportive activity. It provides a humanized, feeder-free platform for robust clinical-grade NK cell production and expands the translational utility of organoid technologies in cell therapy.

OBJECTIVE: To investigate the effectiveness of free palmaris longus tendon graft reconstruction in the treatment of gouty tophus erosion lesions in flexor tendon of wrist and hand. METHODS: A retrospective analysis was conducted on 8 patients with gouty tophus erosion lesions in flexor tendon of wrist and hand who underwent free palmaris longus tendon graft reconstruction between June 2017 and December 2023. All patients were male, aged 22-65 years, with an average of 45.9 years. The duration of gout history ranged from 2 to 18 years, with an average of 8.8 years. The duration from the discovery of gouty tophus to operation ranged from 12 to 26 months, with an average of 17.6 months. The gouty tophus eroded the flexor pollicis longus tendon in 4 cases, with Verdan flexor tendon zones being Ⅰ-Ⅱ in 1 case and Ⅳ-Ⅴ in 3 cases. The flexor digitorum profundus tendons were affected in 2 cases for the index finger, 1 for the middle finger, and 1 for the ring finger, all located in zone Ⅳ-Ⅴ. The long axis of the gouty tophus ranged from 2.3 to 4.5 cm, with an average of 3.4 cm. All 8 patients presented with limited finger flexion and extension. Among them, 4 cases were accompanied by median nerve compression symptoms, and 1 case had associated bone and joint destruction in the hand. The total active motion (TAM) of the affected finger was (81.3±30.2)° before operation according to the hand function evaluation criteria for tendon repair by the Chinese Society of Hand Surgery of the Chinese Medical Association, and the functional evaluation was poor. The harvested palmaris longus tendon intraoperatively was 7-9 cm in length. RESULTS: Surgical incisions in all 8 patients healed by first intention, with no infections, graft non-union, or significant adhesion complications. All patients were followed up 8-25 months, with an average of 14.8 months. Numbness symptoms resolved in all 4 patients who presented with median nerve compression symptoms. Patients did not experience wrist pain or other discomfort, and function was not compromised. At last follow-up, according to the hand function evaluation criteria for tendon repair by the Chinese Society of Hand Surgery of the Chinese Medical Association, the TAM of 8 patients was (197.5±55.8)°, which significantly improved when compared with that before operation ( t=11.638, P<0.001); the hand function of 1 patient with gouty tophus in zone Ⅰ-Ⅱ flexor pollicis longus tendon was good, and the other 7 patients were excellent. CONCLUSION Free palmaris longus tendon graft reconstruction demonstrates good effectiveness in treating gouty tophus erosion lesions in flexor tendon of wrist and hand.
Humans ; Middle Aged ; Male ; Adult ; Tendons/surgery* ; Retrospective Studies ; Aged ; Gout/complications* ; Wrist/surgery* ; Plastic Surgery Procedures/methods* ; Hand/surgery* ; Treatment Outcome ; Young Adult

Objective Utilizing a specially engineered miR-144-GFP-H1 human embryonic stem cell(hESC)reporter line,this study leverages GFP fluorescence as an indicator of miR-144 expression to gauge the progression of erythropoiesis.The investigation is aimed at elucidating the potential roles of lncRNAs within the erythropoietic framework and conducting an initial assessment of their functional impact.Methods The miR-144/451-GFP-H1 cell line(hereafter referred to as 144-H1)was utilized for in vitro erythrocyte induction culture.The subpopulations of cells entering the erythropoiesis stage were characterized by the surface molecules CD71 and GPA.The GFP reporter gene of miR-144 served as a critical determi-nant to distinguish between GFP-positive cells(with a high propensity for erythropoiesis)and GFP-negative cells(with a low propensity for erythropoiesis).Transcriptome sequencing was performed on both groups to identify differentially ex-pressed long non-coding RNAs(lncRNAs).LncRNA entries with potential for validation were selected for preliminary func-tional verification.The CRISPR/Cas9 gene editing technique was employed to design functional interference strategies for the targeted lncRNAs,obtaining 144-H1 cell lines with knocked-out function of the specific lncRNAs.These knockout cell lines,along with non-knockout 144-H1 cell lines,were used for parallel erythrocyte induction culture to identify differential nodes.This approach preliminarily verified their impact on erythropoiesis in an in vitro development model.Results 1)The constructed 144-H1 cell line was capable of expressing GFP fluorescence upon entering the stage of in vitro erythrocyte in-duction,indicating the activation of miR-144/451.2)Within the CD71,GPA double-positive group,significant differences in lncRNA expression were observed between the GFP-positive and GFP-negative subpopulations.3)Gene editing strategies involving the deletion of sequence segments capable of effectively interfering with the function of multiple lncRNA entries were designed and verified for successful editing.In the knockout cell lines,parts of the lncRNA sequences were directly de-leted.4)In parallel validation experiments of erythrocyte induction culture,cell lines with LINC01569 knocked out exhibited significant differences in flow cytometric subpopulations and cell proliferation capabilities compared to the non-knockout cell lines:①The knockout cell lines showed sustained high expression of GFP fluorescence.②The proportion of the CD71-GPA double-positive group in the knockout cell lines continuously decreased during erythrocyte maturation.③No significant ex-pression of hemoglobin was observed in the knockout cell lines,lacking the characteristic red color.④The cell proliferation capability of the knockout cell lines was significantly lower than that of the non-knockout cell lines(P＜0.05).Conclusion The successful employment of the 144-H1 cell line facilitated an exploration into the potential functions of lncRNAs in e-rythropoiesis.This enables the design of more refined in vitro developmental experiments to enhance the precision in captu-ring lncRNA functions.Among the differentially expressed lncRNA entries,LINC01569 was preliminarily validated to play a regulatory role in erythropoiesis.The functional absence of LINC01569 severely impacts the normal differentiation and prolif-eration of erythrocytes.The specific regulatory mechanism of LINC01569 in erythropoiesis warrants further investigation and research.

Objective:To investigate the clinical effect of turbocharged large free anterolateral thigh flaps (ALTF) by anastomosis with a superior perforator of the flap in reconstruction of large soft tissue defects of limbs.Methods:From June 2017 to June 2021, 6 patients with large soft tissue defects of limbs with exposed joints and tendons were treated in the Department of Hand and Foot Surgery of the Affiliated Hospital of Qingdao University with turbocharged large free ALTFs. The pressurised blood supply of ALTF was achieved by anastomosing a superior perforating branch carried in the flap. Such large and turbocharged ALTFs were used to repair large soft tissue defects with exposed joints and tendons in limbs. Of the 6 patients, there were 4 males and 2 females, and aged 32-60(46.0±8.1) years old. Cause of injury: 5 by traffic accident and 1 by machine crush. Four patients had soft tissue defects in lower limbs: 2 with open tibia and fibula fractures, 1 had patellar defect and fibula fracture, and 1 associated with fibula fracture. The other 2 patients had soft tissue defect in upper limbs with bone and tendon exposed but without fracture. The sizes of wound were 25.0 cm×12.0 cm-35.0 cm×19.0 cm. In the primary surgery, Vacuum sealing drainage (VSD) was applied. In the second stage, free ALTFs were used to cover the wound. The area of flap incision was increased by anastomosing the superior perforators and as the consequence, the size of flaps was achieved to 26.0 cm×13.0 cm-36.0 cm×15.0 cm. Donor site of 6 cases were reduced by direct suture, and the remaining wound was covered by free skin graft. Postoperative follow-ups were conducted at outpatient clinic reviews at 1, 2, 3 and 6 months after surgery, and followed by telephone or WeChat interviews. The results of the operation were evaluated according to the appearance, texture and sensory recovery of the flap.Results:All 6 flaps survived and the patients completed the postoperative follow-up that lasted for 6-24 (16.7±5.0) months. No necrosis of flap occurred after surgery. The appearance and texture of the flaps were satisfactory without wear and tear. Sensation recover was evaluated by the standered of British Medical Research Council (BMRC), 4 patients recovered to S 3 and 2 patients to S 2. The Mayo score of the elbow joint was good in 2 patient with upper extremity injuries. Of the other 4 patients with lower limb injuries, the knee function evalued by Hospital for Special Surgery(HSS) score were excellent in 3 patients and good in 1 patient, and the American Orthopedic Foot and Ankle Societ(AOFAS) ankle-hind foot function score was excellent in 2 patients and good in 2 patients. There was no infection or function loss at all donor sites. Conclusion:The perforator of an ALTF is relatively constant, and the flap can partially restore sensation. The superior perforator is reliable and the incision area of the flap can be enlarged by anastomosing the superior perforator vessels. It is a better way to reconstruct a large soft tissue defects in limbs.