SOX2/DRD2 signaling pathway facilitates astrocytic dedifferentiation in cerebral ischemic mice

Objective:To explore the effects of dopamine receptor D2(DRD2)on astrocytic dedifferentiation based on SOX2-regulated genes in neural stem cells(NSCs)and astrocytes.Methods:Immunofluorescence staining and SOX2-GFP mice were used to examine the lineage differentiation of SOX2-positive cells during the development of cerebral cortex.Primary NSCs/astrocytes culture,ChIP-seq and Western Blot were adopted to analyze and verify the expression of candidate genes.Pharmacological manipulation,neurosphere formation,photochemical ischemia,immunofluorescence staining and behavior tests were adopted to evaluate the effects of activating DRD2 signaling on astrocytic dedifferentiation.Results:Immunofluorescence staining demonstrated the NSC-astrocyte switch of SOX2-expression in the normal development of cerebral cortex.ChIP-seq revealed enrichment of DRD2 signaling by SOX2-bound enhancers in NSCs and SOX2-bound promoters in astrocytes.Western Blot and immunofluorescence staining verified the expression of DRD2 in NSCs and reactive astrocytes.Application of quinagolide hydrocholoride(QH),an agonist of DRD2,significantly promoted astrocytic dedifferentiation both in vitro and in vivo following ischemia.In addition,quinagolide hydrocholoride treatment improved locomotion recovery.Conclusion:Activating DRD2 signaling facilitates astrocytic dedifferentiation and may be used to treat ischemic stroke.

Toripalimab in combination with chemotherapy effectively suppresses local recurrence and metastatic sarcomatoid renal cell carcinoma:A case report

BACKGROUND Sarcomatoid renal cell carcinoma(SRCC)is a rare variant of renal cell carcinoma associated with an unfavorable prognosis.The efficacy of conventional chemo-therapy and targeted therapies are limited,whereas the emergence of immune checkpoint inhibitor has introduced new avenues for managing advanced SRCC.CASE SUMMARY A 77-year-old female patient was referred to our hospital following the incidental detection of a right kidney tumor without specific symptoms.The tumor was successfully resected,and subsequent pathological examination confirmed SRCC.She experienced both local recurrence and distant metastasis eight months after the initial laparoscopic resection.Following six cycles of toripalimab combined with pirarubicin chemotherapy,the patient achieved a partial response.Subse-quently,the patient attained an almost-complete continuous response to toripa-limab monotherapy maintenance for an additional six cycles.She has not experienced disease progression for 15 months,and her overall survival has reached 24 months thus far.CONCLUSION Combination therapy with programmed death 1 antibodies and cytotoxic agents may be a recommended first-line treatment approach for SRCC.

Dedifferentiating initiation and embryogenesis from freshly-isolated microspores of barley

By using DNA-specific fluorescent dye and a confocal laser scanning microscope, the present study was designed to investigate the cytological characteristics of dedifferentiating initiation during pretreatment and em-bryogenesis during culture in freshly-isolated microspores of barley, and the difference in main developmental pathway between freshly-isolated and cold-treated microspores. The results revealed that ( i ) freshly-isolated microspores started the initiation within 12 h of mannitol pretreatment, whose main cytological characteristics were that: cell vol-ume was obviously extended; the volume of nuclei and nucleoli were also greatly increased; nucleoli were extremely clear and highly condensed; N/C ratio was very high; ( ii ) all the pretreatment methods led to the initiation of the mi-crospores, thus triggering the embryogenic process; ( iii ) pretreatment methods influenced the main developmental pathway of microspores by changing the pattern of the first mitosis. The cold-treated microspores formed main devel-opmental pathway via A patterns, but freshly-isolated microspores via B pattern.

Organoid-derived human retinal progenitor cells promote early dedifferentiation of Müller glia in Royal College of Surgeons rats

AIM:To explore whether the subretinal transplantation of retinal progenitor cells from human embryonic stem cell-derived retinal organoid(h ERO-RPCs)could promote Müller glia dedifferentiation and transdifferentiation,thus improving visual function and delaying retinal degenerative progression.METHODS:h ERO-RPCs were subretinally transplanted into Royal College of Surgeons(RCS)rats.Electroretinography(ERG)recording was performed at 4 and 8wk postoperation to assess retinal function.Using immunofluorescence,the changes in outer nuclear layer(ONL)thickness and retinal Müller glia were explored at 2,4,and 8wk postoperation.To verify the effect of h ERO-RPCs on Müller glia in vitro,we cocultured h ERO-RPCs with Müller glia with a Transwell system.After coculture,Ki67 staining and quantitative polymerase chain reaction(q PCR)were performed to measure the proliferation and m RNA levels of Müller glia respectively.Cell migration experiment was used to detect the effect of h ERO-RPCs on Müller glial migration.Comparisons between two groups were performed by the unpaired Student’s t-test,and comparisons among multiple groups were made with one-way ANOVA followed by Tukey’s multiple comparison test.RESULTS:The visual function and ONL thickness of RCS rats were significantly improved by transplantation of h ERO-RPCs at 4 and 8wk postoperation.In addition to inhibiting gliosis at 4 and 8wk postoperation,h ERO-RPCs significantly increased the expression of dedifferentiation-associated transcriptional factor in Müller glia and promoted the migration at 2,4 and 8wk postoperation,but not the transdifferentiation of these cells in RCS rats.In vitro,using the Transwell system,we found that h ERO-RPCs promoted the proliferation and migration of primary rat Müller glia and induced their dedifferentiation at the m RNA level.CONCLUSION:These results show that h ERO-RPCs might promote early dedifferentiation of Müller glia,which may provide novel insights into the mechanisms of stem cell therapy and Müller glial reprogramming,contributing to the development of novel therapies for retinal degeneration disorders.

Primary dedifferentiated chondrosarcoma of the lung with a 4-year history of breast cancer:A case report

BACKGROUND Primary dedifferentiated chondrosarcoma(DDCS)of the lung is extremely rare and has a poor prognosis,especially in patients with a history of carcinomas and related treatment.Herein,we report a case of primary DDCS of the lung in a patient with a 4-year history of breast cancer and related treatment.CASE SUMMARY A 49-year-old woman was admitted to our hospital with complaints of headache,dizziness,slurred speech,and dyskinesia in May 2021.Computed tomography(CT)examinations showed multiple nodules in the brain,vertebral body,and both lungs with multiple enlarged lymph nodes in the right hilum and mediastinum,which were considered metastases of breast cancer.No obvious mass was discovered in the right hilum.After several months of related administration,the patient's headache disappeared,and her condition improved.However,new problems of asthma,dyspnea,cough,and restricted activity appeared in late November 2021.Although the CT scan indicated that the lesions in the brain,lung,and vertebral body had shrunk or disappeared,a soft tissue density lesion appeared in her right hilum and blocked the bronchial lumen.To relieve her dyspnea,part of the mass was resected,and a stent was placed via fiberoptic bronchoscopy.Following a complete pathological examination of the tumor,it was confirmed to be a primary DDCS of the lung.The patient then received two rounds of systemic chemotherapy with a regimen of cisplatin+ifosfamide+doxorubicin hydrochloride liposome,palliative radiotherapy for the tumor in her right lung,and four cycles of systemic chemotherapy and targeted therapy with a regimen of temozolomide combined with bevacizumab successively.She was in stable condition after the completion of the systemic chemotherapy and targeted therapy but underwent rapid progression after lung radiotherapy.The CT examinations showed multiple nodules in the brain and in both lungs,and the tumor in the right hilum was increased in size.CONCLUSION This case revealed a rare primary DDCS of the lung with a medical history of breast cancer,meaning a worse prognosis and making it more difficult to treat.

Giant dedifferentiated liposarcoma of the gastrocolic ligament:A case report

BACKGROUND Dedifferentiated liposarcoma(DDLS)has a worse prognosis and occurs most commonly in the retroperitoneal region and rarely in the intraperitoneal region.Histological diagnosis was revolutionized by the combined contributions of histoimmuno-chemistry and molecular biology.Aside from surgery,there is no consensus on the optimal treatment for this chemoresistant cancer.CASE SUMMARY A thirty-year-old black female presented with a large painful abdominal mass occupying nearly the entire abdomen and progressive weight loss was admitted for surgery.Abdominal computed tomography showed a large heterogeneous mass of the mesentery that was sized 18 cm×16 cm in size and had heterogeneous contrast enhancement.During laparotomy,en bloc excision of the large and multilobulated gastrocolic ligament mass was performed.The initial postoperative histopathological diagnosis was undifferentiated sarcoma.Finally,the results of immunohistochemistry and molecular biology allowed us to confirm the diagnosis of DDLS.The tumour followed an aggressive evolution with diffuse metastasis,causing the death of the patient less than 5 mo after the operation.CONCLUSION Dedifferentiated liposarcomas are rare tumours that typically originate in the retroperitoneum but may arise in unexpected locations.

Ultracytochemical Localization of ATPase During the Secondary Xylem Differentiation and Dedifferentiation in Eucommia ulmoides Trunk

The ultracytochemical localization of ATPase in the secondary xylem cells during their differentiation and dedifferentiation in the girdled Eucommia ulmoides Oliv. was carried out using a lead phosphate precipitation technique. Throughout the differentiation, which is a typical programmed cell death (PCD) process, ATPase deposits increased in the nucleus but decreased and progressively disappeared in the cell organelles. At the same time, the distribution of ATPase increased in the inner face of the cell wall and pits with cytoplasmic degeneration. The results demonstrated that the PCD was an energy dependent active process and was controlled by nuclear genes. On the other hand, the distribution of ATPase in the intercellular spaces increased with the formation of the new cambium resulted from the dedifferentiation of the secondary xylem cells after girdling. However, ATPase was not found in the nucleus of the dividing cells, suggesting that nutrients were transported through protoplast during differentiation, and through both protoplast and apoplast during dedifferentiation. Thus, the energy required in cell division was provided mainly by intercellular spaces. These findings indicate that the dynamic distribution of ATPase reflected which cell component was actively taking part in the cell metabolism at various stages of the plant development, and its distribution was associated with the physiological state of the cell. Based on the characteristic distributions of ATPase, the critical stage of cell differentiation and the relationship between the critical stage and dedifferentiation were discussed.

Research Progress on the Biological Basis of Cereal Pollen Culture

This paper summarizes the physiological and metabolic mechanism of a series of processes in the cereal microspore culture from the angle of plant physiological metabolism, explores the physiological or cytology mechanism of several key processes, including microspore dedifferentiation and callus formation, differentiation and transformation, and sums up the current problems in this field and forecasts the direction of future development.

Study on the Redifferentiation Technology after the Dedifferentiation of Blades of Camellia oleifera Abel.

Based on selecting MS minimal medium, through changing the concentrations and additive amounts of two plant growth regulators of NAA and BA, the redifferentiation experiments of plant morphology on callus and embryos cell which got after the dedifferentiation of ＂Xianglin No.1＂ Camellia oleifera Abel. were carried out.The experimental results showed that callus lines with white, yellowish white or oyster colors, obvious uneven surface and loose texture were inoculated on the medium of MS ＋NAA（0.3 mg/L） ＋BA（2.0 mg/L） ＋saccharose（30 g/L） ＋agar（7 g/L）for 30 d,then multiple shoots were differentiated from the white protuberant part, moreover,the growth vigor was good. If inoculating using regeneration buds of C. oleifera, its multiplication coefficient was 6.50.

Dedifferentiated fat cells: an alternative source of adult multipotent cells from the adipose tissues

When adipose-derived stem cells （ASCs） arc retrieved from the stromal vascular portion of adipose tissue, a large amount of mature adipocytes are often discarded. However, by modified ceiling culture technique based on their buoyancy, mature adipocytes can be easily isolated from the adipose cell suspension and dediffercn- tiated into lipid-frce fibroblast-like cells, named dediffercntiated fat （DFAT） cells. DFAT cells rc-establish active proliferation ability and undertake multipotent capacities. Compared with ASCs and other adult stem cells, DFAT cells showed unique advantages in their abundance, isolation and homogeneity. In this concise review, the establishment and culture methods of DFAT cells arc introduced and the current profiles of their cellular nature are summarized. Under proper inducti~,n culture in vitro or environment in vivo, DFAT cells could demonstrate adipogenic, osteogenic, chondrogenie and myogenic potentials. In angiogenie conditions, DFAT cells could exhibit perivascular characteristics antt elicit neovascularization. Our preliminary findings also suggested the pericyte phenotype underlying such cell lineage, which supported a novel interpretation about the common origin of mesenchymal stem cells and tissue-specific stem cells within blood vessel walls. Current research on DFAT cells indicated that this alternative source of adult multipotent cells has great potential in tissue engineering and regenerative medicine.

Axon degeneration： make the Schwann cell great again

Axonal degeneration is a pivotal feature of many neurodegenerative conditions and substantially accounts for neurological morbidity. A widely used experimental model to study the mechanisms of axonal degeneration is Wallerian degeneration （WD）, which occurs after acute axonal injury. In the peripheral nervous system （PNS）, WD is characterized by swift dismantling and clearance of injured axons with their myelin sheaths. This is a prerequisite for successful axonal regeneration. In the central nervous system （CNS）, WD is much slower, which significantly contributes to failed axonal regeneration. Although it is well documented that Schwann cells （SCs） have a critical role in the regenerative potential of the PNS, to date we have only scarce knowledge as to how SCs ＇sense＇ axonal injury and immediately respond to it. In this regard, it remains unknown as to whether SCs play the role of a passive bystander or an active director during the execution of the highly orchestrated disintegration program of axons. Older reports, together with more recent studies, suggest that SCs mount dynamic injury responses minutes after axonal injury, long before axonal breakdown occurs. The swift SC response to axonal injury could play either a pro degenerative role, or alternatively a supportive role, to the integrity of distressed axons that have not yet committed to degenerate. Indeed, supporting the latter concept, recent 昀ndings in a chronic PNS neurodegeneration model indicate that deactivation of a key molecule promoting SC injury responses exacerbates axonal loss. If this holds true in a broader spectrum of conditions, it may provide the grounds for the development of new glia-centric therapeutic approaches to counteract axonal loss.

Dedifferentiated fat cells:A cell source for regenerative medicine

The identification of an ideal cell source for tissue regeneration remains a challenge in the stem cell field. The ability of progeny cells to differentiate into other cell types is important for the processes of tissue reconstruction and tissue engineering and has clinical, biochemical or molecular implications. The adaptation of stem cells from adipose tissue for use in regenerative medicine has created a new role for adipocytes. Mature adipocytes can easily be isolated from adipose cell suspensions and allowed to dedifferentiate into lipidfree multipotent cells, referred to as dedifferentiated fat(DFAT) cells. Compared to other adult stem cells, the DFAT cells have unique advantages in their abundance, ease of isolation and homogeneity. Under proper condition in vitro and in vivo, the DFAT cells have exhibited adipogenic, osteogenic, chondrogenic, cardiomyogenc, angiogenic, myogenic, and neurogenic potentials. In this review, we first discuss the phenomena of dedifferentiation and transdifferentiation of cells, and then dedifferentiation of adipocytes in particular. Understanding the dedifferentiation process itself may contribute to our knowledge of normal growth processes, as well as mechanisms of disease. Second, we highlight new developments in DFAT cell culture and summarize the current understanding of DFAT cell properties. The unique features of DFAT cells are promising for clinical applications such as tissue regeneration.

Streptozotocin-induced expression of Ngn3 and Pax4 in neonatal rat pancreatic α-cells

AIM： To investigate the mechanism behind β-cell regeneration in neonatal rat pancreas treated with strep- tozotocin （STZ）. METHODS： Neonatal Sprague Dawley rats were intra- peritoneally injected with 70 mg/kg STZ. Body weight, pancreas weight and blood glucose were recorded every two days after the treatment. To identify the expression and location of transcription factors in the rat pancreas, double immunofluorescent staining was performed using antibodies to specific cell markers and transcription factors. RESULTS： Expression of Neurogenin 3 （Ngn3）, a marker for endocrine precursor cells, was observed by immunofluorescence in a few β-cells and many a-cells. The expression reached a peak 12 d after treatment. Pax4, a transcription factor that lies downstream of Ngn3 and plays an important role in β-cell differentiation, was also expressed in the α-cells of STZ-treated rats. We did not observe significant changes in Nkx6.1, which is essential for β-cell maturation in the treated rats. CONCLUSION： α-cells dedifferentiated into endocrine precursor cells and acquired the ability to dedifferentiate in the neonatal rat pancreas after STZ treatment.

Activation of extracellular signal-related kinases 1 and 2 in Sertoli cells in experimentally cryptorchid rhesus monkeys

Aim： To assess the spatiotemporal changes in the expression of extracellular signal-regulated kinases 1 and 2 （ERK1/ 2）, c-Jun N-terminal kinases （JNK） and p38 mitogen-activated protein kinases （MAPK） in response to heat stress in the cryptorchid testis, and to investigate a possible relation to Sertoli cell dedifferentiation. Methods： Immunohistochemistry and western blot were used to examine the expression and activation of ERK1/2, p38 and JNK in the cryptorchid testis at various stages after experimental cryptorchidism. Results： The abdominal temperature did not obviously change the total ERK1/2 expression but significantly activated phospho-ERK1/2 in the Sertoli cells of the cryptorchid testis. Heat stress increased total JNK expression in the Sertoli cells of the cryptorchid testis but did not activate phospho-JNK. Neither total p38 nor phospho-p38 was induced by heat stress in the Sertoli cells of the cryptorchid testis. Changes in the spatiotemporal expression of cytokeratin 18 （CK18）, a marker of immature or undifferentiated Sertoli cells, were induced in the cryptorchid testis in a pattern similar to the activation of ERK1/2. Condusion： The activation of ERK1/2 in the testis may be related to dedifferentiation of Sertoli cells under heat stress induced by experimental cryptorchidism.

Dedifferentiated liposarcoma of the rectum:A case report

Liposarcoma is one of the most common soft tissue sarcomas found in adults,and it usually occurs in the retroperitoneum and the extremities.Here,we describe a case of dedifferentiated liposarcoma originating from a well-differentiated liposarcoma of the mesorectum that presented as a protruding mass in the rectal lumen.Hartmann's operation with total mesorectal excision was performed and the tumor was removed radically.No management guidelines are currently available for liposarcoma of the rectum.We propose that complete surgical resection be required for the treatment of rectal liposarcoma and that a long-term detailed follow up is necessary.

Pancreatic β cell regeneration induced by clinical and preclinical agents

Diabetes,one of the most common chronic diseases in the modern world,has pancreaticβcell deficiency as a major part of its pathophysiological mechanism.Pancreatic regeneration is a potential therapeutic strategy for the recovery ofβcell loss.However,endocrine islets have limited regenerative capacity,especially in adult humans.Almost all hypoglycemic drugs can protectβcells by inhibitingβcell apoptosis and dedifferentiation via correction of hyperglycemia and amelioration of the consequent inflammation and oxidative stress.Several agents,including glucagon-like peptide-1 andγ-aminobutyric acid,have been shown to promoteβcell proliferation,which is considered the main source of the regeneratedβcells in adult rodents,but with less clarity in humans.Pancreatic progenitor cells might exist and be activated under particular circumstances.Artemisinins andγ-aminobutyric acid can induceα-to-βcell conversion,although some disputes exist.Intestinal endocrine progenitors can transdeterminate into insulin-producing cells in the gut after FoxO1 deletion,and pharmacological research into FoxO1 inhibition is ongoing.Other cells,including pancreatic acinar cells,can transdifferentiate intoβcells,and clinical and preclinical strategies are currently underway.In this review,we summarize the clinical and preclinical agents used in different approaches forβcell regeneration and make some suggestions regarding future perspectives for clinical application.

Dedifferentiated liposarcoma arising from the sigmoid mesocolon: A case report

Dedifferentiated liposarcoma is a variant of liposarcoma with a more aggressive course. It occurs most commonly in the retroperitoneum and rarely in other anatomic locations. In the present report, we describe a case of dedifferentiated liposarcoma that occurred in an unusual location, sigmoid mesocolon, which has not yet been documented.

Intraperitoneal dedifferentiated liposarcoma:A case report

Dedifferentiated liposarcoma is a variant of liposarcoma with a more aggressive course. Mutations of the p53 gene have been found in different types of soft tissue sarcoma. It is generally accepted that p53 mutations in human malignant tumors are often related to a poor prognosis. In our case, analysis of p53 gene mutation in tumor samples was performed. p53 gene mutation was observed in dedifferentiated tumor tissue samples but not in well-differentiated tumor tissue samples. It has been reported that p53 gene mutation occurs most commonly in the retroperitoneum and rarely in other anatomic locations. Herein we report a case of dedifferentiated liposarcoma located at intraperitoneum.

Segment boundaries of the adult rat epididymis limit interstitial signaling by potential paracrine factors and segments lose differential gene expression after efferent duct ligation

The epididymis is divided into caput, corpus and cauda regions, organized into intraregional segments separated by connective tissue septa （CTS）. In the adult rat and mouse these segments are highly differentiated. Regulation of these segments is by endocrine, lumicrine and paracrine factors, the relative importance of which remains under investigation. Here, the ability of the CTS to limit signaling in the interstitial compartment is reviewed as is the effect of 15 days of unilateral efferent duct ligation （EDL） on ipsilateral segmental transcriptional profiles. Inter-segmental microperifusions of epidermal growth factor （EGF）, vascular endothelial growth factor （VEGFA） and fibroblast growth factor 2 （FGF2） increased phosphorylation of mitogen activated protein kinase （MAPK） in segments 1 and 2 of the rat epididymis and the effects of all factors were limited by the CTS separating the segments. Microan＇ay analysis of segmental gene expression determined the effect of 15 days of unilateral EDL on the transcriptome-wide gene expression of rat segments 1-4. Over 11 000 genes were expressed in each of the four segments and over 2 000 transcripts in segment 1 responded to deprivation of testicular lumicrine factors. Segments 1 and 2 of control tissues were the most transcriptionally different and EDL had its greatest effects there. In the absence of lumicrine factors, all four segments regressed to a transcriptionally undifferentiated state, consistent with the less differentiated histology. Deprivation of lumicrine factors could stimulate an individual gene＇s expression in some segments yet suppress it in others. Such results reveal a higher complexity of the regulation of rat epididymal segments than that is generally appreciated. （Asian J Androl 2007 July; 9： 565-573）

Adult neurogenesis from reprogrammed astrocytes

The details of adult neurogenesis,including environmental triggers,region specificity,and species homology remain an area of intense investigation.Slowing or halting age-related cognitive dysfunction,or restoring neurons lost to disease or injury represent just a fraction of potential therapeutic applications.New neurons can derive from stem cells,pluripotent neural progenitor cells,or non-neuronal glial cells,such as astrocytes.Astrocytes must be epigenetically"reprogrammed"to become neurons,which can occur both naturally in vivo,and via artificial exogenous treatments.While neural progenitor cells are localized to a few neurogenic zones in the adult brain,astrocytes populate almost every brain structure.In this review,we will summarize recent research into neurogenesis that arises from conversion of post-mitotic astrocytes,detail the genetic and epigenetic pathways that regulate this process,and discuss the possible clinical relevance in supplementing stem-cell neurogenic therapies.