Mesenchymal stem cells (MSCs) are converted to neural cells using growth factors and chemicals. Although these neural cells are effective at modulating disease symptoms, they are less effective at replacing lost neural cells. Direct transdifferentiation seems to be a promising method for generating the required cells for regenerative medicine applications. Sox2 is a key transcription factor in neural progenitor (NP) fate determination and has been frequently used for transdifferentiating different cell types to NPs. Here, we demonstrated that the overexpression of a single transcription factor, Sox2, in human adipose tissue-derived mesenchymal stem cells (hAT-MSCs) led to the generation of induced NPs-like cells that were clonogenic, proliferative and passageable, and showed the potential to differentiate into three neural lineages. NPs are known as progenitors with the potential to differentiate into oligodendrocytes. In vivo, following transplantation into demyelinated adult mouse brains, they survived, differentiated and integrated into the adult brain while participating in the remyelination process and behavioral improvement. This report introduces a beneficial, low-cost and effective approach for generating NPs from an accessible adult source for autologous applications in treating neurodegenerative diseases, including remyelination therapies for multiple sclerosis and other demyelinating diseases.

BACKGROUND: Pancreatic islet β-cell mass expands during pregnancy, but underlying mechanisms are not fully understood. This study examines the impact of pregnancy and cafeteria diet on islet morphology, associated cellular proliferation/apoptosis rates as well as β-cell lineage.
METHODS: Non-pregnant and pregnant Ins1Cre/+;Rosa26-eYFP transgenic mice were maintained on either normal or high-fat cafeteria diet, with pancreatic tissue obtained at 18 days gestation. Immunohistochemical changes in islet morphology, β-/α-cell proliferation and apoptosis, as well as islet cell identity, neogenesis and ductal cell transdifferentiation were assessed.
RESULTS: Pregnant normal diet mice displayed an increase in body weight and glycaemia. Cafeteria feeding attenuated this weight gain while causing overt hyperglycaemia. Pregnant mice maintained on a normal diet exhibited typical expansion in islet and β-cell area, owing to increased β-cell proliferation and survival as well as ductal to β-cell transdifferentiation and β-cell neogenesis, alongside decreased β-cell dedifferentiation. Such pregnancy-induced islet adaptations were severely restricted by cafeteria diet. Accordingly, islets from these mice displayed high levels of β-cell apoptosis and dedifferentiation, together with diminished β-cell proliferation and lack of pregnancy-induced β-cell neogenesis and transdifferentiation, entirely opposing islet cell modifications observed in pregnant mice maintained on a normal diet.
CONCLUSIONS: Augmentation of β-cell mass during gestation arises through various mechanisms that include proliferation and survival of existing β-cells, transdifferentiation of ductal cells as well as β-cell neogenesis. Remarkably, cafeteria feeding almost entirely annuls pregnancy-induced islet adaptations, which may contribute to the development of gestational diabetes in the setting of dietary provoked metabolic stress.

During the first week of development, human embryos form a blastocyst composed of an inner cell mass and trophectoderm (TE) cells, the latter of which are progenitors of placental trophoblast. Here, we investigated the expression of transcripts in the human TE from early to late blastocyst stages. We identified enrichment of the transcription factors GATA2, GATA3, TFAP2C and KLF5 and characterised their protein expression dynamics across TE development. By inducible overexpression and mRNA transfection, we determined that these factors, together with MYC, are sufficient to establish induced trophoblast stem cells (iTSCs) from primed human embryonic stem cells. These iTSCs self-renew and recapitulate morphological characteristics, gene expression profiles, and directed differentiation potential, similar to existing human TSCs. Systematic omission of each, or combinations of factors, revealed the crucial importance of GATA2 and GATA3 for iTSC transdifferentiation. Altogether, these findings provide insights into the transcription factor network that may be operational in the human TE and broaden the methods for establishing cellular models of early human placental progenitor cells, which may be useful in the future to model placental-associated diseases.

Malignant melanoma is a formidable tumor originating from melanocytes of neural crest origin, found in various anatomical locations, primarily in the skin, followed by the eyes and mucosal membranes. This tumor stands out due to its remarkable phenotypic diversity. Transdifferentiation, the process of differentiation into cell lineages other than the one from which the tumor originated, and phenotypic plasticity, characterized by changes in behavior, morphology, and physiology in response to different environmental conditions, can make melanoma a diagnostic conundrum for unwary pathologists. In this case report, we present a challenging case of melanoma with cartilaginous transdifferentiation to shed light on its clinical, pathological, and molecular aspects.

Huntington\'s disease (HD) is an incurable hereditary disease caused by expansion of the CAG repeats in the HTT gene encoding the mutant huntingtin protein (mHTT). Despite numerous studies in cellular and animal models, the mechanisms underlying the biological role of mHTT and its toxicity to striatal neurons have not yet been established and no effective therapy for HD patients has been developed so far. We produced and characterized a new line of dermal fibroblasts (HDDF, Huntington\'s disease dermal fibroblasts) from a patient with a confirmed HD diagnosis. We also studied the growth characteristics of HDDF cells, stained them for canonical markers, karyotyped these cells, and investigated their phenotype. HDDF cells was successfully reprogrammed into induced striatal neurons via transdifferentiation. The new fibroblast line can be used as a cell model to study the biological role of mHTT and manifestations of HD pathogenesis in both fibroblasts and induced neuronal cells obtained from them by reprogramming techniques.

CKLF-like MARVEL transmembrane domain-containing 3 (CMTM3), a member of the CMTM family that is closely related to tumor occurrence and progression, plays crucial roles in the immune system, cardiovascular system, and male reproductive system. Recently, CMTM3 has emerged as a potential target for treating diseases related to bone formation. However, additional studies are needed to understand the mechanisms by which CMTM3 regulates the process of osteogenic differentiation. In this study, we observed a significant downregulation of Cmtm3 expression during the transdifferentiation of C2C12 myoblasts into osteoblasts induced by BMP4. Cmtm3 overexpression suppressed proliferation and osteogenic differentiation in BMP4-induced C2C12 cells, whereas its knockdown conversely facilitated the process. Mechanistically, Cmtm3 overexpression upregulated both the protein and mRNA levels of p53 and p21. Conversely, Cmtm3 knockdown exerted the opposite effects. Additionally, we found that Cmtm3 interacts with p53 and increases protein stability by inhibiting proteasome-mediated ubiquitination and degradation. Notably, Trp53 downregulation abrogated the inhibitory effect of Cmtm3 on BMP4-induced proliferation and osteogenic differentiation of C2C12 myoblasts. Collectively, our findings provide key insights into the role of CMTM3 in regulating myoblast proliferation and transdifferentiation into osteoblasts, highlighting its significance in osteogenesis research.

Parkinson\'s disease (PD) is a neurodegenerative disorder resulting from the loss of dopamine-producing neurons in the brain, causing motor symptoms like tremors and stiffness. Although current treatments like medication and deep brain stimulation can alleviate symptoms, they don\'t address the root cause of neuron loss. Therefore, cell replacement therapy emerges as a promising treatment strategy. However, the generation of engraftable dopaminergic (DA) cells in clinically relevant quantities is still a challenge. Recent advances in cell reprogramming technologies open up vast possibilities to produce patient-specific cells of a desired type in therapeutic quantities. The main cell reprogramming strategies involve the enforced expression of individual or sets of genes through viral transduction or transfection, or through small molecules, known as the chemical approach, which is a much easier and safer method. In our previous studies, using a small molecule approach (combinations of epigenetic modifiers and SMAD inhibitors such asDorsomorphin and SB431542), we have been able to generate DA progenitors from human mesenchymal stem cells (hMSCs). The aim of this study was to further improve the method for the generation of DA progenitors and to test their therapeutic effect in an animal model of Parkinson\'s. The results showed that the addition of an autophagy enhancer (AE) to our DA cell induction protocol further increased the yield of DA progenitor cells. The results also showed that DA progenitors transplanted into the mouse model of PD survived, integrated, and improved PD motor symptoms. These data suggest that chemically-produced DA cells can be very promising and safe cellular therapeutics for PD.

Aim: Type II diabetes (T2D) stems from insulin resistance, with β-cell dysfunction as a hallmark in its progression. Studies reveal that β cells undergo apoptosis or dedifferentiation during T2D development. The transcription factor PAX4 is vital for β differentiation and survival, thus may be a potential enhancer of β-cell function in T2D islets. Materials & methods: Human PAX4 cDNA was delivered into T2D human islets with an adenoviral vector, and its effects on β cells were examined. Results: PAX4 gene delivery significantly improved β-cell survival, and increased β-cell composition in the T2D human islets. Basal insulin and glucose-stimulated insulin secretion in PAX4-expressing islets were substantially higher than untreated or control-treated T2D human islets. Conclusion: Introduced PAX4 expression in T2D human islets improves β-cell function, thus could provide therapeutic benefits for T2D treatment.
Type II diabetes (T2D) results from insulin resistance, with β-cell dysfunction playing a pivotal role in its progression. Deficits in β-cell mass and function have been attributed primarily to β-cell death through apoptosis; however, recent studies suggest β-cell failure can also arise from β-cell dedifferentiation – that is, β cells undergo a loss of mature identity, adopting either progenitor-like or glucagon-producing α cell states during T2D development. Therefore, a strategy preventing β-cell dedifferentiation while promoting its survival is beneficial for T2D treatment. In this study, we explored whether PAX4, a critical transcription factor for β differentiation and survival, could alleviate β-cell dysfunction in human islets derived from T2D patients. To accomplish that, human PAX4 cDNA was delivered into human islets isolated from T2D donors by an adenoviral vector-based vector, Ad5.Pax4 and its effects on β-cell function were evaluated. The results showed PAX4 expression significantly improved β-cell survival and increased β-cell composition in the T2D islets. Notably, PAX4-treated T2D islets exhibited significantly higher basal insulin secretion and glucose-stimulated insulin secretion than control-treated islets. The data demonstrate that PAX4 gene delivery into T2D human islets enhances β-cell mass and function, and thus may offer therapeutic benefits in the treatment of T2D.

Direct reprogramming provides a novel breakthrough for generating functional endothelial cells (ECs) without the need for intermediate stem or progenitor states, offering a promising resource for cardiovascular research and treatment. ETV2 is a key transcription factor that has been identified as a pioneering factor for specifying endothelial lineage. Achieving precise ETV2 induction is essential for effective endothelial reprogramming, and maintaining the reprogrammed cellular phenotype relies on a specific combination of growth factors and small molecules. Thus, we hereby provide a straightforward and comprehensive protocol for generating two distinct types of reprogrammed ECs (rECs) from human dermal fibroblasts (HDFs). Early rECs demonstrate a robust neovascularization property but lack the mature EC phenotype, while late rECs exhibit phenotypical similarity to human postnatal ECs and have a neovascularization capacity similar to early rECs. Both cell types can be derived from human somatic source cells, making them suitable for personalized disease investigations, drug discovery, and disease therapy.

The β-cells within the pancreas play a pivotal role in insulin production and secretion, responding to fluctuations in blood glucose levels. However, factors like obesity, dietary habits, and prolonged insulin resistance can compromise β-cell function, contributing to the development of Type 2 Diabetes (T2D). A critical aspect of this dysfunction involves β-cell dedifferentiation and transdifferentiation, wherein these cells lose their specialized characteristics and adopt different identities, notably transitioning towards progenitor or other pancreatic cell types like α-cells. This process significantly contributes to β-cell malfunction and the progression of T2D, often surpassing the impact of outright β-cell loss. Alterations in the expressions of specific genes and transcription factors unique to β-cells, along with epigenetic modifications and environmental factors such as inflammation, oxidative stress, and mitochondrial dysfunction, underpin the occurrence of β-cell dedifferentiation and the onset of T2D. Recent research underscores the potential therapeutic value for targeting β-cell dedifferentiation to manage T2D effectively. In this review, we aim to dissect the intricate mechanisms governing β-cell dedifferentiation and explore the therapeutic avenues stemming from these insights.