Authors

  • Golib Tolmasovich Kurbanov
    Ph.D., Samarkand State Medical University, Uzbekistan

DOI:

https://doi.org/10.37547/ajsshr/Volume05Issue05-40

Keywords:

Regeneration transforming growth factor beta 1 (TGF-β1) signaling pathways

Abstract

According to Charles Darwin’s first rule of regeneration, the higher the level of biological organization in a species, the lower its regenerative capacity. Regeneration is the biological process through which living organisms restore worn-out or damaged structures, often synonymously referred to as reparation. From a biological standpoint, regeneration is considered an adaptive mechanism. Virtually all diseases cause structural damage to tissues and organs, while recovery depends on the organism’s ability to regenerate these structures. This article explores the role of transforming growth factor beta 1 (TGF-β1) in tissue regeneration, highlighting its action through both dependent and independent signaling pathways.  


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American Journal Of Social Sciences And Humanity Research

162

https://theusajournals.com/index.php/ajsshr

VOLUME

Vol.05 Issue05 2025

PAGE NO.

162-167

DOI

10.37547/ajsshr/Volume05Issue05-40



The Influence Of TGF-

Β1

Blood Level Regulation on

Regenerative Processes in The Human Body

Golib Tolmasovich Kurbanov

Ph.D., Samarkand State Medical University, Uzbekistan

Received:

28 March 2025;

Accepted:

24 April 2025;

Published:

26 May 2025

Abstract:

According to Charles Darwin’s firs

t rule of regeneration, the higher the level of biological organization

in a species, the lower its regenerative capacity. Regeneration is the biological process through which living
organisms restore worn-out or damaged structures, often synonymously referred to as reparation. From a
biological standpoint, regeneration is considered an adaptive mechanism. Virtually all diseases cause structural

damage to tissues and organs, while recovery depends on the organism’s ability to regenerate these structures.

This article explores the role of transforming growth factor beta 1 (TGF-

β1) in tissue regeneration, highlighting its

action through both dependent and independent signaling pathways.

Keywords:

Regeneration, transforming growth factor beta 1 (TGF-

β1), signaling pathways

, tissue repair, cytokines,

homeostasis.

Introduction:

The regulation of tissue repair and

regeneration is governed at multiple levels of biological
organization. These regulatory mechanisms ensure
tissue integrity and functional recovery in response to
injury or pathological conditions. The primary
regulatory systems include:

Intracellular and intercellular mechanisms

Hormonal and cytokine signaling

Neural regulation

Functional (compensatory) responses

Inter-organ coordination

Each of these systems plays a critical role in
orchestrating the complex processes of regeneration
and maintaining homeostasis following tissue damage.

Intracellular and Intercellular Regulation

. Intracellular

regeneration is a universal feature shared by all cells,
including neurons. Under normal physiological
conditions, cellular proliferation is restrained by
chalones

a class of glycoproteins that inhibit cell

division. When tissue injury occurs, antichalones are
produced to counteract chalones, thereby promoting
cell proliferation.

Additionally, degradation products released from
damaged cells can exert stimulatory effects on
neighboring undamaged cells, prompting them to enter
the mitotic cycle and contribute to tissue restoration.

Hormonal and Cytokine Mechanisms

. Experimental

studies have demonstrated that hormones secreted by
the pituitary gland, thyroid, adrenal cortex, gonads,
and pancreas influence reparative processes. Notably,
TGF-

β1 exhibits three principal biological effects:

1.

Inhibition of proliferation in most somatic and

immune cells

2.

Stimulation of growth in certain mesenchymal

cells

3.

Immunosuppressive

action,

particularly

enhancing the production of extracellular matrix
components

As such, TGF-

β1 is integral to tissue remodeling and

fibrosis, particularly in chronic inflammatory conditions
and wound healing.

Neural Mechanisms. The nervous system fulfills a
trophic role in regeneration through the release of
neurotrophic factors from nerve terminals. These
factors stimulate cell survival, differentiation, and


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proliferation, thereby contributing significantly to
tissue repair.

Functional (Compensatory) Mechanisms. In the
context of organ or tissue damage, the remaining viable
cells are subjected to increased physiological workload,
which results in elevated metabolic activity. This
metabolic shift triggers intracellular regenerative
processes and may also lead to cell proliferation or
hypertrophy, thereby compensating for functional loss.

Inter-Organ Coordination. Inter-organ regulatory
mechanisms involve the coordination of multiple organ
systems, facilitated through neuroendocrine pathways.
These include the hypothalamic-pituitary-adrenal axis
and autonomic signaling, which mobilize immune cells
and stem/progenitor cells to sites of tissue injury,
thereby enhancing regeneration.

Regeneration can be stimulated through a variety of
localized interventions, which include:

Physical stimuli: e.g., mechanical injury that

initiates a regenerative response;

Chemical agents: the application of specific

chemical compounds;

Biological materials: use of biological tissues to

promote regeneration;

Prosthetic methods: implementation of

temporary or permanent prostheses to facilitate
structural or functional restoration.

Additionally, a number of pharmacological agents and
nutritional strategies are employed to support
regenerative processes. For example, in experimental
settings, fetal serum has been shown to accelerate the
union of long bones. Hormones secreted by various
endocrine glands also contribute significantly to
reparative regeneration. Furthermore, diet has a
considerable impact on the dynamics and effectiveness
of the regenerative response.

Reparative Regeneration: Typology and Mechanisms

.

Reparative regeneration refers to the restoration of a
div part following its damage or loss. It is classified
into two primary types:

Typical reparative regeneration: the lost part is

replaced with an identical structure. This may result
from external injury (e.g., amputation) or through
autotomy

a deliberate shedding of a div part for

survival, such as a lizard detaching its tail.

Atypical

reparative

regeneration:

the

regenerated structure differs quantitatively or
qualitatively from the original tissue.

Regeneration Forms Based on Morphological
Outcomes

1.

Homomorphosis: the exact same organ or part

is restored at the site of the loss.

Example: A new limb develops in a newt following
amputation.

2.

Heteromorphosis: a different organ or

structure forms in place of the lost one.

Example: In crustaceans, an antenna may regenerate at
the site of an excised eye.

3.

Hypermorphosis: more than one structure

regenerates in place of a single lost organ.

Example: Two forelimbs may grow in a newt in place of
one removed.

4.

Regenerative hypertrophy: only the mass of an

organ is restored, not its form.

Example: After partial hepatectomy, the remaining
liver tissue increases in volume rather than
regenerating the exact removed segment.

5.

Compensatory hypertrophy: the remaining

organ of a paired system enlarges and assumes the
function of the lost one.

Example: Enlargement of one kidney after the removal
of the other.

6.

Somatic embryogenesis: a complete organism

develops from a fragment of the div.

Example: A hydra can regenerate entirely from one of
its ~200 div segments.

Types of Regeneration Based on Mechanism

1.

Epimorphosis:

the

missing

part

is

reconstructed via outgrowth from the wound site.

Example: Limb regeneration in salamanders.

2.

Morphallaxis: structural reorganization of the

remaining tissue forms a smaller but functionally
complete organ.

Example: Limb regeneration in cockroaches.

3.

Endomorphosis: enhanced cell proliferation

within the remaining part of an organ restores its
function.

Example: Regrowth of liver tissue in vertebrates.

Stem Cells in Regenerative Medicine

. Some experts in

regenerative medicine posit that regenerative function
can be reactivated through the use of stem cells. In
adults, stem cells are rare and are typically located in
the lower spine, near the dorsal root ganglia. These are
pluripotent cells that played a fundamental role in
embryogenesis. The first eight cells formed after
fertilization are classified as primordial stem cells,
which initiate embryonic development.

Researchers have proposed that stimulating these cells
may require activation of a specific vortex field (often
referred to in esoteric contexts as Merkaba), which


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could potentially induce stem cell proliferation and
systemic regeneration

an ideal yet speculative vision

in regenerative medicine.

Role of TGF-

β1 in Regeneration. Transforming Growth

Factor Beta 1 (TGF-

β1) is a multifunctional cytokine

that regulates:

1.

Inhibition of proliferation in most somatic cells;

2.

Stimulation of mesenchymal cell growth;

3.

Immunosuppressive

activity,

including

enhancement of extracellular matrix (ECM) synthesis.

Since the early 2000s, especially after 2005, TGF-

β1 has

been recognized as a key mediator in the immune
pathogenesis of hereditary connective tissue diseases
and other immune-related conditions.

The TGF-

β family was first described in 1978, with TGF

-

β1 being the first identified isoform, initially isolated

from platelets in the 1990s. The TGF-

β1 gene is located

on chromosome 19. The name reflects the protein’s

ability to induce phenotypic transformation in cultured
normal cells.

Cellular Sources and Activation of TGF-

β1

TGF-

β1 is produced by:

Monocytes

and

macrophages

(primary

sources);

Fibroblasts, endothelial cells, neutrophils,

eosinophils, mast cells, smooth muscle cells, and
various tumor cells.

It is synthesized as an inactive precursor
(prepropeptide). Following processing, a signal peptide
and prodomain are cleaved off, resulting in the mature
protein. However, the latency-associated peptide (LAP)
remains non-covalently bound to the mature TGF-

β1,

rendering it biologically inactive and stored in the
extracellular matrix.

Activation of TGF-

β1 occurs in response to tissue injury

and involves several mechanisms, including:

Proteolytic cleavage,

Integrin interactions,

pH shifts, and

Reactive oxygen species (ROS).

Once activated, TGF-

β1 initiates downstream signaling

cascades crucial to tissue remodeling, fibrosis, and
wound healing.

Three main types of TGF-

β receptors are distinguished:

Type I, II, and III receptors. Type I and II receptors are
transmembrane glycoproteins with molecular weights
of approximately 55 and 70 kDa, respectively. Due to its
dimeric structure, TGF-

β1 can simultaneously bind to

both type I and type II specific receptors, while type III

receptor facilitates this interaction by steric support.

The type I receptor possesses serine/threonine kinase
activity, which enables it to phosphorylate a group of
intracellular proteins known as Smads (Smad and mad-
related proteins). Upon TGF-

β1 binding, the type I and

type

II

receptor

complex

undergoes

trans-


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phosphorylation, activating the signaling cascade.

Once activated, type I receptors phosphorylate
receptor-regulated Smads (R-Smads), which then form
a complex with Smad4. This complex translocates into
the nucleus, where it regulates transcription of target
genes. Divergent inhibitory Smads (Smad6 and Smad7)
act as negative regulators of the TGF-

β1 signaling

pathway.

TGF-

β1 exhibits inhibitory effects on the proliferation

of T and B lymphocytes, as well as on the maturation
and activation of macrophages, thus playing a critical
role in immune homeostasis, particularly in
downregulating inflammatory responses. Additionally,
TGF-

β1 suppresses NK cell activity, inhibits cytotoxicity

of CD8+ T lymphocytes, as well as lymphokine-
activated killer cells, and reduces cytokine production
and secretion of certain immunoglobulins.

In lymphoid, epithelial, and endothelial cells, TGF-

β1

functions as a growth inhibitor. It is also involved in
nephron development, especially in the formation of
the glomerular capillary network.

Clinical

Implications

and

Diagnostic

Utility.

Measurement of TGF-

β1 levels in peripheral blood is

recommended in the diagnosis and monitoring of
various

conditions

associated

with

chronic

inflammation, including:

Alzhei

mer’s disease

Down syndrome

Acquired immunodeficiency syndrome (AIDS)

Parkinson’s disease

Bone marrow and skeletal disorders

Glomerulonephritis

Nephropathy

Diabetes mellitus

Glomerulosclerosis

Systemic lupus erythematosus

Autoimmune hepatitis

Chronic fatigue syndrome

Sepsis

Stroke

Various cancers (e.g., prostate, bladder, liver)

Elevated levels of TGF-

β1 have been detected in

chronic fatigue syndrome and in patients with Guillain

Barré

Strohl syndrome. In Kawasaki disease, an inverse

correlation between TGF-

β1 levels and disease activity

has been observed, particularly in patients with IgA
deficiency.

Increased serum TGF-

β1 levels in patients with

thrombocytopenic purpura suggest its involvement in
hematopoiesis. The cytokine also plays an essential role
in bone marrow metabolism, and its regulatory
function in osteoblast-osteoclast interactions is
currently under investigation.

Elevated TGF-

β1 expression has been reported in

prostate cancer, bladder cancer, and hepatocellular
carcinoma. In contrast, reduced serum levels of TGF-

β1

observed in sepsis and stroke may reflect alterations in

the patient’s immunoinflammatory status.

Furthermore, it is hypothesized that inhibition of TGF-

β1

si

gnaling

pathways

may

contribute

to

atherosclerotic changes in the vascular wall, by
enhancing inflammation and reducing collagen
synthesis, thereby weakening atheromatous plaques.


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It has been established that elevated levels of TGF-

β1

in patients represent one of the key prognostic markers
of pathological fibrosis. The activation of stromal
elements is considered a central mechanism in the
airway wall remodeling process. The number of stromal
mesenchymal cells increases proportionally with the
thickening and densification of the reticular collagen
layer.

In patients with ischemic heart disease, serum TGF-

β1

levels are significantly higher compared to healthy
individuals. Several authors suggest that a dysbalance
between pro-inflammatory and anti-inflammatory
cytokines, with a predominance of the latter, underlies
the development and maintenance of chronic
inflammation, which ultimately culminates in fibrosis.

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Ghosh A.K., Bradham W.S., Gleaves L.A., et al.
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References

Iriskulov B.U., Kurbanov G.T. Role of the transforming growth factor β in the pathogenesis of structural remodeling of the tracheal slice in experimental tracheobronchitis. Natural Volatiles & Essential Oils, 2021; 8(5): 12116-12120.

Zubova S.G., et al. Synthesis and expression of transforming growth factor beta by activated macrophages. Questions of Oncology, 1996; 42(5): 80–85. (in Russian)

Bartram U., Christian P. Role of transforming growth factor-alpha (TGF-α) in neonatal lung disease. Chest, 2004; 125: 754–765.

Bakin A.V. p38 mitogen-activated protein kinase is required for TGF-beta-mediated fibroblastic transdifferentiation and cell migration. Journal of Cell Science, 2002; 115: 3193–3206.

Weber V.R., Gubskaya P.M., Bondarenko V.S. Structural changes of the heart in experimental animals during modeling of different versions of acute stress and opportunities for medical correction. Vestnik of Novgorod State University, Medical Sciences, 2011; 62: 39–43.

Huntgeburth M., Tiemann K., Shahverdyan R., et al. Transforming Growth Factor β1 oppositely regulates the hypertrophic and contractile response to β-adrenergic stimulation in the heart. PLoS ONE, 2011; 6: e26628. doi:10.1371/journal.pone.0026628.

Ghosh A.K., Bradham W.S., Gleaves L.A., et al. Involvement of constitutive transforming growth factor—signaling and endothelial-to-mesenchymal transition. Circulation, 2010; 122: 1200–1209.

Kurbanov G.T. Role of macrophages and cytokines in the formation of inflammation and progression of chronic obstructive pulmonary disease. Science and Education Scientific Journal, 2023; 4(10): 66–72. ISSN 2181-0842.

Kurbanov G.T., Iriskulov B.U. Role of the transforming growth factor β in the pathogenesis of structural remodeling of the tracheal slice in experimental tracheobronchitis. American Journal of Medicine and Medical Sciences, 2022; 12(2). DOI:10.5923/j.ajmms.

Trulev A.S., Kudryavtsev I.V., Nazarov P.G. Acute phase inflammatory factors as modulators of mast cell and fibroblast interactions. Bulletin of the West Siberian Scientific Center of the Siberian Branch of the Russian Academy of Medical Sciences, 2012; 3(85), Part 2. (in Russian)